0000000000082899
AUTHOR
Gunther Burkhardt
Biphenyls and xanthones from the podostemaceae
Abstract Investigation of the fruiting parts of Mourera fluviatilis afforded 6-desoxyjacareubin, trapezifoliaxanthone and a series of eight new biphenyl derivatives; 3,5-dimethoxybiphenyl; 2,2-dimethyl-5-methoxy-7-phenylchromene; 2,2-dimethyl-7-methoxy-5-phenylchromene; 2-(3,3-dimethylallyl)-3-hydroxy-5-methoxybiphenyl; 2,3-dihydro-6-methoxy-4-phenyl-2,3,3-trimethylcoumarone; [(2,3-dihydro-3,3-dimethyl-6-methoxy-4-phenyl)-2-coumaronyl]methanol; 2,3-dihydro-3,3-dimethyl-6-methoxy-2-oxo-4-phenylcoumarone; and a dimeric biphenyl.
Bioactive chromenes from Rhyncholacis penicillata.
Investigation of the aerial parts of Rhyncholacis penicillata afforded the new chromenes, 7-hydroxy-6-(3-methylbutyryl)-5-oxymethyl-chromene (rhynchonin A) and 7-hydroxy-6-(2-methylbutyryl)-6-oxymethylchromene (rhynchonin B). Structures were elucidated by spectroscopic methods and independent synthesis. Rhynchonin A showed broad insecticidal, acaricidal and nematicidal potency including strong biological activity against Heliothis zea.