[Synthesis and biological activity of a series of benzopyran derivatives].

Thirteen benzopyran derivatives were synthesized and their activity stimulating the differentiation of preadipocytes into adipocytes were evaluated with 3T3-L1 cells. Compound 8 was also tested for its hypoglycemic activity on db diabetes mice model. Results indicated that compounds 3, 8 and 11 exhibited strong differentiation-stimulating activity on 3T3-L1 cells model, and compound 8 can reduce the blood-sugar level of db diabetes mice dramatically.

[Design, synthesis and anti-HBV activity of L-amino acid ester prodrugs of acyclic nucleoside phosphonates].

To design and synthesis a series of novel L-amino acid esters prodrugs of acyclic nucleoside phosphonates with more potent anti-HBV activity, adefovir dipivoxil was used as lead compound, according to the results of enhanced oral bioavailability and antiviral activities of nucleoside L-amino acid ester prodrugs. Eleven novel L-amino acid ester prodrugs of acyclic nucleoside phosphonates were designed and synthesized, their anti-HBV activities were evaluated in HepG2 2.2.15 cells. Eight compounds exhibited antiviral activity, and compound 11 showed the most potent anti-HBV activity and highest selective index in vitro (EC50 0.0952 micromol x L(-1), SI 69523). Moreover, by analyzing the primary structure and activity relationship of these compounds, it could be suggested that L-amino acid ester strategy has significant potential in the acyclic nucleoside phosphonates prodrug design.

[Design and synthesis of a type of benzopyran derivatives with insulin-sensitizing activity].

Ten novel compounds were designed and synthesized on the basis of compound 1, their insulin-sensitizing activities were evaluated in 3T3-L1 cells. Results showed that compound 10 exhibited strong differentiation-stimulating activity on 3T3-L1 cells model, which indicated that compound 10 may possess well insulin-sensitizing activity.

[Design, synthesis and insulin-sensitizing activity of indole derivatives].

AIM: To design and synthesize compounds with insulin-sensitizing activity. METHODS: Using association principle of drug design, ten title compounds were designed and synthesized on the basis of known compounds with insulin-sensitizing activity, and their insulin-sensitizing activity were evaluated on 3T3-L1 pre-adipocyte cells. RESULTS: One of the synthesized compounds showed strong insulin-sensitizing activity in vitro. CONCLUSION: This compound may possess good sugar-lowering activity, and will be chosen for further hypoglycemic evaluation in vivo.

Assignment of Proton Resonances and Conformational Characterization of Oligodeoxyribonucleic Acid d(CCGTACGG) in Solution.

Lycobetaine prepared from lycorine is a new anticancer agent. The experimental and quantum pharmacological studies revealed that lycobetaine can interact with DNA by intercalation, preferentially into GO base pairs. In order to provide detailed interaction model of lycobetaine-DNA, a self-complementary octanucleotide d(CCGTACGG) was designed and synthesized by using new HELP (high efficiency Liquid phase) According to its nature, the sample was prepared to the desired final concentration by adding salt and buffer solutions. Two-dimensional (1)H-(1)H COSY and NOESY spectra in 99.8% D(2)O and 95% H(2)O were recorded for the duplex, and the NMR techniques of presaturation and WATERGATE were applied to water suppression. Protons of every spin system were identified by their scalar couplings, then through their special couplings all protons in the molecule were assigned except the poorly resolved H5' and H5' ' resonances. The chemical shifts of exchangeable protons and NOE intensities of nonexchangeable protons indicate qualitatively that the d(CCGTACGG) helix is right-handed B-DNA in aqueous solution.

A Computer Model for the Pore of Potassium Channel: Oxygen Cage Mechanism.

We have constructed a structural motif for the pore of voltage-gated K(+) channel by computer modeling. The model developed here predicts that the narrowest part of the pore is formed by the four carbonyl oxygens of Gly444 or Gly446, and that the ion selectivity is achieved through "oxygen cage" mechanism. Residues 447, 448 and 449 make the external entrance to the narrowest part of the pore. Of these residues, 449 and 447 are believed to interact directly with TEA. This model agrees well with many available experimental data.

Insulin-sensitizing effects of a novel alpha-methyl- alpha -phenoxylpropionate derivative in vitro.

AIM: To examine the insulin sensitizing effects of a novel alpha-methyl-alpha- phenoxylpropionate derivative YY20 in insulin-sensitive cell lines. METHODS: The peroxisome proliferator-activated receptor gamma (PPAR gamma) agonist bioactivities of YY20 were detected by a preadipocyte differentiation assay. RT-PCR and Western blotting analysis were used to detect the expression of the target gene or protein. The effects of YY20 on insulin-mediated glucose consumption were determined in the HepG2 human hepatocellular carcinoma line. RESULTS: YY20 could enhance the differentiation of preadipocytes to adipocytes and upregulate the gene expression of PPAR gamma 2, as well as the protein expression of insulin receptor substrate- 1 (IRS-1), glucose transporter-4 (GLUT4), and adiponectin (ACRP30). The effects on GLUT4 and ACRP30 could be reversed by the PPAR gamma inhibitor SR-202. Furthermore, YY20 efficiently reduced glucose consumptions in HepG2 cells after 24 h culture, and the effects were related to insulin and YY20 concentrations. CONCLUSION: YY20, a potential insulin-sensitizing agent like rosiglitazone, could enhance glucose consumption in HepG2 cells in a concentration- and insulindependent manner. It may improve the insulin resistance associated with type 2 diabetes.

A density-functional study of the mechanism for the diastereoselective epoxidation of chiral allylic alcohols by the titanium peroxy complexes.

The epoxidation of three stereolabeled methyl-substituted chiral allylic alcohols with (1,2)A and/or (1,3)A allylic strain, namely 3-methylbut-3-en-2-ol (1a), pent-3-en-2-ol (1b), and 3-methylpent-3-en-2-ol (1c), have been studied by the density-functional theory method, B3LYP/6-31+G(d,p). For each substrate we calculated the two prereaction complexes with Ti(OH)(4)/MeOOH (the oxidant model for Ti(O-i-Pr)(4)/t-BuOOH), their threo and erythro transition states for oxygen transfer, and the corresponding product complexes. For substrate 1a, the erythro transition state is 0.91 kcal/mol of lower energy than the threo one; for substrates 1b and 1c, the threo compared to the erythro transition states are by 1.05 and 0.21 kcal/mol more favorable, respectively. The threo/erythro product ratios have been estimated from the computed free energies for the competing threo and erythro transition states 3a-c in CH(2)Cl(2) solution to be 12:88 (1a), 92:8 (1b), and 77:23 (1c), which are in good accordance with the experimental values 22:78 (1a), 91:9 (1b), and 83:17 (1c). The diastereoselectivity of this diastereoselective oxyfunctionalization is rationalized in terms of the competition between (1,3)A and (1,2)A strain and the electronic advantage for the spiro transition state. In addition, solvent effects are also play a role for the diastereoselectivity at the same time.