A new ferulic acid ester and other constituents from Tamarix nilotica leaves

Phytochemical investigation of the leaves of Tamarix nilotica (Tamaricaceae) has led to isolation of methyl ferulate 3-O-sulphate (1) for the first time from natural sources. In addition, coniferyl alcohol 4-O-sulphate (2), kaempferol 4'-methyl ether (3), tamarixetin (4) and quercetin 3-O-beta-D-glucupyranuronide (5) were isolated from the n-butanol soluble fraction of the extract. The pentacyclic triterpenoid, 3alpha-(3'',4''-dihydroxy-trans-cinnamoyloxy)-D-friedoolean-14-en-28-oic acid (6) was isolated from the n-hexane soluble fraction of the extract. The structures of these compounds were determined on the basis of spectroscopic analyses including 2 dimensional NMR. Compounds 3, 4 and 6 exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity with IC(50) values of 35.2, 37.0 and 21.2 muM, respectively.