title: Cucurbitane-type triterpenes from Citrullus lanatus (watermelon) seeds.
abstract: Two new cucurbitane-type triterpenes, 24-hydroperoxycucurbita-5,25-dien-3beta-ol (1) and 25-hydroperoxycucurbita-5,23-dien-3beta-ol (2), were isolated from a MeOH extract of Citrullus lanatus seeds. Compounds 1 and 2 exhibited moderate cytotoxic activities with IC50 values of 33.4-52.4 microM against HL-60 (human leukemia), P388 (murine leukemia), and L1210 (murine leukemia) cells. Compound 1 showed melanogenesis inhibitory activity (melanin content 80.0 %) with low cytotoxicity (cell viability 97.6%) at a low concentration (10 microM).
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kikuchi
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Okada
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Harada
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Ikushima
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamakawa
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Tanaka
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification*; D029773:Citrullus / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D018922:HL-60 Cells; D006801:Humans; D051379:Mice; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D014315:Triterpenes