Didemnin B : comparative study and conpormational approach in solution

Abstract

Abatmct : A comparative study of isodidemnine-1 and dkkmrdn B ia presental using apuWmw@cmethods, partial degradation and partial synthesis. Tbia leads to the conch&on of the presence of a sin& depsipeptide, namely didem& B, with (3S,4R,SS) isxtatine instead of the previous staline residue. An attempt to determjne the whole conformation in solution of didemninBbyusingZD-NMRisahodesa'ibed.Over the last decade, the widely-distributed order of Aplowobranchiata

Macrocyclic N-Methylated Cyclic Peptides and Depsipeptides

“…Banaigs et al [125] reported the isolation of didemnin B 176 from another species of Trididemnum, T. cyanophorum. The isolation technique involved repeated extractions followed by separation by some chromatographic techniques including low bar silica gel column chromatography and reversed-phase HPLC.…”

Ascidians: producers of amino acid-derived metabolites

“…37,38 Several investigations into the solution conformations of didemnin B and related analogs have been carried out. [39][40][41] One of the most remarkable features of the didemnins is the variability in biological activity, depending on the acyl substitution pattern. 42 For example, when the side chain is acetyl or longer, the cytotoxic activities are enhanced.…”

Marine natural products

“…The structures of ( 407) and (408) were deduced by interpretation of spectral data. The structures of antheliolides A and B, which are metabolites of the Red Sea soft coral Anthelia g l a u ~a , ~' ~ have been revised from ( 409) and ( 410) to (41 1) and (412) as the result of a single crystal X-ray analysis of antheliolide A (411).315 A Japanese gorgonian of the genus Acalycigorgia produces the known norditerpene ginamallene (413) and two new minor metabolites, acalycixeniolides B' (414) and C (415), that were identified by comparison of their spectral data with those of known Four new briarane diterpenoids, junceellolides A-D (41 6)- (41 9), together with the known compounds praelolide (420)317 and junceellin (421),318 were isolated from the South China Sea gorgonian Junceella fragilis. The structures of the junceellolides (41 6)- (419), which exhibit significant anti-inflammatory activity, were elucidated by interpretation of spectral data.319 A Briareum species from the Great Barrier Reef has yielded nine new briarane derivatives ( 422)- (430), two new cladiellin-based Two novel polyhydroxylated sterols, numesterols A (436) and B (437), from Sinularia nurnerosa have been identified as 24-meth ylenec holes tane-1 a,3P, 5a,6p-te trol and 25-me thylene-22-homocholestane-1,8,3/3,5a-tri01.~~~ The Okinawan soft coral Litophyton viridis contains two new 19-hydroxy sterols, litosterol (438) and 5,6-epoxylitosterol (439), which exhibits antileukaemic…”