Neolaxiflorin A (1), an unprecedented ent-kaurane diterpenoid with a bicyclo[3.1.0]hexane unit, and its seco-derivative, neolaxiflorin B (2), along with two known compounds 3 and 4 were isolated from the leaves of Isodon eriocalyx var. laxiflora. The absolute configuration of 1 was determined by spectral methods and single crystal X-ray diffraction analysis. Compound 4 and the synthesized compound 5 exhibited significant cytotoxicity.
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