title: Cytotoxic clerodane diterpenes from Polyalthia longifolia.
abstract: Bioassay-directed chemical investigation of the stem bark of Polyalthia longifolia Thw. (Annonaceae) has led to a novel clerodane diterpene, 16-oxo-cleroda-3, 13(14)Z-dien-15-oic acid, which was named polyalthialdoic acid (3). The bioassays also led to the previously known related diterpenes, kolavenic acid (2) which has not been reported as a constituent of this plant, and 16 alpha-hydroxy-cleroda-3,13(14)Z-dien-15,16-olide (1) which is previously known to be in this plant. These structures were identified by chemical and spectroscopic methods. All three compounds (1-3) were significantly bioactive in the brine shrimp bioassay; they strongly inhibited the growth of crown gall tumors on potato discs; and they were cytotoxic in three human tumor cell lines. These activities suggest potential antitumor applications. Compound 3 was the most active (ED50 values ca. 6 x 10(-1) micrograms/ml in the human tumor cell culture systems).
authors.affiliation: Nanjing College of Traditional Chinese Medicine, W.H.O. Nanjing Collaborative Center of Traditional Medicine, People's Republic of China.
authors.forename: G X
authors.initials: GX
authors.lastname: Zhao
authors.forename: J H
authors.initials: JH
authors.lastname: Jung
authors.forename: D L
authors.initials: DL
authors.lastname: Smith
authors.forename: K V
authors.initials: KV
authors.lastname: Wood
authors.forename: J L
authors.initials: JL
authors.lastname: McLaughlin
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification; D004224:Diterpenes / Q000302:isolation & purification / Q000494:pharmacology*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D010944:Plants; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004224:Diterpenes; C072583:polyalthialdoic acid; C072582:kolavenic acid; C072581:16-hydroxycleroda-3,13(14)-dien-15,16-olide