Dendrimer hydrazides as multivalent transient inter-cellular linkers.

Three-dimensional (3D) multi-cellular aggregates (MCAs), as a model scaffold-free tissue construct, are useful for engineering cell-dense and matrix-poor tissues for repair and regeneration applications. To facilitate rapid MCA formation with high degrees of linker consistency and performance, we synthesized a class of dendrimer hydrazides with 8, 16 and 32 arms that can react with the aldehyde on the modified cell surfaces to form MCAs. DAB-AM-16 hydrazide with 32 arms demonstrated the best cell aggregation ability as compared to the dendrimer hydrazides with fewer arms, facilitating MCA formation at lower linker concentrations, minimizing cytotoxicity.

Synthesis and in vitro anti-hepatitis B virus activities of 4-aryl-6-chloro-quinolin-2-one and 5-aryl-7-chloro-1,4-benzodiazepine derivatives.

A series of 4-aryl-6-chloro-quinolin-2-ones and 5-aryl-7-chloro-1,4-benzodiazepine were synthesized and assayed for their in vitro anti-hepatitis B virus activities and cytotoxicities for the first time. Some of the tested compounds were active against HBsAg and HBeAg secretion in Hep G2.2.

Periglaucines A-D, anti-HBV and -HIV-1 alkaloids from Pericampylus glaucus.

Four new hasubanane-type alkaloids, periglaucines A-D (1-4), and three known alkaloids, norruffscine (5), (-)-8-oxotetrahydropalmatine (6), and (-)-8-oxocanadine (7), were isolated from the aerial parts of Pericampylus glaucus. Their structures were elucidated on the basis of extensive NMR and EIMS data, and that of periglaucine A (1) was confirmed by single-crystal X-ray diffraction. Alkaloids 1-4 inhibited hepatitis B virus (HBV) surface antigen (HBsAg) secretion in Hep G2.

[Studies on chemical constituents from rhizomes of Panax notoginseng].

Objective: To study the chemical constituents from rhizomes of Panax notoginseng.

Methods: The constituents were isolated and purified by various chromatogragraphic methods, all compounds were identified on the basis of special analysis and physicochemical characters.

Results: Eight compounds were isolated from the 80% alcohol extract of the rhizomes and their structures were identified as ginsenoside Rh4 (I), ginsenoside Rh1 (II), ginsenoside Re (III), notoginsenoside R1 (IV) , ginsenoside Rd (V), ginsenoside Rh1 (VI), notoginsenoside S (VII), notoginsenoside T (VIII).

1-Aryl-tetrahydroisoquinoline analogs as active anti-HIV agents in vitro.

A series of 1-aryl-6,7-dihydroxyl(methoxy)-1,2,3,4-tetrahydroisoquinolines (compounds 1-36) were synthesized via Pictet-Spengler cyclization. All the synthesized compounds were assayed for activities against HIV-1(IIIB) in C8166 cell cultures by MTT method for the first time. The results of the anti-HIV screening revealed that 6,7-dihydroxytetrahydroisoquinolines possessed higher selective index than 6,7-dimethoxyl analogs due to the significantly decreased cytotoxicities.

Bicyclic guanidine-catalyzed enantioselective phospha-Michael reaction: synthesis of chiral beta-aminophosphine oxides and beta-aminophosphines.

Chiral bicyclic guanidine has been found to catalyze the phospha-Michael reactions of diaryl phosphine oxide to nitroalkenes with high enantioselectivities, offering a direct methodology to prepare chiral beta-aminophosphine oxides and beta-aminophosphines.

[Studies on chemical constituents of rhizomes of Ligusticum chuanxiong].

Objective: To study chemical constitutents of the rhizomes of Ligusticum chuanxiong.

Method: The rhizomes of L. chuanxiong were extracted with water to afford a water extract which was participated between H2O and EtOAc, n-BuOH, successively.

Isatisine A, a novel alkaloid with an unprecedented skeleton from leaves of Isatis indigotica.

9alpha,13alpha-Dihydroxylisopropylidenylisatisine A (1), which was derived from isatisine A (2) and possessed an unprecedented fused pentacyclic skeleton, was isolated from the leaves of Isatis indigotica Fort. The structure and relative configuration were elucidated on the basis of extensive NMR analyses and finally determined by single-crystal X-ray diffraction. Compound 1 showed moderate anti-HIV-1 activity with EC50 = 37.

Simultaneous determination of phenols in Radix Polygalae by high performance liquid chromatography: quality assurance of herbs from different regions and seasons.

Radix Polygalae, roots of Polygala tenuifolia or of Polygala sibirica, is a Chinese herbal medicine commonly used to prevent dementia. Reliable chemical markers for quality assurance of this herb are missing. Here, a high performance liquid chromatography method coupled with diode array detection was developed to simultaneously determine nine different phenols in Radix Polygalae, including sibiricose A(5), sibiricose A(6), glomeratose A, tenuifoliside A, glomeratose D, 3',6-di-O-sinapoyl sucrose ester, mangiferin, polygalaxanthone III, and polygalaxanthone XI.

Synthesis and biological evaluation of N-acetyl-beta-aryl-1,2-didehydroethylamines as new HIV-1 RT inhibitors in vitro.

A variety of N-acetyl-beta-aryl-1,2-didehydroethylamines were synthesized by direct reduction-acetylation of beta-aryl-nitroolefins and assayed as HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) for the first time. Compound 7a exhibited a TI value of >13.2 with CC50 value of >0.

Two new sesquiterpenes from Alisma orientalis.

Two new sesquiterpenoids named alismorientols A (1) and B (2) were isolated from the rhizomes of Alisma orientalis collected in Sichuan province, People's Republic of China. Their structures were elucidated based on spectroscopic analyses (1D and 2D NMR data including HSQC, HMBC, COSY, and ROESY) and X-ray crystallographic analysis. Anti-hepatitis B virus (HBV) bioassay revealed that compound 1 showed moderate anti-HBV activity in vitro with IC50 for HBsAg: 1.

[Studies on chemical constituents from leaves of Isatis indigotica].

Objective: To study the chemical constituents of the leaves of Isatis indigotica.

Method: The leaves of I. indigotica were extracted with 80% ethanol.

A new triterpene and anti-hepatitis B virus active compounds from Alisma orientalis.

A new triterpenoid named alisol O ( 1) was isolated from the rhizomes of Alisma orientalis, together with six known compounds: alisol A 24-acetate ( 2), 25-anhydroalisol A ( 3), 13 beta,17 beta-epoxyalisol A ( 4), alisol B 23-acetate ( 5), alisol F ( 6), and alisol F 24-acetate ( 7). Based on 1D and 2D-NMR data (HMQC, HMBC, COSY, ROESY), the structure of the new compound was deduced to be 11-dehydroxy-12-dehydroalisol F-24-acetate ( 1). Compounds 2 - 7 exhibited inhibitory activity in vitro on hepatitis B virus (HBV) surface antigen (HBsAg) secretion of the Hep G2.

Two new triterpenoid glycosides from Cyclocarya paliurus.

Two new dammarane triterpenoid glycosides named cyclocarosides B (1) and C (2) were isolated from the leaves of Cyclocarya paliurus. Based on FAB-MS, HRESI-MS, IR, 1H NMR, 13C NMR, and 2D-NMR (HMQC, HMBC, COSY, ROESY) data, the structures of cyclocarosides B (1) and C (2) were elucidated as (20S,24R)-epoxydammarane (3beta,12beta)-25-hydroxyl-12-O-beta-D-quinovopyranosyl-3-O-beta-D-quinovopyranoside (1), and (20S,24R)-epoxydammarane (3beta, 12beta)-25-hydroxyl-12-O-alpha-L-arabinopyranosyl-3-O-(5'-O-acetyl)-alpha-L-arabinofuranoside (2).

Synthesis of enantiopure sulfinimines (thiooxime S-oxides) catalyzed by Yb(OTf)(3) from p-toluenesulfinamide and aldehydes in mild reaction conditions.

Enantiomerically pure sulfinimines as important building blocks in the asymmetric synthesis of amine derivatives are prepared in good to excellent yields from chiral p-toluenesulfinamide with aromatic, heteroaromatic, and aliphatic aldehydes. The unprecedented feature of the reported procedure is that the formation of the sulfinimines was achieved by the catalytic action of Yb(OTf)(3) in THF at room temperature. The reaction conditions were also applicable to Ellman's sulfinimines.