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The chemical investigation on the n-hexane extract of Withania somnifera roots has yielded octacosane, oleic and stearic fatty acids, stigmasterone, stigmasterol, sitostanone, oleanolic acid along with the ergosterol and 1,4-dioxane derivatives as new compounds. The isolation of alkenyl-1,4-dioxane compound is rare, whereas the ergosterol derivative may have biogenetic significance in the lactone formation in the E ring of withanolides. The presence of a 1,4-dioxane derivative in the nonpolar extract of roots assumes importance as this type of compound has not been reported earlier from W. somnifera. The structures of new compounds were elucidated by spectroscopic methods and chemical transformations. [ABSTRACT FROM AUTHOR]

Bioassay-guided fractionation of the fruits of Piper longum afforded two new minor amides, piperlongimin A (2) [2E-N-isobutyl-hexadecenamide] and piperlongimin B (4) [2E-octadecenoylpiperidine] together with five known compounds with moderate cytotoxic activity. The structures were elucidated on the basis of spectroscopic evidences. All these compounds inhibited cell proliferation of human leukemia, HL-60 cell lines, and displayed major apoptosis-inducing effects. [ABSTRACT FROM AUTHOR]