Two new dalbergiphenols from Zhuang medicine Dalbergia rimosa Roxb / 药学学报

Twelve compounds were isolated from the ethyl acetate fraction of the 80% aqueous ethanol extract of the roots and stems of Dalbergia rimosa Roxb. by silica gel, MCI, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Their structures were identified by spectral analysis such as UV, IR, MS, 1D/2D NMR and by comparison with literature information as dalbergiquinol A (1), dalbergiquinol B (2), R-(-)-3′-hydroxy-2,4,5-trimethoxydalbergiquinol (3), neokhriol A (4), mucronulatol (5), (3R)-7,2′,3′-trihydroxy-4′-methoxy-isoflavane (6), isomucronulatol (7), (3S)-violanone (8), 3′-O-methylviolanone (9), eryvarin M (10), (±)-α,3,4,2′,4′-pentahydroxydihydrochalcone (11) and (-)-butin (12). Compound 1 and 2 are new compounds, and compounds 3-12 were isolated from this plant for the first time. Compounds 1, 2, 4, 6, 8, 11, 12 showed good scavenging effect on DPPH free radical.

Characterization of the pH-dependent protein stability of 3α-hydroxysteroid dehydrogenase/carbonyl reductase by differential scanning fluorimetry.

The characterization of protein stability is essential for understanding the functions of proteins. Hydroxysteroid dehydrogenase is involved in the biosynthesis of steroid hormones and the detoxification of xenobiotic carbonyl compounds. However, the stability of hydroxysteroid dehydrogenases has not yet been characterized in detail. Here, we determined the changes in Gibbs free energy, enthalpy, entropy, and heat capacity of unfolding for 3α-hydroxysteroid dehydrogenase/carbonyl reductase (3α-HSD/CR) by varying the pH and urea concentration through differential scanning fluorimetry and presented pH-dependent protein stability as a function of temperature. 3α-HSD/CR shows the maximum stability of 30.79 kJ mol-1 at 26.4°C, pH 7.6 and decreases to 7.74 kJ mol-1 at 25.7°C, pH 4.5. The change of heat capacity of 30.25 ± 1.38 kJ mol-1 K-1 is obtained from the enthalpy of denaturation as a function of melting temperature at varied pH. Two proton uptakes are linked to protein unfolding from residues with differential pKa of 4.0 and 6.5 in the native and denatured states, respectively. The large positive heat capacity change indicated that hydrophobic interactions played an important role in the folding of 3α-HSD/CR. These studies reveal the mechanism of protein unfolding in HSD and provide a convenient method to extract thermodynamic parameters for characterizing protein stability using differential scanning fluorimetry.

Two new 2,3-seco triterpenoids from Rubus pirifolius Smith / 药学学报

Eight compounds were isolated from the ethyl acetate fraction of the 80% aqueous ethanol extract of the roots and stems of Rubus pirifolius Smith by AB-8 macroporous resin, silica gel, ODS, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Their structures were identified by spectral analysis such as 1D/2D NMR, MS, UV, IR and by comparison with literature information as rubussecotriterpene A (1), rubussecotriterpene B (2), cecropiacic acid (3), cecropiacic acid 3-methyl ester (4), alphitolic acid (5), betulinic acid (6), betulin (7), and obtusalin (8). Compounds 1 and 2 are new compounds, and compounds 3-8 were isolated from this plant for the first time.

A pair of new isoflavonoid enantiomers from Dalbergia benthamii Prain / 药学学报

Thirteen isoflavones were separated and purified from an ethanol extract of the rhizome of Dalbergia benthamii Prain by using silica gel, Sephadex LH-20, recrystallization et al. Their structures were identified by physicochemical properties and spectral analysis such as MS, 1D/2D-NMR as dalbergibenthamin (1), butesuperin A (2), xanthocercin A (3), butesuperin B (4), di-O-methylalpinum isoflavone (5), 2′-deoxgisoaunculutin (6), robustone (7), 4′-hydroxy-5,7-dimethoxy-6-(3-methyl-2-butenyl)-isoflavone (8), formononetin (9), 6″-O-rhamnosyldaidzin (10), 3′,4′-di-O-methylene-5-hydroxy-7-methoxy-6-isopentenyl isoflavone (11), derrubone dimethyl enter (12), and derrubone (13). Compound 1 is a pair of new isoflavonoid enantiomers, compound 12 is a new natural product and compounds 1-7 and 10-13 were obtained from D. benthamii Prain for the first time. In vitro cytotoxic activities of the compounds were explored by MTS testing with HL-60, A-549, SMMC-7721, MCF-7 and SW480 cell lines. Results show that compound 8 significantly inhibited cellular proliferation. The IC50 of compound 8 in A-549 and SW480 cells was 16.68 ± 0.19 and 15.21 ± 0.60 μmol·L-1.

[Structural Design and Finite Element Analysis of New Type Posterior Integral Glaucoma Valve].

The treatment of refractory Glaucoma is a difficult problem in clinical ophthalmology. For refractory glaucoma patients with hyphema, shallow anterior chamber, anterior conglutination of peripheral chamber angle, corneal endothelium dystrophy or decompensated, at present, there is no effective treatment. In order to solve this problem, a new type posterior integral glaucoma valve with IOP control device was designed using medical titanium alloy, and the valve model was established by Abaqus software, and the stiffness and preload of the valve were analyzed by finite element method. The results showed that the opening and closing of the valve were controlled automatically by the pressure difference between the front and back of the valve, and the opening and flow rate of the valve increase dynamically with the increase of intraocular pressure, and finally reached the set ideal IOP value of steady state.

Studies on chemical constituents in n-butyl alcohol extract of roots of Actinidia deliciosa in Guangxi / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of n-butyl alcohol extract in the roots of Actinidia deliciosa in Guangxi.</p><p><b>METHOD</b>The constituents were separated with various chromatographic techniques and their structures were elucidated by means of physicochemical properties and the analysis of their spectral data.</p><p><b>RESULT</b>Six compounds were isolated and identified as eriantic acid B (1), 2alpha, 3beta, 24-trihydroxyursa-12-en-28-oic acid (2), 2alpha, 3alpha, 24-trihydroxyursa-12-en-28-oic acid (3), 2alpha, 3alpha, 23-tri-hydroxyursa-12, 20 (30)-dien-28-oic acid (4), 2alpha, 3alpha, 24-trihydroxyursa-12, 20 (30)-dien-28-oic acid (5), n-butyl-O-beta-D-fruto-pyranoside (6).</p><p><b>CONCLUSION</b>Compounds 1-4, 6 were obtained from this plant for the first time. Compound 6 was obtained from the genus Actinidia for the first time.</p>