Pingzhu Zhang

DNA binding and anticancer activity of naphthalimides with 4-hydroxyl-alkylamine side chains at different lengths.

A series of novel naphthalimide derivatives modified with various hydroxyl-alkylamines at 4-position have been synthesized. Their DNA binding properties were investigated by UV-Vis, fluoescence, and circular dichroism (CD) spectroscopies and thermal denaturation. The results showed that compounds 3a-e as the DNA intercalator exhibited middle binding affinities with Ct-DNA. The anticancer activities of 3a-e were preliminarily evaluated, compounds 3c and 3e exhibited potent anticancer activities against Bel-7402 cell line with IC(50) values of 5.57 and 9.17μM, respectively. More interestingly, enhancement of the fluorescence emission was found in the complexes of 3a-e with Ct-DNA, especially for 3c. This would make these compounds as potential DNA staining agents.

Synthesis and biological activities of novel isoxazoline-linked pseudodisaccharide derivatives

A series of novel isoxazoline linked pseudodisaccharide derivatives were regiospecifically synthesized by 1,3-dipolar cycloaddition of α-allyl-C-glycopyranosides and sugar-derived nitrile oxides with good yields. The structures of the compounds were characterized by NMR spectroscopy and MS spectrometry and confirmed by the X-ray crystallographic analysis of compound ((5S)-3-(2,3-O-isopropylidene-5-deoxy-d-lyxofuranose-4-yl)isoxazoline-5-yl) methyl α- C-D-galactopyranoside. Their biological activities against glycosidases (α-amylase, α-glucosidase, and β-glucosidase) and HIV-RT, and antitumor activity were preliminarily evaluated. Some of them exhibited potent inhibitory activity to HIV-RT.

Synthesis of C-Pseudonucleosides Bearing Thiazolidin-4-one as a Novel Potential Immunostimulating Agent.

Several novel C-pseudonucleosides bearing thiazolidin-4-one were synthesized by one-pot three-component condensation using unprotected sugar aldehyde at room temperature, and their effects on T cells, B cells, the cytokine secretion of IL-2, IL-4, and IFN-γ, T cell-associated molecules (CD3, CD4, CD8), and B cell-associated molecules (CD19) were first evaluated. The experimental data demonstrated that such thiazolidin-4-one C-pseudonucleosides hold potential as immunostimulating agents.

Synthesis of bi-/tricyclic azasugars fused thiazinan-4-one and their HIV-RT inhibitory activity.

Novel bi-/tricyclic azasugars fused thiazinan-4-one were conveniently synthesized by the tandem Staudinger/aza-Wittig/cyclization reaction under microwave radiation. The aryl group (phenyl or pyridyl) in mercaptan acid had an important effect on the formation of the diastereomers of the tricyclic hybrids 12b-15b. The new bi/tricyclic azasugars 3a-8a, 4b, 6b, 8b and the known ones 2a, 2b were examined for their HIV reverse transcriptase (RT) inhibitory activities. The result showed that compounds 2a-b, 4a, 4b, 5a, and 6a could effectively inhibit RT activity. Among them, the tricyclic azasugar 5a was the best one with the IC50 value of 0.49 μM. Structure-activity relationship analysis suggested that the phenyl group in the tricyclic azasugars was benefit for their anti-HIV RT activity.

Direct and Convenient Method of Regioselective Benzylation of Methyl α‐D‐Glucopyranoside

Abstract A facile and convenient method for the direct preparation of methyl 2,3,6‐tri‐O‐benzyl‐α‐D‐glucopyranoside (2) by the regioselective benzylation of methyl α‐D‐glucopyranoside (1) with benzyl bromide in the presence of mild bases K2CO3 and KOH (1∶1) without solvents is reported.

A convenient synthesis of novel aza-C-disaccharide analogues

Novel aza-C-disaccharide analogues have been conveniently synthesized by using the isoxazoline-linked C-disaccharide derivatives as the intermediates. Firstly, the C=N of isoxazoline was reduced to C-N by using DIBAL-H as reducing agent, then followed by the tandem multi-step reactions through catalytic hydrogenation with Pd(OH)2/C involving debenzylated, reductive cleavage of the N-O, condensation-cyclization of the aldehyde and the in situ generated amine group to form imine C=N and then C=N hydrogenation to form C-N, thus providing a practical and new access to the synthesis of novel aza-C-disaccharide analogues.

Convenient, Microwave-Assisted, One-Pot Synthesis of Photochromic Fulgimides Bearing Reactive Groups

A convenient, microwave-assisted, one-pot synthesis of the fulgimides (3) bearing reactive groups on N-substituents from the corresponding fulgides (1a–d) and amines (2a–e) is described. The synthesis provided the functionalized fulgimides (3) in yields of 50–84% under microwave irradiation within 25 min in the presence of 4-dimethylaminopyridine (DMAP) and dicyclohexylcarbodiimide (DCC).

Synthesis of novel sugar or azasugar modified anthra[1,2-d] imidazole-6,11-dione derivatives and biological evaluation

A series of novel, sugar or azasugar modified anthra[1,2-d] imidazole-6,11-dione derivatives, with different side chain were synthesized, using the synthetic route of imidazole cyclization reaction of 1,2-diaminoanthraquinone with various sugar (azasugar)-derived aldehydes, and imidazole cyclization reaction of 1,2-diaminoanthraquinone with chloroacetic acid and then followed by the nucleophilic substitution of N-alkylamino azasugar. Their biological activities against HIV-RT and cytotoxic activities against A549, Hela and MCF-7 cells were preliminary evaluated, most compounds showed similar HIV-RT inhibition to the control drug (AZT).