Bioactive compounds

Cephalostatin 1 has been isolated from the colonial marine worm Cephalodiscus gilchristi (Phylum Hemichordata) in the Indian Ocean. It has shown biomedical potential in preclinical trials as a cell growth inhibitor, active against U. S. murine P388 lymphocyte leukemia ED5010^-7-10^-9 μ/ml and a potent growth inhibitor against solid tumor types. Our research is focusing on developing methodology to produce disteroidal pyrazine and the introduction of delta 14, 15 unsaturation and C-16 hydroxyl groups in Cephalostatin 1A. The synthetic intermediates may be useful for biosynthetic studies and also analogues can be used to study structure-activity relationships.

In this present work we have examined the biophysical characterization of two peptides. One alpha-helical (SPARC) and the other triple-helical (collagen). We have compared the effect of lipidation on stabilizing of the alpha-helical and triple-helical peptides. For the first peptide, amino acids from the angiogenesis-inducing region of SPARC were incorporated into alpha-helical peptide sequence. A Tyr was placed between the alpha-helical sequence and the peptide to provide a chromophore; Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys-Ala-Glu-Ile-Glu-Ala-Leu-Lys-Ala-Tyr-Lys-His-Gly-Lys-NH 2 was the final sequence. For the second peptide, the sequence chosen to mimic the alpha2beta1 integrin binding site in type I collagen was (Gly-Pro-Hyp)4-Gly-Pro-Ala-Gly-Lys-Asp-Gly-Glu-Ala-Gly-Ala-Gln-(Gly-Pro-Hyp) 4-NH2. Next, each peptide was lipidated with a C-16 acid and was biophysically characterized to determine physiological compatibility. Techniques used included circular dichroism spectroscopy, gel electrophoresis, and Fourier transform infrared spectroscopy. Lastly, one of the peptide amphiphiles was examined as a biomaterial modifier.