8-isopentenyl isoflavone derivatives from the whole herb of Sphaerophysa salsula.

Phytochemical studies on the whole herb of Sphaerophysa salsula has resulted in the discovery of one new 8-isopentenyl isoflavone derivative, named sphaerosin s2 (3-(8-(2-hydroxypropan-2-yl)-3,4-dihydro-2H-furo[2,3-h]chromen-3-yl)-2,6-dimethoxyphenol) (1), along with four know 8-isopentenyl isoflavone derivatives (2-5). Compounds (2, 4 and 5) were isolated for the first time from this species. Their structures were elucidated on the basis of ESI-MS, UV, IR, 1D NMR and 2D NMR data.

Isolation and identification of antioxidant and α-glucosidase inhibitory compounds from fruit juice of Nitraria tangutorum.

Nitraria tangutorum Bor., having edible berries, is valued for reputed health benefits in Qinghai-Tibet plateau. The phytochemical research on the fruit juice of N. tangutorum led to the isolation of twenty-six compounds including five new compounds, tangutorids A-D (1, 2, 3a, and 3b), and (3E,5E)-7-O-ß-glucosyl-4-(2-methoxy-2-oxoethyl)hepta-3,5-dienoic acid (15). The structures of these compounds were elucidated through comprehensive spectroscopic analyses. Tangutorids A-F were the first examples of glucose-derived ß-carbolines from natural products. The biogenetic pathways of 1-8 were proposed to involve Pictet-Spengler reactions and described starting from the co-isolated tryptophan (10) and corresponding aldehydes. All isolates were evaluated for their antioxidant and α-glucosidase inhibitory activities. Compounds 21, 22, and 24 showed antioxidant activity with SC50 values ranging from 12.2±1.9 to 30.4±2.7µg/mL, and compound 1 showed strong α-glucosidase inhibitory effect with IC50 value of 63.3±4.6µg/mL.

Anti-hepatitis, antioxidant activities and bioactive compounds of Dracocephalum heterophyllum extracts.

BACKGROUND: Dracocephalum heterophyllum was a traditional Tibetan medicine possesses various pharmacological effects involved in anti-inflammatory, antibacterial activities. However, its anti-hepatitis, antioxidant activity and bioactive compounds have not been reported, the objective of this research work was to investigate the pharmacological activity and bioactive compounds of D. heterophyllum extracts. RESULTS: In the present study, the anti-hepatics and antioxidant activities of four D. heterophyllum extracts (i.e. petroleum ether extracts, ethyl acetate extracts, n-BuOH extracts, and water extracts) were conducted. The main chemical constituent of petroleum ether and ethyl acetate extracts were also isolated using chromatographic techniques and identified by NMR spectroscopic methods. The anti-hepatitis assay showed that the petroleum ether and ethyl acetate extracts of D. heterophyllum significantly prolonged the mean survival times and reduced the mortality of mouse hepatitis model induced by concanavalin A (ConA). The levels of alanine transaminase, aspartate transaminase in blood serum could be decreased obviously by ethyl acetate extracts compared with ConA group (P < 0.01). The histological analysis demonstrated that the ethyl acetate extracts could inhibit apoptosis and necrosis caused by ConA. In addition, the antioxidant activities of the four extracts of D. heterophyllum were measured by DPPH assay, ABTS assay, anti-lipidperoxidation assay, ferric reducing antioxidant power assay, ferrous metal ions chelating assay and determination of total phenolic contents. The results showed that the ethyl acetate extract had the highest antioxidant activities, followed by petroleum ether extract. Finally, nine mainly compounds were isolated from the Petroleum ether and ethyl acetate extracts, including four triterpenes: oleanolic acid (1), ursolic acid (2), pomolic acid (3), 2α- hydroxyl ursolic acid (4), three flavonoids: apigenin-7-O-rutinoside (5), luteolin (8), diosmetin (9) and two phenolic acids: rosmarinic acid (6), methyl rosmarinate (7). CONCLUSION: The Ethyl acetate extract of D. heterophyllum had the highest anti-hepatitis and antioxidants activities, followed by petroleum ether extract. The bioactive substances may be triterpenes, flavonoids and phenolic acids, the ethyl acetate extracts of D. heterophyllum may be possible candidates in developing anti-hepatitis medicine.

Separation and purification of water-soluble iridoid glucosides by high speed counter-current chromatography combined with macroporous resin column separation.

Four iridoid glucosides, shanzhiside methyl ester, phloyoside II, chlorotuberside, and penstemonoside, were isolated and purified from an herbal medicinal plant for the first time by high-speed counter-current chromatography (HSCCC) using a two-phase solvent system composed of ethyl acetate-n-butanol-water (5:14:12, v/v/v). A total of 37mg of shanzhiside methyl ester, 29mg of phloyoside II, 27mg of chlorotuberside, and 21mg of penstemonoside with the purity of 99.2%, 98.5%, 97.3%, and 99.3%, respectively, were obtained in one-step separation within 4h from 150mg of crude extract. To the best of our knowledge, this is the first report of separation and purification of iridoid glucosides from natural sources by HSCCC. The chemical structures of all the four compounds were identified by ESI-MS, (1)H NMR, and (13)C NMR.

[Effects of continuous enclosure and fertilization on soil microbial community structure in alpine meadow].

By using phospholipid fatty acid (PLFA) method, this paper studied the changes of soil microbial community structure in an alpine meadow under six years continuous enclosure and its combination with fertilization, taking grazing area as the control. Both continuous enclosure and its combination with fertilization had significant effects on the microbial flora and total PLFA in different soil layers, and the effects were greater for 0-10 cm than for 10-20 cm soil layer. The species of PLFA in different soil layers also changed significantly. Under enclosure and its combination with fertilization, the number of gram-negative bacteria in different soil layers was lower than that of the control, and the numbers of bacteria, fungi, and gram-positive bacteria and the total PLFA in 0-10 cm soil layer were also lower, but the number of actinomycetes was higher than that of the control. In 10-20 cm soil layer, the number of gram-positive bacteria had no significant differences among different treatments, whereas the numbers of bacteria, fungi, and actinomycetes and the total PLFA were notably higher under enclosure but decreased markedly after fertilization. As compared with that of the control, the ratio of bacteria and fungi in different soil layers under enclosure and its combination with fertilization increased, the ratios of saturated fatty acid to monounsaturated fatty acid (SAT/MONO) and of gram-positive bacteria to gram-negative bacteria (G+/G-) under enclosure were all lower, but those after fertilization were in adverse. It was suggested that continuous enclosure and its combination with fertilization led to the decline of soil microbial diversity and activity and soil ecosystem stability.

[Soil quality assessment of alpine meadow in Haibei State of Qinghai Province].

Taking the typical alpine meadows Potentilla froticosa shrub meadow, Kobresia humilis meadow, and K. pygmaea meadow in the Haibei State of Qinghai Province as the research objects, a comprehensive assessment of soil quality was conducted by principal component analysis (PCA), with seven indices of soil microbial activities and ten indices of soil chemical properties. The soil quality of the alpine meadow could be characterized by three principal components (PC). In the first component (PC1), 13 indices had high factorial loads; in the second component (PC2), 3 indices had high factorial loads; in the third component (PC3), only one index, total phosphors, had high factorial load. In combining with Norm values, eleven indices including microbial biomass carbon (MBC), urease, alkaline phosphatase, protease, organic matter, total N, available N, available P, available K, bulk density, and CEC were selected to establish minimum data set (MDS) for the comprehensive assessment of soil quality of alpine meadow in Haibei. The PCA and corresponding weight coefficient analysis showed that the soil quality (0-10 cm and 10-20 cm layers) of the three kind meadows was in the order of K. humilis meadow > P. froticosa shrub meadow > K. pygmaea meadow, and P. froticosa shrub meadow > K. pygmaea meadow > K. humilis meadow, respectively.

[Changes in plant communities and soil microbial physiological groups of artificial grasslands established for different years in headwater region of Yangtze River and Yellow River].

An investigation was made on the plant communities of artificial grasslands established for different years in headwater region of Yangtze River and Yellow River, and the related soil physical and chemical properties and soil microbial physiological groups were analyzed. With the increase of establishment years, most of plant communities on the grasslands showed a "V" type change trend in their quantities, i.e., high-low-high, but the forbs biomass had a "A" type change trend and the sedge biomass increased gradually. Soil nutrients presented a "V" type but soil bulk density presented a "A" type change trend, while soil pH presented a decreasing trend. Most of soil microbial physiological groups and microbial biomass carbon showed a "V" type change trend, phosphorus-dissolving bacteria showed a "A" type change trend, denitrifying bacteria decreased gradually, while cellulose-decomposing bacteria showed an increasing trend. The numbers of soil microbes had a close relationship with tested soil factors, and the soil microbial physiological groups were directly or indirectly affected by the soil factors. All the results indicated that the establishment of artificial grassland and the positive succession of vegetation could effectively improve soil physical and chemical properties, which benefit for the beneficial microbes to settle down and propagation, while proliferation of the non-beneficial microbes was inhibited.

[Characteristics of artificial grassland plant communities with different establishment duration and their relationships with soil properties in the source region of three rivers in China].

This paper studied the biomass, species composition, and diversity index of artificial grassland plant communities with different establishment duration in the source region of the Three Rivers, and examined the relationships of soil physical and chemical properties with the changes of the plant community biomass and species diversity. The results showed that the species composition, functional group composition, and quantitative characters of the plant communities varied greatly. Soil moisture content increased with increasing species diversity, while soil bulk density was in adverse. Soil microbial biomass carbon significantly positively correlated with soil moisture and organic matter contents, but negatively correlated with soil bulk density. Soil organic carbon content had a "V" type change, which was consistent with the change pattern of soil moisture content, and decreased with increasing soil bulk density. Plant community biomass had significant positive correlations with the contents of soil nutrients and moisture, and the increase of the above- and below-ground biomass of plant communities promoted the increase of soil nutrient contents.

Jiangella gansuensis gen. nov., sp. nov., a novel actinomycete from a desert soil in north-west China.

A novel actinomycete strain, designated YIM 002(T), was isolated from a desert soil sample in Gansu Province, north-west China. This actinomycete isolate formed well-differentiated aerial and substrate mycelia. In the early stages of growth, the substrate mycelia fragmented into short or elongated rods. Chemotaxonomically, it contained ll-2,6-diaminopimelic acid in the cell wall. The cell-wall sugars contained ribose and glucose. Phospholipids present were phosphatidylinositol mannosides, phosphatidylinositol and diphosphatidylglycerol. MK-9(H(4)) was the predominant menaquinone. The major fatty acids were anteiso C(15 : 0) (35.92 %), anteiso C(17 : 0) (15.84 %), iso C(15 : 0) (10.40 %), iso C(16 : 0) (7.07 %) and C(17 : 1)omega8c (9.37 %). The G+C content of the DNA was 70 mol%. Phylogenetic analysis and signature nucleotide data based on 16S rRNA gene sequences showed that strain YIM 002(T) is distinct from all recognized genera of the family Nocardioidaceae in the suborder Propionibacterineae. On the basis of the phenotypic and genotypic characteristics, it is proposed that isolate YIM 002(T) be classified as a novel species in a new genus, Jiangella gansuensis gen. nov., sp. nov. The type strain is YIM 002(T) (=DSM 44835(T)=CCTCC AA 204001(T)=KCTC 19044(T)).

[Study on actinomycetes population of alpine meadow soil in Qinghai].

Soil samples were collected from six kinds of soil in Haibei alpine meadow ecosystem during 2001 - 2002. More than 300 strains of actinomycete were isolated by five agar media. On the basis of morphological characteristics and some chemotaxonomic properties, the isolated strains were classified into different genera, such as Micromonospora, Nocardia, Saccharopolyspora, Promicromonospora, Streptomyces, and the Streptomyces strains were classified into seven groups. The result indicated that the biodiversity of actinomycetes in different soils and the actinomycetes abundance of different kinds showed significant differences. The activities of some enzymes produced by mesophilic and psychrophilic actinomycetes also discussed in this paper. It is found that many strains of streptomyces not only have some enzyme activities such as starch decomposition, nitrate deoxidization, gelatin utilization etc., but also have some inhibiting activities for fungi and bacteria offered to test, whereas the rare actinomyces showed low positive rate of enzyme activities and inhibiting activities for fungi and bacteria.