On the Chemistry of Resiniferonol, II [1] Preparation and Bioactivities of 15,16-Dihydrosimplexin and Methods for its Tritium Labeling

• Published in: Zeitschrift für Naturforschung. B, A journal of chemical sciences Vol. 49; no. 1; pp. 128 - 134
• Main Authors: Schäfer, T., Sorg, B., Karalai, C., Hecker, E.
• Format: Journal Article
• Language: English
• Published: Tübingen Verlag der Zeitschrift für Naturforschung 01.01.1994
• Subjects: Alicyclic compounds, terpenoids, prostaglandins, steroids; Chemistry; Daphnane Derivatives; Diterpene Esters; Exact sciences and technology; Organic chemistry; Preparations and properties; Simplexin; Skin Irritant Activity; Skin Tumor Promoting Activity; Terpenoids; Aliphatic compound; Tumor promotor; Ketol; Tritium; Hydrogen Isotopes; Tricyclic compound; Biological activity; Epoxide; Diterpene; Irritant compound; Orthoester; Enone; Labelled compound; Glycol
• ISSN: 0932-0776; 1865-7117
• DOI: 10.1515/znb-1994-0120

Excoecaria factor O 1 -the daphnane type polyfunctional diterpene ester 5 β-hydroxy-6 α,7 α-epoxyresiniferonol-9,13,14-orto-(2,4,6-decatrienoate) -may be obtained in reason­ able amounts from the latex of Excoecaria oppositifolia from South East Asia. O 1 was partially hydrogenated with H -Pd/C to yield, by saturation of the three double bonds in the orthoester, and of ⊿ in the diterpene moiety, the new 15,16-dihydro derivative of simplexin. The latter is the well known daphnane prototype of polyfunctional diterpene esters occurring in Euphorbiaceae and Thymelaeaceae. 15,16-Dihydrosimplexin (DHS) showed pro­nounced irritant and tumor promoting activities. By analogous hydrogenation of O1 with a mixture of a selectively labeled [ H]DHS was obtained that exhibited a particularly high specific activity of 30 Ci/mmole. Thus it is considered most appropriate for use to study the toxicokinetics and -dynamics of daphnane type diterpene esters. To device an alternative of H-labeling of DHS or simplexin (SIM) in position 20 of the diterpene moiety DHS-5-benzoate was oxidized by pyridinium chlorochromate. The resultant 20-aldehyde was reduced by sodium borohydride to reconstitute DHS-5-benzoate and, after deprotection, DHS. This route appears appropriate to prepare similarly [20- H]DHS as well as [20- H]SIM using sodium [ H]borohydride.