Jatrophane diterpenoids with multidrug resistance-modulating activity from Euphorbia mongolica Prokh.

Four novel (1-4) and one known (5) diterpene polyesters with the jatrophane skeleton were isolated from a methanol extract of the aerial parts of the East Asian weed Euphorbia mongolica Prokh. The isolated compounds were characterized structurally and evaluated for multidrug resistance (MDR) reversing activity on human MDR gene-transfected L5178 mouse lymphoma cells; all these compounds were found to modulate the intracellular drug accumulation. The results highlighted some aspects of the structural requirements of jatrophane diterpenes as MDR modulators.