Abstract (EN):
The CHCl3 extract of the bark of Garcinia speciosa contained four 17,14-friedolanostanes and five lanostanes as well as friedelin and common plant constituents. The friedolanostanes were the previously known methyl ester of (24E)-3α,23α-dihydroxy-17,14-friedolanostan-8,14,24-trien-26-oic acid and the methyl esters of three hitherto unknown acids, 3α-hydroxy- 16α,23α-epoxy-17,14-friedolanostan-8,14,24-trien-26-oic acid, 3α,23α-dihydroxy-8α,9α-epoxy-17,14-friedolanostan-15- oxo-24-en-26-oic acid and 3α,23α-dihydroxy-17,14-friedolanostan-15- oxo-8(14),24-dien-26-oic acid. New lanostanes were 3β,9α- dihydroxylanost-24-en-26-al and the methyl ester of 3β-hydroxy-23-oxo-9,16- lanostadien-26-oic acid. Structures were established by analysis of spectroscopic data. In the case of the lanostanes the previously unassigned C-25 stereochemistry was shown to be 25R by X-ray analysis of 3β-hydroxy-23-oxo-9,16-lanostadien-26-oic acid. In the case of the friedolanostanes the configuration at C-23 was established as 23R, identical with the absolute configuration at C-23 of mariesiic acids A and B.
Language:
English
Type (Professor's evaluation):
Scientific