Improved access to highly unsaturated skin irritants of the daphnane type from latex of Excoecaria oppositifolia

• Published in: Planta medica Vol. 60; no. 6; p. 566
• Main Authors: Karalai, C, Wiriyachitra, P, Sorg, B, Hecker, E. (Prince of Songkla Univ., Hat-Yai (Thailand). Faculty of Science. Dept. of Chemistry)
• Format: Journal Article
• Language: English
• Published: Germany 01.12.1994
• Subjects: daphnane orthoesters; Diterpenes - isolation & purification; Diterpenes - pharmacology; ENFERMEDADES DE LA PIEL; ESTER; ESTERES; EUPHORBIACEAE; Excoecaria oppositifolia; FARMACOLOGIA; Irritants - chemistry; Irritants - isolation & purification; Irritants - pharmacology; LATEX; Latex - chemistry; MALADIE DE LA PEAU; Molecular Structure; Pflanzenbau; PHARMACOLOGIE; PLANTAS MEDICINALES; PLANTE MEDICINALE; Plants, Medicinal - chemistry; Skin - drug effects; Terpenes - chemistry
• ISSN: 0032-0943; 1439-0221
• DOI: 10.1055/s-2006-959573

A new and more efficient procedure was developed to obtain 5beta-hydroxyresiniferonol-6alpha, 7alpha-epoxide-9,13,14-ortho(2,4,6-decatrienoate) (Excoecaria factor O1) by alkaline transesterification of corresponding 20-ester(s) genuinely present in latex of Excoecaria oppositifolia. It was obtained in a 10-fold better yield than previously, probably due to speeding up the separation procedures of the sensitive compound. O1 is an appropriate starting material for the preparation of the daphnane prototype irritant and tumor-promoting orthoester simplexin (SIM) especially of a multiple tritium-labeled form thereof. Moreover, a new Excoecaria factor O3, i.e. the 9,13,14-ortho(2,4,6,8-hexadecatetraenoate) of 5beta,12beta-dihydroxyresiniferonol-6alpha, 7alpha-epoxide was isolated after alkaline transesterification of a TLC-uniform fraction, composed of corresponding 20-ester(s).