Functional characterization of three flavonoid glycosyltransferases from Andrographis paniculata.

Andrographis paniculata is an important traditional medicinal herb in South and Southeast Asian countries with diverse pharmacological activities that contains various flavonoids and flavonoid glycosides. Glycosylation can transform aglycones into more stable, biologically active and structurally diverse glycosides. Here, we report three glycosyltransferases from the leaves of A. paniculata (ApUFGTs) that presented wide substrate spectra for flavonoid glycosylation and exhibited multi-site glycosylation on the substrate molecules. They acted on the 7-OH position of the A ring and were able to glycosylate several other different types of compounds. The biochemical properties and phylogenetic analysis of these glycosyltransferases were also investigated. This study provides a basis for further research on the cloning of genes involved in glycosylation from A. paniculata and offers opportunities for enhancing flavonoid glycoside production in heterologous hosts. These enzymes are expected to become effective tools for drug discovery and for the biosynthesis of derivatives via flavonoid glycosylation.

Separation of Five Iridoid Glycosides from Lonicerae Japonicae Flos Using High-Speed Counter-Current Chromatography and Their Anti-Inflammatory and Antibacterial Activities.

A high-speed counter-current chromatography (HSCCC) method, using a two-phase solvent system composed of ethyl acetate/n-butanol/methanol/water (5:1:1:5, v/v/v/v), was successfully established to separate the five iridoid glucosides 7-O-ethyl sweroside (1), secologanin dimethylacetal (2), adinoside F (3), (7R)-secologain n-butyl methyl acetal (4) and adinoside G (5) from Lonicerae Japonicae Flos. Their purities were 96.8%, 98.5%, 93.3%, 98.0% and 99.9%, respectively. All the iridoid glucosides were identified by HR-ESI-MS, 1D and 2D NMR. Compounds 3 and 5 are new iridoid glucosides. The anti-inflammatory tests showed that compounds 1⁻5 all expressed moderate inhibitory effects on ß-glucuronidase release in rat polymorphonuclear leukocytes (PMNs) induced by platelet-activating factor (PAF) with IC50 values ranging from 4.52 to 6.50 µM, while the antibacterial assays demonstrated that all the compounds displayed mild inhibitory activities against Staphylococcus aureus ATCC 25923 with MIC values ranging from 13.7 to 26.0 µg/mL.

Understanding the patterns and mechanisms of urban water ecosystem degradation: phytoplankton community structure and water quality in the Qinhuai River, Nanjing City, China.

The temporal and spatial distribution characteristics of environmental parameters and the phytoplankton community were investigated in October 2010 and January 2011 in the Qinhuai River, Nanjing, China. Results showed that the water quality in the study area was generally poor, and the main parameters exceeding standards (level V) were nitrogen and phosphorus. The observed average concentrations of the total nitrogen (TN) were 4.90 mg L(-1) in autumn and 9.29 mg L(-1) in winter, and those of the total phosphorus (TP) were 0.24 mg L(-1) in autumn and 0.88 mg L(-1) in winter, respectively. Thirty-seven species, 30 genera, and four phyla of phytoplankton were detected in the river. Cyanophyta and Bacillariophyta were the dominant phyla in autumn, with average abundance and biomass of 221.5 × 10(4) cells L(-1) and 4.41 mg L(-1), respectively. The dominant population in winter was Bacillariophyta, and the average abundance and biomass were 153.4 × 10(4) cells L(-1) and 6.58 mg L(-1), respectively. The results of canonical correspondence analysis (CCA) between environmental parameters and phytoplankton communities showed that Chlorophyta could tolerate the higher concentrations of the permanganate index, nitrogen, and phosphorus in eutrophic water; Bacillariophyta could adapt well to changing water environments; and the TN/TP ratio had obvious impacts on the distributions of Cyanophyta, Euglenophyta, and some species of Chlorophyta. CCA analyses for autumn and winter data revealed that the main environmental parameters influencing phytoplankton distribution were water temperature, conductivity, and total nitrogen, and the secondary factors were dissolved oxygen, NH4(+)-N, NO3-N, TN, CODMn, TN/TP ratio, and oxidation-reduction potential.

Molecular authentication of the traditional medicinal plant Fallopia multiflora.

The root of Fallopia multiflora is one of the most widely used traditional Chinese medicines. However, it is often confused and substituted with the roots of F. multiflora var. ciliinervis, Pteroxygonum giraldii, Cynanchum auriculatum, and Stephania cepharantha. To establish a DNA polymorphism-based assay for the identification of F. multiflora, the nuclear ribosomal DNA (nrDNA) internal transcribed spacer (ITS) regions of six Fallopia species were sequenced and analyzed. Based on the diversity of ITS regions among the species the diagnostic primers PMITS28 and PMITS545, which amplified an expected 517-bp DNA fragment from F. multiflora DNA, were designed. No amplified product was observed when DNA from other species was used. This method can be used for the authentication of F. multiflora.

Natural gas and indoor air pollution: a comparison with coal gas and liquefied petroleum gas.

OBJECTIVE: The study was designed to compare the combustion products of coal gas, liquefied petroleum gas and natural gas in relation to indoor air pollution. METHODS: Regular pollutants including B(a)P were monitored and 1-hydroxy pyrene were tested in urine of the enrolled subjects. Radon concentrations and their changes in four seasons were also monitored in the city natural gas from its source plant and transfer stations to final users. To analyze organic components of coal gas, liquefied petroleum gas and natural gas, a high-flow sampling device specially designed was used to collect their combustion products, and semi-volatile organic compounds contained in the particles were detected by gas chromatograph-mass spectrograph (GC/MS). RESULTS: Findings in the study showed that the regular indoor air pollutants particles and CO were all above the standard in winter when heating facilities were operated in the city, but they were lowest in kitchens using natural gas; furthermore, although NO2 and CO2 were slightly higher in natural gas, B(a)P concentration was lower in this group and 1-hydroxy pyrene was lowest in urine of the subjects exposed to natural gas. Organic compounds were more complicated in coal gas and liquefied petroleum gas than in natural gas. The concentration of radon in natural gas accounted for less than 1% of its effective dose contributing to indoor air pollution in Beijing households. CONCLUSION: Compared to traditional fuels, gases are deemed as clean ones, and natural gas is shown to be cleaner than the other two gases.