Diterpenoids from the needles and twigs of the cultivated endangered pine Pinus kwangtungensis and their PTP1B inhibitory effects

Publication date: June 2017 Source:Phytochemistry Letters, Volume 20 Author(s): Chang-Ling Hu, Juan Xiong, Pei-Pei Wang, Guang-Lei Ma, Yu Tang, Guo-Xun Yang, Jia Li, Jin-Feng Hu Pinus kwangtungensis is an endangered pine species native to China. In the present study, 15 diterpenoids including three new labdane-type analogs were isolated and characterized during a pioneer phytochemical investigation on a mass-limited sample of the needles and twigs of this plant, which is growing in a Cantonese garden. The new structures, (4S,5R,9S,10R)-6-oxo-labd-7,13-dien-16,15- olid-19-oic acid (1), 15(S)-n-butoxypinusolidic acid (2), and β-d-glucopyranosyl- (4S,5R,9S,10R)-labda-8(17),13-dien-15,16-olid-19-oate (3), were established by extensive spectroscopic methods and some chemical transformations. Among the isolates, lambertianic acid (10) and cassipourol (15) showed inhibitory activities against human protein tyrosine phosphatase 1B (PTP1B), a target for the treatment of type-II diabetes and obesity, with IC50 values of 25.5 and 11.2 μM, respectively. Graphical abstract
Source: Phytochemistry Letters - Category: Chemistry Source Type: research