Yan-Wen Zhang

Pallidifloside D from Smilax riparia enhanced allopurinol effects in hyperuricemia mice.

Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to be effective in hyperuricemic control. Allopurinol is a commonly used medication to treat hyperuricemia and its complications. In this study, we evaluated whether Pallidifloside D could enhance allopurinols effects by decreasing the serum uric acid level in a hyperuricemic mouse model induced by potassium oxonate. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly decreased the serum uric acid level and increased the urine uric acid level (both P<0.05), leading to the normalized serum and urine uric acid concentrations. Data on serum, urine creatinine and BUN supported these observations. Our results showed that the synergistic effects of allopurinol combined with Pallidifloside D were linked to the inhibition of both serum and hepatic xanthine oxidase (XOD), the down-regulation of renal mURAT1 and mGLUT9, and the up-regulation of mOAT1. Our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.

Terpene alkaloids from Tripterygium wilfordii

Two new sesquiterpene alkaloids, 1β-hydroxy-2β,5α,11-triacetoxy-7β-nicotinoyl-8β-benzoyl-dihydroagarofuran (1), and 1β,5α,11-triacetoxy-7β-nicotinoyl-8β-benzoyl-dihydroagarofuran (2) were isolated from the xylem of Tripterygium wilfordii, together with six known compounds. Their structures were elucidated on the basis of spectroscopic studies.

Acetylated anthraquinone glycosides from Cassia obtusifolia

Three new acetylated anthraquinone glycosides (1–3) were isolated from the seed of Cassia obtusifolia, together with one parent anthraquinone glycoside (1a). Their structures were determined on the basis of spectroscopic methods and physicochemical properties as obtusifoline-2-O-β-d-2, 6-di-O-acetylglucopyranoside (1), obtusifoline-2-O-β-d-glucopyranoside (1a), obtusifoline-2-O-β-d-3, 6-di-O-acetylglucopyranoside (2), and obtusifoline-2-O-β-d-4, 6-di-O-acetylglucopyranoside (3).

A new labdanic norditerpene from Pinus sylvestris.

A new labdanic norditerpene and six known labdanic diterpenes were isolated from the petroleum ether extract of the needles of Pinus sylvestris. By spectroscopic methods, the isolated compounds were determined as 15-norpinifolic acid (1), pinifolic acid (2), 4-eplimbricataloic acid (3), monomethyl pinifolate (4), 18α-acetoxylabd-8(17)-en-15-oic acid (5), 2-pentenoic acid (6) and 3β-hydroxy-8(17),E-13-labdadien-15-oic acid (7), respectively. Compound 1 showed significant anti-tumour activity.

Six new cycloartane triterpene glycosides from Actaea asiatica

Six new cycloartane triterpene glycosides, (3′,12β)-O-diacetyl-cimigenol-3-O-β-d-xylopyranoside (1), (4′,25)-O-diacetyl-cimigenol-3-O-β-d-xylopyranoside (2), 2′-O-acetyl-25-O-methyl-cimigenol-3-O-β-d-xylopyranoside (3), 2′-O-acetyl-25-O-ethyl-cimigenol-3-O-β-d-xylopyranoside (4), 3′-O-acetyl-cimicifugoside (5), and 4′-O-acetyl-23-epi-26-deoxycimifugoside (6), were isolated from the rhizomes of Actaea asiatica. Their structures were elucidated on the basis of chemical methods and spectroscopic analysis. Compounds 1, 2, 4–6 exhibited positive cytotoxic activities.

Hypouricemic effect of allopurinol are improved by Pallidifloside D based on the uric acid metabolism enzymes PRPS, HGPRT and PRPPAT

Allopurinol is a commonly used medication to treat hyperuricemia and its complications. Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to enhanced hypouricemic effect of allopurinol based on uric acid metabolism enzyme XOD. In this study, we evaluated whether Pallidifloside D (5mg/kg) enhanced hypouricemic effect of allopurinol (5mg/kg) related to others uric acid metabolism enzymes such as PRPS, HGPRT and PRPPAT. We found that, compared with allopurinol alone, the combination of allopurinol and Pallidifloside D significantly up-regulated HGPRT mRNA expression and down-regulated the mRNA expression of PRPS and PRPPAT in PC12 cells (all P<0.01). These results strongly suggest that hypouricemic effect of allopurinol are improved by Pallidifloside D via numerous mechanisms and our data may have a potential value in clinical practice in the treatment of gout and other hyperuricemic conditions.

Three new acetylated benzyl-beta-resorcylate glycosides from Cassia obtusifolia.

Three new acetylated benzyl-beta-resorcylate glycosides (1-3) were isolated from seeds of Cassia obtusifolia. Their structures were determined on the basis of the spectroscopic methods and physicochemical properties as 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[2,6-O-diacetyl]-D-glucopyranoside (1), 2-benzyl-4,6-dihydroxy benzoic acid-6-O-[3,6-O-diacetyl]-D-glucopyranoside (2) and 2-benzyl-4, 6-dihydroxy benzoic acid-6-O-[4,6-O-diacetyl]-D-glucopyranoside (3), respectively.

Intestinal absorption of pallidifloside D are limited by P-glycoprotein in mice

Abstract 1. Pallidifloside D, a saponin glycoside constituent from the total saponins of Smilax riparia, had been proved to be very effective in hyperuricemic control. But it is poorly bioavailable after oral administration. Here, we determined the role of P-glycoprotein (P-gp) in the intestinal absorption of Pallidifloside D. 2. We found that Pallidifloside D significantly stimulated P-gp ATPase activity in vitro ATPase assay with a small EC50 value of 0.46 μM. 3. In the single-pass perfused mouse intestine model, the absorption of Pallidifloside D was not favored in the small intestine (duodenum, jejunum and ileum) with a P*w value of 0.35–0.78. By contrast, this compound was well-absorbed in the colon with a P*w value of 1.23. The P-gp inhibitors cyclosporine significantly enhanced Pallidifloside D absorption in all four intestinal segments (duodenum, jejunum, ileum and colon) and the fold change ranged from 5.5 to 15.3. Pharmacokinetic study revealed that cyclosporine increased the systemic exposure of Pallidifloside D by a 2.5-fold after oral administration. 4. These results suggest that P-gp-mediated efflux is a limiting factor for intestinal absorption of Pallidifloside D in mice.

Polyphenols from the Rhizomes of Potentilla freyniana

A new polyphenol, Potentillanin A (1), together with two known compounds (2–3), was isolated from the chloroform soluble fraction of Potentilla freyniana. The structure of Potentillanin A (1) was elucidated by spectroscopicmethods.