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The complete spectral assignment of didemnin H a new constituent of the tunicate Trididemnum cyanophorum

✍ Scribed by Anna Boulanger; Eliane Abou-Mansour; Ayoub Badre; Bernard Banaigs; Georges Combaut; Christian Francisco

Book ID: 104214568
Publisher: Elsevier Science
Year: 1994
Tongue: French
Weight: 342 KB
Volume: 35
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(00)73350-8

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✦ Synopsis

Complete *I I and k spectral assignmenrs by 2D NMFI mcam m presenled for a new cyclodepsipqMe namely didcmnin H. ixthtcd fmm 7iididpnvlum ryunophmm~ (Ilkkmnidm). Didemnins arc a &ss of dclx+ptidcs isolated from Caribbean tunicates of the I)ldemnidac family showing antitumor* and zmtiviral2 pprtics and a polent immunosuppressive activityx. Didemnin B, the most prominent mcmbcr of this pcptidic group, was lirsl isolated by Rinehart and his ~wwt~rkers in 19814, then later by Van dcr Helms and Fcnical6 from Trididemnum solidum and by GuyotT and us8 from Trididemnum cyanophorum (an ascidian living in symbiotic association with an unicellular alga -Cyanqhyta -Synechocys~is trididemni )9. This family of cyclodcpsipcptides has numerous mcmbcrs such as didcmnins A, C . D, E and notdidcmnins 4.1". More rcccnlly, Lu)ntinucd examination pmvidcd three new congcncrs from R: H IMemuin B Structures of didemnhw B, H, E and D. Trididemnum solidum : didemnins G, X, Y 1 I-I2 and, from [email protected] albicuns (Polyclinidae), a Mediterranean tunicatc, dehydmdidcmnin B -1 T~ Id. The structural elucidaticm of most of these compounds was mainly based on HRFAB mass spcctrometry. We report hcrc the structural elucidation of didcmnin H and the crmpletc tH and t3C NMR spectral assignments by means of a combination of mass spcctromctry and one and two-dimensional NMR cxpcrimcnts.

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