Saponin and Sapogenol. XLVII. On the Constituents of the Roots of Glycyrrhiza uralensis Fischer from Northeastern China. 1. Licorice-Saponins A3, B2, and C2.

Abstract

From the air-dried root of Glycyrrhiza uralensis, collected in the northeastern part of China, ten new oleanane-type triterpene oligoglycosides were isolated together with glycyrrhizin (1) and several known flavonoids. Among the newly isolated triterpene oligoglycosides, the chemical structures of licorice-saponin A3 (2), licorice-saponin B2 (3), and licorice-saponin C2 (4) have been determined, on the basis of chemical and physicochemical evidence, to be expressed as 30-O-beta-D-glucopyranosylglycyrrhizin, 11-deoxo-glycyrrhizin, and 3-O-[beta-D-glucuronpyranosyl(1-->2)-beta-D-glucuronpyranosyl++ +]oleana- 11,13(18)-dien-30-oic acid, respectively. During the course of these studies, facile conversions from glycyrrhizin (1) to licorice-saponins A3 (2), B2 (3), and C2 (4) have been accomplished.

Bioactive Saponins and Glycosides. XXV. Acylated Oleanane-Type Triterpene Saponins from the Seeds of Tea Plant (Camellia sinensis)

“…Theasaponin H 1 (7) 13 C-NMR data of 7 and 7a were similar to those of 3 and 3a, respectively, except for the signals due to the 23-aldehyde group. The oligoglycoside structures and positions of an angeloyl moiety and functional groups in the aglycon moiety were characterized by the HMBC experiment on 7, which showed long-range correlations between the following proton and carbon pairs [24-H 3 , 1Ј-H and 3-C; 24-H 3 , 23-methoxycarbonyl methyl proton and 4-C; 16-H, 22-H, 28-H 2 and 17-C; 29-H 3 , 30-H 3 and 20-C, 21-C; 21-H 2 , 28-H 2 and 22-C; 22-H and 21-C, angeloyl carbonyl carbon (d C 168.0); 24-H 3 and 23-C; 1Љ-H and 2Ј-C; 1ٞ-H and 3Ј-C; 1ЉЉ-H and 2ٞ-C (Fig.…”

“…Theasaponin E 9 (5) was also obtained as colorless fine crystals from CHCl 3 13 C-NMR data for 5 with those for 4 revealed an acetylation shift around the 28-position of the theasapogenol E moiety. This evidence was supported by the HMBC experiment of 5, in which longrange correlations were observed between the 16-proton and the acetyl carbonyl carbon (d C 169.8), between the 21-proton and the tigloyl carbonyl carbon (d C 168.1), and between the 28-protons and the acetyl carbonyl carbon (d C 170.5).…”

“…1)]. Finally, reduction of 7a with sodium borohydride (NaBH 4 ) in EtOH liberated 3a, 13) so that the structures of the new aglycon part and the tetraglycoside moiety were confirmed. Consequently, the structure of theasaponin H 1 (7) was determined to be as shown.…”

“…1,3-7) The 1 H-(pyridine-d 5 ) and 13 C-NMR (Tables 1, 2) spectra of 1, which were assigned by various NMR experiments, 9) showed signals assignable to six methyls [ 13 C-NMR data for 2 with those for 1 revealed an acetylation shift around the 28-position of the aglycon moiety. Consequently, the structure of theasaponin A 5 was determined to be 21…”

Human Udp-Glucuronosyltransferase, Ugt1a8, Glucuronidates Dihydrotestosterone to a Monoglucuronide and Further to a Structurally Novel Diglucuronide

“…DHT diglucuronide was attached to the C17 position of DHT and that the second glucuronosyl moiety was attached at the C2Ј position of the first glucuronosyl moiety. Interestingly, the regiochemistry of the two glucuronosyl moieties in DHT diglucuronide [␤-D-glucuronopyranosyl-(1Љ32Ј)-␤-D-glucuronopyranosyl] is common to all the previously characterized diglucuronides of nalmefene (Dixon et al, 1989), 4-hydroxybiphenyl (Murai et al, 2002), and estrone and testosterone (Murai et al, 2005), as well as some plant saponins including glycyrrhizic acid (Kitagawa et al, 1993;Yoshida et al, 1993). These accumulating observations suggest that the 2Ј-hydroxyl group of specific monoglucuronides could particularly be recognized as a functional group for further glucuronidation by some UGT enzymes in animals and the plant enzymes involved in the biosynthesis of some saponins.…”