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Antonio Evidente - One of the best experts on this subject based on the ideXlab platform.
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Alkaloids with Activity against the Zika Virus Vector Aedes aegypti (L.)—Crinsarnine and Sarniensinol, Two New Crinine and Mesembrine Type Alkaloids Isolated from the South African Plant Nerine sarniensis
Molecules, 2016Co-Authors: Marco Masi, Antonio Cala, Nurhayat Tabanca, Willem A L Van Otterlo, Jeffrey R. Bloomquist, Alessio Cimmino, Francisco A. Macías, Ivan R Green, Antonio EvidenteAbstract:Two new Amaryllidaceae alkaloids, belonging to the mesembrine- and Crinine-types, named crinsarnine (1) and sarniensinol (2), were isolated from the dried bulbs of Nerine sarniensis together with bowdensine (3), sarniensine (4), hippadine (5) and 1-O-acetyl-lycorine (6). Crinsarnine (1) and sarniensinol (2) were characterized using spectroscopic and chiroptical methods as (1S,2S,4aR,10bS)-2,7-dimethoxy-1,2,3,4,4a,6-hexahydro-5,11b-ethano[1,3]dioxolo-[4,5-j]phenanthridin-1-yl acetate and (6-(3aR,4Z,6S,7aS)-6-methoxy-1-methyl-2,3,3a,6,7,7a-hexa-hydro-1H-indol-3a-yl)benzo[d][1,3]dioxol-5-yl)methanol, respectively. Furthermore, the complete spectroscopic characterization of bowdensine (3) is reported for the first time. Compounds 1–6 were evaluated against the Orlando reference strain of Aedes aegypti. None of compounds showed mortality against 1st instar Ae. aegypti larvae at the concentrations tested. In adult topical bioassays, only 1 displayed adulticidal activity with an LD50 = 2.29 ± 0.049 μg/mosquito. As regards the structure-activity relationship, the pretazettine and Crinine scaffold in 2 and 4 and in 1 and 3 respectively, proved to be important for their activity, while the pyrrole[de]phenanthridine scaffold present in 5 and 6 was important for their reactivity. Among the pretazettine group compounds, opening of the B ring or the presence of a B ring lactone as well as the trans-stereochemistry of the A/B ring junction, appears to be important for activity, while in Crinine-type alkaloids, the substituent at C-2 seems to play a role in their activity.
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Alkaloids with Activity against the Zika Virus Vector Aedes aegypti (L.)-Crinsarnine and Sarniensinol, Two New Crinine and Mesembrine Type Alkaloids Isolated from the South African Plant Nerine sarniensis.
Molecules (Basel Switzerland), 2016Co-Authors: Marco Masi, Antonio Cala, Nurhayat Tabanca, Jeffrey R. Bloomquist, Alessio Cimmino, Francisco A. Macías, Ivan R Green, Willem A. L. Van Otterlo, Antonio EvidenteAbstract:Two new Amaryllidaceae alkaloids, belonging to the mesembrine- and Crinine-types, named crinsarnine (1) and sarniensinol (2), were isolated from the dried bulbs of Nerine sarniensis together with bowdensine (3), sarniensine (4), hippadine (5) and 1-O-acetyl-lycorine (6). Crinsarnine (1) and sarniensinol (2) were characterized using spectroscopic and chiroptical methods as (1S,2S,4aR,10bS)-2,7-dimethoxy-1,2,3,4,4a,6-hexahydro-5,11b-ethano[1,3]dioxolo-[4,5-j]phenanthridin-1-yl acetate and (6-(3aR,4Z,6S,7aS)-6-methoxy-1-methyl-2,3,3a,6,7,7a-hexa-hydro-1H-indol-3a-yl)benzo[d][1,3]dioxol-5-yl)methanol, respectively. Furthermore, the complete spectroscopic characterization of bowdensine (3) is reported for the first time. Compounds 1–6 were evaluated against the Orlando reference strain of Aedes aegypti. None of compounds showed mortality against 1st instar Ae. aegypti larvae at the concentrations tested. In adult topical bioassays, only 1 displayed adulticidal activity with an LD50 = 2.29 ± 0.049 μg/mosquito. As regards the structure-activity relationship, the pretazettine and Crinine scaffold in 2 and 4 and in 1 and 3 respectively, proved to be important for their activity, while the pyrrole[de]phenanthridine scaffold present in 5 and 6 was important for their reactivity. Among the pretazettine group compounds, opening of the B ring or the presence of a B ring lactone as well as the trans-stereochemistry of the A/B ring junction, appears to be important for activity, while in Crinine-type alkaloids, the substituent at C-2 seems to play a role in their activity.
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5,10b-Ethanophenanthridine amaryllidaceae alkaloids inspire the discovery of novel bicyclic ring systems with activity against drug resistant cancer cells
European journal of medicinal chemistry, 2016Co-Authors: S. Henry, Ria Kidner, Mary R. Reisenauer, Igor V. Magedov, Robert Kiss, Véronique Mathieu, Florence Lefranc, Ramesh Dasari, Antonio EvidenteAbstract:Plants of the Amaryllidaceae family produce a large variety of alkaloids and non-basic secondary metabolites, many of which are investigated for their promising anticancer activities. Of these, Crinine-type alkaloids based on the 5,10b-ethanophenanthridine ring system were recently shown to be effective at inhibiting proliferation of cancer cells resistant to various pro-apoptotic stimuli and representing tumors with dismal prognoses refractory to current chemotherapy, such as glioma, melanoma, non-small-cell lung, esophageal, head and neck cancers, among others. Using this discovery as a starting point and taking advantage of a concise biomimetic route to the Crinine skeleton, a collection of Crinine analogues were synthetically prepared and evaluated against cancer cells. The compounds exhibited single-digit micromolar activities and retained this activity in a variety of drug-resistant cancer cell cultures. This investigation resulted in the discovery of new bicyclic ring systems with significant potential in the development of effective clinical cancer drugs capable of overcoming cancer chemotherapy resistance.
Yongqiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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concise total synthesis of Crinine
Synlett, 2009Co-Authors: Jian-dong Liu, Fumin Zhang, Shaohua Wang, Yongqiang ZhangAbstract:The concise total synthesis of (+/-)-Crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of allylic alcohols. The hydroindole skeleton with the sterically congested quaternary carbon center was established concisely by utilizing this semipinacol rearrangement followed by a combination of intramolecular aldol and aza-Michael reactions.
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a general approach to Crinine type amaryllidaceae alkaloids total syntheses of haemanthidine pretazettine tazettine and crinamine
Tetrahedron, 2006Co-Authors: Fumin Zhang, Yongqiang Tu, Xiangdong Hu, Shaohua Wang, Yongqiang ZhangAbstract:A general strategy for synthesizing the Crinine-type Amaryllidaceae alkaloids was developed. And total syntheses of four representative Crinine-type Amaryllidaceae alkaloids: (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine, were accomplished via a common intermediate 17. This crucial precursor was achieved on the basis of the NBS-promoted semipinacol rearrangement recently developed by our group and an intramolecular Michael addition, which efficiently constructed the sterically congested quaternary carbon center and the hydroindole skeleton of the Crinine-type alkaloids, respectively.
Fumin Zhang - One of the best experts on this subject based on the ideXlab platform.
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concise total synthesis of Crinine
Synlett, 2009Co-Authors: Jian-dong Liu, Fumin Zhang, Shaohua Wang, Yongqiang ZhangAbstract:The concise total synthesis of (+/-)-Crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of allylic alcohols. The hydroindole skeleton with the sterically congested quaternary carbon center was established concisely by utilizing this semipinacol rearrangement followed by a combination of intramolecular aldol and aza-Michael reactions.
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Concise Total Synthesis of(±)-Crinine
Synlett, 2009Co-Authors: Jian-dong Liu, Shaohua Wang, Fumin Zhang, Yong‐qiang ZhangAbstract:The concise total synthesis of (+/-)-Crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of allylic alcohols. The hydroindole skeleton with the sterically congested quaternary carbon center was established concisely by utilizing this semipinacol rearrangement followed by a combination of intramolecular aldol and aza-Michael reactions.
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a general approach to Crinine type amaryllidaceae alkaloids total syntheses of haemanthidine pretazettine tazettine and crinamine
Tetrahedron, 2006Co-Authors: Fumin Zhang, Yongqiang Tu, Xiangdong Hu, Shaohua Wang, Yongqiang ZhangAbstract:A general strategy for synthesizing the Crinine-type Amaryllidaceae alkaloids was developed. And total syntheses of four representative Crinine-type Amaryllidaceae alkaloids: (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine, were accomplished via a common intermediate 17. This crucial precursor was achieved on the basis of the NBS-promoted semipinacol rearrangement recently developed by our group and an intramolecular Michael addition, which efficiently constructed the sterically congested quaternary carbon center and the hydroindole skeleton of the Crinine-type alkaloids, respectively.
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A general approach to Crinine-type Amaryllidaceae alkaloids: total syntheses of (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine
Tetrahedron, 2006Co-Authors: Fumin Zhang, Xiang‐dong Hu, Yongqiang Tu, Shaohua Wang, Yong‐qiang ZhangAbstract:A general strategy for synthesizing the Crinine-type Amaryllidaceae alkaloids was developed. And total syntheses of four representative Crinine-type Amaryllidaceae alkaloids: (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine, were accomplished via a common intermediate 17. This crucial precursor was achieved on the basis of the NBS-promoted semipinacol rearrangement recently developed by our group and an intramolecular Michael addition, which efficiently constructed the sterically congested quaternary carbon center and the hydroindole skeleton of the Crinine-type alkaloids, respectively.
Xiaodong Yang - One of the best experts on this subject based on the ideXlab platform.
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synthetic studies towards Crinine typeamaryllidaceae alkaloids synthesis of oxoCrinineand formal synthesis of Crinine
Synlett, 2011Co-Authors: Lijuan Yang, Xue-quan Wang, Zhi-qiang Pan, Ming Zhou, Wen Chen, Xiaodong YangAbstract:A flexible strategy leading to the synthesis of Crinine-type Amaryllidaceae alkaloids, (±)-oxoCrinine and (±)-Crinine, has been developed. A notable feature in this synthetic route is the construction of tetrahydro-1 H-benzo[c]azepine framework using an intramolecular Heck reaction and the formation of the sterically congested spiro cyclohexenone intermediate with a Robinson annulation.
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Synthetic Studies Towards Crinine-TypeAmaryllidaceae Alkaloids: Synthesis of (±)-OxoCrinineand Formal Synthesis of (±)-Crinine
Synlett, 2010Co-Authors: Lijuan Yang, Xue-quan Wang, Zhi-qiang Pan, Ming Zhou, Wen Chen, Xiaodong YangAbstract:A flexible strategy leading to the synthesis of Crinine-type Amaryllidaceae alkaloids, (±)-oxoCrinine and (±)-Crinine, has been developed. A notable feature in this synthetic route is the construction of tetrahydro-1 H-benzo[c]azepine framework using an intramolecular Heck reaction and the formation of the sterically congested spiro cyclohexenone intermediate with a Robinson annulation.
Shaohua Wang - One of the best experts on this subject based on the ideXlab platform.
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concise total synthesis of Crinine
Synlett, 2009Co-Authors: Jian-dong Liu, Fumin Zhang, Shaohua Wang, Yongqiang ZhangAbstract:The concise total synthesis of (+/-)-Crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of allylic alcohols. The hydroindole skeleton with the sterically congested quaternary carbon center was established concisely by utilizing this semipinacol rearrangement followed by a combination of intramolecular aldol and aza-Michael reactions.
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Concise Total Synthesis of(±)-Crinine
Synlett, 2009Co-Authors: Jian-dong Liu, Shaohua Wang, Fumin Zhang, Yong‐qiang ZhangAbstract:The concise total synthesis of (+/-)-Crinine was accomplished in 24% overall yield and eleven steps starting from an easily available allylic alcohol. The key step of the current synthesis involved the NBS-promoted semipinacol rearrangement reaction of allylic alcohols. The hydroindole skeleton with the sterically congested quaternary carbon center was established concisely by utilizing this semipinacol rearrangement followed by a combination of intramolecular aldol and aza-Michael reactions.
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a general approach to Crinine type amaryllidaceae alkaloids total syntheses of haemanthidine pretazettine tazettine and crinamine
Tetrahedron, 2006Co-Authors: Fumin Zhang, Yongqiang Tu, Xiangdong Hu, Shaohua Wang, Yongqiang ZhangAbstract:A general strategy for synthesizing the Crinine-type Amaryllidaceae alkaloids was developed. And total syntheses of four representative Crinine-type Amaryllidaceae alkaloids: (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine, were accomplished via a common intermediate 17. This crucial precursor was achieved on the basis of the NBS-promoted semipinacol rearrangement recently developed by our group and an intramolecular Michael addition, which efficiently constructed the sterically congested quaternary carbon center and the hydroindole skeleton of the Crinine-type alkaloids, respectively.
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A general approach to Crinine-type Amaryllidaceae alkaloids: total syntheses of (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine
Tetrahedron, 2006Co-Authors: Fumin Zhang, Xiang‐dong Hu, Yongqiang Tu, Shaohua Wang, Yong‐qiang ZhangAbstract:A general strategy for synthesizing the Crinine-type Amaryllidaceae alkaloids was developed. And total syntheses of four representative Crinine-type Amaryllidaceae alkaloids: (±)-haemanthidine, (±)-pretazettine, (±)-tazettine, and (±)-crinamine, were accomplished via a common intermediate 17. This crucial precursor was achieved on the basis of the NBS-promoted semipinacol rearrangement recently developed by our group and an intramolecular Michael addition, which efficiently constructed the sterically congested quaternary carbon center and the hydroindole skeleton of the Crinine-type alkaloids, respectively.