In order to investigate the relations between different phenolic compounds and alternative branches of the biosynthetic pathway of phenolic metabolites, we analyzed the concentrations of condensed tannins and a wide range of nontannin phenolics, including cinnamic acid derivatives, flavonol glycosides, and
flavone aglycones.
Flavonoids have been identified as active constituents of many medicinal plants such as Hypericum perforatum used in traditional system of medicine for the treatment of depression.[2,3] Many
flavone compounds have been reported in literature to possess potent antinociceptive effect in different animal models.[4-6] A reciprocal association has been suggested between chronic pain and depression or anxiety disorders.
The compounds are Loasifolin (1), Eremoside A (2), Eremoside B (3), Kaempferol (3,4',5,7-tetrahydroxyflavone) (4), 5-Hydroxy-6,7,8,4'-tetramethoxyflavone (5), 5-Hydroxy-3',4',6,7,8-pentamethoxyflavone (6), Apigenin (4',5,7-trihydroxyflavone) (7), Luteolin (3',4',5,7-tetrahydroxy-flavone) (8), Apigenin 7-O-[beta]-D-glucopyranose (9) 4'-Methyl Kaempferol (3,5,6-trihydroxy-4methoxy
flavone) (10) 5-Hydroxy-7,4-dimethoxy
flavones (11), 6,7-Dime-thoxy-4,5-hydroxyflavone (12) and 3,5,7-Trihydroxy-3',4'-dimethoxyflavone (13).The structures of all isolated compounds are showed in Fig.