Improved Access to Highly Unsaturated Skin Irritants of the Daphnane Type from Latex of Excoecaria oppositifolia1

C. Karalai; P. Wiriyachitra; B. Sorg; E. Hecker

doi:10.1055/s-2006-959573

Planta Medica, Inhaltsverzeichnis

Planta Med 1994; 60(6): 566-568
DOI: 10.1055/s-2006-959573

Papers

Improved Access to Highly Unsaturated Skin Irritants of the Daphnane Type from Latex of Excoecaria oppositifolia ¹

C. Karalai² , P. Wiriyachitra³ , B. Sorg⁴ , E. Hecker⁴

²Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Province of Songhkla, Thailand
³Research Centre for National Products, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
⁴Deutsches Krebsforschungszentrum (DKFZ), Division Mechanisms of Tumorigenesis, Research Program 3: Risk Factors of Cancer and Cancer Prevention, Im Neuenheimer Feld 280, D-69009 Heidelberg, Federal Republic of Germany

1 Part IV in the series “Medicinal plants of Euphorbiaceae occurring and utilized in Thailand”. For part III, see Ref. (1)

Abstract

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Abstract

A new and more efficient procedure was developed to obtain 5β-hydroxyresiniferonol-6α,7α-epoxide-9,13,14-ortho(2,4,6-decatrienoate) [Excoecaria factor 01] 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. 01 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 03, i.e. the 9,13,14-ortho(2,4,6,8-hexadecatetraenoate) of 5β,12β-dihydroxyresiniferonol-6α,7α-epoxide was isolated after alkaline transesterification of a TLC-uniform fraction, composed of corresponding 20-ester(s).

Key words

Excoecaria oppositifolia - Euphorbiaceae - daphnane orthoesters

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Improved Access to Highly Unsaturated Skin Irritants of the Daphnane Type from Latex of Excoecaria oppositifolia 1

Improved Access to Highly Unsaturated Skin Irritants of the Daphnane Type from Latex of Excoecaria oppositifolia ¹