title: Two new lignans and melanogenesis inhibitors from Schisandra nigra.
abstract: An acetone extract from the stems of Schisandra nigra MAX. (Schisandraceae) exhibited significant inhibition of 3-isobutyl-1-methylxanthine (IBMX)-stimulated melanogenesis in murine B16 melanoma F10 cells. Fractionation and purification of the extract led to the isolation of two new tetrahydrofuran-type lignans, (+)-5-methoxyzuonin A (2) and kadlongirin C (3), along with eight known compounds (1, 4-10). The structures of the new compounds were determined by spectroscopic analyses. Of the isolated compounds (1, 3 -10), (+)-zuonin A (1) showed remarkable inhibition of melanogenesis at concentrations without cytotoxicity in B16 melanoma F10 cells. (+)-Zuonin A (1) did not inhibit tyrosinase; however, Western blot analysis revealed that it decreased protein levels of tyrosinase and tyrosinase-related proteins (TRP)-1 and TRP-2 without changing phosphorylation level of cAMP response element-binding protein.
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Narukawa
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Komatsu
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
authors.forename: Rina
authors.initials: R
authors.lastname: Yamauchi
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
authors.forename: Sakiko
authors.initials: S
authors.lastname: Shibayama
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
authors.forename: Mayuko
authors.initials: M
authors.lastname: Hachisuka
authors.affiliation: Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan. kiuchi-fm@pha.keio.ac.jp.
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Kiuchi
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D017705:Lignans / Q000378:metabolism*; D008543:Melanins / Q000378:metabolism*; D051379:Mice; D015394:Molecular Structure; D032141:Schisandra / Q000737:chemistry*
chemical_list: D017705:Lignans; D008543:Melanins
keywords: Melanogenesis inhibitors; Schisandra nigra; Tetrahydrofuran-type lignans