Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihyd...Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a- L-rhamnopyranosyl (1→2)[ a-L-rhamnopyranosyl (1→4)]-b-D-glucopyranoside and (20S)3b, 14a, 16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a-L-rhamnopyranosyl (1→2) [b-D-glucopyranosyl(1→3)]-b-D-glucopyranoside by means of 2D NMR spectral and chemical methods. It is the first time that steroidal lactone glycosides were isolated from the genus Dracaena.展开更多
The osmium tetroxide catalyzed asymmetric dihydroxylation of the(22E)- steroidal sidechain is described and an unexpected 8:1 ratio of(22R,23R)and (22S,23S)was obtained from the(22E,24S)-24-ethyl substituted sidechain.
Two new C-27 steroidal: glycosides, named ophiopojaponin A(1)and B(2), were isolated from the tubers of famous traditional Chinese herb-Ophiopogon japonicus. The spectroscopic and chemical evidences revealed their str...Two new C-27 steroidal: glycosides, named ophiopojaponin A(1)and B(2), were isolated from the tubers of famous traditional Chinese herb-Ophiopogon japonicus. The spectroscopic and chemical evidences revealed their structures to be Pennogenin 3-O-[2'-O-acetyl-alpha-L-rhamnopyranosyl (1-->2)]-beta-D-xylopyranosyl (1-->3)-beta-D-glucopyranoside (1) and 26-O-beta-D-glucopyranosyl-(22 xi, 25R)-3 beta, 14 alpha, 22 xi, 26-tetrahydroxyfurost-5-ene 3-O-alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranoside (2), respectively.展开更多
文摘Two new C-22 steroidal lactone glycosides, named dracaenoside A and B were isolated from the methanol extract of the fresh stem of Dracaena cochinchinensis. Their structures were established as (20S)3b,14a,16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a- L-rhamnopyranosyl (1→2)[ a-L-rhamnopyranosyl (1→4)]-b-D-glucopyranoside and (20S)3b, 14a, 16b-trihydroxy pregn-5-ene-22-carboxylic acid (22,16)-lactone 3-O-a-L-rhamnopyranosyl (1→2) [b-D-glucopyranosyl(1→3)]-b-D-glucopyranoside by means of 2D NMR spectral and chemical methods. It is the first time that steroidal lactone glycosides were isolated from the genus Dracaena.
文摘The osmium tetroxide catalyzed asymmetric dihydroxylation of the(22E)- steroidal sidechain is described and an unexpected 8:1 ratio of(22R,23R)and (22S,23S)was obtained from the(22E,24S)-24-ethyl substituted sidechain.
基金a key project of Chinese Academy of sciences. We are grateful to the members of Instrument Group of Phytochemistry Laboratory, K
文摘Two new C-27 steroidal: glycosides, named ophiopojaponin A(1)and B(2), were isolated from the tubers of famous traditional Chinese herb-Ophiopogon japonicus. The spectroscopic and chemical evidences revealed their structures to be Pennogenin 3-O-[2'-O-acetyl-alpha-L-rhamnopyranosyl (1-->2)]-beta-D-xylopyranosyl (1-->3)-beta-D-glucopyranoside (1) and 26-O-beta-D-glucopyranosyl-(22 xi, 25R)-3 beta, 14 alpha, 22 xi, 26-tetrahydroxyfurost-5-ene 3-O-alpha-L-rhamnopyranosyl (1-->2)-beta-D-glucopyranoside (2), respectively.