Three new cleistanthane diterpenes named tomocinon (1), tomocinol A (2), and tomocinol B (3), were isolated from the EtOAc extract of the seed of Caesalpinia sappan. Their structures were determined by extensive NMR spectroscopic analysis. The absolute stereochemistry of tomocinon (1) has been established by CD spectroscopic analysis. Cleistanthane diterpenes (1-3) represents the novel class of antiausterity agents having preferential cytotoxicity against PANC-1 human pancreatic cancer cell line under nutrient deprived condition with PC50 value of 34.7 μM, 42.4 μM and 39.4 μM, respectively.
Keywords: Antiausterity strategy; Anticancer drug discovery; Caesalpinia sappan; Cleistanthane diterpene; Nutrient starvation; PANC-1.
© 2013.