Biologically active compounds from tunicates and a sponge
Part I. Studies on structures and biological activities of didemnins. Six new cyclic depsipeptides related to didemnins were isolated from a relatively polar extract of the tunicate T. solidum. Their structures were determined by spectroscopic techniques and chemical degradations as follows: didemnins X ((R)-3-hydroxydecanoyl-(Gln)$\sb3$-Lac-Pro-didemnin A); Y ((R)-3-hydroxydecanoyl-(Gln)$\sb4$-Lac-Pro-didemnin A); M (pGlu-Gln-Lac-Pro-didemnin A); N ( (Tyr$\sp5$) didemnin B); nordidemnin N ( (Tyr$\sp5$) nordidemnin B); and epididemnin A ( ($2S,4R$-Hip$\sp2$) didemnin A). Twenty two new didemnin analogues were prepared semisynthetically. Structure elucidation, chemical conversion, biological activities including cytotoxicity, antiviral and immunosuppressive activities and structure-activity relationships for the above compounds are described.
Chemistry, Organic, Chemistry, Pharmaceutical
University of Illinois - Urbana-Champaign
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