Glycoside, xxii

Noda K, Tsuji K, Kawasaki T, Miyahara K, Hanazono H, Yang CR (1995) Resin glycosides. XXII. A novel resin glycoside, merremin (tuguajalapin X dimer), from Merremia hungaiensis. Chem Pharm BuU 43 1061-1063... 

Constituents (See also table II) The dyes contained in the roots of these two plants are pseudopurpurin (XXII), its primveroside galiosin, purpurin (XXI) (formed in some cases from pseudopurpurin by decarboxylation), rubiadin (III), its 3-B-primveroside, lucidin (V) (jpartly as glycoside), purpuroxanthin (II), and alizarin (I) (partly as glycoside) (51). 

Appropriate studies with methyl glycosides have shown that oxidation with periodate occasions scission between C2 and C3, with the consequent formation of a dialdehyde structure (XXII). Similarly, each oxi-... 

Sometimes, a simple change of column is unsuccessful in ensuring resolution of certain mixtiues of glycosides, or a glycoside may lack suflBcient volatility. In such circumstances, the glycoside may be converted into a derivative, usually a trimethylsilyl ether or acetate, or the sugar may be transformed into some other type of compound. These alternatives are examined in Sections XIX to XXII (see pp. 24-33). 

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