Cytotoxic constituents from the stem bark of Dichapetalum gelonioides collected in the Philippines

J Nat Prod. 2006 Mar;69(3):332-7. doi: 10.1021/np058083q.

Abstract

Fractionation of an ethyl acetate-soluble extract of the stem bark of Dichapetalum gelonioides, collected in the Philippines, using the LNCaP (hormone-dependent human prostate) cell line as a monitor, led to the purification of three dichapetalin-type triterpenoids [dichapetalins A (1), I (2), and J (3)], along with two dolabrane norditerpenoids (6, 7), and the additional triterpenoids zeylanol (8), 28-hydroxyzeylanol (9), and betulinic acid. Since compounds 1-3 exhibited promising selectivity against the SW626 (human ovarian cancer) cell line, a re-collection of the plant material was carried out, to obtain more of these compounds for additional biological testing. Two further phenylpyranotriterpenoids [dichapetalins K (4) and L (5)] were isolated from the re-collected plant material. The structures of the new compounds 2-5 and 9 were determined on the basis of spectroscopic data interpretation, and the relative configuration of 6 was confirmed using X-ray crystallography. Compounds 4-6 and the methyl ester, 6a, exhibited broad cytotoxic activity when tested against a panel of human tumor cell lines. Dichapetalin A (1) was not active when evaluated in an in vivo hollow fiber assay in the dose range 1-6 mg/kg.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Antineoplastic Agents, Phytogenic / chemistry
  • Antineoplastic Agents, Phytogenic / isolation & purification*
  • Antineoplastic Agents, Phytogenic / pharmacology
  • Betulinic Acid
  • Diterpenes / chemistry
  • Diterpenes / isolation & purification*
  • Diterpenes / pharmacology
  • Drug Screening Assays, Antitumor
  • Humans
  • Malpighiaceae / chemistry*
  • Molecular Structure
  • Pentacyclic Triterpenes
  • Philippines
  • Plant Bark / chemistry
  • Plants, Medicinal / chemistry*
  • Triterpenes / pharmacology
  • Tumor Cells, Cultured

Substances

  • Antineoplastic Agents, Phytogenic
  • Diterpenes
  • Pentacyclic Triterpenes
  • Triterpenes
  • Betulinic Acid