Operculins

Ipomoea operculata has afforded three resin glycosides containing this glyco-sidic acid, operculins VI (19), XI (20), and XII (21). The macrolactone site was located at C-2 of the first rhamnose unit for 19 while in compounds 20 and 21 the lactonization was placed at C-3, the same site for mammosides A (17) and B (18). Two dodecanoyl residues are the fatty acids present in these resin glycosides and located at C-2 of the second rhamnose and at C-4 of the third rhamnose for operculin VI (19). For operculins XI (20) and XII (21), they were placed at C-2 or C-3 of the second rhamnose and C-4 at the third rhamnose (27). 

Operculinic acids E (hexadecanoic acid, (115)-[(0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 2)-jS-D-glucopyranosyl)oxy]) and F (hexadecanoic acid, (115)-[(0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 4)-0-6-deoxy-a-L-mannopyranosyl-(1 2)-/i-D-xylopyranosyl)oxy]) were obtained by alkaline hydrolysis of the ether-soluble crude resin glycosides from the roots of Ipomoea... 

The methyl ester of operculinic acid E was obtained by basic hydrolysis and methylation of the crude resin glycoside mixture of 7. murucoides. Mumcoidins XII (53) and XIII (54) afford operculinic acid E as their oligosaccharide core. The lactonization site was placed at C-3 of the first rhamnose unit. These resin glycosides contain an esterifying residue that is composed of n-dodecanoic or (25)-methylbu-tyric acids at the C-2 or C-3 positions on the second rhamnose unit of the oligosaccharide core and (25)-methylbutyric acid at C-4 on the third rhamnose (30). 

Batatins V (234) and VI (235) are acylated tetrasaccharide ester-t3 pe dimers isolated from Ipomoea batatas, which yielded operculinic acid C through saponification. A mild alkaline hydrolysis of both afforded compound 30, one of the monomeric units, identified by coelution in UPLC with natural batatinoside 111 (31), placing the lactonization at C-3 of the second saccharide in the macrocyclic portion. C-3 of the third saccharide unit was identified as the position for the ester linkage. Both dimers showed acylations at C-4 of the terminal rhamnose... 

Ono M, Fujimoto K, Kawata M, Fukunaga T, Kawasaki T, Miyahara K (1992) Resin Glycosides. XIII. Operculins VI, XI, XII, XIII, XIV and XV, the Ether-Soluble Resin Glycosides ( Jalapin ) from Rhizoma Jalapae Brasiliensis (Roots of Ipomoea operculata). Chem Pharm Bull 40 1400... 

Ono M, Kawasaki T, Miyahara K (1991) Resin Glycosides XI. Operculins III, IV, IX, X, XVI, XVII and XVIII. New Ether-Soluble Resin Glycosides of Rhizoma Jalapae Braziliensis (Root of Ipomoea operculata). Chem Pharm Bull 39 2534... 

Constit. of the capsular antigen of Klebsiella K12, K18, K41 type specific antigen of Streptococcus pneumoniae type 2, type 6A O-antigen of Serratia marces-cens extracellular polysaccharide from Mycobacterium album B-88 in operculinic acid (see 3,12-Dihydroxyhexadecanoic acid) formed from the resin of Ipomoea operculata. 

Urban sub tuber see also sis resina) EISP Grctf (= opetcuUnic add operculinic iva, tga, ESP Auterhoff and... 

HFA of both groups-. convolvulinolic acid IV operculinic acid A HFA jalapinolic acid ... 

GA ofmurucins murucinic acid GA of murucoidins simonic acid B (I - HI), operculinic add A (IV, V) GA of stoloniferin I simonic acid B common HFA jalapinolic acid... 

It was only detected in three glycosidic acids, cuscutic acid B from Cuscuta chin-ensis as well as operculinic acids D and F from Operculina macrocarpa. Interestingly, - by pure chance or not - to date no resin glycosides corresponding to these three glycosidic acids could be identified. 

Operculin V Both palmitoyl (C e) residues substituted by lauroyl (C12)... 

Fig. 8.5 Tuguajalapin VII, the largest known resin glycoside monomer (MM 1771 and operculin V as examples for branched pentasaccharides conjugated to jalapinolic acid with saturated straight-long-chain fatty acid residues linked to different positions of different monosaccharide units. Both resin glycosides share a common glycosidic acid, operculinic acid A...

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