Preost-Woodward hydroxylation of 2 gave the 22S,23S-glycol(3), contrary to expectation.It is suggested that the formation of the two possible iodonium ions(4a and 4b)are reversible,thus allowing the discriminatory ace...Preost-Woodward hydroxylation of 2 gave the 22S,23S-glycol(3), contrary to expectation.It is suggested that the formation of the two possible iodonium ions(4a and 4b)are reversible,thus allowing the discriminatory acetoxy group to follow the less hindered route,reacting with 4a virtually exclusively.展开更多
On an example of spontaneous changes 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one at room temperature, a new example of condensations in a solid station is opened. The single crystal of 2-(3’, 5'-di-tert-but...On an example of spontaneous changes 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one at room temperature, a new example of condensations in a solid station is opened. The single crystal of 2-(3’, 5'-di-tert-butyl-4'-hydroxy-phenyl)-ethyloxy-p-cresole is produced as result of a structure transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one in a solid phase at room temperature except a single crystal at transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one a new substance is formed too. Spectrums 1Н and 13С NMR differ from similar spectrums of initial compound and the single crystal. New substance represents an admixture of isomeric compounds, capable reversible to be transformed in initial 5,7-di-tert-butylspiro(2,5) octa-4,7-diene-6-one and 2-(3’, 5'-di-tert-butyl-4'-hydroxyphenyl)-ethyloxy-p-cresole.展开更多
The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional pe...The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional permeability tests were carried out, and the apparent permeability coefficients （Papp） were calculated. The two protopanaxatriol epimers showed good permeability with Papp values of-10^-5 cm/s, whereas dammar-20（22）E,24-diene-3β,6α, 12β-triol showed poor permeability with Papp of 〈1 × 10^-7 cm/s. The three compounds showed differences in intracellular accumulations due to their different structures. Inhibition of P-gp with verapamil showed that the transport mechanisms in MDCK-pHaMDR cell monolayer for compounds 1 and 2 epimers were not only simple passive diffusion but also involving an effiux way mediated by P-gp. These findings provided new basis for the further study of compounds 1 and 2 acting on the brain.展开更多
In this paper,obtainment of 3 by simultaneous inversion of configurations of C_(22),C_(23) in 2 via its ditosylate or dimesylate was unsuccessful,leading to elimination products instead.However, monotosylate of 2 can ...In this paper,obtainment of 3 by simultaneous inversion of configurations of C_(22),C_(23) in 2 via its ditosylate or dimesylate was unsuccessful,leading to elimination products instead.However, monotosylate of 2 can be readily obtained with exclusive regioselectivity,which in turn gave a single epoxide 7b Hydrolysis of 7b gave 3 and 2 is a ratio of 2:1,with a combined yield of 80%.The recovered 2 can of course be recycled again.展开更多
Twelve steroids, including eight ergostane-type sterols and four mono-glucosides of ergostane-type sterols, were isolated from the ethyl acetate soluble fraction of the fungus Pleurotus ostreatus ( Jacq. : Fr.) Kummer...Twelve steroids, including eight ergostane-type sterols and four mono-glucosides of ergostane-type sterols, were isolated from the ethyl acetate soluble fraction of the fungus Pleurotus ostreatus ( Jacq. : Fr.) Kummer. A new compound 3-O-beta-D-glucopyranosyl-22E, 24R-ergosta-7, 22-diene-5alpha, 6beta, 9alpha-triol, was structurally elucidated by spectroscopic and chemical methods. The eleven known compounds were 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6beta, 9alpha-tetraol; 3-O-beta-D-glucopyranosyl-22E, 24R-ergosta-7, 22-diene-5alpha, 6beta-diol; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6beta-triol; 22E, 24R-ergosta-5, 7, 22-trien-3beta-ol 3-O-beta-D-glucopyranoside; ergosterol; 22E, 24R-ergosta-7, 22-dien-3beta-ol 3-O-beta-D-glucopyranoside; 22E, 24R-ergosta-7, 22-diene-3beta-ol; 22E, 24R-ergosta-4, 6, 8, 22-tetraen-3-one; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha, 6alpha-triol; ergosterol peroxide; 22E, 24R-ergosta-7, 22-diene-3beta, 5alpha-diol-6-one.展开更多
A new sterol, ergosta-8(9),22-diene-3,5,6,7-tetraol(3β,5α,6β,7α,22E)(A) together with three known sterols: 3β, 5α,6β-trihydroxyergosta-7,22-diene (B), 3β-hydroxy-5α,8α- epidioxyer-gosta-6,22-diene (C) and er...A new sterol, ergosta-8(9),22-diene-3,5,6,7-tetraol(3β,5α,6β,7α,22E)(A) together with three known sterols: 3β, 5α,6β-trihydroxyergosta-7,22-diene (B), 3β-hydroxy-5α,8α- epidioxyer-gosta-6,22-diene (C) and ergosterol (D) were isolated from the mycelia of an unidentified endophytic fungus separated from Castaniopsis fissa (chestnut tree). Compound A exhibited potent selective cytotoxicity against Bel-7402, NCI4460 and L-02 cell lines with IC50 values 8.445, 5.03, 13.621 μg/mL, respectively.展开更多
文摘Preost-Woodward hydroxylation of 2 gave the 22S,23S-glycol(3), contrary to expectation.It is suggested that the formation of the two possible iodonium ions(4a and 4b)are reversible,thus allowing the discriminatory acetoxy group to follow the less hindered route,reacting with 4a virtually exclusively.
文摘On an example of spontaneous changes 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one at room temperature, a new example of condensations in a solid station is opened. The single crystal of 2-(3’, 5'-di-tert-butyl-4'-hydroxy-phenyl)-ethyloxy-p-cresole is produced as result of a structure transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one in a solid phase at room temperature except a single crystal at transformation 5,7-di-tert-butylspiro (2,5) octa-4,7-diene-6-one a new substance is formed too. Spectrums 1Н and 13С NMR differ from similar spectrums of initial compound and the single crystal. New substance represents an admixture of isomeric compounds, capable reversible to be transformed in initial 5,7-di-tert-butylspiro(2,5) octa-4,7-diene-6-one and 2-(3’, 5'-di-tert-butyl-4'-hydroxyphenyl)-ethyloxy-p-cresole.
基金The National New Drug R&D Program(Grant No.2011BAI07B082009ZX09301-010)of China
文摘The blood-brain barrier permeability of 20（S） and 20（R）-protopanaxatriol epimers and dammar-20（22）E,24-diene- 313,6α,12β-triol were investigated using the MDCK-pHaMDR cell monolayer model. The bidirectional permeability tests were carried out, and the apparent permeability coefficients （Papp） were calculated. The two protopanaxatriol epimers showed good permeability with Papp values of-10^-5 cm/s, whereas dammar-20（22）E,24-diene-3β,6α, 12β-triol showed poor permeability with Papp of 〈1 × 10^-7 cm/s. The three compounds showed differences in intracellular accumulations due to their different structures. Inhibition of P-gp with verapamil showed that the transport mechanisms in MDCK-pHaMDR cell monolayer for compounds 1 and 2 epimers were not only simple passive diffusion but also involving an effiux way mediated by P-gp. These findings provided new basis for the further study of compounds 1 and 2 acting on the brain.
文摘In this paper,obtainment of 3 by simultaneous inversion of configurations of C_(22),C_(23) in 2 via its ditosylate or dimesylate was unsuccessful,leading to elimination products instead.However, monotosylate of 2 can be readily obtained with exclusive regioselectivity,which in turn gave a single epoxide 7b Hydrolysis of 7b gave 3 and 2 is a ratio of 2:1,with a combined yield of 80%.The recovered 2 can of course be recycled again.
文摘A new sterol, ergosta-8(9),22-diene-3,5,6,7-tetraol(3β,5α,6β,7α,22E)(A) together with three known sterols: 3β, 5α,6β-trihydroxyergosta-7,22-diene (B), 3β-hydroxy-5α,8α- epidioxyer-gosta-6,22-diene (C) and ergosterol (D) were isolated from the mycelia of an unidentified endophytic fungus separated from Castaniopsis fissa (chestnut tree). Compound A exhibited potent selective cytotoxicity against Bel-7402, NCI4460 and L-02 cell lines with IC50 values 8.445, 5.03, 13.621 μg/mL, respectively.
