Analysis of the methanol-soluble resin glycosides from the roots of Operculina macrocarpa was assessed by generating NMR profiles of five glycosidic acids obtained through saponification, acetylation, and recycling HPLC purification. Operculinic acid H (1), two novel hexasaccharides, operculinic acids I (2) and J (3), the known purgic acid A (4), and a quinovopyranoside of (−)-(7R)-hydroxydecanoic acid, operculinic acid K (5), were isolated. Three intact resin glycosides related to 1, the novel macrocarposidic acids A (6) and B (7), in addition to the previously known macrocarposidic acid C (8), were also purified with isovaleroyl, tigloyl, and exogonoyl [(3S,9R)-3,6:6,9-diepoxydecanoyl] groups as esterifying residues. A selective intramolecular lactonization was produced to generate a macrocyclic artifact (17) during acetylation of 1, resembling the distinctive structure of the Convolvulaceous resin glycosides.

Brazilian jalap root, Operculina hamiltonii (G. Don) D.F. Austin & Staple, Convolvulaceae, belongs to the morning glory family and is used as a purgative or laxative medicinal plant. After hydrolysis and peracetylation of the EtOHsoluble extract, the known operculinic acids A and B and turpethic acid C, in addition to three undescribed glycosidic acids, operculinic acids L-N with a tetrasaccharide or pentasaccharide moieties with unusual 12-hydroxy fatty acid aglycones of different chain lengths (C 17 and C 18 ), were isolated from a commercial sample of pulverized roots by preparative recycling HPLC. Analysis of sixteen samples, including crude drugs and commercial phytopharmaceuticals based on jalap root, led to the generation of distinctive chromatographic profiles for each sample. The major isolated glycosidic acids were used as diagnostic peaks for HPLC-ESIMS fingerprinting by selected ion monitoring mode using target ions at [M + Na] + .

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