Cytotoxic clerodane diterpenes from Glossocarya calcicola
Three clerodane diterpenes were isolated and identified from leaf extract of Glossocarya calcicola. Compound 1 has been characterised as (rel)-10âH-trans-12î-(2-methylbut-2(E)-enoyl)-1â-(isobutanoyl)-6á,13î-dihydroxyclerodan-4(20),8(18)-dien-7,15-dione-15,16-oxide, to which we have assigned the trivial name calcicolin-A. The other two compounds had the same skeletal structure and C-12 substituent but in compound 2, the C-1 esterifying group becomes 2-methylbut-2(E)-enoic acid and in 3 it becomes 2-methylbutanoic acid. Although anti-insect activity was not observed for G. calcicola, cytotoxicity against insect and human carcinoma cell lines was detected.
Rasikari, HL, Leach, DN, Waterman, PG, Spooner-Hart, RN, Basta, AH, Banbury, LK, Winter, KM & Forster, PI 2005, 'Cytotoxic clerodane diterpenes from Glossocarya calcicola', Phytochemistry, vol. 66, no. 24, pp. 2844-2850.
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Publisher's version of article available at http://dx.doi.org/10.1016/j.phytochem.2005.09.024