Identification and characterization of organic and glycosidic acids in the crude resin glycoside fraction of Ipomoea lacunosa seeds

• Published in: Carbohydrate research Vol. 536; p. 109048
• Main Authors: Uemura, Kazutaka, Murakami, Renjyu, Kimura, Eiki, Kai, Marina, Misuda, Nodoka, Yasuda, Shin, Miyashita, Hiroyuki, Yoshimitsu, Hitoshi, Tsuchihasi, Ryota, Okawa, Masafumi, Kinjo, Junei, Ono, Masateru
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01.02.2024; Elsevier
• Subjects: Biochemistry & Molecular Biology; Chemistry; Chemistry, Applied; Chemistry, Organic; Convolvulaceae; Glycosidic acid; Ipomoea lacunosa; Life Sciences & Biomedicine; Organic acid; Physical Sciences; Resin glycoside; Science & Technology; Resin glycoside; Glycosidic acid; Ipomoea lacunosa; Convolvulaceae; Organic acid; CONVOLVULIN; BISDESMOSIDE; COMPONENTS; SHIFTS; JALAPINOSIDE; AGLYCONE; QUAMOCLIT; MULTIDRUG-RESISTANCE
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2024.109048

Resin glycosides are commonly found in plants belonging to the Convolvulaceae family. Ipomoea lacunosa L. (Convolvulaceae) is an herbaceous vine native to the United States. The resin glycosides of this plant have not been studied in detail. In this study, the components of the crude resin glycoside fraction extracted from the seeds of I. lacunosa are characterized. Alkaline hydrolysis of the crude resin glycoside fraction obtained from methanolic extract of the seeds yielded three organic acids, namely, 2S-methylbutyric, (E)-2-methylbut-2-enoic, and 2R-methyl-3R-hydroxybutyric acids, and a glycosidic acid fraction. Acidic hydrolysis of the glycosidic acid fraction yielded hydroxyl fatty acid components, including 7S-hydroxydecanoic, 11S-hydroxytetradecanoic, 11S-hydroxyhexadecanoic, 3S,11S-dihydroxytetradecanoic, 3S,11S-dihydroxyhexadecanoic, and 3S,12S-dihydroxyhexadecanoic acids, as well as monosaccharide components, including d-glucose, d-quinovose, d-fucose, and l-rhamnose. Trimethylsilyldiazomethane–hexane treatment of the glycosidic acid fraction further yielded eleven previously undescribed glycosidic acid methyl esters and two known glycosidic acid methyl esters. The structures of the obtained compounds were characterized using various spectral techniques. Four of the undescribed compounds were hexaglycosides, five were heptaglycosides, and two were octaglycosides. The aglycone of these compounds was either methyl 11S-hydroxytetradecanoate, methyl 3S,11S-dihydroxytetradecanoate, or methyl 3S,11S-dihydroxyhexadecanoate. Among the undescribed compounds identified, eight contained novel glycans, and three were rare bisdesmosides with sugar linkages at the C-3 and C-11 positions of methyl 3S,11S-dihydroxytetradecanoate. [Display omitted] •Thirteen glycosidic acid components of I. lacunosa were isolated as methyl esters.•Of the glycosidic acid methyl esters isolated, eleven were undescribed compounds.•Eight glycosidic acid methyl esters contained undescribed glycans.•Two of the undescribed glycosidic acid methyl esters were octaglycosides.•Three glycosidic acid methyl esters were rare bisdesmosides.