Pimarane Diterpenoids from the Seeds of Caesalpinia minax as PTP1B Inhibitors and Insulin Sensitizers

Protein-tyrosine phosphatase 1B (PTP1B) has been considered as a promising target for treating insulin resistance. In searching for naturally occurring PTB1B antagonists, two new pimarane diterpenoids, named 2α-hydroxy-7-oxo-pimara-8(9),15-diene (1) and 19-hydroxy-2α-acetoxy-7-oxo-pimara-8(9),15-diene (2), were isolated from the seeds of Caesalpinia minax. Their structures were determined by extensive analysis of NMR and HR-ESIMS data, and their...