Mallotumides A-C: Potent Cytotoxic Cycloheptapeptides from the Roots of .

The structures of potent cytotoxic cycloheptapeptides, mallotumides A-C (-, respectively) isolated from the roots of Airy Shaw, were elucidated by extensive spectroscopic analysis. The absolute configuration of was determined by single-crystal X-ray crystallographic data. All three cycloheptapeptides exhibited potent cytotoxicity against various cancer cell lines with IC values ranging from 0.

VR-3848, a novel peptide derived from Euphobiaceae, induces mitochondria-dependent apoptosis in human leukemia cells.

VR-3848, a novel peptide derived from Euphobiaceae, is shown herein to induce apoptosis at nanomolar concentrations in the leukemic Jurkat cell line. Apoptosis was associated with activation of caspases, release of cytochrome c from mitochondria, fragmentation of nuclear DNA, and externalization of phosphatidylserine on the cell surface. Overexpression of mitochondria-targeted Bcl-2 abrogated VR-3848-induced killing in this model.