Structure Identification: |
Phytochemistry (Oxford), 1996, 42(4):1157-1161. | Four stilbenoids from the orchid Agrostophyllum khasiyanum.[Reference: WebLink] | METHODS AND RESULTS:
The orchid Agrostophyllum khasiyanum, which earlier yielded agrostophyllin (7-hydroxy-2,6-dimethoxy-5H-phenanthro(4,5-bcd)pyran), on further chemical investigation has now yielded four more new stilbenoids, besides imbricatin (2,7-dihydroxy-6-methoxy-9,10-dihydro-5H-phenanthro(4,5-bcd)pyran), flaccidinin (2,6-dihydroxy-7-methoxy-5H-phenanthro(4,5-bcd)pyran-5-one),isoflaccidin in(2,7-dihydroxy-6methoxy-5H-phenanthro(4,5-bcd)pyran-5-one) and moscatilin (4,4'-dihydroxy-3,3',5-trimethoxybibenzyl) of previously known structures.
CONCLUSIONS:
The structures of the new stilbenoids, designated agrostophyllone, agrostophylloxin, agrostophylloxidin and Agrostophyllidin, were established as 7-hydroxy-2,6-dimethoxy-5H-phenanthro(4,5bcd)pyran-5-one, 2,6,7-trimethoxy-5H-phenanthro(4,5-bcd)pyran-5-one, 7-hydroxy-2,5,6-trimethoxy-5Hphenanthro(4,5-bcd)pyran and 7-hydroxy-2,6-dimethoxy-9,10-dihydro-5H-phenanthro(4,5-bcd)pyran, respectively, from spectral and chemical evidence. |
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