The synthesis of a cyclic heptapeptide, delavayin-C, cyclo(gly-tyr-tyr-tyr-pro-val-pro) is described. The structure of this compound was established on the basis of analytical IR, (1)H NMR and FAB mass spectral data. The antibacterial and antifungal activities of this peptide are also described.

In this work, linear and cyclic disulfide heptapeptides of Longicalycinin A have been successfully synthesized by solid phase methodology with Fmoc /t-Bu and solution phase, respectively. 2-Chlorotrityl chloride resin (2-CTC) was used as a solid support. The synthesized linear disulfide analogue of Longicalycinin A was cleaved from the resin as a protected peptide. The final deprotection was pe...

Mate attraction in the marine mollusk Aplysia involves long-distance waterborne chemical signaling via the release of the peptide pheromone attractin during egg laying. Aplysia californica attractin attracts conspecifics, reduces the latency to mating, and stimulates hermaphroditic mating. Four additional members of the Aplysia attractin family have recently been characterized from Aplysia bras...

Harmful cyanobacterial blooms pose an environmental health hazard due to the release of water-soluble cyanotoxins. One most prevalent cyanotoxins in nature is microcystins (MCs), a class cyclic heptapeptide hepatotoxins, and they are produced by several common cyanobacteria aquatic environments. Once released from cells, MCs subjected physical chemical biological transformations natural can als...

The synthesis of a proline-rich cyclic heptapeptide, fanlizhicyclopeptide A (8), previously isolated from the fruits of Annona squamosa (sugar-apples), is described via coupling of tetrapeptide -prolyl--tyrosyl--leucyl--proline methyl ester with tripeptide Boc-glycyl--valyl--proline followed by cyclization of the linear fragment having seven amino acid units. Structure of the synthesized cycloo...

Melanotan II is a synthetic cyclic heptapeptide used to prevent a sunlight-induced skin cancer by stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2)+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the epsilon-amino gro...

A peptide hepatotoxin was isolated by reversed phase liquid chromatography from the cyanobacterium Oscillatoria agardhii and characterized structurally and toxicologically. Amino acid analyses, proton nuclear magnetic resonance and fast atom bombardment mass spectrometry showed that the toxin is a cyclic heptapeptide (mol. wt 1023.5) with the structure cyclo-(Ala-Arg-Asp-Arg-Adda-Glu-N-methylde...

The study of protein kinase in Dictyostelium discoideum has a tortuous history. The cyclic AMP-dependent protein kinase was first reported by Sampson [1]. Upon DEAE chromatography of cells starved for 2 h he found two cAMP-dependent and two cAMP-independent activities. Shortly thereafter reports by Veron and Patte [2] and Rahmsdorf and Gerisch [3] described protein kinase activity but no cAMP a...