In our continuing search of discovering bioactive substances from marine organisms, a sample of soft coral Sarcophyton crassocaule Mosre collected off the Sanya bay, China, was investigated. Two polyhydroxylated stero...In our continuing search of discovering bioactive substances from marine organisms, a sample of soft coral Sarcophyton crassocaule Mosre collected off the Sanya bay, China, was investigated. Two polyhydroxylated sterols 1 and 2 were isolated from the 95% ethanol extract of the sample by chromatography over silica gel. Compound 1, named sarcrasterol, was a new compound, its structure was established as(22R*,24ξ)-methyl-cholest-5-en-3β,22α,25,28-tetraol by spectroscopic methods. Compound 2, a known compound, was first obtained by Kobayashi, however, the relative configuration of C24 has not been determined yet. This paper reports the stereochemistry of compound 2 established as (24S*)-methyl cholest-3β,5β,6α,25-tetraol by means of X-ray single crystal diffraction analysis. Bioassay results show that compound 2 has a moderate activity against human tumor cell lines MGC-803 with an IC50 value of 23.0 μg/mL.展开更多
On the basis of the investigation on natural product antitumor agents,a new diterpenoid named macrocalyxin J was isolated from the leaves of Rabdosia macrocalyx（Dunn） Hara by silica gel column chromatography.Based o...On the basis of the investigation on natural product antitumor agents,a new diterpenoid named macrocalyxin J was isolated from the leaves of Rabdosia macrocalyx（Dunn） Hara by silica gel column chromatography.Based on IR,MS,1H NMR,13C NMR and 2D NMR spectroscopies,the structure of macrocalyxin J was determined as（1α,6β,11β,14α）-1,7∶6,20-diepoxy-6,11-dihydroxy-6,7-seco-ent-kaur-16-ene-7,15-dione-14-acetate.The antitumor activity of the compound was assayed by MTT method.Macrocalyxin J was shown to have a potency in vitro against the cultures of Hela cells.展开更多
文摘In our continuing search of discovering bioactive substances from marine organisms, a sample of soft coral Sarcophyton crassocaule Mosre collected off the Sanya bay, China, was investigated. Two polyhydroxylated sterols 1 and 2 were isolated from the 95% ethanol extract of the sample by chromatography over silica gel. Compound 1, named sarcrasterol, was a new compound, its structure was established as(22R*,24ξ)-methyl-cholest-5-en-3β,22α,25,28-tetraol by spectroscopic methods. Compound 2, a known compound, was first obtained by Kobayashi, however, the relative configuration of C24 has not been determined yet. This paper reports the stereochemistry of compound 2 established as (24S*)-methyl cholest-3β,5β,6α,25-tetraol by means of X-ray single crystal diffraction analysis. Bioassay results show that compound 2 has a moderate activity against human tumor cell lines MGC-803 with an IC50 value of 23.0 μg/mL.
文摘On the basis of the investigation on natural product antitumor agents,a new diterpenoid named macrocalyxin J was isolated from the leaves of Rabdosia macrocalyx（Dunn） Hara by silica gel column chromatography.Based on IR,MS,1H NMR,13C NMR and 2D NMR spectroscopies,the structure of macrocalyxin J was determined as（1α,6β,11β,14α）-1,7∶6,20-diepoxy-6,11-dihydroxy-6,7-seco-ent-kaur-16-ene-7,15-dione-14-acetate.The antitumor activity of the compound was assayed by MTT method.Macrocalyxin J was shown to have a potency in vitro against the cultures of Hela cells.
