二氢异喹啉抗菌物质对植物种子萌发及幼苗生长的影响

【目的】研究2-芳基-6,7-亚甲二氧基-3,4-二氢异喹啉盐类化合物对植物种子发芽和幼苗生长的安全性,为此类化合物作为新型植物抗菌药物的开发应用提供理论依据。【方法】将糜子和油菜种子在14种2-芳基-6,7-亚甲二氧基-3,4-二氢异喹啉盐类化合物(Z-1~Z-14)溶液中浸种20h后,均匀点播于含无离子水的培养皿中,在设定条件下进行培养,测定种子的发芽率、根长、茎长、总鲜质量、总干质量和相对含水量。【结果】在100μg/mL测试质量浓度下,化合物Z-1、Z-3、Z-12、Z-13和Z-14对1种或2种作物的个别生长指标有显著的抑制作用,化合物Z-2、Z-4、Z-9和Z-10能够显著促进糜子根和茎的生长,同时对糜子的发芽率和幼苗的相对含水量没有显著影响;其他供试化合物对糜子和油菜的种子发芽和幼苗生长均无显著影响。【结论】除化合物Z-1、Z-3、Z-12、Z-13和Z-14外,其他供试的化合物在质量浓度≤100μg/mL时,对受试作物的种子萌发和幼苗生长均不会产生不良影响,部分化合物还具有促进作物根茎生长的效果,具备进一步评测后作为作物抗菌剂开发的可能。     

黄芪多糖和氧化苦参碱协同增强鸡新城疫疫苗免疫效果研究

【目的】研究黄芪多糖(Astragalus polysaccharides,APS)和氧化苦参碱(Oxymatrine,OM)对新城疫疫苗免疫的影响。【方法】将14日龄非免疫罗曼蛋公鸡550羽随机均分为11组,1~9组分别为OAP(以OM与APS质量比为6∶4配成)、OM和APS的高(4mg/mL)、中(2mg/mL)、低(1mg/mL)剂量组,10组为免疫对照组,11组为空白对照组。除空白对照组外,各组试验鸡只均于14日龄首免NDV-Ⅳ系疫苗,28日龄重复免疫。在首次免疫的同时,1~9组分别口服高、中、低剂量药物,免疫对照组和空白对照组口服等量生理盐水,每天1次,连续3d。分别于14,21,28,35和42日龄采血,用MTT法测定T淋巴细胞增殖的变化,用β-微量法测定血清抗体效价变化。于14,21,28和35日龄,每组随机抽取鸡4羽,称体质量,剖杀,摘取法氏囊和脾脏并称质量,计算免疫器官指数。【结果】OAP、OM、APS高、中剂量在各时间点均能促进T淋巴细胞增殖;OAP高、中剂量组在各时间点抗体效价显著高于免疫对照组;OAP高、中、低剂量组在各时间点的脾指数和法氏囊指数均显著高于免疫对照组(OAP低剂量组35日龄除外)。【结论】黄芪多糖和氧化苦参碱能协同增强鸡新城疫疫苗的免疫效果。     

Synthesis and cyclization of aromatic polyhydroxyamides containing trifluoromethyl groups

Polyhydroxyamides derivatized with trifluoromethyl ether and trifluoromethyl ester groups were investigated as possible candidates for a new flame retardant polymer. Model compounds for these derivatized polyhydroxyamides were synthesized and their cyclization chemistry was investigated. The model compound study revealed that trifluoromethyl ester group containing model compounds can cyclize on heating, while trifluromethyl ether group containing model compounds cannot. The non-fluorinated ester and ether derivatives behaved similarly. The trifluoromethyl ester derivatized polyhydroxyamides were synthesized according to the procedures for the model compounds. TGA characterization revealed that the fluorinated polymers have nearly same thermal stability as the underivatized PHA after cyclization.     

Biomedical Compounds from Marine organisms

The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.     

Effect of hydrostatic high pressure pretreatment on flavor volatile profile of cooked rice

The impact of high hydrostatic-pressure (HHP) processing on the volatile profile of cooked Japonica rice (Wuchang) and Jasmine rice (Complete Wheel) was investigated by SPME–GC/MS. Presoaked samples were treated at 200, 400 and 600 MPa for 10 min and then cooked for volatile compound analysis. Seventy-seven compounds were identified in two cooked rice varieties: 20 aldehydes, 16 alcohols, 14 ketones, 9 arenes, 7 esters, 5 alkanes, 3 olefins and 3 hetero-cycle compounds. Results showed that both pressure level (P < 0.01) and rice variety (0.01 < P < 0.05) significantly impact the volatile compounds in rice and there is also an interaction between pressure and rice variety (P < 0.01). Overall, HPP decreased the amount of aldehydes more obviously in Complete Wheel rice than that in Wuchang variety. Both 200 and 400 MPa increased the levels of alcohols, ketones, esters and olefins, but reduced those of heterocycles, alkanes and arenes. Similar volatile change trends were found at 600 MPa except the concentration of each component was closer to that of control group. Based on the changes in the three key flavor compounds in rice (aldehydes, alcohols and ketones), the HPP process could be a suitable alternative to traditional pretreatment for improving flavor in cooked rice.     

Storage stability,micronisation, and application of nutrient-dense fraction of proso millet bran in gluten-free bread

This study aimed to valorise the underutilised by-product of proso millet decortication. Millet bran was sieved into three fractions with substantially different nutritional profile. The fraction with diameter <500 μm had the highest nutrient density (14% protein, 26% starch, 36% dietary fibre, 9% fat, and 3 mg GAE/g phenolics (d.w.)) and was analysed for oxidative stability, micronisation effect under cryogenic or ambient conditions (2, 4, 8, 12 min), and baking applicability. The bran was oxidatively stable under refrigerator conditions for 150 days. Micronisation slightly increased the antioxidant activity measured by FRAP and ABTS assays as well as the content of fibre soluble in water and 78% ethanol as the bran particle size decreased from 171 μm to 26–46 μm. Gluten-free bread containing 10% of the nutrient-dense fraction of millet bran had higher dietary fibre (76%) and phenolics content (117%), improved volume and crumb softness, regardless of the bran particle size (diameter of 50th percentile 171 vs. 26 μm).     

Effects of various water or hydrothermal treatments on certain antinutritional compounds in the seeds of the tribal pulse,Dolichos lablab var.vulgaris L.

Effects of soaking, cooking and autoclaving on changes in polyphenols, phytohaemagglutinating activity, phytic acid, hydrogen cyanide (HCN), oligosaccharides and in vitro protein digestibility were investigated in seeds ofDolichos lablab var.vulgaris. Both distilled water and NaHCO₃ solution soaking and autoclaving significantly reduced the contents of total free phenolics (85–88%) compared to raw seeds. Autoclaving (45 min) reduced the content of tannins by upto 72%. Soaking seemed to have limited effect in eliminating phytohaemagglutinating activity, whereas autoclaving (45 min) seemed to eliminate the haemagglutinating activity completely. The reduction in content of phytic acid was found to be some what greater in distilled water soaking (28%) compared to NaHCO₃ solution soaking (22%). Only a limited loss in content of phytic acid was observed under cooking as well as autoclaving. Loss of HCN was greater under autoclaving (87%) compared to the other processes studied. Of the three sugars analysed, soaking reduced the level of verbascose more than that of stachyose and raffinose. Autoclaving reduced the content of oligosaccharides more efficiently (67–86%) than ordinary cooking (53–76%). Autoclaving improved the in vitro protein digestibility (IVPD) significantly (13%). Of all the different water and hydrothermal treatments studied autoclaving seemed to be the most efficient method in improving IVPD and eliminating the antinutrients investigated except phytic acid.     

Compounds from Ageratum conyzoides: isolation, structural elucidation and insecticidal activity

This work aimed at identifying plant compounds with insecticidal activity against Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Musca domestica (L.) (Diptera: Muscidae), Periplaneta americana (L.) (Blattodea: Blattidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetaefolia L.), Jimson weed (Datura stramonium L.), 'baleeira' herb (Cordia verbenaceae L.), mint (Mentha piperita L.), wild balsam apple (Mormodica charantia L.) and billy goat weed (Ageratum conyzoides L.). Firstly, the insecticidal activities of hexane and ethanol plant extracts were evaluated against adults of R. dominica. Among them, only the hexane extract of A. conyzoides showed insecticidal activity. The hexane extract of this plant species was therefore fractionated by silica gel column chromatography to isolate and purify its bioactive chemical constituents. Three compounds were identified using IR spectra, (1)H NMR, (13)C NMR, HMBC and NOE after gel chromatography: 5,6,7,8,3', 4', 5'-heptamethoxyflavone, 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone and coumarin. The complete assignment of (13)C NMR to 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone was successfully made for the first time. 5,6,7,8,3'-Pentamethoxy-4', 5'-methylenedioxyflavone did not show any insecticidal activity against the four insect species tested. 5,6,7,8,3', 4', 5'-Heptamethoxyflavone showed low activity against D. hyalinata and R. dominica and was not toxic to M. domestica or P. americana. In contrast, coumarin showed insecticidal activity against all four insect pest species tested, with the following order of susceptibility: R. dominica < P. americana < D. hyalinata < M. domestica after 24 h exposure.     

辐照对发酵香肠品质特性的影响

本文以0、2、4、6kGy剂量60Co γ射线辐照发酵香肠,以水分活度、水分含量、pH值、含盐量、氨基酸总量、非蛋白氮、总氮、硫代巴比妥酸值、挥发性风味物质、肌浆蛋白与肌原纤维蛋白降解情况为指标,研究辐照对香肠品质的影响。结果表明：发酵香肠经不同剂量辐照后水分含量差异显著(P<0.05),氯化钠含量差异并不显著,而0、2kGy辐照后发酵香肠的pH值显著高于4、6kGy辐照,4kGy剂量辐照的发酵香肠中氨基酸总量显著高于2、6kGy处理的样品(P<0.05),4kGy剂量辐照香肠烯烃、酸和酮类物质含量最多,6kGy辐照组中醇类物质含量最多。辐照处理的发酵香肠中肌浆蛋白和肌原蛋白的降解情况低于对照。     

杭州市主城区道路绿化树种组成与VOCs成分分析

为分析杭州市主城区道路绿化树种叶表面区域的VOCs成分、研究VOCs与城市道路绿化的关系,文章对该地区道路绿化资源进行调查,并采用气相色谱质谱联用仪(GC/MS)对主要绿化树种叶表面区域的VOCs进行测定,结果显示,杭州主城区的主要乔木为香樟、悬铃木、朴树、无患子、栾树、枫杨、雪松、玉兰、银杏,主要灌木为红叶石楠、金森女贞、红花檵木、月季、无刺枸骨、紫薇、紫叶李、桂花、金边黄杨;在这些树种叶表面区域检测到的VOCs可分为卤烃类、芳烃类、醛类、烷烃类、酮类、酯类、烯烃类和其他类;在现有的主要树种中,挥发物质相对较少的是香樟、悬铃木、朴树、金森女贞、红花檵木、无刺枸骨、桂花,挥发物质相对较多的则是雪松、枫杨、紫叶李、金边黄杨等,研究结果对城市道路绿化植物的筛选具有重要指导意义。