Short-chain phorbol ester constituents of croton oil

Five phorbol diesters, three 4-deoxy-4α-phorbol diesters, two phorbol monoesters, and one 4-deoxy-4α-phorbol monoester were isolated from a commercial sample of croton oil and characterized spectroscopically. Their purification was achieved using combinations of droplet countercurrent chromatography, low-pressure column chromatography over phase-bonded silica gel, and preparative thin layer chromatography. All of these isolates were shown to possess short-chain ester functionalities, with 12-O-tiglylphorbol-13-isobutyrate, 12-O-(2-methyl)butyrylphorbol-13-isobutyrate, 12-O-(2-methyl)butyrylphorbol-13-acetate, 12-O-tiglyl-4-deoxy-4α-phorbol-13-isobutyrate, 12-O-tiglyl-4-deoxy-4α-phorbol-13-acetate, 12-O-(2-methyl)butyryl-4-deoxy-4α-phorbol-13-acetate, phorbol-12-tiglate and 4-deoxy-4α-phorbol-13-acetate being new compounds. A contribution from the Program for Collaborative Research in the Pharmaceutical Sciences, College of Pharmacy, University of Illinois at Chicago.