title: Racemosin C, a novel minor bisindole alkaloid with protein tyrosine phosphatase-1B inhibitory activity from the green alga Caulerpa racemosa.
abstract: A novel minor bisindole alkaloid, racemosin C (1), characterized by a naturally unprecedented 8-hydroxy-2,4,6-cyclooctatrienone ring fused with two indole systems, was isolated from the green alga Caulerpa racemosa, together with one known related metabolite, caulersin (2). The structure of 1 was elucidated on the basis of extensive spectroscopic analysis, and by comparison with the data of related known compounds. A plausible biosynthetic pathway of 1 was proposed. Compounds 1 and 2 exhibited significant PTP1B inhibitory activity with IC50 values of 5.86 ± 0.57 and 7.14 ± 1.00 μM, respectively, compared with the positive control oleanolic acid (IC50 = 3.03 ± 0.20 μM). On the basis of the data obtained, the Caulerpa bisindole alkaloids may be considered as a new class of PTP1B inhibitors.
authors.affiliation: a School of Pharmacy, Nanchang University , Nanchang 330006 , China.
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
authors.forename: Ding-Quan
authors.initials: DQ
authors.lastname: Liu
authors.forename: Tong-Jun
authors.initials: TJ
authors.lastname: Liang
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.forename: Ai-Hong
authors.initials: AH
authors.lastname: Liu
authors.forename: Peng
authors.initials: P
authors.lastname: Yang
authors.forename: Kun
authors.initials: K
authors.lastname: Lin
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Yu
authors.forename: Yue-Wei
authors.initials: YW
authors.lastname: Guo
authors.forename: Shui-Chun
authors.initials: SC
authors.lastname: Mao
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
mesh_terms: D046068:Caulerpa / Q000737:chemistry*; D026121:Indole Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D007546:Isoquinolines; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009792:Oceans and Seas; D009828:Oleanolic Acid / Q000737:chemistry; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors*
chemical_list: D026121:Indole Alkaloids; D007546:Isoquinolines; C551565:racemosinine C; D009828:Oleanolic Acid; C516607:PTPN1 protein, human; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1
keywords: Caulerpa racemosa; PTP1B inhibitory activity; bisindole alkaloid; green alga; racemosin C