Alkaloids from Sri Lankan curry-leaf (Murraya koenigii) display melanogenesis inhibitory activity: structures of karapinchamines A and B

  • Bioorg Med Chem. 2013 Mar 1;21(5):1043-9. doi: 10.1016/j.bmc.2013.01.012.
Seikou Nakamura  1 Souichi Nakashima Yoshimi Oda Nami Yokota Katsuyoshi Fujimoto Takahiro Matsumoto Tomoe Ohta Keiko Ogawa Sayuri Maeda Shino Nishida Hisashi Matsuda Masayuki Yoshikawa
Affiliations
  • 1. Department of Pharmacognosy, Kyoto Pharmaceutical University, Misasagi, Kyoto 607-8412, Japan.
Abstract

A methanolic extract and its ethyl acetate-soluble fraction from Sri Lankan curry-leaf, the leaves of Murraya koenigii, inhibited melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. Two new Carbazole Alkaloids, karapinchamines A and B, were isolated from the ethyl acetate-soluble fraction together with 12 known Carbazole Alkaloids. The structures of karapinchamines A and B were determined by physicochemical analyses. The principal alkaloid constituents were found to display potent melanogenesis inhibitory activity. The structural requirements of the Carbazole Alkaloids for melanogenesis inhibitory activity were discussed.