title: Dimeric pyrrolidinoindoline-type alkaloids with melanogenesis inhibitory activity in flower buds of Chimonanthus praecox.
abstract: A methanol extract of the flower buds of Chimonanthus praecox (L.) Link (Calycanthaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, five dimeric pyrrolidinoindoline alkaloids and four sesquiterpenes were isolated, together with 16 known compounds. Among them, (-)-chimonanthine (1, IC50 = 0.93 μM), (-)-folicanthine (2, 1.4 μM), and (-)-calycanthidine (3, 1.8 μM) showed potent inhibitory effects without notable cytotoxicity at the effective concentrations. The most potent alkaloid (1) inhibited both tyrosinase and tyrosine-related protein-1 mRNA expressions, to which the melanogenesis inhibitory activity would be ascribable.
authors.affiliation: Pharmaceutical Research and Technology Institute, Kinki University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Morikawa
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Ninomiya
authors.forename: Hisashi
authors.initials: H
authors.lastname: Matsuda
authors.forename: Souichi
authors.initials: S
authors.lastname: Nakashima
authors.forename: Hisako
authors.initials: H
authors.lastname: Miki
authors.forename: Yu
authors.initials: Y
authors.lastname: Miyashita
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Takao
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Osamu
authors.initials: O
authors.lastname: Muraoka
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D031237:Calycanthaceae / Q000737:chemistry*; D045744:Cell Line, Tumor; D019281:Dimerization; D035264:Flowers / Q000737:chemistry; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology*; D008543:Melanins / Q000096:biosynthesis*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000378:metabolism; D011758:Pyrroles / Q000737:chemistry / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D007211:Indoles; D008543:Melanins; D011758:Pyrroles; D012717:Sesquiterpenes; D014442:Monophenol Monooxygenase