Solvent effects on extraction and HPLC analysis of soybean isoflavones and variations of isoflavone compositions as affected by crop season

Spring (February to June) and fall (August to December) crops of soybean grown yearly in Taiwan with reverse temperature patterns provide a novel model to assess the effect of the crop season. In this study, three soybean cultivars, namely CH 1, VS-KS 2, and HBS, were grown for 2001 fall, 2002 spring, 2003 fall, 2004 spring, 2004 fall, and 2005 spring crops. The harvested and sun-dried soybeans were lyophilized, pulverized, and stored at -25 degrees C until HPLC analyses of isoflavone compositions were performed. As affected by extraction solvent and HPLC mobile phase, the amount of isoflavones extracted by methanol-H(2)O was higher than those extracted by acetic acid-acetonitrile. In addition, when both extracts were subjected to HPLC analysis with reversed C18 column run respectively with methanol-H(2)O and acetic acid-acetonitrile mobile phases, malonyldaidzin, malonylglycitin, and malonylgenistin were not detected in the former phase. Accordingly, all harvested soybeans were subjected to methanol-H(2)O extraction and HPLC analysis with the acetic acid-acetonitrile mobile phase. Among the detected soybeans, daidzin, genistin, malonyldaidzin, and malonylgenistin were the majors and glycitin, malonylglycitin, daidzein, and genistein were the minors of isoflavones. As affected by crop season for each cultivar grown for 3 years, daidzin, genistin, malonyldaidzin, and malonylgenistin contents of soybeans of the fall crops were significantly higher than those of their spring crops ( p < 0.05).     

Rapid differentiation of tea products by surface desorption atmospheric pressure chemical ionization mass spectrometry

Protonated water molecules generated by an ambient corona discharge were directed to impact tea leaves for desorption/ionization at atmospheric pressure. Thus, a novel method based on surface desorption chemical ionization mass spectrometry (DAPCI-MS) has been developed for rapid analysis of tea products without any sample pretreatment. Under the optimized experimental conditions, DAPCI MS spectra of various tea samples are recorded rapidly, and the resulting mass spectra are chemical fingerprints that characterize the tea samples. On the basis of the mass spectral fingerprints, 40 tea samples including green tea, oolong tea, and jasmine tea were successfully differentiated by principal component analysis (PCA) of the mass spectral raw data. The PCA results were also validated with cluster analysis and supervised PCA analysis. The alteration of signal intensity caused by rough surfaces of tea leaves did not cause failure in the separation of the tea products. The experimental findings show that DAPCI-MS creates ions of both volatile and nonvolatile compounds in tea products at atmospheric pressure, providing a practical and convenient tool for high-throughput differentiation of tea products.     

浅谈当前基层畜牧管理部门存在的主要问题与对策

近年来,各地基层畜牧管理部门紧紧围绕农业、农村经济发展和农民增收,着力发展畜牧业生产,取得了较好的成效。但是,随着农业产业结构调整的进一步深化,有些地方畜牧业发展的步伐明显减慢了,甚至出现停滞不前的现象,其原因是没有与时俱进地创新管理模式,更新服务观念,管理措施过     

红心猕猴桃优质丰产载培技术要点

猕猴桃优质丰产栽培技术,是采用水平架式,通过园地选择、肥水管理、整形修剪、授粉疏果等技术措施,控制病害滋生,减少农药污染,促进植株健壮生长,果实优质丰产的栽培方法。     

江西省宁都县2011年6月中旬暴雨天气过程分析

2011年6月12～15日江西宁都县受高空低槽等影响,出现了大到暴雨天气过程,通过环流形势及物理量分析得出,高空低槽、切变线、低空急流等是此次强降水过程的主要影响系统。     

羧化壳聚糖对蚊净香草外植体诱导过程酶活性的影响

以蚊净香草叶柄和叶片为外植体,研究不同浓度羧化壳聚糖对其诱导过程各种酶活性的影响。结果表明,在蚊净香草叶柄初代培养基中,附加4g·L-1羧化壳聚糖使过氧化物酶活性比对照组提高8.57倍;附加2g·L-1羧化壳聚糖使吲哚乙酸氧化酶活性比对照组提高了3倍;叶片初代培养基中,附加2g·L-1羧化壳聚糖中硝酸还原酶活性是对照组的3.5倍。说明羧化壳聚糖能提高蚊净香草叶柄和叶片中相关酶活性,从而使愈伤组织诱导的效率更高。     

兔对桂牧1号杂交象草营养成分的消化率

试验测定了桂牧1号杂交象草{[(Pennisetum purpureum.cv.Mott)×(P.americanum×P.pu-rureum)]cv.Guimu No.1}的营养成分及消化率,其营养成分为:粗蛋白(CP)13.95%,粗纤维(CF)30.63%,粗脂肪(EE)2.72%,无氮浸出物(NFE)41.99%,粗灰分(ASH)10.72%,钙(Ca)0.61%,磷(P)0.42%。兔对桂牧1号杂交象草营养成分的消化率分别为:CP 76.79%、CF 42.26%、EE 80.23%、NFE 58.42%、ASH43.17%、Ca 45.52%、P 22.30%。表明桂牧1号杂交象草营养丰富,各种营养成分能很好地被兔消化利用。     

Residues and persistence of neem formulations on strawberry after field treatment

Azadirachtoids were determined by liquid chromatography/mass spectrometry (LC/MS) in five methanolic seed extracts of the neem tree and in a commercial formulation. On average, seed extracts contain azadirachtin A (10.9%), azadirachtin B (3.5%), nimbin (10.4%), and large quantities of salannin (19.0%). The composition of the commercial formulations may present different azadirachtoids contents depending on the natural extracts used in the preparation. Because these compounds may also show insecticide activity, the efficacy on field of these formulations may be very different. Photodegradation of pure azadirachtoids was also studied. Azadirachtins and related compounds are very sensitive to sunlight, degrading rapidly, with half-lives of the order of 11.3 h for azadirachtin A and 5.5 h for azadirachtin B and few minutes for the other limonoids compounds studied. The residues of azadirachtins and the main constituents, e.g., salannin, nimbin, deacetylnimbin, and deacetylsalannin, of the neem seed extract were determined on strawberries after field treatment using two different formulations. This residue study on strawberry was carried out to assess not only the azadirachtin content but also the main azadirachtoids contents. Three days after field application at five times the dose recommended by the manufacturer, residues of azadirachtin A and B were 0.03 and 0.01 mg/kg, respectively, while residues of salannin (LOQ 0.01 mg/kg) and nimbin (LOQ 0.5 mg/kg) were not detectable.     

Arabidopsis ENDO2: its catalytic role and requirement of N-glycosylation for function

The Arabidopsis thaliana At1g68290 gene encoding an endonuclease was isolated and designated ENDO2, which was cloned into a binary vector to overexpress ENDO2 with a C-terminal 6 × His-tag in A. thaliana. Our Arabidopsis transgenic lines harboring 35SP::ENDO2 produced stable active enzyme with high yield. The protein was affinity purified from transgenic plants, and its identity was confirmed by liquid chromatography-mass spectrometry and automatic Edman degradation. ENDO2 enzyme digests RNA, ssDNA, and dsDNA, with a substrate preference for ssDNA and RNA. The activity toward ssDNA (361.7 U/mg) is greater than its dsDNase activity (14.1 U/mg) at neutral pH. ENDO2 effectively cleaves mismatch regions in heteroduplex DNA containing single base pair mismatches or insertion/deletion bases and can be applied to high-throughput detection of single base mutation. Our data also validated that the removal of sugar groups from ENDO2 strongly affects its enzymatic stability and activity.     

Abundance,perceptions and utilizations of termite mounds in Cambodia

In the Lower Mekong Basin, paddy fields often appear as mosaics, with soil mounds covered by trees or other plants in a spotty distribution. These soil mounds are commonly named termite ‘lenticular mounds’ because termite bioturbation is considered to be at their origin. Termite mounds host a large diversity of animals and plants, increasing landscape patchiness. Because the preservation of these islands of biodiversity is threatened by modern agricultural practices, the aim of this study was to quantify their abundance and the services they provide to the local population. The abundance of mounds and their use by the population were quantified in a catchment in Cambodia. We found that mounds density reached ~2 mounds ha⁻¹. Interviews carried out within the catchment showed that most of the interviewees used mounds for increasing the fertility of their field and for the cultivation of rice and other plants (e.g. sponge gourd and pumpkin). In addition to their potential to increase plant productivity, the survey revealed that animals (rats and snakes), mushrooms and 13 plant species found on or in mounds were consumed by the population. In addition to potentially contributing to an increase in food diversity, mounds also impacted farmers' health by allowing access to 20 medicinal plant species and indirectly via a reduction in pesticide use. In conclusion, this study is the first attempt to quantify the large number of services provided by termite mounds in Cambodia. This increase in the knowledge of the diversity of environmental and socioeconomic services provided by termite mounds is likely to contribute to their preservation and provide a basis for the sustainable management of biodiversity in paddy fields in the Lower Mekong Basin region.