Two novel resin glycosides isolated from Ipomoea cairica with α-glucosidase inhibitory activity.

In the present study, two new compounds from Ipomoea cairica were identified and demonstrated to have α-glucosidase inhibitory activity. They were isolated by column chromatography on silica gel and sephadex LH-20 and finally purified by prep-HPLC, with their structures being elucidated by spectroscopic methods, such as 1D- and 2D-NMR and HR-TOF-MS, and chemical methods. Compounds 1 and 2, named cairicoside A and cairicoside B, were evaluated for α-glucosidase inhibitory activity by the MTT method, with the IC50 values being 25.3 ± 1.6 and 28.5 ± 3.3 µmol·L(-1), respectively.

Four new pentasaccharide resin glycosides from Ipomoea cairica with strong α-glucosidase inhibitory activity.

Six pentasaccharide resin glycosides from Ipomoea cairica, including four new acylated pentasaccharide resin glycosides, namely cairicoside I-IV (1-4) and the two known compounds cairicoside A (5) and cairicoside C (6), were isolated from the aerial parts of Ipomoea cairica. Their structures were established by a combination of spectroscopic, including two dimensional (2D) NMR and chemical methods. The core of the six compounds was simonic acid A, and they were esterfied the same sites, just differing in the substituent groups. The lactonization site of the aglycone was bonded to the second saccharide moiety at C-2 in 1-4, and at C-3 in 5-6. Compounds 1 and 5, 4 and 6 were two pairs of isomers. The absolute configuration of the aglycone in 1-6 which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid) was established by Mosher's method. Compounds 1-4 have been evaluated for inhibitory activity against α-glucosidase, which all showed inhibitory activities.

Diaqua-bis-(3-nitro-benzoato-κO)bis-[1H-5-(3-pyrid-yl)-3-(4-pyrid-yl)-1H-1,2,4-triazole-κN]cobalt(II) dihydrate.

In the centrosymmetric title compound, [Co(C(7)H(4)NO(4))(2)(C(12)H(9)N(5))(2)(H(2)O)(2)]·2H(2)O, the Co(II) atom, located on an inversion center, is coordinated by two N atoms [Co-N = 2.155 (3) Å] and four O atoms [Co-O = 2.099 (2)-2.117 (3) Å] in a distorted octa-hedral geometry. Inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds link the components into a three-dimensional supramolecular framework.