ABSTRACT
Eleven known flavonoids (1-11) were isolated from Dikamali, the gum resin of Gardenia lucida. Three of them, desmethylnobiletin, pectolinarigenin and xanthomicrol, are a new report from this source. Nuclear magnetic resonance (NMR) data are being given for all the isolates. For two of them, viz., 3',4'-dimethoxywogonin and 4'-hydroxywogonin, such data have not been reported in literature. Furthermore, correct NMR data are being provided for gardenin C as the data reported in literature were found to be incorrect.
Subject(s)
Chromones/isolation & purification , Flavones/isolation & purification , Flavonoids/isolation & purification , Gardenia/chemistry , Resins, Plant/chemistry , Chromones/chemistry , Flavones/chemistry , Flavonoids/chemistry , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
Chemical investigation of Selaginella chrysocaulos from Northeast India yielded three new (i.e., 1-3) and two known biflavonoids. From Selaginella bryopteris, collected in the southern part of India, one new (11) and eleven known biflavonoids of the amentoflavone- and hinokiflavone-type were isolated and identified. The structures of the compounds were elucidated by 1D- and 2D-NMR spectroscopy, and by mass spectrometry. The absolute configurations of chiral biflavonoids with flavanone subunits (from S. bryopteris) were determined with the aid of circular-dichroism (CD) spectroscopy. Several very rare or even unprecedented substructures in biflavonoids were found.
