title: The structure and synthesis of malformin A.
abstract: A structure (the disulfide form of cyclo-D-cysteinyl-L-valyl-D-cysteinyl-D-leucyl-L-isoleucyl), previously proposed for malformin A, was reexamined. On the basis of chemical degradations, a different structure (the disulfide form of cyclo-D-cysteinyl-D-cysteinyl-L-valyl-D-leucyl-L-isoleucyl) was established. Accordingly, a compound with this structure was synthesized and was found to be identical with malformin A. The synthetic product causes curvatures on corn roots; maximum effect was seen at a concentration of 0.1 mug/ml, the optimal concentration for malformin A.
mesh_terms: D000595:Amino Acid Sequence; D003553:Cystine; D004220:Disulfides / Q000138:chemical synthesis; D006868:Hydrolysis; D007532:Isoleucine; D007930:Leucine; D009842:Oligopeptides / Q000138:chemical synthesis*; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D010944:Plants / Q000187:drug effects; D011487:Protein Conformation; D014633:Valine
chemical_list: D004220:Disulfides; D009842:Oligopeptides; D010456:Peptides, Cyclic; D007532:Isoleucine; C001675:malformins; D003553:Cystine; D007930:Leucine; D014633:Valine