Characterization of free radicals formed from COX-catalyzed DGLA peroxidation.

Like arachidonic acid (AA), dihomo-γ-linolenic acid (DGLA) is a 20-carbon ω-6 polyunsaturated fatty acid and a substrate of cyclooxygenase (COX). Through free radical reactions, COX metabolizes DGLA and AA to form well-known bioactive metabolites, namely, the 1 and 2 series of prostaglandins (PGs1 and PGs2), respectively. Unlike PGs2, which are viewed as proinflammatory, PGs1 possess anti-inflammatory and anticancer activities.

Characterization of novel radicals from COX-catalyzed arachidonic acid peroxidation.

The peroxidation of arachidonic acid (AA) catalyzed by cyclooxygenase (COX) is a well-known free radical-mediated process that forms many bioactive products. Because of a lack of appropriate methodologies, however, no comprehensive structural evidence has been found previously for the formation of COX-mediated and AA-derived free radicals. Here we have used a combination of LC/ESR and LC/MS with a spin trap, alpha-[4-pyridyl-1-oxide]-N-tert-butylnitrone (POBN), to characterize the carbon-centered radicals formed from COX-catalyzed AA peroxidation in vitro, including cellular peroxidation in human prostate cancer cells (PC-3).

Targeted delivery of methotrexate to skeletal muscular tissue by thermosensitive magnetoliposomes.

Thermosensitive magnetoliposomes (TMs) encapsulated with methotrexate (MTX) were prepared with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol by reverse-phase evaporation. Encapsulation efficiency of MTX and hydrophilic magnetite Fe(2)O(3)-glu, liposome particle size, zeta-potential, and in vitro and in vivo drug release were studied. More than 80% of loaded MTX was released from TMs within 30min when the environmental temperature increased from 37 degrees C to 41 degrees C, while 60% of the drug was remained inside TMs for up to 24h at 37 degrees C.

Spectroscopic studies on the interaction of pazufloxacin with calf thymus DNA.

Fluorescence spectra, absorption spectra, DNA viscosity titrations, competition experiment, and iodide quenching experiment were used to study the interaction of DNA with pazufloxacin. DNA quenches the fluorescence of pazufloxacin significantly. No red shift and isobestic points are observed in UV titration experiment.

Marine drugs--macrolactins.

The increasing demands for new lead compounds in pharmaceutical and agrochemical industries have driven scientists to search for new bioactive natural products. Marine microorganisms are rich sources of novel, bioactive secondary metabolites, and have attracted much attention of chemists, pharmacologists, and molecular biologists. This mini-review mainly focuses on macrolactins, a group of 24-membered lactone marine natural products, aiming at giving an overview on their sources, structures, biological activities, as well as their potential medical applications.

LC/ESR/MS study of spin trapped carbon-centred radicals formed from in vitro lipoxygenase-catalysed peroxidation of gamma-linolenic acid.

Gamma-linolenic acid (GLA) has been reported as a potential anti-cancer and anti-inflammatory agent and has received substantial attention in cancer care research. One of the many proposed mechanisms for GLA biological activity is free radical-mediated lipid peroxidation. However, no direct evidence has been obtained for the formation of GLA-derived radicals.

Development and validation of a LC-MS/MS method for the determination of viaminate in human plasma.

A sensitive and specific method for determination of viaminate in human plasma by using high-performance liquid chromatography coupled with electrospray tandem mass spectrometry (LC-MS/MS) was developed in this study. The plasma samples were simply deproteinated, extracted, evaporated, and then reconstituted in 200 microl of methanol prior to analysis. Chromatographic separation was carried out on a Shimadzu VP-ODS column (250 mm x 2.

[Simultaneous analysis of six effective components in the anti-Alzheimer's disease effective component group of Xiao-Xu-Ming Decoction].

A method based on high performance liquid chromatography (HPLC) was developed for the quantitative determination of six components in an anti-Alzheimer medicine, Xiao-Xu-Ming Decoction, which is an effective prescription in treating stroke and the sequela of stroke by herbalist doctors for thousands years. The effective component group (ECG) was made according to the results of high-throughput screening, and the curative effect of ECG was validated on aging rats. In this method an ODS column was used.

Identification of polymethoxylated flavones from green tangerine peel (Pericarpium Citri Reticulatae Viride) by chromatographic and spectroscopic techniques.

Polymethoxylated flavones (PMFs) were extracted from Pericarpium Citri Reticulatae Viride using a procedure that obtained a consistent mixture of PMFs both in identity and proportion. The mixture consisted of isosinensetin (0.2%) (1), sinensetin (1.

Association of IL1B polymorphisms with gastric cancer in a Chinese population.

Objectives: To investigate the association between IL1B polymorphisms and risk of gastric cancer in a Chinese population, seven SNPs in the IL1B gene were selected for this study.

Methods: A multiplex genotyping method, which is based on adapter ligation and allele-specific amplification, was established to type seven SNPs on the IL1B gene simultaneously. One hundred and forty-one non-cancer outpatients and 97 patients with gastric cancer were genotyped, and the relation between IL1B polymorphisms and gastric cancer was statistically analyzed.

Determination of vertilmicin sulfate and its related substances by HPLC-ELSD and HPLC-MS2.

A new and simple high-performance liquid chromatography (HPLC)-evaporative light scattering detection (ELSD) method for the determination of vertilmicin sulfate and its related substances is developed. The column is an Agilent SB-C(18) (250 x 4.6 mm, 5 microm).

Multiplex single nucleotide polymorphism genotyping by adapter ligation-mediated allele-specific amplification.

An improved approach for increasing the multiplex level of single nucleotide polymorphism (SNP) typing by adapter ligation-mediated allele-specific amplification (ALM-ASA) has been developed. Based on an adapter ligation, each reaction requires n allele-specific primers plus an adapter-specific primer that is common for all SNPs. Thus, only n+1 primers are used for an n-plex PCR amplification.

Determination of spectinomycin hydrochloride and its related substances by HPLC-ELSD and HPLC-MSn.

A new and simple high-performance liquid chromatography-evaporative light scattering detection (HPLC-ELSD) method for the determination of spectinomycin hydrochloride and its related substances was developed. The column was Agilent SB-C(18) (250 mm x 4.6 mm, 5 microm).

[Adapter-ligation mediated allele-specific amplification (ALM-ASA) for multiplex SNP genotyping].

To establish adapter-ligation mediated allele-specific amplification ("ALM-ASA" for short) for multiplex SNP genotyping, five SNPs, 100C>T, 1661G>C, 1758G>T, 2470T>C and 2850C>T in CYP2D6 gene were used as an example for evaluating the method. Firstly, a preamplification was carried out for producing a long target containing all SNPs of interest. Secondly, the preamplified DNA fragments were digested with a restriction endonuclease to form sticky ends.

[Approaches for SNP genotyping].

With the completion of the Human Genome Project (HGP), typing single nucleotide polymorphisms (SNP) has become one of the main tasks in the post-genome era. Consequently, a robust, flexible and cost-effective technique for SNP typing is essential to analyze a large number of SNPs. The latest genotyping technologies and the relative detection platforms were introduced systematically.

[Interaction between balofloxacin and DNA and the influence of Mg2+ on the interaction].

Aim: To study the binding mode of balofloxacin with DNA and evaluate the influence of Mg2+ on the binding between balofloxacin and DNA.

Methods: Fluorescent spectroscopy was used to study the interaction of balofloxacin with DNA and to calculate the thermodynamic constants. UV-Vis spectra, DNA viscosity titration, competition experiment and the effect of dsDNA and ssDNA on the fluorescense intensity were used to identify the binding mode.

Structural characterization of chlorobenzylidine.

Aim: To study the structure and crystal forms of chlorobenzylidine.

Methods: Karl Fischer titrimetry, FTIR, thermal analysis, single and powder X-ray diffraction were used for the studies of the structure of chlorobenzylidine and for the identification of two forms of chlorobenzylidine.

Results: Chlorobenzylidine and its diastereoisomer have been studied in this article.

The interaction of human serum albumin with a novel antidiabetic agent--SU-118.

SU-118 is a newly synthesized antidiabetic agent and shows the best hypoglycemic effect among a series of analogs. Its binding properties and binding sites located on human serum albumin (HSA) have been studied using UV absorption and fluorescence spectroscopy. The results of spectroscopic study and the thermodynamic parameters obtained suggest that SU-118 binds to the hydrophobic cavity of human serum albumin and the hydrophobic interaction is the predominant intermolecular force stabilizing the complex.