Screening of polyacetylenic alcohols in crude drugs using the ELISA for panaxytriol

Polyacetylenic alcohols such as panaxytriol, panaxynol and panaxydol isolated from the roots of Panax ginseng C. A. MEYER have antiproliferative activity against various cultured tumor cells. Anti-panaxytriol antibody was obtained by immunizing rabbits with panaxytriol-bovine serum albumin conjugates. Although the antibody reactivity was directed mainly toward panaxytriol, there was a slight cross-reactivity with other polyacetylenic compounds. The antibody was, therefore, used for screening a large number of crude drugs for polyacetylenic compounds such as panaxytriol. Methanol-extracts from 31 crude drugs were examined. Significant reactivity was observed in 15 methanol-extracts from Aralieaceae, Compositae and Umbelliferae as reported by other investigators. Three out of the 15 crude drugs were selected for determination of the potent cross-reactive compounds. Four kinds of cross-reactive compounds were isolated by silica gel column chromatography, monitoring each fraction using the enzyme-linked immunosorbent assay (ELISA). Among them, panaxynol and heptadeca-1,8-diene-4,6-diyne-3,10-diol were identified from Saposhnikoviae Radix. Falcarindiol was newly identified from Peucedani Radix. A new polyacetylenic alcohol, 9,10-epoxy-16-hydroxy-octadeca-17-ene-12,14-diyne-1-al, was also isolated from Foeniculi Fructus. All these polyacetylenic alcohols inhibited the growth of a human gastric adenocarcinoma cell line, MK-1 cells, in a dose-dependent manner. These results indicate that the antibody against panaxytriol is an effective tool for "screening" antiproliferative polyacetylenic compounds.