TY  - CONF
AU  - Bangay, Gabrielle
AU  - Isca, Vera
AU  - Domínguez-Martín, Eva María
AU  - Santos, Daniel J.V.A.
AU  - Díaz-Lanza, Ana María
AU  - Saraiva, Lucília
AU  - Afonso, Carlos A.M.
AU  - Jovanović, Mirna
AU  - Pešić, Milica
AU  - Rijo, Patricia
PY  - 2023
UR  - https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0043-1774270
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/6435
AB  - Multidrug resistant (MDR) cancer cases continue to increase, such that the search for novel and more effective anti-cancer therapeutics is of high priority. In some MDR cancers, the overexpression of membrane transport proteins, like P-glycoprotein (P-gp), continues to be a major impediment to successful therapy. Plectranthus genus (Lamiaceae), known for their medicinal and therapeutic properties, is a well-known source of bioactive diterpenoids, such as 7α-acetoxy-6β-hydroxyroyleanone (Roy) and 6,7- dehydroroyleanone (DeRoy). Based on in silico molecular docking studies, a small library of semi-synthetic derivates was prepared. The antitumoural activity of the compounds was assessed in resistant human cancer cell lines NCI-H460/R and DLD1-TxR. Cell viability was assessed using MTT assay and cell death induction by Annexin V/PI. Overall, it was demonstrated that three of the abietane diterpenoid analogues induced P-gp inhibition in MDR cancer cell lines, presenting novel selective compounds for the possible treatment of lung and colon cancer. Moreover, Roy and DeRoy nano-formulations were successfully prepared. DeRoy hybrid nanoparticles significantly increased the efficacy of DeRoy in NCI-H460 and NCI- H460/R. Roy, conjugated with oleic acid afforded self-assembly nanoparticles, to improve aqueous solubility and bioavailability of Roy. This new nano formulation did not decrease cell viability of Vero-E6 cells when compared to Roy with potential as a pro-drug delivery system. Currently, top hit derivatives are being prepared into nano-formulations for prospective pharmaceutical use as P-gp modulators.
PB  - Georg Thieme Verlag KG
C3  - 71st International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2023 Jul 2-5; Dublin, Ireland
T1  - New formulations with royleanone derivatives from Plectranthus spp. to inhibit P-glycoprotein activity
DO  - 10.1055/s-0043-1774270
SP  - 1424
ER  - 

@conference{
author = "Bangay, Gabrielle and Isca, Vera and Domínguez-Martín, Eva María and Santos, Daniel J.V.A. and Díaz-Lanza, Ana María and Saraiva, Lucília and Afonso, Carlos A.M. and Jovanović, Mirna and Pešić, Milica and Rijo, Patricia",
year = "2023",
abstract = "Multidrug resistant (MDR) cancer cases continue to increase, such that the search for novel and more effective anti-cancer therapeutics is of high priority. In some MDR cancers, the overexpression of membrane transport proteins, like P-glycoprotein (P-gp), continues to be a major impediment to successful therapy. Plectranthus genus (Lamiaceae), known for their medicinal and therapeutic properties, is a well-known source of bioactive diterpenoids, such as 7α-acetoxy-6β-hydroxyroyleanone (Roy) and 6,7- dehydroroyleanone (DeRoy). Based on in silico molecular docking studies, a small library of semi-synthetic derivates was prepared. The antitumoural activity of the compounds was assessed in resistant human cancer cell lines NCI-H460/R and DLD1-TxR. Cell viability was assessed using MTT assay and cell death induction by Annexin V/PI. Overall, it was demonstrated that three of the abietane diterpenoid analogues induced P-gp inhibition in MDR cancer cell lines, presenting novel selective compounds for the possible treatment of lung and colon cancer. Moreover, Roy and DeRoy nano-formulations were successfully prepared. DeRoy hybrid nanoparticles significantly increased the efficacy of DeRoy in NCI-H460 and NCI- H460/R. Roy, conjugated with oleic acid afforded self-assembly nanoparticles, to improve aqueous solubility and bioavailability of Roy. This new nano formulation did not decrease cell viability of Vero-E6 cells when compared to Roy with potential as a pro-drug delivery system. Currently, top hit derivatives are being prepared into nano-formulations for prospective pharmaceutical use as P-gp modulators.",
publisher = "Georg Thieme Verlag KG",
journal = "71st International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2023 Jul 2-5; Dublin, Ireland",
title = "New formulations with royleanone derivatives from Plectranthus spp. to inhibit P-glycoprotein activity",
doi = "10.1055/s-0043-1774270",
pages = "1424"
}

Bangay, G., Isca, V., Domínguez-Martín, E. M., Santos, D. J.V.A., Díaz-Lanza, A. M., Saraiva, L., Afonso, C. A.M., Jovanović, M., Pešić, M.,& Rijo, P.. (2023). New formulations with royleanone derivatives from Plectranthus spp. to inhibit P-glycoprotein activity. in 71st International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2023 Jul 2-5; Dublin, Ireland
Georg Thieme Verlag KG., 1424.
https://doi.org/10.1055/s-0043-1774270

Bangay G, Isca V, Domínguez-Martín EM, Santos DJ, Díaz-Lanza AM, Saraiva L, Afonso CA, Jovanović M, Pešić M, Rijo P. New formulations with royleanone derivatives from Plectranthus spp. to inhibit P-glycoprotein activity. in 71st International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2023 Jul 2-5; Dublin, Ireland. 2023;:1424.
doi:10.1055/s-0043-1774270 .

Bangay, Gabrielle, Isca, Vera, Domínguez-Martín, Eva María, Santos, Daniel J.V.A., Díaz-Lanza, Ana María, Saraiva, Lucília, Afonso, Carlos A.M., Jovanović, Mirna, Pešić, Milica, Rijo, Patricia, "New formulations with royleanone derivatives from Plectranthus spp. to inhibit P-glycoprotein activity" in 71st International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2023 Jul 2-5; Dublin, Ireland (2023):1424,
https://doi.org/10.1055/s-0043-1774270 . .

TY  - CONF
AU  - Isca, Vera
AU  - Bangay, Gabrielle
AU  - Princiotto, Salvatore
AU  - Dinić, Jelena
AU  - Pešić, Milica
AU  - Saraíva, Lucília
AU  - Afonso, Carlos
AU  - Rijo, Patrícia
PY  - 2022
UR  - https://stratagem-cost.eu/wp-content/uploads/2022/07/Abstract-Book-Coimbra.pdf
UR  - https://stratagem-cost.eu/2022/04/stratagems-5th-co-located-annual-conference-and-wg3-4-training-school-to-be-held-in-coimbra-portugal-june-july-2022/
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5622
AB  - Plectranthus genus (Lamiaceae family) is widely used in traditional medicine, and the presence of
pharmacologically active compounds, specifically diterpenes, is well reported. The cytotoxic diterpene
royleanones 7α-acetoxy-6β-hydroxyroyleanone (Roy) and 6,7-dehydroroyleanone (DeRoy) are the
major compounds of P. grandidentatus Gürke (acetonic extract) and P. madagascariensis (Pers.) Benth.
(essential oil), respectively. In this work, Roy and DeRoy were investigated as potential antitumor
agents through the activation of protein kinase C (PKC) isoforms (α, βI, δ, ε and ζ) and inhibition of
the efflux pump, P-glycoprotein (P-gp). Additionally, the reactivity of Roy and DeRoy was explored
to synthesize a library of new derivatives to be also evaluated as cytotoxic agents. PKC-α, βI, δ, ε, and
ζ activation was tested on a yeast-based screening assay. Interestingly, one benzoylated derivative
showed selective PKC-δ activation, while DeRoy exhibited enhanced PKC activity in all tested
isoforms, compared to the positive control. Moreover, inhibition of P-gp activity was evaluated in
human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R. It was
possible to identify an analogue with P-gp inhibitory activity higher than the natural diterpenes Roy
and DeRoy, and comparable to Dexverapamil (positive control). Several other semi-synthetic
products are currently under investigation as potential chemotherapeutic agents.
PB  - STRATAGEM COST Action
C3  - Abstract Book: STRATAGEM’s 5th Annual Meeting: New Diagnostic and Therapeutic Tools against Multidrug Resistant Tumours; 2022 Jun 29 - Jul 1; Coimbra, Portugal
T1  - Cytotoxic Activity of diterpenes from Plectranthus spp. for MDR cancer therapy
SP  - 73
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_5622
ER  - 

@conference{
author = "Isca, Vera and Bangay, Gabrielle and Princiotto, Salvatore and Dinić, Jelena and Pešić, Milica and Saraíva, Lucília and Afonso, Carlos and Rijo, Patrícia",
year = "2022",
abstract = "Plectranthus genus (Lamiaceae family) is widely used in traditional medicine, and the presence of
pharmacologically active compounds, specifically diterpenes, is well reported. The cytotoxic diterpene
royleanones 7α-acetoxy-6β-hydroxyroyleanone (Roy) and 6,7-dehydroroyleanone (DeRoy) are the
major compounds of P. grandidentatus Gürke (acetonic extract) and P. madagascariensis (Pers.) Benth.
(essential oil), respectively. In this work, Roy and DeRoy were investigated as potential antitumor
agents through the activation of protein kinase C (PKC) isoforms (α, βI, δ, ε and ζ) and inhibition of
the efflux pump, P-glycoprotein (P-gp). Additionally, the reactivity of Roy and DeRoy was explored
to synthesize a library of new derivatives to be also evaluated as cytotoxic agents. PKC-α, βI, δ, ε, and
ζ activation was tested on a yeast-based screening assay. Interestingly, one benzoylated derivative
showed selective PKC-δ activation, while DeRoy exhibited enhanced PKC activity in all tested
isoforms, compared to the positive control. Moreover, inhibition of P-gp activity was evaluated in
human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R. It was
possible to identify an analogue with P-gp inhibitory activity higher than the natural diterpenes Roy
and DeRoy, and comparable to Dexverapamil (positive control). Several other semi-synthetic
products are currently under investigation as potential chemotherapeutic agents.",
publisher = "STRATAGEM COST Action",
journal = "Abstract Book: STRATAGEM’s 5th Annual Meeting: New Diagnostic and Therapeutic Tools against Multidrug Resistant Tumours; 2022 Jun 29 - Jul 1; Coimbra, Portugal",
title = "Cytotoxic Activity of diterpenes from Plectranthus spp. for MDR cancer therapy",
pages = "73",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_5622"
}

Isca, V., Bangay, G., Princiotto, S., Dinić, J., Pešić, M., Saraíva, L., Afonso, C.,& Rijo, P.. (2022). Cytotoxic Activity of diterpenes from Plectranthus spp. for MDR cancer therapy. in Abstract Book: STRATAGEM’s 5th Annual Meeting: New Diagnostic and Therapeutic Tools against Multidrug Resistant Tumours; 2022 Jun 29 - Jul 1; Coimbra, Portugal
STRATAGEM COST Action., 73.
https://hdl.handle.net/21.15107/rcub_ibiss_5622

Isca V, Bangay G, Princiotto S, Dinić J, Pešić M, Saraíva L, Afonso C, Rijo P. Cytotoxic Activity of diterpenes from Plectranthus spp. for MDR cancer therapy. in Abstract Book: STRATAGEM’s 5th Annual Meeting: New Diagnostic and Therapeutic Tools against Multidrug Resistant Tumours; 2022 Jun 29 - Jul 1; Coimbra, Portugal. 2022;:73.
https://hdl.handle.net/21.15107/rcub_ibiss_5622 .

Isca, Vera, Bangay, Gabrielle, Princiotto, Salvatore, Dinić, Jelena, Pešić, Milica, Saraíva, Lucília, Afonso, Carlos, Rijo, Patrícia, "Cytotoxic Activity of diterpenes from Plectranthus spp. for MDR cancer therapy" in Abstract Book: STRATAGEM’s 5th Annual Meeting: New Diagnostic and Therapeutic Tools against Multidrug Resistant Tumours; 2022 Jun 29 - Jul 1; Coimbra, Portugal (2022):73,
https://hdl.handle.net/21.15107/rcub_ibiss_5622 .

TY  - CONF
AU  - Isca, Vera
AU  - Ntungwe, Epole
AU  - Bangay, Gabrielle
AU  - Princiotto, Salvatore
AU  - Dinić, Jelena
AU  - Pešić, Milica
AU  - Saraiva, Lucilia
AU  - Afonso, Carlos
AU  - Rijo, Patricia
PY  - 2022
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5611
AB  - Natural products are an important source of lead compounds for drug discovery. Plectranthus (Lamiaceae family) is an Old-World genus widely used in traditional medicine, whose species are rich in pharmacologically active compounds, specifically diterpenes. Two important lead molecules reported in Plectranthus spp. are the diterpenoids 7α-acetoxy-6β-hydroxyroyleanone (Roy, [Fig. 1]) and 6,7-dehydroroyleanone (DeRoy, [Fig. 1]) [1]. Previous studies reported in vitro activity of Roy and DeRoy against several breast cancer cell lines [1], [2]. Furthermore, in silico studies suggested promising interactions of these natural royleanones with protein kinase C (PKC) isoforms [2]. The key point of this work was to prepare new functionalized derivatives of Roy and DeRoy and evaluate their effect on two cancer targets, PKC isoforms and the efflux pump, P-glycoprotein (P-gp). New royleanone derivatives were obtained by hemi-synthesis, starting from Roy and DeRoy. Some of these compounds were evaluated as PKC (α, βI, δ, ε and ζ) activators. One benzoylated analogue showed the ability to selectively activate PKC-δ, while DeRoy displayed improved PKC activity, compared with the positive control, in all tested isoforms. Additionally, P-gp inhibitory potential was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R. Natural royleanones Roy and DeRoy showed similar cytotoxic activity against both NCI-H460 and MDR cancer cell lines. Interestingly, the benzoylated derivatives displayed the most promising results, showing an increased P-gp inhibitory activity and suggesting a relevant role of this moiety for the cytotoxic activity. Several other derivatives are currently under investigation as potential chemotherapeutic agents.
PB  - Thieme Medical Publishers
C3  - 70th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2022 Aug 28-31; Thessaloniki, Greece
T1  - Natural and semi-synthetic royleanone diterpenoids from Plectranthus spp. as potential anti-tumoral agents
DO  - 10.1055/s-0042-1759260
SP  - 1540
ER  - 

@conference{
author = "Isca, Vera and Ntungwe, Epole and Bangay, Gabrielle and Princiotto, Salvatore and Dinić, Jelena and Pešić, Milica and Saraiva, Lucilia and Afonso, Carlos and Rijo, Patricia",
year = "2022",
abstract = "Natural products are an important source of lead compounds for drug discovery. Plectranthus (Lamiaceae family) is an Old-World genus widely used in traditional medicine, whose species are rich in pharmacologically active compounds, specifically diterpenes. Two important lead molecules reported in Plectranthus spp. are the diterpenoids 7α-acetoxy-6β-hydroxyroyleanone (Roy, [Fig. 1]) and 6,7-dehydroroyleanone (DeRoy, [Fig. 1]) [1]. Previous studies reported in vitro activity of Roy and DeRoy against several breast cancer cell lines [1], [2]. Furthermore, in silico studies suggested promising interactions of these natural royleanones with protein kinase C (PKC) isoforms [2]. The key point of this work was to prepare new functionalized derivatives of Roy and DeRoy and evaluate their effect on two cancer targets, PKC isoforms and the efflux pump, P-glycoprotein (P-gp). New royleanone derivatives were obtained by hemi-synthesis, starting from Roy and DeRoy. Some of these compounds were evaluated as PKC (α, βI, δ, ε and ζ) activators. One benzoylated analogue showed the ability to selectively activate PKC-δ, while DeRoy displayed improved PKC activity, compared with the positive control, in all tested isoforms. Additionally, P-gp inhibitory potential was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R. Natural royleanones Roy and DeRoy showed similar cytotoxic activity against both NCI-H460 and MDR cancer cell lines. Interestingly, the benzoylated derivatives displayed the most promising results, showing an increased P-gp inhibitory activity and suggesting a relevant role of this moiety for the cytotoxic activity. Several other derivatives are currently under investigation as potential chemotherapeutic agents.",
publisher = "Thieme Medical Publishers",
journal = "70th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2022 Aug 28-31; Thessaloniki, Greece",
title = "Natural and semi-synthetic royleanone diterpenoids from Plectranthus spp. as potential anti-tumoral agents",
doi = "10.1055/s-0042-1759260",
pages = "1540"
}

Isca, V., Ntungwe, E., Bangay, G., Princiotto, S., Dinić, J., Pešić, M., Saraiva, L., Afonso, C.,& Rijo, P.. (2022). Natural and semi-synthetic royleanone diterpenoids from Plectranthus spp. as potential anti-tumoral agents. in 70th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2022 Aug 28-31; Thessaloniki, Greece
Thieme Medical Publishers., 1540.
https://doi.org/10.1055/s-0042-1759260

Isca V, Ntungwe E, Bangay G, Princiotto S, Dinić J, Pešić M, Saraiva L, Afonso C, Rijo P. Natural and semi-synthetic royleanone diterpenoids from Plectranthus spp. as potential anti-tumoral agents. in 70th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2022 Aug 28-31; Thessaloniki, Greece. 2022;:1540.
doi:10.1055/s-0042-1759260 .

Isca, Vera, Ntungwe, Epole, Bangay, Gabrielle, Princiotto, Salvatore, Dinić, Jelena, Pešić, Milica, Saraiva, Lucilia, Afonso, Carlos, Rijo, Patricia, "Natural and semi-synthetic royleanone diterpenoids from Plectranthus spp. as potential anti-tumoral agents" in 70th International Congress and Annual Meeting of the Society for Medicinal Plant and Natural Product Research (GA); 2022 Aug 28-31; Thessaloniki, Greece (2022):1540,
https://doi.org/10.1055/s-0042-1759260 . .

TY  - CONF
AU  - Isca, Vera
AU  - Duro, Ana
AU  - Bangay, Gabrielle
AU  - Princiotto, Salvatore
AU  - Dinić, Jelena
AU  - Pešić, Milica
AU  - Saraiva, Lucilia
AU  - Afonso, Carlos
AU  - Rijo, Patricia
PY  - 2022
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5612
AB  - Nature is the most important source of novel pharmacologically active compounds for cancer
treatment. Plectranthus genus (Lamiaceae) has been widely used in traditional medicine and
seems to be promising for the research of new drug leads. In fact, Plectranthus spp. are rich in
cytotoxic diterpenoids, such as the 6,7-dehydroroyleanone (DeRoy) and the 7α-acetoxy-6β-
hydroxyroyleanone (Roy). (1) Royleanone diterpenoids are commonly very low water-soluble
compounds and nanotechnology can be employed to improve drug solubility and targeted
delivery: moreover, nanoformulations are often able to decrease the most frequent side effects
associated to chemotherapy. (2) Hybrid nanoparticles of DeRoy have shown an increased efficacy
of the natural royleanone on NCI-H460 and NCI-H460/R cell lines. (3) Additionally, self-
assembling nanoparticles combined with Roy reduced the cytotoxicity against normal cells (Vero-
E6) compared to parent compound (Roy) and displayed a low release of Roy at physiological pH.
(2) These results suggest that nano-assemblies of royleanones may act as a promising anticancer
strategy.
In this report, we describe the extraction and isolation of Roy from P. grandidentatus. Also, Roy
was derivatized with the goal of improving its antitumoral proprieties. Several derivatives were
prepared with overall good yields and are currently under in vitro antitumoral evaluation. So far,
two benzoylated derivatives revealed promising cytotoxic properties to be further exploited in
nanoformulations. Overall, we expect that derivatives in nanosystems can improve the drug
delivery and lead to an enhanced anticancer activity.
PB  - ALIES - Associação Lusófona para o Desenvolvimento da Investigação e do Ensino das Ciências da Saúde
C3  - Book of abstracts: InnovDelivery '22; I Lusophone Meeting on Innovative Delivery Systems; 2022 Jun 30; Virtual Meeting
T1  - Nanosystem of royleanone diterpenoids from Plectranthus spp to improve targeted delivery into cancer cells
DO  - 10.19277/bbr.19.2.289
SP  - 28
ER  - 

@conference{
author = "Isca, Vera and Duro, Ana and Bangay, Gabrielle and Princiotto, Salvatore and Dinić, Jelena and Pešić, Milica and Saraiva, Lucilia and Afonso, Carlos and Rijo, Patricia",
year = "2022",
abstract = "Nature is the most important source of novel pharmacologically active compounds for cancer
treatment. Plectranthus genus (Lamiaceae) has been widely used in traditional medicine and
seems to be promising for the research of new drug leads. In fact, Plectranthus spp. are rich in
cytotoxic diterpenoids, such as the 6,7-dehydroroyleanone (DeRoy) and the 7α-acetoxy-6β-
hydroxyroyleanone (Roy). (1) Royleanone diterpenoids are commonly very low water-soluble
compounds and nanotechnology can be employed to improve drug solubility and targeted
delivery: moreover, nanoformulations are often able to decrease the most frequent side effects
associated to chemotherapy. (2) Hybrid nanoparticles of DeRoy have shown an increased efficacy
of the natural royleanone on NCI-H460 and NCI-H460/R cell lines. (3) Additionally, self-
assembling nanoparticles combined with Roy reduced the cytotoxicity against normal cells (Vero-
E6) compared to parent compound (Roy) and displayed a low release of Roy at physiological pH.
(2) These results suggest that nano-assemblies of royleanones may act as a promising anticancer
strategy.
In this report, we describe the extraction and isolation of Roy from P. grandidentatus. Also, Roy
was derivatized with the goal of improving its antitumoral proprieties. Several derivatives were
prepared with overall good yields and are currently under in vitro antitumoral evaluation. So far,
two benzoylated derivatives revealed promising cytotoxic properties to be further exploited in
nanoformulations. Overall, we expect that derivatives in nanosystems can improve the drug
delivery and lead to an enhanced anticancer activity.",
publisher = "ALIES - Associação Lusófona para o Desenvolvimento da Investigação e do Ensino das Ciências da Saúde",
journal = "Book of abstracts: InnovDelivery '22; I Lusophone Meeting on Innovative Delivery Systems; 2022 Jun 30; Virtual Meeting",
title = "Nanosystem of royleanone diterpenoids from Plectranthus spp to improve targeted delivery into cancer cells",
doi = "10.19277/bbr.19.2.289",
pages = "28"
}

Isca, V., Duro, A., Bangay, G., Princiotto, S., Dinić, J., Pešić, M., Saraiva, L., Afonso, C.,& Rijo, P.. (2022). Nanosystem of royleanone diterpenoids from Plectranthus spp to improve targeted delivery into cancer cells. in Book of abstracts: InnovDelivery '22; I Lusophone Meeting on Innovative Delivery Systems; 2022 Jun 30; Virtual Meeting
ALIES - Associação Lusófona para o Desenvolvimento da Investigação e do Ensino das Ciências da Saúde., 28.
https://doi.org/10.19277/bbr.19.2.289

Isca V, Duro A, Bangay G, Princiotto S, Dinić J, Pešić M, Saraiva L, Afonso C, Rijo P. Nanosystem of royleanone diterpenoids from Plectranthus spp to improve targeted delivery into cancer cells. in Book of abstracts: InnovDelivery '22; I Lusophone Meeting on Innovative Delivery Systems; 2022 Jun 30; Virtual Meeting. 2022;:28.
doi:10.19277/bbr.19.2.289 .

Isca, Vera, Duro, Ana, Bangay, Gabrielle, Princiotto, Salvatore, Dinić, Jelena, Pešić, Milica, Saraiva, Lucilia, Afonso, Carlos, Rijo, Patricia, "Nanosystem of royleanone diterpenoids from Plectranthus spp to improve targeted delivery into cancer cells" in Book of abstracts: InnovDelivery '22; I Lusophone Meeting on Innovative Delivery Systems; 2022 Jun 30; Virtual Meeting (2022):28,
https://doi.org/10.19277/bbr.19.2.289 . .

TY  - CONF
AU  - Bangay, Gabrielle
AU  - Isca, Vera M. S.
AU  - Dos Santos, Daniel J. V. A.
AU  - Ferreira, Ricardo J.
AU  - Princiotto, Salvatore
AU  - Jovanović, Mirna
AU  - Pešić, Milica
AU  - Rijo, Patricia
PY  - 2022
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5471
AB  - The number of multidrug resistant (MDR) cancer cases across the globe is continuing to rise,
such that the search for novel anti-cancer therapeutics is paramount. For instance, the overexpression
of membrane transport proteins, such as P-glycoprotein (P-gp), or the selective modulation of protein
kinases C (PKC) isoforms continues to be a major impediment to effective therapy. Known for
their medicinal properties, species from Plectranthus have been reported to have cytotoxicity against
various cancer cell lines due to diterpenes, such as 7 -acetoxy-6 -hydroxyroyleanone (Roy) and 6,7-
dehydroroyleanone (DeRoy). Based on molecular docking simulations, 10 semi-synthetic derivatives
of Roy that displayed strong P-gp interactions in silico were prepared. The antitumoral activity was
evaluated in resistant human cancer cell lines NCI-H460/R and DLD1-TxR, showing three derivatives
having the most prominent selectivity towards cancer cells, compared to normal lung fibroblasts
MRC5. Moreover, they showed a reduction in P-gp activity in Rho123 accumulation and indicated
P-gp inhibition in the DOX accumulation assay using the same resistant cell lines. Overall, it was
demonstrated that three abietane diterpenoids induced P-gp inhibition in MDR cancer cell lines. As
regards the PKC activity, further analogues were tested as PKC ( ,  I,  , " and  ) modulators; one
benzoylated derivative showed the ability to selectively activate PKC- , while the natural compound
DeRoy displayed improved PKC activity, compared with the positive control, in all tested isoforms.
Further investigations are ongoing to prepare analogues of other biologically active diterpenoids to
obtain potential hits as P-gp and PKC modulators.
PB  - Basel: MDPI
C3  - The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event
T1  - Royleanone Analogues from Plectranthus spp. Demonstrate P-gp Inhibition and PKC Modulation
DO  - 10.3390/ECMC2022-13459
SP  - 144
ER  - 

@conference{
author = "Bangay, Gabrielle and Isca, Vera M. S. and Dos Santos, Daniel J. V. A. and Ferreira, Ricardo J. and Princiotto, Salvatore and Jovanović, Mirna and Pešić, Milica and Rijo, Patricia",
year = "2022",
abstract = "The number of multidrug resistant (MDR) cancer cases across the globe is continuing to rise,
such that the search for novel anti-cancer therapeutics is paramount. For instance, the overexpression
of membrane transport proteins, such as P-glycoprotein (P-gp), or the selective modulation of protein
kinases C (PKC) isoforms continues to be a major impediment to effective therapy. Known for
their medicinal properties, species from Plectranthus have been reported to have cytotoxicity against
various cancer cell lines due to diterpenes, such as 7 -acetoxy-6 -hydroxyroyleanone (Roy) and 6,7-
dehydroroyleanone (DeRoy). Based on molecular docking simulations, 10 semi-synthetic derivatives
of Roy that displayed strong P-gp interactions in silico were prepared. The antitumoral activity was
evaluated in resistant human cancer cell lines NCI-H460/R and DLD1-TxR, showing three derivatives
having the most prominent selectivity towards cancer cells, compared to normal lung fibroblasts
MRC5. Moreover, they showed a reduction in P-gp activity in Rho123 accumulation and indicated
P-gp inhibition in the DOX accumulation assay using the same resistant cell lines. Overall, it was
demonstrated that three abietane diterpenoids induced P-gp inhibition in MDR cancer cell lines. As
regards the PKC activity, further analogues were tested as PKC ( ,  I,  , " and  ) modulators; one
benzoylated derivative showed the ability to selectively activate PKC- , while the natural compound
DeRoy displayed improved PKC activity, compared with the positive control, in all tested isoforms.
Further investigations are ongoing to prepare analogues of other biologically active diterpenoids to
obtain potential hits as P-gp and PKC modulators.",
publisher = "Basel: MDPI",
journal = "The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event",
title = "Royleanone Analogues from Plectranthus spp. Demonstrate P-gp Inhibition and PKC Modulation",
doi = "10.3390/ECMC2022-13459",
pages = "144"
}

Bangay, G., Isca, V. M. S., Dos Santos, D. J. V. A., Ferreira, R. J., Princiotto, S., Jovanović, M., Pešić, M.,& Rijo, P.. (2022). Royleanone Analogues from Plectranthus spp. Demonstrate P-gp Inhibition and PKC Modulation. in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event
Basel: MDPI., 144.
https://doi.org/10.3390/ECMC2022-13459

Bangay G, Isca VMS, Dos Santos DJVA, Ferreira RJ, Princiotto S, Jovanović M, Pešić M, Rijo P. Royleanone Analogues from Plectranthus spp. Demonstrate P-gp Inhibition and PKC Modulation. in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event. 2022;:144.
doi:10.3390/ECMC2022-13459 .

Bangay, Gabrielle, Isca, Vera M. S., Dos Santos, Daniel J. V. A., Ferreira, Ricardo J., Princiotto, Salvatore, Jovanović, Mirna, Pešić, Milica, Rijo, Patricia, "Royleanone Analogues from Plectranthus spp. Demonstrate P-gp Inhibition and PKC Modulation" in The 8th International Electronic Conference on Medicinal Chemistry; 2022 Nov 1-30; Virtual Event (2022):144,
https://doi.org/10.3390/ECMC2022-13459 . .

TY  - CONF
AU  - Isca, Vera
AU  - Coelho, Jaime
AU  - Monteiro, Carlos
AU  - Ntungwe, Epole
AU  - Dominguez-Martin, Eva Maria
AU  - Dinić, Jelena
AU  - Diaz-Lanza, Ana Maria
AU  - Candeias, Nuno R.
AU  - Afonso, Carlos A.M.
AU  - Pešić, Milica
AU  - Rijo, Patricia
PY  - 2020
UR  - https://stratagem-cost.eu/wp-content/uploads/2020/11/Abstract-Book-WG3-meeting-Nov-2020.pdf
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5624
AB  - Multidrug resistance (MDR) is one of the main challenges in cancer treatment, in which overexpression of
P-glycoprotein (P-gp) plays an important role. Therefore, there is an urgent need to identify new
compounds that can exert anticancer effects and at the same time revert MDR. In this context, Plectranthus
genus (Lamiaceae) is a great source of cytotoxic compounds that could be used as lead molecules for
drug development, such as 6,7-dehydroroyleanone (1) (P. madagascariensis (Pers.) Benth. essential oil)
and 7α-acetoxy-6β-hydroxyroyleanone (2) (P. grandidentatus Gürke) [1].
The aim of this work was to prepare a small library of new 12-O-substituted derivatives with potential P-gp
inhibitory effect by exploring the reactivity of the natural royleanones 1 and 2. In this study, we identified a
new derivative that exhibited a P-gp inhibitory activity higher than the natural diterpenes 1 and 2, and
comparable to Dexverapamil. Furthermore, this compound showed the ability to sensitize the resistant cell
line NCI-H460/R to doxorubicin. This activity was evaluated in the human non-small cell lung carcinoma
(NCI-H460) cell line and its MDR counterpart NCI-H460/R with the P-gp overexpression by using the MTT
and Rhodamine 123 accumulation assays. Further derivatizations and quantitative structure–activity
relationship analysis are ongoing to discover new derivatives with improved activity.

References: [1] Isca VMS et al. (2020). ACS Med Chem Lett. 11 (5): 839-845
PB  - COST Action CA17104
C3  - Abstract book: COST Action 17104 (STRATAGEM) WG3 Meeting - International Online Symposium on “New Therapeutic Tools Against Preclinical Models of Multidrug Resistant Tumors”; 2020 Nov 4; Online.
T1  - Novel class of P-glycoprotein inhibitors from Plectranthus spp.
SP  - 30
UR  - https://hdl.handle.net/21.15107/rcub_ibiss_5624
ER  - 

@conference{
author = "Isca, Vera and Coelho, Jaime and Monteiro, Carlos and Ntungwe, Epole and Dominguez-Martin, Eva Maria and Dinić, Jelena and Diaz-Lanza, Ana Maria and Candeias, Nuno R. and Afonso, Carlos A.M. and Pešić, Milica and Rijo, Patricia",
year = "2020",
abstract = "Multidrug resistance (MDR) is one of the main challenges in cancer treatment, in which overexpression of
P-glycoprotein (P-gp) plays an important role. Therefore, there is an urgent need to identify new
compounds that can exert anticancer effects and at the same time revert MDR. In this context, Plectranthus
genus (Lamiaceae) is a great source of cytotoxic compounds that could be used as lead molecules for
drug development, such as 6,7-dehydroroyleanone (1) (P. madagascariensis (Pers.) Benth. essential oil)
and 7α-acetoxy-6β-hydroxyroyleanone (2) (P. grandidentatus Gürke) [1].
The aim of this work was to prepare a small library of new 12-O-substituted derivatives with potential P-gp
inhibitory effect by exploring the reactivity of the natural royleanones 1 and 2. In this study, we identified a
new derivative that exhibited a P-gp inhibitory activity higher than the natural diterpenes 1 and 2, and
comparable to Dexverapamil. Furthermore, this compound showed the ability to sensitize the resistant cell
line NCI-H460/R to doxorubicin. This activity was evaluated in the human non-small cell lung carcinoma
(NCI-H460) cell line and its MDR counterpart NCI-H460/R with the P-gp overexpression by using the MTT
and Rhodamine 123 accumulation assays. Further derivatizations and quantitative structure–activity
relationship analysis are ongoing to discover new derivatives with improved activity.

References: [1] Isca VMS et al. (2020). ACS Med Chem Lett. 11 (5): 839-845",
publisher = "COST Action CA17104",
journal = "Abstract book: COST Action 17104 (STRATAGEM) WG3 Meeting - International Online Symposium on “New Therapeutic Tools Against Preclinical Models of Multidrug Resistant Tumors”; 2020 Nov 4; Online.",
title = "Novel class of P-glycoprotein inhibitors from Plectranthus spp.",
pages = "30",
url = "https://hdl.handle.net/21.15107/rcub_ibiss_5624"
}

Isca, V., Coelho, J., Monteiro, C., Ntungwe, E., Dominguez-Martin, E. M., Dinić, J., Diaz-Lanza, A. M., Candeias, N. R., Afonso, C. A.M., Pešić, M.,& Rijo, P.. (2020). Novel class of P-glycoprotein inhibitors from Plectranthus spp.. in Abstract book: COST Action 17104 (STRATAGEM) WG3 Meeting - International Online Symposium on “New Therapeutic Tools Against Preclinical Models of Multidrug Resistant Tumors”; 2020 Nov 4; Online.
COST Action CA17104., 30.
https://hdl.handle.net/21.15107/rcub_ibiss_5624

Isca V, Coelho J, Monteiro C, Ntungwe E, Dominguez-Martin EM, Dinić J, Diaz-Lanza AM, Candeias NR, Afonso CA, Pešić M, Rijo P. Novel class of P-glycoprotein inhibitors from Plectranthus spp.. in Abstract book: COST Action 17104 (STRATAGEM) WG3 Meeting - International Online Symposium on “New Therapeutic Tools Against Preclinical Models of Multidrug Resistant Tumors”; 2020 Nov 4; Online.. 2020;:30.
https://hdl.handle.net/21.15107/rcub_ibiss_5624 .

Isca, Vera, Coelho, Jaime, Monteiro, Carlos, Ntungwe, Epole, Dominguez-Martin, Eva Maria, Dinić, Jelena, Diaz-Lanza, Ana Maria, Candeias, Nuno R., Afonso, Carlos A.M., Pešić, Milica, Rijo, Patricia, "Novel class of P-glycoprotein inhibitors from Plectranthus spp." in Abstract book: COST Action 17104 (STRATAGEM) WG3 Meeting - International Online Symposium on “New Therapeutic Tools Against Preclinical Models of Multidrug Resistant Tumors”; 2020 Nov 4; Online. (2020):30,
https://hdl.handle.net/21.15107/rcub_ibiss_5624 .

TY  - JOUR
AU  - Garcia, Catarina
AU  - Isca, Vera
AU  - Pereira, Filipe
AU  - Monteiro, Carlos
AU  - Ntungwe, Epole
AU  - Sousa, Francisco
AU  - Dinić, Jelena
AU  - Holmstedt, Suvi
AU  - Roberto, Amílcar
AU  - Díaz-Lanza, Ana
AU  - Reis, Catarina
AU  - Pešić, Milica
AU  - Candeias, Nuno
AU  - Ferreira, Ricardo
AU  - Duarte, Noélia
AU  - Afonso, Carlos
AU  - Rijo, Patrícia
PY  - 2020
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/4261
AB  - Cancer is among the leading causes of death worldwide. One of the most challenging obstacles in cancer treatment is multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp) is associated with MDR. The growing incidence of cancer and the development of MDR drive the search for novel and more effective anticancer drugs to overcome the MDR problem. Royleanones are natural bioactive compounds frequently found in Plectranthus spp. The cytotoxic diterpene 6,7-dehydroroyleanone (1) is the main component of the P. madagascariensis (Pers.) Benth. essential oil, while 7α-acetoxy-6β-hydroxyroyleanone (2) can be isolated from acetonic extracts of P. grandidentatus Gürke. The reactivity of the natural royleanones 1 and 2 was explored to obtain a small library of new P-gp inhibitors. Four new derivatives (6,7-dehydro-12-O-tert-butyl-carbonate-royleanone (20), 6,7-dehydro-12-O-methylroyleanone (21), 6,7-dehydro-12-O-benzoylroyleanone (22), and 7α-acetoxy-6β-hydroxy-12-O-benzoylroyleanone (23) were obtained as pure with overall modest to excellent yields (21-97%). P-gp inhibition potential of the derivatives 20-23 was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R with the P-gp overexpression, through MTT assay. Previously prepared diterpene 7α-acetoxy-6β-benzoyloxy-12-O-(4-chloro)benzoylroyleanone (4), has also been tested. The P-gp inhibiting effects of compounds 1-4 were also assessed through a Rhodamine 123 accumulation assay. Derivatives 4 and 23 have significant P-gp inhibitory potential. Regarding stability and P-gp inhibition potential, results suggest that the formation of benzoyl esters is a more convenient approach for future derivatives with enhanced effect on the cell viability decrease. Compound 4 presented higher anti-P-gp potential than the natural diterpenes 1, 2, and 3, with comparable inhibitory potential to Dexverapamil. Moreover, derivative 4 showed the ability to sensitize the resistant NCI-H460/R cells to doxorubicin.
PB  - Lausanne : Frontiers
T2  - Frontiers in Pharmacology
T1  - Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors
VL  - 11
DO  - 10.3389/fphar.2020.557789
SP  - 557789
ER  - 

@article{
author = "Garcia, Catarina and Isca, Vera and Pereira, Filipe and Monteiro, Carlos and Ntungwe, Epole and Sousa, Francisco and Dinić, Jelena and Holmstedt, Suvi and Roberto, Amílcar and Díaz-Lanza, Ana and Reis, Catarina and Pešić, Milica and Candeias, Nuno and Ferreira, Ricardo and Duarte, Noélia and Afonso, Carlos and Rijo, Patrícia",
year = "2020",
abstract = "Cancer is among the leading causes of death worldwide. One of the most challenging obstacles in cancer treatment is multidrug resistance (MDR). Overexpression of P-glycoprotein (P-gp) is associated with MDR. The growing incidence of cancer and the development of MDR drive the search for novel and more effective anticancer drugs to overcome the MDR problem. Royleanones are natural bioactive compounds frequently found in Plectranthus spp. The cytotoxic diterpene 6,7-dehydroroyleanone (1) is the main component of the P. madagascariensis (Pers.) Benth. essential oil, while 7α-acetoxy-6β-hydroxyroyleanone (2) can be isolated from acetonic extracts of P. grandidentatus Gürke. The reactivity of the natural royleanones 1 and 2 was explored to obtain a small library of new P-gp inhibitors. Four new derivatives (6,7-dehydro-12-O-tert-butyl-carbonate-royleanone (20), 6,7-dehydro-12-O-methylroyleanone (21), 6,7-dehydro-12-O-benzoylroyleanone (22), and 7α-acetoxy-6β-hydroxy-12-O-benzoylroyleanone (23) were obtained as pure with overall modest to excellent yields (21-97%). P-gp inhibition potential of the derivatives 20-23 was evaluated in human non-small cell lung carcinoma NCI-H460 and its MDR counterpart NCI-H460/R with the P-gp overexpression, through MTT assay. Previously prepared diterpene 7α-acetoxy-6β-benzoyloxy-12-O-(4-chloro)benzoylroyleanone (4), has also been tested. The P-gp inhibiting effects of compounds 1-4 were also assessed through a Rhodamine 123 accumulation assay. Derivatives 4 and 23 have significant P-gp inhibitory potential. Regarding stability and P-gp inhibition potential, results suggest that the formation of benzoyl esters is a more convenient approach for future derivatives with enhanced effect on the cell viability decrease. Compound 4 presented higher anti-P-gp potential than the natural diterpenes 1, 2, and 3, with comparable inhibitory potential to Dexverapamil. Moreover, derivative 4 showed the ability to sensitize the resistant NCI-H460/R cells to doxorubicin.",
publisher = "Lausanne : Frontiers",
journal = "Frontiers in Pharmacology",
title = "Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors",
volume = "11",
doi = "10.3389/fphar.2020.557789",
pages = "557789"
}

Garcia, C., Isca, V., Pereira, F., Monteiro, C., Ntungwe, E., Sousa, F., Dinić, J., Holmstedt, S., Roberto, A., Díaz-Lanza, A., Reis, C., Pešić, M., Candeias, N., Ferreira, R., Duarte, N., Afonso, C.,& Rijo, P.. (2020). Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors. in Frontiers in Pharmacology
Lausanne : Frontiers., 11, 557789.
https://doi.org/10.3389/fphar.2020.557789

Garcia C, Isca V, Pereira F, Monteiro C, Ntungwe E, Sousa F, Dinić J, Holmstedt S, Roberto A, Díaz-Lanza A, Reis C, Pešić M, Candeias N, Ferreira R, Duarte N, Afonso C, Rijo P. Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors. in Frontiers in Pharmacology. 2020;11:557789.
doi:10.3389/fphar.2020.557789 .

Garcia, Catarina, Isca, Vera, Pereira, Filipe, Monteiro, Carlos, Ntungwe, Epole, Sousa, Francisco, Dinić, Jelena, Holmstedt, Suvi, Roberto, Amílcar, Díaz-Lanza, Ana, Reis, Catarina, Pešić, Milica, Candeias, Nuno, Ferreira, Ricardo, Duarte, Noélia, Afonso, Carlos, Rijo, Patrícia, "Royleanone Derivatives From Plectranthus spp. as a Novel Class of P-Glycoprotein Inhibitors" in Frontiers in Pharmacology, 11 (2020):557789,
https://doi.org/10.3389/fphar.2020.557789 . .

TY  - JOUR
AU  - Isca, Vera M. S.
AU  - Ferreira, Ricardo J.
AU  - Garcia, Catarina
AU  - Monteiro, Carlos M.
AU  - Dinić, Jelena
AU  - Holmstedt, Suvi
AU  - André, Vânia
AU  - Pešić, Milica
AU  - Dos Santos, Daniel J. V. A.
AU  - Candeias, Nuno R.
AU  - Afonso, Carlos A. M.
AU  - Rijo, Patrícia
PY  - 2020
UR  - https://pubs.acs.org/doi/10.1021/acsmedchemlett.9b00642
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3820
AB  - The development of multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. Several abietane diterpenes with antitumoral activities have been isolated from Plectranthus spp. such as 6,7-dehydroroyleanone (DHR, 1) and 7α-acetoxy-6β-hydroxyroyleanone (AHR, 2). Several royleanone derivatives were prepared through hemisynthesis from natural compounds 1 and 2 to achieve a small library of products with enhanced anti-P-glycoprotein activity. Nonetheless, some derivatives tend to be unstable. Therefore, to reason such lack of stability, the electron density based local reactivity descriptors condensed Fukui functions and dual descriptor were calculated for several derivatives of DHR. Additionally, molecular docking and molecular dynamics studies were performed on several other derivatives to clarify the molecular mechanisms by which they may exert their inhibitory effect in P-gp activity. The analysis on local reactivity descriptors was important to understand possible degradation pathways and to guide further synthetic approaches toward new royleanone derivatives. A molecular docking study suggested that the presence of aromatic moieties increases the binding affinity of royleanone derivatives toward P-gp. It further suggests that one royleanone benzoylated derivative may act as a noncompetitive efflux modulator when bound to the M-site. The future generation of novel royleanone derivatives will involve (i) a selective modification of position C-12 with chemical moieties smaller than unsubstituted benzoyl rings and (ii) the modification of the substitution pattern of the benzoyloxy moiety at position C-6.
PB  - Washington : ACS Publications
T2  - ACS Medicinal Chemistry Letters
T1  - Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors
IS  - 5
VL  - 11
DO  - 10.1021/acsmedchemlett.9b00642
SP  - 839
EP  - 845
ER  - 

@article{
author = "Isca, Vera M. S. and Ferreira, Ricardo J. and Garcia, Catarina and Monteiro, Carlos M. and Dinić, Jelena and Holmstedt, Suvi and André, Vânia and Pešić, Milica and Dos Santos, Daniel J. V. A. and Candeias, Nuno R. and Afonso, Carlos A. M. and Rijo, Patrícia",
year = "2020",
abstract = "The development of multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. Several abietane diterpenes with antitumoral activities have been isolated from Plectranthus spp. such as 6,7-dehydroroyleanone (DHR, 1) and 7α-acetoxy-6β-hydroxyroyleanone (AHR, 2). Several royleanone derivatives were prepared through hemisynthesis from natural compounds 1 and 2 to achieve a small library of products with enhanced anti-P-glycoprotein activity. Nonetheless, some derivatives tend to be unstable. Therefore, to reason such lack of stability, the electron density based local reactivity descriptors condensed Fukui functions and dual descriptor were calculated for several derivatives of DHR. Additionally, molecular docking and molecular dynamics studies were performed on several other derivatives to clarify the molecular mechanisms by which they may exert their inhibitory effect in P-gp activity. The analysis on local reactivity descriptors was important to understand possible degradation pathways and to guide further synthetic approaches toward new royleanone derivatives. A molecular docking study suggested that the presence of aromatic moieties increases the binding affinity of royleanone derivatives toward P-gp. It further suggests that one royleanone benzoylated derivative may act as a noncompetitive efflux modulator when bound to the M-site. The future generation of novel royleanone derivatives will involve (i) a selective modification of position C-12 with chemical moieties smaller than unsubstituted benzoyl rings and (ii) the modification of the substitution pattern of the benzoyloxy moiety at position C-6.",
publisher = "Washington : ACS Publications",
journal = "ACS Medicinal Chemistry Letters",
title = "Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors",
number = "5",
volume = "11",
doi = "10.1021/acsmedchemlett.9b00642",
pages = "839-845"
}

Isca, V. M. S., Ferreira, R. J., Garcia, C., Monteiro, C. M., Dinić, J., Holmstedt, S., André, V., Pešić, M., Dos Santos, D. J. V. A., Candeias, N. R., Afonso, C. A. M.,& Rijo, P.. (2020). Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors. in ACS Medicinal Chemistry Letters
Washington : ACS Publications., 11(5), 839-845.
https://doi.org/10.1021/acsmedchemlett.9b00642

Isca VMS, Ferreira RJ, Garcia C, Monteiro CM, Dinić J, Holmstedt S, André V, Pešić M, Dos Santos DJVA, Candeias NR, Afonso CAM, Rijo P. Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors. in ACS Medicinal Chemistry Letters. 2020;11(5):839-845.
doi:10.1021/acsmedchemlett.9b00642 .

Isca, Vera M. S., Ferreira, Ricardo J., Garcia, Catarina, Monteiro, Carlos M., Dinić, Jelena, Holmstedt, Suvi, André, Vânia, Pešić, Milica, Dos Santos, Daniel J. V. A., Candeias, Nuno R., Afonso, Carlos A. M., Rijo, Patrícia, "Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors" in ACS Medicinal Chemistry Letters, 11, no. 5 (2020):839-845,
https://doi.org/10.1021/acsmedchemlett.9b00642 . .

TY  - JOUR
AU  - Isca, Vera M. S.
AU  - Ferreira, Ricardo J.
AU  - Garcia, Catarina
AU  - Monteiro, Carlos M.
AU  - Dinić, Jelena
AU  - Holmstedt, Suvi
AU  - André, Vânia
AU  - Pešić, Milica
AU  - Dos Santos, Daniel J. V. A.
AU  - Candeias, Nuno R.
AU  - Afonso, Carlos A. M.
AU  - Rijo, Patrícia
PY  - 2020
UR  - https://pubs.acs.org/doi/10.1021/acsmedchemlett.9b00642
UR  - https://radar.ibiss.bg.ac.rs/handle/123456789/3817
AB  - The development of multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. Several abietane diterpenes with antitumoral activities have been isolated from Plectranthus spp. such as 6,7-dehydroroyleanone (DHR, 1) and 7α-acetoxy-6β-hydroxyroyleanone (AHR, 2). Several royleanone derivatives were prepared through hemisynthesis from natural compounds 1 and 2 to achieve a small library of products with enhanced anti-P-glycoprotein activity. Nonetheless, some derivatives tend to be unstable. Therefore, to reason such lack of stability, the electron density based local reactivity descriptors condensed Fukui functions and dual descriptor were calculated for several derivatives of DHR. Additionally, molecular docking and molecular dynamics studies were performed on several other derivatives to clarify the molecular mechanisms by which they may exert their inhibitory effect in P-gp activity. The analysis on local reactivity descriptors was important to understand possible degradation pathways and to guide further synthetic approaches toward new royleanone derivatives. A molecular docking study suggested that the presence of aromatic moieties increases the binding affinity of royleanone derivatives toward P-gp. It further suggests that one royleanone benzoylated derivative may act as a noncompetitive efflux modulator when bound to the M-site. The future generation of novel royleanone derivatives will involve (i) a selective modification of position C-12 with chemical moieties smaller than unsubstituted benzoyl rings and (ii) the modification of the substitution pattern of the benzoyloxy moiety at position C-6.
PB  - Washington : ACS Publications
T2  - ACS Medicinal Chemistry Letters
T1  - Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors
IS  - 5
VL  - 11
DO  - 10.1021/acsmedchemlett.9b00642
SP  - 839
EP  - 845
ER  - 

@article{
author = "Isca, Vera M. S. and Ferreira, Ricardo J. and Garcia, Catarina and Monteiro, Carlos M. and Dinić, Jelena and Holmstedt, Suvi and André, Vânia and Pešić, Milica and Dos Santos, Daniel J. V. A. and Candeias, Nuno R. and Afonso, Carlos A. M. and Rijo, Patrícia",
year = "2020",
abstract = "The development of multidrug resistance (MDR) is a major cause of failure in cancer chemotherapy. Several abietane diterpenes with antitumoral activities have been isolated from Plectranthus spp. such as 6,7-dehydroroyleanone (DHR, 1) and 7α-acetoxy-6β-hydroxyroyleanone (AHR, 2). Several royleanone derivatives were prepared through hemisynthesis from natural compounds 1 and 2 to achieve a small library of products with enhanced anti-P-glycoprotein activity. Nonetheless, some derivatives tend to be unstable. Therefore, to reason such lack of stability, the electron density based local reactivity descriptors condensed Fukui functions and dual descriptor were calculated for several derivatives of DHR. Additionally, molecular docking and molecular dynamics studies were performed on several other derivatives to clarify the molecular mechanisms by which they may exert their inhibitory effect in P-gp activity. The analysis on local reactivity descriptors was important to understand possible degradation pathways and to guide further synthetic approaches toward new royleanone derivatives. A molecular docking study suggested that the presence of aromatic moieties increases the binding affinity of royleanone derivatives toward P-gp. It further suggests that one royleanone benzoylated derivative may act as a noncompetitive efflux modulator when bound to the M-site. The future generation of novel royleanone derivatives will involve (i) a selective modification of position C-12 with chemical moieties smaller than unsubstituted benzoyl rings and (ii) the modification of the substitution pattern of the benzoyloxy moiety at position C-6.",
publisher = "Washington : ACS Publications",
journal = "ACS Medicinal Chemistry Letters",
title = "Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors",
number = "5",
volume = "11",
doi = "10.1021/acsmedchemlett.9b00642",
pages = "839-845"
}

Isca, V. M. S., Ferreira, R. J., Garcia, C., Monteiro, C. M., Dinić, J., Holmstedt, S., André, V., Pešić, M., Dos Santos, D. J. V. A., Candeias, N. R., Afonso, C. A. M.,& Rijo, P.. (2020). Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors. in ACS Medicinal Chemistry Letters
Washington : ACS Publications., 11(5), 839-845.
https://doi.org/10.1021/acsmedchemlett.9b00642

Isca VMS, Ferreira RJ, Garcia C, Monteiro CM, Dinić J, Holmstedt S, André V, Pešić M, Dos Santos DJVA, Candeias NR, Afonso CAM, Rijo P. Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors. in ACS Medicinal Chemistry Letters. 2020;11(5):839-845.
doi:10.1021/acsmedchemlett.9b00642 .

Isca, Vera M. S., Ferreira, Ricardo J., Garcia, Catarina, Monteiro, Carlos M., Dinić, Jelena, Holmstedt, Suvi, André, Vânia, Pešić, Milica, Dos Santos, Daniel J. V. A., Candeias, Nuno R., Afonso, Carlos A. M., Rijo, Patrícia, "Molecular Docking Studies of Royleanone Diterpenoids from Plectranthus spp. as P-Glycoprotein Inhibitors" in ACS Medicinal Chemistry Letters, 11, no. 5 (2020):839-845,
https://doi.org/10.1021/acsmedchemlett.9b00642 . .