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Didemnin group

Deprotection of a robust MOM ether amidst a welter of polar and hydrolytically sensitive groups was a challenge confronted by the Joulli group in their synthesis of the antitumour Didemnins.464 Treatment of 249,1 [Scheme 4 249 with bromodimethylborane in dichloromethane at low temperature liberated the desired hydroxyl in 249,2 in 93% yield ... [Pg.297]

The utility of the phenacyl group is exemplified in the C-terminal deprotection [Scheme 6.70] taken from Schmidt s synthesis of the immunosuppressive and antiviral cyclodepsipeptide Didemnin.113 Here, the phenacyl ester was reduc-tively cleaved with zinc in acetic acid. A similar transformation was used in a synthesis of the potent protein serine/threonine phosphatase inhibitor Motupor-in.lM Zinc-copper couple is an attractive alternative that can be used on a large scale [Scheme 6.71 ]J70... [Pg.402]

Me2BBr, CH2CI2, -78°C, then NaHCOj/HjO, 87-95% yield. This reagent also cleaves the MEM, MTM, and acetal groups. An ester, a BOC, and a TIPS group were unaffected by this reagent in a synthesis of the Didemnins. ... [Pg.35]

The 2,5-anhydro-3,4-diamino-pentose diethyl acetal 72 was synthesized from L-xylose by sequential reaction of epoxide and triflate intermediates with azide ion. After reduction to a 3,4-diamino-2,5-anhydroalditol, oxoruthenium(V) complexes of it and related 2,3-diamino-nucleosides (see Chapter 17) were prepared and evaluated as ribonuclease inhibitors. A number of routes were investigated for the preparation of the 2-amino-3-azido-2,3-dideoxy-D-glucoside 73, a precursor for a mimetic of the cyclopdepsipeptide didemnin B, from 2-acetamido-2-deoxy-D-glucose. Because A -deacetylation was much easier in the presence of a free 3-hydroxy-group, the best route involved preparation of a 2-deoxy-2-trifluoroacetamido-D-allopyranoside, and displacement of a mesylate group from C-3 by azide ion with inversion. ... [Pg.136]

The didemnins are cyclic molecules composed of amino acids that were isolated from the marine invertebrate Trididemnum solidum. One of the amino acids is proline. The didemnins exhibit antitumor, antiviral, and i m m u n osu ppressi ve activity. The group labeled "R" in the structure is a side chain that contains additional amino acids. [Pg.1117]

A quite different method converted the amino moiety of isoleucine to an hydroxyl group (see 6.204). Conversion to the azide, reduction to the amine and condensation of the ester with lithio methyl (2-trimethylsilyloxycarboxy) acetate gave 6.205. Sodium borohydride reduction gave 6.206, along with 9% of 5.207. Hydrolysis and re-protection of 6.206 gave N-Boc isostatine, 6.208. In this work, it was noted that amino acid 6.208 is a component of didemnin cyclodipeptide. [Pg.223]

These two closely related molecules are extracted from tunicates (Urodiordata) that are members of the family Didemnidae. The spedes of this family are known to contain many antitumor and/or antiviral substances. Among these, the group of the didemnins has been intensively studied since their discovery in 1978 in the Caribbean Sea during the Alpha Helix Caribbean expedition (Rinehart et al, 1981). Didemnin B was isolated from... [Pg.48]

Discovered in the early 1980s in spedes of the genus Trididemnum harvested in the Caribbean during the Alpha Hehx" expedition, the didemnins are a group of strongly antiviral and cytotoxic depsipeptides didemnin B is the first molecule of marine origin that has entered Phase II... [Pg.850]

Hochster, H., Oratz, R., Ettinger, D.S., and Borden, E. (1999) A phase 11 study of didemnin B (NSC 325319) in advanced malignant melanoma an Eastern Cooperative Oncology Group study (PB687). Invest. New Drugs, 16, 259-263. [Pg.874]


See other pages where Didemnin group is mentioned: [Pg.570]    [Pg.355]    [Pg.355]    [Pg.357]    [Pg.90]    [Pg.89]    [Pg.203]    [Pg.528]    [Pg.174]    [Pg.404]    [Pg.347]    [Pg.74]    [Pg.428]    [Pg.528]    [Pg.286]    [Pg.88]    [Pg.851]    [Pg.851]    [Pg.880]    [Pg.882]    [Pg.1714]    [Pg.1717]   
See also in sourсe #XX -- [ Pg.4 , Pg.83 ]

See also in sourсe #XX -- [ Pg.4 , Pg.83 ]




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Didemnin

Didemnins

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