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  • Author or Editor: Q. Li x
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Summary  

The comprehension of the behavior of radioactive nuclides in aquifer requires the study of the sorption processes of nuclides in various geochemical conditions. The sorption/desorption of 65Zn(II) on surface sediments (0-2 cm) was investigated by batch method in sea water (pH 8.20, 35‰ salinity, filtered by 0.45mm) at ambient temperature. The surface sediments were obtained from four stations around the Daya Bay of Guangdong Province (China), where the first nuclear power station of China has been running from 1994. The sorption process is fast initially and around 39% average of sorption percentage (SP%) can be quickly obtained in 15 minutes for all the surface sediments. Then, the sorption percentage becomes constant. In 30 days of contact time 79.6% sorption percentage and K d=3.9. 103ml/g distribution coefficient was obtained. The value of K dbecame constant, 4.0. 103ml/g, in contact time more than 120 hours. The distribution coefficient K ddecreases with increasing sediment concentration from 4.0 to 250 mg/l from 1.31. 104to 1.68. 103ml/g, respectively. Then the value of K dgoes up to 5.38. 103ml/g with sediment concentration of 3000 mg/l. The desorption experiments suggest that the sorption of Zn(II) is irreversible with a hyteresis coefficient of 66%.

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Gibberellins (GAs) are a class of plant hormones that play important roles in diverse aspects during plant growth and development. A series of GA synthesis and metabolism genes have been reported or proved to have essential functions in different plant species, while a small number of GA 2-oxidase genes have been cloned or reported in wheat. Previous studies have provided some important findings on the process of GA biosynthesis and the enzymes involved in its related pathways. These may facilitate understanding of the complicated process underlying GA synthesis and metabolism in wheat. In this study, GA 2-oxidase genes TaGA2ox1-1, TaGA2ox1-2, TaGA2ox1-3, TaGA2ox1-4, TaGA2ox1-5, and TaGA2ox1-6 were identified and further overexpressed in rice plants to investigate their functions in GA biosynthesis and signaling pathway. Results showed overexpression of GA 2-oxidase genes in rice disrupted the GA metabolic pathways and induced catalytic responses and regulated other GA biosynthesis and signaling pathway genes, which further leading to GA signaling disorders and diversity in phenotypic changes in rice plants.

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Influence of different maturity stages and treatments of ethephon, exogenous ABA, and fluridone on the ripening and hormone level of ‘Zhonghuashoutao’ peach during development and post-harvest storage were investigated. The accumulation of endogenous ABA appeared at the onset of ripening and peaked at two weeks before harvest. Fruit firmness decreased, while ethylene release and SSC/TA increased sharply after a maximum peak of ABA, which have triggered the initiation of the fruit ripening. The fruits, harvested at 170 d when fruits have ripened and stored at 20 °C, showed an ethylene climacteric peak, and the pulp started softening normally, and the SSC/TA value increased. Compared with them, the immature green fruits harvested at other dates, could not mature normally due to the lack of normal reciprocity between ABA and ethylene. The ethylene release was promoted by the treatment of exogenous ABA and ethephon during ripening until the endogenous ABA reached a maximum value. However, fluridone treatment showed an inhibitory effect. The above-mentioned changes occurred again in the peach fruits after harvest. The results indicated that both ABA and ethylene play important roles in peach ripening, and their action depended on the ripening stage of peach.

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Hydrogen sulfide (H2S) has been recently found to be a gaseous signaling molecule in plants. In this work, we studied the role of H2S in alleviating salinity stress during wheat grain germination (Triticum aestivum L. Yangmai 158). Pretreatment with NaHS, a H2S donor, during wheat grain imbibition, could significantly attenuate the inhibitory effect of salinity stress on wheat germination. NaHS-pretreated grain showed higher amylase and esterase activities than water control. NaHS pretreatment differentially stimulated the activities of catalase (CAT), guaiacol peroxidase (POD) and ascorbate peroxidase (APX), decreased the level of malondialdehyde (MDA) and reduced NaCl-induced changes in plasma membrane integrity in the radicle tips of seedlings compared with water control. We conclude that H2S plays an important role in protecting wheat grain from oxidative damage induced by salinity stress.

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Thinopyrum intermedium, which has many useful traits, is valuable for wheat breeding. A new wheat-Thinopyrum addition line, SN100109, was developed from the progeny of common wheat cultivar Yannong 15 and Th. intermedium. It was resistant to most races of Blumeria graminis f. sp tritici (Bgt), which caused powdery mildew in wheat, and its reactions were different from the reactions of gene Pm40 and Pm43. Genomic in situ hybridization (GISH) and molecular marker analysis were used to identify the genomic composition of SN100109. GISH results showed that SN100109 was a wheat-Th. intermedium disomic addition line containing one pair of J chromosomes, and the resistance gene was located on the alien additional chromosomes of SN100109. And four molecular markers BE425942, BF482714, Xgdm93 and BV679214 which were assigned to homologous group 2, were specific molecular markers of the additional chromosomes. All the results indicated that SN100109 contained one pair of 2J chromosomes. SN100109 can be used as a novel germplasm source for introducing powdery mildew resistance genes to wheat in breeding programs.

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Abstract

Oleogels have been extensively investigated in the food processing in recent years, and they have become one of the healthier alternative. The possibility of constructing oleogel material in a manner similar to hydrocolloid gel has now been gradually becoming a reality. In this regard, this review provides coverage of the latest developments and applications of oleogels in terms of preparation strategies, physicochemical properties, health aspects, and potential food applications. Both solid fat content and crystallisation behaviour are discussed for oleogels fabricated by gelators and under different conditions. Oleogels could replace hydrogenated vegetable oils in food product, reduce the fatty acid content, and be used to prepare food products such as meat, ice-cream, chocolate, bread, and biscuits with desirable properties. The aims were to assess the formation mechanism, construction methods of oleogels and the advance on the application of oleogel structures in the food field, as well as the further exploration of oleogels and in complex food systems in the future.

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Summary

A reversed-phase chiral liquid chromatographic method had been developed and validated for resolution of the enantiomers of racemic fudosteine. The effects on the separation of the amounts of anhydrous cupric sulfate and l-phenylalanine, the methanol content, mobile phase pH, and temperature were investigated. The method was validated for linearity, repeatability, intermediate precision, sample recovery, solution stability, and limits of detection (LOD). l-Phenylalanine and anhydrous cupric sulfate as chiral ligand-exchange complexes were used for separation, isomer identification, related substance investigation, and analysis of fudosteine enantiomers in fudosteine bulk drugs and fudosteine tablets.

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A method was developed for the preparative separation of two alkaloids from the crude extract of the radix of Rauvolfia verticillata (Lour.) Baill. in a single run. The two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–water (5:5:2:8, v/v), where triethylamine (40 mmol/L) was added to the upper organic phase as the stationary phase and hydrochloric acid (10 mmol/L) was added to the lower aqueous phase as the mobile phase, was selected for this separation by pH-zone-refining counter-current chromatography (PZRCCC). For the preparative separation, the apparatus was rotated at a speed 850 rpm, while the mobile phase was pumped into the column at 2 mL/min. As a result, 112 mg of reserpine and 21 mg of yohimbine were obtained from 3 g of crude extract in a single run. The analysis of the isolated compounds was determined by high-performance liquid chromatography (HPLC) at 230 nm with purities of over 91.0%, and the chemical identification was carried out by the data of electrospray ionization–mass spectrometry (ESI–MS) and nuclear magnetic resonance (NMR) spectroscopy. The technique introduced in this paper is an efficient method for preparative separation of reserpine and yohimbine from devil pepper radix. It will be beneficial to utilize medicinal materials and also useful for the separation, purification, and pharmacological study of Chinese herbal ingredients.

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An efficient and sensitive analytical method based on precolumn derivatization and gas chromatography—mass spectrometry—selected ion monitoring (GC—MS—SIM) was proposed and validated for analysis of two cembrenediols (CBDs) which are α-cembrenediol and β-cembrenediol in tobacco samples. CBDs in tobacco samples were extracted by sonication with 50 mL dichloromethane for 10 min before derivatized with 2:3 (v/v) bis(trimethylsilyl)trifluoroacetamide (BSTFA)—pyridine at 20 °C for 100 min. CBDs’ level in tobacco samples was analyzed by GC—MS—SIM and quantified by the internal standard method. The linear range for α-CBD and β-CBD was 13.6–554.6 μg mL−1 and 4.11–162.6 μg mL−1, and the correlation coefficients of both were 0.9998. The limit of detection (LOD) and limit of quantification (LOQ) of α-cembrenediol and β-cembrenediol were 0.40 μg g−1 and 1.34 μg g−1, and 0.27 μg g−1 and 0.90 μg g−1, respectively. Average recoveries of α-CBD and β-CBD were 94.4–99.9% and 91.9–98.2% while the relative standard deviations (RSDs, n = 5) were ranged from 2.67 to 5.6% and 2.04 to 4.22%, respectively. This proposed analytical method has been successfully applied to analyze CBDs in tobacco samples.

Open access

Abstract

Conversion of economic microcrystalline cellulose (MCC) into high value-added prebiotic glucans, is not only stimulates utilisation of renewable lignocellulosic biomass, but also provides cheap prebiotics to reduce high incidence of obesity and metabolic syndrome. Herein, glucans (C0.25–C0.50–C1.00) from MCC were prepared by pre-impregnation with dilute sulphuric acid (0.25–0.50–1.00%) and ball-milling treatment for 1 h. NMR spectroscopy and gel-permeation chromatography of the glucan products showed a significant reduction in the degree of polymerisation (DP) and molecular weights (Mw). All prepared glucans improved gut stress evaluated by in vitro digestion and fermentation (young and aging mouse faecal inocula). C1.00 with lower DP and Mw showed better water solubility, earlier peak, and exhibited increased 1-diphenyl-2-picrylhydrazyl activity, higher ratios of Lactobacillus to Escherichia coli, and a higher level of short chain fatty acids better than C0.25 and C0.50 treatment (P < 0.05). Better prebiotic effects were observed in aging mice than in young mice. The highest ratio of Lactobacillus to E. coli was a 2.13-fold increase for aging mice compared to a 1.79-fold increase for young mice, relative to the initial value after C1.00 treatment. The study provides a novel pathway and a new resource for producing glucan.

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