Biodegradable Biomaterial Arterial Stent in the Treatment of Coronary Heart Disease.

This study aims to evaluate the clinical application value of two materials, drug-eluting stent, and biodegradable stent, in the treatment of coronary heart disease. The results show that the therapeutic effects of drug-eluting stents and biodegradable stents are similar. Both treatment methods have high safety and effectiveness. The ideal coronary artery stent should have good biocompatibility, safety, and possibility.

Switchable Chemoselective Transfer Hydrogenations of Unsaturated Carbonyls Using Copper(I) N-Donor Thiolate Clusters.

Unsaturated alcohols and saturated carbonyls are important chemical, pharmaceutical, and biochemical intermediates. We herein report an efficient transfer hydrogenation protocol in which conversion of unsaturated carbonyl compounds to either unsaturated alcohols or saturated carbonyls was catalyzed by Cu(I) N-donor thiolate clusters along with changing hydrogen source (isopropanol or butanol) and base (NaOH or K2CO3). Mechanistic studies supported by DFT transition state modeling indicate that such a chemoselectivity can be explained by the relative concentrations of Cu(I) monohydride and protonated Cu(I) hydride complexes in each catalytic system.

Ligand-Controlled Copper(I)-Catalyzed Cross-Coupling of Secondary and Primary Alcohols to α-Alkylated Ketones, Pyridines, and Quinolines.

One hexanuclear Cu(I) cluster of 4,6-dimethylpyrimidine-2-thiolate efficiently catalyzes the dehydrogenative cross-coupling of secondary and primary alcohols to α-alkylated ketones with high selectivity. This transformation proceeds through a one-pot sequence of dehydrogenation of alcohols, condensation of aldehydes and ketones, hydrogenation of the resulting α,ß-unsaturated ketones, and dehydrogenation of the α-alkylated alcohols to generate α-alkylated ketones. This catalytic system also displays high activity for the annulation reaction of secondary alcohols with γ-amino- and 2-aminobenzyl alcohols to yield pyridines and quinolines, respectively.

Syntheses and structures of copper complexes of 3-(6-(1H-pyrazol-1-yl)pyridin-2-yl)pyrazol-1-ide and their excellent performance in the syntheses of nitriles and aldehydes.

Reactions of a pincer ligand 2-(1H-pyrazol-1-yl)-6-(1H-pyrazol-3-yl)pyridine (pzpypzH) with Cu(NO3)2, Cu(ClO4)2, CuSO4, CuCl2 or CuI produced three dinuclear Cu(ii) complexes [{Cu(NO3)}(µ-pzpypz)]2 (1), [{Cu(ClO4)}(µ-pzpypz)]2 (2), [Cu2(µ-SO4)(µ-pzpypz)2]·2MeOH (3·2MeOH), one mononuclear Cu(ii) complex [CuCl2(pzpypzH)] (4) and one trinuclear Cu(i)/Cu(ii) complex [(ICu)(µ-I)2Cu2(µ-pzpypz)2] (5), respectively. Treatment of 4 with two equiv. of AgNO3 in DMF also gave rise to 1. Complexes 1-5 were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. Complex 1 or 2 has a dimeric structure in which two {Cu(X)} (X = NO3, ClO4) fragments are interconnected by two µ-pzpypz(-) ligands. 3 also adopts a dimeric structure in which two Cu(ii) centers are interconnected by a pair of µ-pzpypz(-) ligands and one µ-SO4(2-) ion. The Cu(ii) center in 4 is five-coordinated by three N atoms of the pzpypzH ligand and two Cl atoms. In 5, two Cu(ii) centers are bridged by two µ-pzpypz(-) ligands and one CuI3(2-) unit, forming a unique trinuclear structure. Complexes 1-5 displayed high catalytic activity toward the ammoxidation of alcohols to nitriles and the aerobic oxidation of alcohols to aldehydes in H2O. The nitrile or aldehyde products could be readily separated from the catalytic system by extraction and the residual aqueous solution containing 1 retained good activity for several cycles.

Steroidal glycosides from the rhizomes of Anemarrhena asphodeloides and their antiplatelet aggregation activity.

Five new steroidal glycosides, timosaponin J ( 1), timosaponin K ( 2), (25 S)-karatavioside C ( 5), timosaponin L ( 6), and (25 S)-officinalisnin-I ( 8), together with eight known steroidal saponins, timosaponin E (1) ( 3), purpureagitosid ( 4), timosaponin BII ( 7), timosaponin B III ( 9), anemarrhenasaponin I ( 10), anemarrhenasaponin III ( 11), anemarrhenasaponin A (2) ( 12), and timosaponin A III ( 13), were isolated from the rhizomes of Anemarrhena asphodeloides. Their structures were elucidated on the basis of spectroscopic and chemical evidence. The aglycones of compounds 1 and 2 are new aglycones. Compounds 1- 13 were evaluated for their platelet aggregation activities, and compound 13 exhibited the strongest inhibitory effect on adenosine diphosphate (ADP)-induced platelet aggregation.

Structure elucidation and complete NMR spectral assignments of glucosylated saponins of cantalasaponin I.

Five new glucosylated steroidal glycosides, cantalasaponin I-B(1) (1), I-B(2) (2), I-B(3) (3), I-B(4) (4) and I-B(5) (5), were isolated and purified from the transformed product of the cantalasaponin I by using Toruzyme 3.0 l as biocatalyst. Their structures were elucidated on the basis of high-resolution electrospray ionization mass spectrometry, one-dimensional ((1) H and (13) C NMR) and two-dimensional [COSY, heteronuclear single-quantum correlation (HSQC), HMBC and HSQC-TOCSY] NMR spectral analyses and chemical evidence.

Characterization of steroidal glycosides from the extract of Paris Polyphylla var. Yunnanensis by UPLC/Q-TOF MSE.

Steroidal saponins in Rhizoma Paridis attract scientific attentions for their structural diversity and significant bioactivities. In this work, an ultra performance liquid chromatography coupled with a hybrid quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) was used to rapidly separate and identify steroidal saponins from the extract of the rhizome of Paris polyphylla var. yunnanensis (PPY). The fragment ions from glycosidic and cross-ring cleavages offered a wealth of structural information that is indicative to the aglycones, sugar types and the connecting sequence of sugar units. Based on the exact mass information, the fragmentation characteristics, and the LC retention times of 21 reference steroidal saponin standards, 98 constituents were tentatively identified with their structures proposed, which covered more than 30 types of steroidal aglycones. The 98 constituents consist of 22 pairs of structural isomers, and 40 steroidal glycosides that are identified for the first time from the nature.

Spirostanol saponins derivated from the seeds of Trigonella foenum-graecum by ß-glucosidase hydrolysis and their inhibitory effects on rat platelet aggregation.

Nine spirostanol saponins (1-9) and seven mixtures of 25 R and 25 S spirostanol saponin isomers (10-16) were obtained from the seeds of Trigonella foenum-graecum after enzymatic hydrolysis of the furostanol saponin fraction by ß-glucosidase. Their structures were determined by NMR and MS spectroscopy. Among them, 1- 4, 6, 8, and 9 were new compounds and five, 11B, 12A, 13B, 14A, and 14B, were new structures observed from seven mixtures. In addition, the inhibitory effects of all saponins on rat platelet aggregation were evaluated.

[Effects of bortezomib alone or combined with arsenic trioxide on the apoptosis of Jurkat cells and expression of livin mRNA].

This study was aimed to investigate the effect of bortezomib alone or combined with arsenic trioxide on the apoptosis of Jurkat cells and expression of livin mRNA. The Jurkat cells were cultured and treated with different concentrations of bortezomib, arsenic trioxide or their combination for 24 hours. Then, the expression of livin mRNA was detected by RT-PCR, the cell proliferation was analyzed with MTT assay and flow cytometry. The results showed that 5 - 25 nmol/L bortezomib could effectively inhibit Jurkat cells in a dose-dependent manner, the group of bortezomib combined with arsenic trioxide showed more inhibitory effect on Jurkat cells than the effect of bortezomib alone or arsenic trioxide alone on Jurkat cells. The expression of livin mRNA in Jurkat cells decreased in a dose-dependent manner after treated with bortezomib, which was downregulated significantly after combined treatment. It is concluded that bortezomib and arsenic trioxide can induce apoptosis by inhibiting the expression of livin mRNA in Jurkat cells. The combination of bortezomib with arsenic trioxide displays a synergistic effect.

[Identification of chemical constituents in qiliqiangxin capsule by UPLC-Q-TOF/MS(E)].

In order to clarify the chemical constituents in Qiliqiangxin capsule, a rapid ultra-performance liquid chromatography/orthogonal acceleration time-of-flight mass spectrometry (UPLC-Q-TOF/MS(E)) method was established. Forty peaks were identified on line using this method. The herbal sources of these peaks were assigned. The results implied that triterpenoid saponins, flavonoid glycosides, C21-steroids and phenolic acids were included in the main components of Qiliqiangxin capsule. The method is simple and rapid for elucidation of the constituents of Qiliqiangxin capsule and the results are useful for the quality control of Qiliqiangxin capsule.

Enzymatic synthesis of alpha-glucosyl-timosaponin BII catalyzed by the extremely thermophilic enzyme: Toruzyme 3.0L.

Timosaponin BII (BII), a steroidal saponin showing potential anti-dementia activity, was converted into its glucosylation derivatives by Toruzyme 3.0L. Nine products with different degrees of glucosylation were purified and their structures were elucidated on the basis of (13)C NMR, HR-ESI-MS, and FAB-MS spectra data. The active enzyme in Toruzyme 3.0L was purified to electrophoretic homogeneity by tracking BII-glycosylase activity and was identified as Cyclodextrin-glycosyltransferase (CGTase, EC 2.4.1.19) by ESI-Q-TOF MS/MS. In this work, we found that the active enzyme catalyzed the synthesis of alpha-(1-->4)-linked glucosyl-BII when dextrin instead of an expensive activated sugar was used as the donor and showed a high thermal tolerance with the most favorable enzymatic activity at 100 degrees C. In addition, we also found that the alpha-amylases and CGTase, that is, GH13 family enzymes, all exhibited similar activities, which were able to catalyze glucosylation in steroidal saponins. But other kinds of amylases, such as gamma-amylase (GH15 family), had no such activity under the same reaction conditions.

Saponins from the processed rhizomes of Polygonatum kingianum.

Two new spirostanol saponins, named kingianoside H (1) and kingianoside I (2), were isolated from the processed rhizomes of Polygonatum kingianum, along with a known triterpenoid saponin ginsenoside-Rc (3), four known spirostanol saponins Tg (4), (5), polygonatoside C(1) (6) and ophiopogonin C' (7). The structures of the new compounds were elucidated by detailed spectroscopic analyses, including 1D and 2D NMR techniques and chemical methods. Compounds 3 and 5 were first reported from the genus Polygonatum. Compounds 4, 6 and 7 are reported for the first time from the processed Polygonatum kingianum.

Three new saponins from the fresh rhizomes of Polygonatum kingianum.

Further studies on the fresh rhizomes of Polygonatum kingianum led to the isolation of one new spirostanol saponin (25R)-kingianoside G (1), and two pairs mixture of 25R and 25S stereoisomeric spirostanol saponins (25R, S)-pratioside D1 (2a, 2b) and (25R, S)-kingianoside A (3a, 3b), among them 2b and 3b were new spirostanol saponins, together with another two known compounds, disporopsin (4) and daucosterol (5). The structures of the new saponins were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences.

Steroidal saponins from the rhizome of Paris polyphylla and their cytotoxic activities.

Two new furostanol saponins and one new spirostanol saponin were isolated from the rhizome of Paris polyphylla Smith var. yunnanensis, together with 18 known steroidal saponins. The structures of the new steroidal saponins were elucidated as 26-O-beta-D-glucopyranosyl-(25R)-5-ene-furost-3 beta, 17 alpha, 22 alpha, 26-tetrol-3-O-alpha-L-arabinofuranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (2, parisyunnanoside A), 26-O-beta-D-glucopyranosyl-(25R)-5, 20 (22)-diene-furost-3 beta, 26-diol-3-O-alpha-L-arabinofuranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (7, parisyunnanoside B), and (25R)-spirost-5-ene-3 beta, 12 alpha-diol-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (13, parisyunnanoside C) by MS and 1 D and 2 D NMR analysis. The isolated compounds were evaluated for their cytotoxicity against HL-60 human promyelocytic leukemia cells. Our results showed that the spirostanol framework of the aglycone and the terminal alpha-L-rhamnopyranosyl with 1-->2 linkage to the sugar chain of saponins at C-3 are essential for their high cytotoxicity, whereas the hydroxy group substitution at C-12 or C-17 of the aglycone causes a reduction in their activity.

1H and 13C NMR assignments for four triterpenoid saponins from Albizziae cortex.

Four triterpenoid saponins were isolated from Albizziae cortex, and a complete assignment of their (1)H and (13)C NMR spectra was carried out using 1D and 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and HSQC-TOCSY) methods. Their (1)H NMR assignments were reported for the first time and some of their (13)C NMR spectral data reported in literature were corrected.

New furostanol saponins from Allium ascalonicum L.

An analysis of the polar extracts from Allium ascalonicum L. led to the isolation of two new furostanol saponins (compound 1 and 2) and two known furostanol saponins (compound 3 and 4). On the basis of 1D and 2D NMR (including (1)H, (13)C NMR, (1)H--(1)H COSY, HSQC, TOCSY, HMBC, and NOESY), FAB-MS spectrometry, and chemical methods, their structures were elucidated as (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside C, 1), (25R)-26-O-beta-D-glucopyranosyl-22-methoxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol- 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside D, 2), (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (dichotomin, 3), and (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinofuranosyl-(1-->4)]-beta-D- glucopyranoside (parisaponin I, 4).

[Study on steroidal saponins of Dioscorea septemloba thunb].

OBJECTIVE: To isolate and identify steroidal saponins from the rhizomes of Dioscorea septemloba Thunb. METHODS: The compounds were isolated by solvent extraction, column chromatography on silica gel and ODS, and their structures were elucidated on the base of chemical and spectral analyses. RESULTS: Three steroidal saponins were isolated from the rhizomes of Dioscorea septemloba Thunb, and their structures were detemined as dioscin (I), protodioscin (II), protogracillin (III). CONCLUSION: Compound II and III were obtained from the rhizomes of Dioscorea septemloba Thunb for the first time.