New circulin macrocyclic polypeptides from Chassalia parvifolia.

K R Gustafson; L K Walton; R C Sowder; D G Johnson; L K Pannell; J H Cardellina; M R Boyd

doi:10.1021/np990432r

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New circulin macrocyclic polypeptides from Chassalia parvifolia.

K R Gustafson·L K Walton·R C Sowder·D G Johnson·L K Pannell·J H Cardellina·M R Boyd

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Abstract

Four new macrocyclic polypeptides were isolated and identified from an extract of the tropical tree Chassalia parvifolia. Circulins C-F are 29-30 amino acid cyclic peptides in which the entire primary amino acid chain is covalently cyclized via peptide bonds. Their structures were deduced from a combination of FABMS analyses, N-terminal Edman degradation, endoproteinase digestion, and amino acid analyses. All the peptides share a high degree of sequence homology and contain six cysteine residues forming three intramolecular disulfide bridges. Circulins C-F inhibited the cytopathic effects of in vitro HIV-1 infection with EC(50) values of 50-275 nM.

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Alkylation Amino Acid Sequence Anti-Bacterial Agents Anti-HIV Agents Chromatography, High Pressure Liquid Cyclotides Cysteine HIV-1 Humans Microbial Sensitivity Tests Molecular Sequence Data Oxidation-Reduction Plant Stems Plants, Medicinal Spectrometry, Mass, Fast Atom Bombardment Tasmania Journal Article Research Support, U.S. Gov't, P.H.S.

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K R Gustafson, L K Walton, R C Sowder, D G Johnson, L K Pannell, J H Cardellina, M R Boyd. 2000. New circulin macrocyclic polypeptides from Chassalia parvifolia.. https://doi.org/10.1021/np990432r

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