- Enantioselective Total Synthesis of (–)-Siphonodictyal B and (+)-8-epi-Siphonodictyal B with Phosphatidylinositol 3-Kinase α (PI3Kα) Inhibitory Activity
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The biologically interesting marine meroterpenoids (–)-siphonodictyal B and (+)-8-epi-siphonodictyal B were efficiently synthesized in 29–40 % overall yield in a longest linear sequence of 11 steps, starting from commercially available (+)-sclareolide. The synthesis involved the following crucial steps: (i) stereodivergent hydrogenation of a homoallylic decalin alcohol to install the requisite C8 stereogenic centre present in the decalin fragments; (ii) coupling of the decalin fragments with an aromatic moiety to assemble the desired carbon skeletons; and (iii) deprotection from multiple O-protective groups on the aromatic ring to complete the project synthesis. Both (–)-siphonodictyal B and (+)-8-epi-siphonodictyal B showed PI3Kα inhibitory activity, with potencies comparable to that of liphagal, a naturally occurring PI3Kα inhibitor. New structure–activity relationships for this class of marine meroterpenoids were also revealed.
- Kikuchi, Takuya,Narita, Koichi,Saijo, Ken,Ishioka, Chikashi,Katoh, Tadashi
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- Biogenetically inspired total synthesis of (+)-liphagal: A potent and selective phosphoinositide 3-kinase α (PI3Kα) inhibitor from the marine sponge Aka coralliphaga
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A biologically attractive and structurally unique marine natural product, (+)-liphagal, was biomimetically synthesized in 29% overall yield in a longest linear sequence of 13 steps from commercially available (+)-sclareolide. This synthesis involved the following crucial steps: (i) stereocontrolled hydrogenation of an endo-olefinic decalin to install the C8 stereogenic centre present in the requisite decalin segment; (ii) coupling of the decalin segment with an aromatic moiety to assemble the desired carbon skeleton; (iii) ring expansion of a proposed biogenetic intermediate followed by benzofuran formation to establish the requisite tetracyclic core structure. A few new aspects of the proposed biosynthetic pathway to this class of natural products were revealed. Copyright
- Kamishima, Takaaki,Kikuchi, Takuya,Narita, Koichi,Katoh, Tadashi
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- Synthesis of the Sesquiterpenes Albicanol, Drimanol, and Drimanic Acid, and the Marine Sesquiterpene Hydroquinone Deoxyspongiaquinol
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A TiIII-mediated radical cyclization cascade has been used for the synthesis of the sesquiterpenes (+)-albicanol, (+)-drimanol, and (+)-drimanic acid. Starting from all-trans-farnesol, (+)-albicanol could be prepared in seven steps in an overal
- G?hl, Matthias,Seifert, Karlheinz
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p. 6975 - 6982
(2016/02/19)
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- Structural requirements for the antifungal activities of natural drimane sesquiterpenes and analogues, supported by conformational and electronic studies
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Seventeen drimanes including polygodial (1), isopolygodial (2), drimenol (3) and confertifolin (4) obtained from natural sources and the semi-synthetic derivatives 5-17 obtained from 1-3, were evaluated in vitro for antifungal properties against a unique panel of fungi with standardized procedures by using two end-points, MIC100 and MIC50. A SAR analysis of the whole series, supported by conformational and electronic studies, allowed us to show that the Δ7,8 -double bond would be one of the key structural features related to the antifungal activity. The MEPs obtained for active compounds exhibit a clear negative minimum value (deep red zone) in the vicinity of the Δ7,8 -double bond, which is not present in the inactive ones. Apart of this negative zone, a positive region (deep blue) appears in 1, which is not observed either in its epimer 2 nor in the rest of the active compounds. The LogP of active compounds varies between 2.33 and 3.84, but differences in MICs are not correlated with concomitant variations in LogP values.
- Derita, Marcos,Montenegro, Ivan,Garibotto, Francisco,Enriz, Ricardo D.,Fritis, Mauricio Cuellar,Zacchino, Susana A.
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p. 2029 - 2051
(2013/04/10)
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- Comparative study on the larvicidal activity of drimane sesquiterpenes and nordrimane compounds against drosophila melanogaster til-til
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Natural compounds from Drimys winteri Forst and derivatives exhibited larvicidal effects against Drosophila melanogaster til-til. The most active compound was isodrimenin (4). The highest lethal concentration to the larvae of D. melanogaster was 4.5 ± 0.8 mg/L. At very low concentrations drimenol (1), confertifolin (3), and drimanol (5) displayed antifeedant and larvae growth regulatory activity. The antifeedant results of nordrimanic and drimanic compounds were better in first instar larvae. The EC50 value of polygodial (2) was 60.0 ± 4.2 mg/L; of diol 15 45.0 ± 2.8 mg/L, and of diol 17 36.9 ± 3.7 mg/L, while the new nordrimane compound 12 presented a value of 83.2 ± 3.5 mg/L.
- Montenegro, Ivan,Pino, Luis,Werner, Enrique,Madrid, Alejandro,Espinoza, Luis,Moreno, Luis,Villena, Joan,Cuellar, Mauricio
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p. 4192 - 4208
(2013/06/26)
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- ALTERNATIVE AND STEREOSELECTIVE SYNTHESIS OF 8β(H)-DRIMANE, A BICYCLIC SESQUITERPANE OF WIDESPREAD OCCURRENCE IN PETROLEUMS
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Starting from drimenol, an alternative and stereoselective synthesis of 8β(H)-drimane, a widespread occurring sesquiterpane in petroleums, is described.The epimer 8α(H)-drimane was also prepared and a comparative 13C NMR spectral analysis of both stereoisomers was carried out.
- Gonzales-Sierra, Manuel,Laborde, Maria de los Angeles,Ruveda, Edmundo A.
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p. 431 - 442
(2007/10/02)
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- Fungal Metabolites. Part 5. Uvidins, New Drimane Sesquiterpenes from Lactarius uvidus Fries
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Uvidin A (IIa) and uvidin B (IIc) along with (-)-drimenol have been isolated from Lactarius uvidus Fries (Basidiomycetes).The structure and the stereochemistry of the two uvidins have been determined both by spectroscopic data and chemical reactions.Compound (IIa) has been correlated with (+)-drimanol (VIII) by transformations into (VI) and then (VII).Reactions and spectroscopic data are discussed.
- Bernardi, Maria De,Mellerio, Giorgio,Vidari, Giovanni,Vita-Finzi, Paola,Fronza, Giovanni
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p. 221 - 226
(2007/10/02)
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