Resin glycosides isolation

The synthesis of the disaccharide subunit 85 of tricolorin A, a cytotoxic resin glycoside isolated from lpomoea tricolor, provides a unique opportunity to compare the efficiency of an RCM-based macro cyclization reaction with that of a more conventional macrolactonization strategy. Furthermore, this specific target molecule challenges the compatibility of the catalysts with various functional groups. 

A novel resin glycoside, isolated from Merremia hungaiensis roots and named merremin, contains two tetrasaccharide moieties linked by an ester bridge. ... 

Scammonin VII (62), as a minor ether-soluble resin glycoside, was isolated by reversed-phase HPLC from Convulvulus scammonia L. (47). Under basic hydrolysis, it gave orizabic acid A as weU as 2-methyIbutyric and tiglic acids. Compound 62 exhibits lactonization at C-3 of the rhamnose unit and is acylated by a (25)-methylbutanoyl residue at C-2 of the rhairmose unit and a tigloyl residue at C-4 of the terminal quinovose. 

Scammonin VIII (104), isolated from Convulvulus scammonia, is a linear tetra-saccharide of jalapinolic acid with two glucoses, one rhamnose, and one quinovose. This compound represents the only macrocyclic resin glycoside of scammonic acid B (hexadecanoic acid, (115)-[(0-jS-D-glucopyranosyl-(l—>4)-0-6-deoxy-a-L-man-nopyranosyl-(1 2)-0- S-D-glucopyranosyl-(l- 2)-6-deoxy- S-D-glucopyranosyl)oxy]). 

Six intact acylated resin glycosides containing simonic acid A have been isolated simonin 11 (183), batatosides M (197) and N (198) from 7. batatas 31, 40)... 

Complete structure elucidation of individual resin glycoside constituents is now achieved readily by the use of a combination of high-resolution mass spectrometry and NMR spectroscopy. These methods are applicable to the isolated natural products or to their peracetylated and methylated derivatives. 

Noda N, Ono M, Miyahara K, Kawasaki T, Okabe M (1987) Resin Glycosides. I. Isolation and Structure Elucidation of Orizabin-I, II, III and IV, Genuine Resin Glycosides from the Root of Ipomoea orizabensis. Tetrahedron 43 3889... 

Noda N, Kobayashi H, Miyahara K, Kawasaki T (1988) Resin Glycosides in. Isolation and Structural Study of the Genuine Resin Glycosides, Muricatins I-VI, from the Seeds of Ipomoea muricata. Chem Pharm Bull 36 920... 

Okabe H, Koshito N, Tanaka K, Kawasaki T (1971) Smdies on Resin Glycosides. II. Unhomogeneity of Pharbitic Acid and Isolation and Partial Structures of Pharbitic Acids C and D, the Major Constituents of Pharbitic Acid . Chem Pharm Bull 19 2394... 

The epipodophyllotoxins (Fig. 42.38) are semisynthetic glycosidic derivatives of podophyllotoxin, the major component of the resinous podophyllin isolated from the dried roots of the American mandrake or mayapple plant (Podophyllum peltatum). Although these compounds are capable of binding to tubulin and inhibiting mitosis, their primary mechanism of antineoplastic action is poisioning topoisomerase II, a mechanism that they share... 

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