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Four novel lactams, colletotrilactam A-D (1-4), along with six known compounds (5-10) were isolated from the culture broth of Colletotrichum gloeosporioides GT-7, a fungal endophyte of Uncaria rhynchophylla. The structures of these compounds were elucidated by comprehensive NMR spectroscopy. Isolates were tested for monoamine oxidase (MAO) inhibitory activity and compound 9 showed potent MAO inhibitory activity with IC50 value of 8.93±0.34μg/mL, when the IC50 value of iproniazid as a standard was 1.80±0.5μg/mL.
Fatty acids in Herpetospermum seed oil from supercritical CO2 extraction were analyzed by HPLC fluorescence detection (HPLC-FLD) with pre-column derivatization and GC-MS. After derivatizing 39 kinds of saturated and unsaturated fatty acids used 1-[ 2- ( p-toluenesulfonate ) ethyl]-2-phenylimidazole [ 4,5-f] 9,10-phenanthrene ( TSPP ) as pre-column derivatization reagent. All the fatty acid derivatives were separated with a good baseline resolution in conjunction with a gradient elution. The external standard method for the simultaneous quantitative determination of 39 fatty acids was developed and applied for the determination of the free fatty acid contents in Herpetospermum seed oil samples obtained from supercritical CO2 extraction coupled with orthogonal tests, ultrasound-assisted extraction and microwave-assisted reflux extraction. The mass percent of oleic acid, linoleic acid and linolenic acid and the ratio of unsaturated fatty acids and all fatty acids in 9 orthogonal test samples were contrasted. The results indicated that the mass percent of oleic acid, linoleic acid and linolenic acid in Herpetospermum seed oil are up to 34.65% ( 147. 14 mg/g), 22.85% (97.03 mg/g), 20. 86% ( 88. 56 rag/g), respectively, and ratio of unsaturated fatty acids and all fatty acids is 79%. Furthermore, by GC-MS method, the acid catalysis and alkaline catalysis of the methyl esterifying reaction were discussed for the analysis fatty acids in Herpetospermum seed oil, and the optimum GC-MS conditions were obtained. Simultaneously, the characteristics of HPLC and GC-MS methods were discussed about analyzing fatty acids.
Diosgenin wastewater produced from <b>Dioscorea zingiberensis</b> C. H. Wright in diosgenin enterprise is the by-product of numerous operations chiefly including washing raw materials, acid hydrolysis, and cleaning the apparatus with water. It requires the removal of high concentrations of various organic and inorganic contaminants from this wastewater in order to avoid pollution to the environment and fresh water system. Currently, several different methods such as chemical, physicochemical, biological recovery resource, constructed wetland, and integrated methods of these processes are being applied for treating diosgenin wastewater. Aiming to get a comprehensive overview, available reports from experimental scale to industry scale about the treatment of this wastewater were collected and summarized. Therefore, this review paper will provide appropriate choice for the efficient treatment of diosgenin wastewater and supportive information for the other scientists who want to continue this valuable research in the future.<br><br>Display Omitted<br>• Studies of diosgenin wastewater treatment between 2003 and 2016 are reviewed. • Characteristics of diosgenin wastewater are presented. • These methods used for diosgenin wastewater are compared. • Merits and demerits of each approach to cope with diosgenin wastewater are stated. • Future promising ways should be updated based on currently available ones.
<P>Nitrogen (N) availability is a key regulator of carbon (C) cycling in terrestrial ecosystems. Anthropogenic N input, such as N deposition and fertilization, increases N availability in soil, which has important implications for an ecosystem’s C storage and loss. Soil respiration (Rs), which is the second largest C flux from terrestrial ecosystems to the atmosphere, plays an important role in terrestrial C cycles. The direction and magnitude of the responses of Rs and its components to N addition have been widely evaluated, but it remains unclear how these processes change across multiple N addition levels. Here we conducted a two-year field experiment to examine the changes of Rs and its autotrophic respiration (Ra) and heterotrophic respiration (Rh) components along a gradient of eight N levels (0, 1 2, 4, 8, 16, 24, 32 g m<SUP>−2</SUP> yr<SUP>−1</SUP>) in a Tibetan alpine steppe, and used structural equation modeling (SEM) to explore the relative contributions of biotic and abiotic variables and their direct and indirect pathways regulating the Ra and Rh. Our results indicated that both Rs and Ra exhibited first increasing and then subsequent decreasing trends at the threshold of 8 g N m<SUP>−2</SUP> yr<SUP>−1</SUP>. In contrast, the Rh declined linearly with the N addition rate continuously increasing. SEM analysis revealed that, among various environmental factors, soil temperature was the most important one modulating Rs, which not only had a direct effect on the two Rs components, but also indirectly regulated the Ra and Rh via root and microbial biomass. These findings suggest that the nonlinear response patterns of Rs should be considered for better predicting terrestrial C balance, given that anthropogenic N input to the terrestrial ecosystems is increasing continuously.</P>
Dynamic microwave-assisted extraction (DMAE) technique was employed for the extraction of polysaccharides from Lycium ruthenicum (LRP). The extracting parameters were optimized by using three-variable-three-level Box-Behnken design and response surface methodology (RSM) based on the single-factor experiments. RSM analysis indicated good correspondence between experimental and predicted values. The optimum extraction parameters for the yield of polysaccharide were ratio of water to raw material 31.5 mL/g, extracting time 25.8 min and microwave power 544.0 W. Polysaccharide was analyzed by chemical methods and Fourier-transform infrared (FT-IR). The antioxidant activities of LRP were investigated including scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide and free radicals of superoxide anion in vitro. The results of antioxidant activity exhibited LRP had the potential to be explored as novel natural antioxidant for using in functional foods or medicine.