No abstract

Quercetin (Quer) is one of the most famous flavonols, being an aglycone of rutin [1]. Quer was founded in grapes, buckwheat, apples, tea, citrus, bilberries, blackberries, and other plants. Quer and rutin have P-vitamin activity. They reduce permeability and fragility of capillaries. Quer also exhibits antioxidant, anti-inflammatory, antispasmodic, antisclerotic, diuretic, and antitumor effects. Glycyram (monoammonium salt of triterpene glycoside glycyrrhizic acid, GC) is an anti-inflammatory and antiallergic drug. The molecular complexation of glycyrrhizic acid and GC with different drugs and biologically active molecules is widely studied [2-4]. A new molecular complex of GC with Quer in a 1 : 1 molar ratio was obtained. The synthesis of GC-Quer complex was carried out in the liquid phase (in a mixture of 96 % aqueous ethanol and chloroform at a 1 : 1 ratio, v/v). The obtained mixture was incubated at 50 °C for 1,5 h with continuous stirring. The complexation was studied by ATR IR Fourier spectroscopy with diamond crystal plate. It was shown that hydrogen bonds are formed between the components of the molecular complex (-С=О GC Н-О-Quer and-(Н)О Н-О-).

The 1:1 molecular complex of ivy triterpene glycoside hederasaponin C (HedC) with cholesterol (Chol) was obtained in aqueous isopropyl alcohol. The stability constant of (3.3 ± 0.7)∙106 (mol/L)–1 was calculated for the complex. The complexation was studied by UV- and ATR IR-Fourier spectroscopy, and method of isomolar series. The hydrogen bonds and hydrophobic interactions are formed in the molecular complex.

No abstract

Quercetin (Quer) is one of the most famous flavonols 1 . Quer was founded in different plants. Quer has P-vitamin activity and exhibits antioxidant, anti-inflammatory, antispasmodic, antisclerotic, diuretic, and antitumor effects. 1,2 Previously, we have studied the molecular complex of Quer with triterpene glycoside glycyram (monoammonium salt of glycyrrhizic acid) 3 . Triterpene glycosides from licorice and ivy are one of the most affordable saponins. However, molecular complexes of Quer with ivy triterpene glycosides are not described. Triterpene glycoside hederasaponin C (hederacoside C, hederagenin 3-O-α-Lrhamnopyranosyl-(1→2)-O-α-L-arabinopyranosyl-28-О-α-L-rhamnopyranosyl-(1→4)-О-β-Dglucopyranosyl-(1→6)-О-β-D-glucopyranoside, HedC) was discovered in the most species of the ivy genus Hedera L. (Araliaceae), in which it is the dominant saponin.The Quer-HedC complex composition was determined by the method of isomolar series at 256 and 370 nm. This method gave a molar ratio ≈2.0, which corresponded to a 1 : 2 complex of Quer with HedC, respectively (in 2 : 8 mixture of 96 % EtOH and aqueous phosphate buffer with pH 7.2 (v/v)).The molecular complexation of Quer with HedC was studied by ATR FT-IR spectroscopy. It was shown that hydrogen bonds are formed between OH groups of complex components, and by C=O group of Quer and carbohydrate OH groups of HedC: (Н)О•••Н-О and С=ОQuer•••Н-ОHedC.