Determination of neutral sugars in soil by capillary gas chromatography after derivatization to aldononitrile acetates

We have quantified ribose, rhamnose, arabinose, xylose, fucose, mannose, glucose, and galactose in soil by gas chromatography (GC) simultaneously after converting to aldononitrile acetate derivatives. A recommended single-hydrolytic step by 4 M trifluoroacetic acid (TFA) at 105 °C for 4 h was more effective for releasing soil neutral sugars from non-cellulosic carbohydrates and better suited to our purification procedure compared with the sulphuric acid hydrolysis. Linearity of the GC detection for each neutral sugar was in the range of 10-640 μg ml⁻¹ and the recovery of neutral sugars from the spiked soil samples ranged from 76% to 109.7%. The coefficients of variation of the neutral sugars in four soils were lower than 2.0% for the instrument and 4.6-7.6% for the whole determination procedures. Compared with the trimethylsilyl (TMS) derivatization, the recovery of our newly modified method was more satisfactory and the reproducibility of ribose was improved significantly. Moreover, the aldononitrile acetate derivative was more stable than TMS derivative. Therefore, it is a promising approach suitable for a routine use in the quantitative analysis of soil neutral sugars, since it is fast, sensitive, and reproducible.     

不同堆肥方式对奶牛粪便处理效果的试验研究

以奶牛粪便为原料，进行了堆肥槽、露天条垛和接种外源微生物的对比试验。结果表明：与露天条垛堆肥相比较，堆肥槽能节省50%以上土地，并可防止二次污染；露天条垛堆体温度升高至50℃比槽式堆体提前了3d；接种外源微生物制剂堆体升温至50℃比未接种的提前2～3d；本试验中各处理的种子发芽指数变化表明，牛粪经过20d堆肥处理后就对植物无毒性。     

化学发光分析中10种重要发光剂及其应用

本文重点介绍了鲁米诺、光泽精、洛粉碱、硅氧烯和双(2,4,6-三氯苯基)过氧草酰的结构、发光性质及其应用,叙述了没食子酸、罗丹明B、连苯三酚、苏木色精、对-氯苯甲酸-5-溴水杨叉酰肼在分析化学中的应用,并对化学发光分析的发展前景作了简要评价。参考文献50篇。     

应用微核试验观察硒抗氯化汞的诱变效应

通过应用大鼠和小鼠骨髓细胞微核测试法，观察了富含硒的植物──大豆、硒及汞化合物对鼠的单独和联合的诱变效应．实验结果表明，氯化汞和亚硒酸钠均能单独引起鼠的骨髓嗜多染红细胞的微核率明显升高．当硒、汞联合作用时，亚硒酸钠对氯化汞可有明显的抗诱变能力．     

维生素A醋酸酯效价变化的初步探讨

本文揭示了维生素A醋酸酯在精制植物油和鳕鱼肝油中效价下降幅度不一样的现象，采取鳕鱼肝油中添加一定比例的精制植物油和抗氧化剂，可减缓维生素A醋酸酯的效价下降。     

Inhibitory components from the buds of clove (Syzygium aromaticum) on melanin formation in B16 melanoma cells

In the course to find a new whitening agent, we evaluated the methanol extract from bud of clove (Syzygium aromaticum) on melanin formation in B16 melanoma cells. Eugenol and eugenol acetate were isolated as the active compounds and showed melanin inhibition of 60% and 40% in B16 melanoma cell with less cytotoxicity at the concentration of 100 and 200 μg/mL, respectively. Furthermore, an essential oil prepared from the bud of clove, which contain eugenol and eugenol acetate as dominant components, showed melanin inhibition of 50% and 80% in B16 melanoma cells at the concentration of 100 and 200 μg/mL, respectively.     

Studies on antidepressant and antinociceptive effects of ethyl acetate extract from Piper laetispicum and structure-activity relationship of its amide alkaloids

Piper laetispicum C.DC. (Piperaceae), is an endemic climbing, glabrous plant distributed in the southern part of China. A novel alkaloid amide, Laetispicine, from it has been proven to possess antidepressant activity. In this present study, antidepressant and antinociceptive effects of the ethyl acetate extract (EAE) of P. laetispicum have been studied in forced swimming, open field, acetic acid writhing and formalin tests in KM mice. A significantly antidepressant-like effect was showing at doses of higher than 60 mg/kg, which was not due to an increase in locomotive activity. The EAE also presented an analgesic effect, in our studies. At lower doses (30 mg/kg) the antinociceptive effect was likely mediated via peripheral inflammation and changes in central processing, and at higher doses (120 mg/kg) that was due to both central and peripheral pathways. We also quantitatively analyzed the major components of EAE by HPLC and approached the structure–activity relationship between structure of amide alkaloids and its antidepressant activities. The antidepressant effective components of EAE might be Leatispiamide A and Laetispicine. In their molecular structures, the isolated double bond from benzene ring and conjugated double bond located at 2–3 and 4–5 were necessary for its antidepressant activity.     

Preventive effect of Kaempferia parviflora ethyl acetate extract and its major components polymethoxyflavonoid on metabolic diseases

Previously, we reported that rhizome powder of Kaempferia parviflora Wall. Ex. Baker prevented obesity and a range of metabolic diseases. In this study, to clarify which molecular mechanisms and active ingredients of K. parviflora have an anti-obesity effect, we investigated the effect of ethyl acetate extract of K. parviflora (KPE) on TSOD mice, a spontaneously obese Type II diabetes model, and on pancreatic lipase. In the TSOD groups, KPE showed a suppressive effect on body weight increase and visceral fat accumulation and also showed preventive effects on symptoms related to insulin resistance, hypertension and fatty liver. In addition, KPE also suppressed body weight increase and food intake in TSNO mice groups, which served as reference animals, at an early stage of administration. Searching for the ingredients in KPE revealed that KPE contains at least 12 kinds of polymethoxyflavonoid (PMF). Furthermore, KPE and its component PMFs showed an inhibitory effect on pancreatic lipase. The above results suggest that KPE has a preventive effect on obesity and various metabolic diseases. The mechanisms of action probably involve inhibition of pancreatic lipase by the PMFs in KPE.     

不同化学引发剂对不结球白菜种子引发效果的研究

为了确定化学引发剂对不结球白菜种子的引发效应,本试验以不结球白菜品种署绿和寒笑种子为试材,分别采用不同种类和不同浓度化学试剂对种子进行引发处理,以筛选出适宜的引发试剂和引发浓度.结果表明:在氯离子、磷酸根离子和硝酸根离子化学引发剂中,氯离子盐溶液和硝酸根离子盐溶液引发效果类似,均比磷酸根离子盐溶液的引发效果好.氯离子盐...     

H9亚型禽流感病毒环介导等温扩增检测方法的建立与荧光指示剂的应用

利用反转录环介导等温核酸扩增技术(RT-LAMP),建立了一种特异、灵敏、便捷的H9亚型禽流感病毒(H9subtype of avian influenza virus,H9-AIV)的检测方法。该方法使用了对应于H9亚型禽流感病毒血凝素(hemagglutinin HA)基因的8个不同区域的6条特异引物,在63℃的等温条件下反应,最低可检测到103拷贝的目的基因重组质粒片段,较RT-PCR方法敏感10倍。通过对15种H亚型禽流感病毒、新城疫病毒(Newcastle disease virus,NDV)、传染性支气管炎病毒(Infectious bronchitis virus,IBV)的检测表明,该方法具有良好的特异性。在反应体系中使用钙黄绿素与Mn2+的混合溶液作为荧光指示剂可以用于RT-LAMP结果判定,并且其判断结果与浊度判断结果一致。对109份禽咽喉拭子及泄殖腔拭子临床样品进行检测,RT-LAMP与RT-PCR检出阳性样本数分别为61份和46份,表明RT-LAMP方法阳性检出率高于RT-PCR。