Studies On The Chemical Constituents And Bioactivities Of Acacia Catechu

Acacia is the second largest genus in the Leguminosae family, comprising more than 1200 species worldwide, with members found in almost all habitats. Out of 1200 Acacia species, approximately 800 are found in Australia,130 in Africa,20 in India, a smaller number in Asia, and the remaining specieses in the New World.Traditional Chinese medicine for Acacia catechu (L.) is the dry extract of the peeled branches of A. catechu. A. catechu is widely used in China. It was used as folk medicine to treat eczema, mouth sores, bruises, traumatic bleeding and so on. The chemical constituents and bioactivities of A. catechu were studied, which was purchased from Beijing Tongrentang Pharmacy.In the course of our search for active compounds from water extract of medical A. catechu,21 compounds were isolated by chromatographed columns of silica gel, macroporous resin, ODS and MCI gel. Their structures were elucidated by analysis of several spectra such as UV, IR, MS,1D-NMR,2D-NMR and CD, as 4-hydroxybenzoic acid (1), kaempferol (2), quercetin (3),3,4',7-trihydroxyl-3,5-dimethoxyflavone (4), catechin (5), epicatechin (6), afzelechin (7), epiafzelechin (8), mesquitol (9), ophioglonin (10), aromadendrin (11), phenol (12), N-tetratriacontane (13),4-hydroxyp henylethanol(14),3,3',5,5',7-pentahydroxyflavanone (15),3,3',4',7-tetra hydroxyflavanone(16),3,3',4',5—tetrahydroxy-7-methoxyflavonoid(17),5-hydroxy-2-[2-(4-hydroxyphenyl)acetyl]-3-methoxybenzoic acid (18), (2 S,3 S)-3,3',4',7, 8-pentahydroxyflavane (19), (3 R,4 R)-3-(3,4-dihydroxyphenyl)-4-hydroxy cyclo hexanone (20), (4 R)-5-[1-(3,4-dihydrophenyl)-3-oxobutyl]-dihydrofuran-2(3 H)-one (21). Among these, compounds 4,9,10 are new compounds, compounds 18-21 are first reported from genus Acacia.The pharmacological experiment indicated the EtOAc fractions of water extract possessed significant leukogenic effect. We did leukogenic experiment with compound 5 and 6, wherein compound 6 showed significant leukogenic effect. In addition, new compounds 18-21 were evaluated in vivo free-radical scavenging effects. It was found that the four new compounds presented a remarkable capacity to scanvenge peroxynitrite. Meantime, compound 19 had an outstanding scavenging effect of stable DHHP free radical.