响应面优化超声辅助提取黄瓜皮多酚工艺及其抗氧化活性研究

应用响应面法对超声波辅助提取黄瓜皮多酚的工艺进行优化,并对多酚的抗氧化活性进行了研究。以多酚提取率为响应值,选取超声温度、乙醇浓度、液料比、超声时间为自变量,应用Box-Behnken对试验进行设计和响应面优化,并通过多酚对羟自由基(·OH)和1,1-二苯基-2-三硝基苯肼自由基(DPPH·)的清除效果来评价其抗氧化活性。结果表明,黄瓜皮多酚的最佳提取工艺为:超声温度65℃,乙醇浓度62%,液料比26∶1(mL/g),超声时间31 min。在此条件下,测得多酚提取率实际值为(10.29±0.14)mg/g,理论值和实际值相对误差是0.39%,由此可以说明应用响应面法所得到的提取工艺参数可行性强、可靠性高。黄瓜皮多酚对·OH和DPPH·清除率的IC50值分别为116.60 mg/L和57.41 mg/L,表明黄瓜皮多酚具有较好的抗氧化活性,且抗氧化活性与多酚浓度呈正相关,该研究为将黄瓜皮多酚开发成天然抗氧剂提供理论基础。     

铁观音与荆芥提取物协同抗氧化作用研究

为研究铁观音提取物和荆芥提取物联用在抗氧化方面的协同作用,采用水浸提法分别萃取铁观音和荆芥得其抗氧化活性成分。以芦丁为标准品检测两种提取物类黄酮含量,其中铁观音提取物为15.13 mg/g,荆芥提取物为0.87 mg/g;以没食子酸为标准品检测两种提取物的总酚含量,其中铁观音水提物为50.87μg/mg,荆芥水提物为47.40μg/mg。用2,2-二苯基-1-苦基肼(DPPH)和2,2'-二氮-双(3-乙基苯并噻唑-6-磺酸)(ABTS)法评估两种提取物联合应用时的抗氧化活性,结果表明,在较低浓度时,铁观音与荆芥提取物联用具有协同增强抗氧化作用。     

桉树生长与土壤因子间的回归分析

应用相关分析和逐步回归分析法对闽南山地桉树生长与土壤因子间的关系进行研究,结果表明:闽南山地尾巨桉DH32-29与土壤中大部分因子存在显著或极显著的相关关系,其逐步回归方程为:Y=11.811 0.033X1-4.0317X3-0.144X4 1.080X6 0.636X8。经检验回归方程的F值为10.730,相关系数R为0.90400,均达到极显著水平,在显著性水平a=0.05的条件下,估计精度达89.67%。说明所拟合的回归方程精度较高,可靠性较强;筛选出影响按树生长的土壤主导因子有有机质、有效磷和土壤密度,这与现实生产实际相吻合。     

我国常见药用植物病毒病的危害与防控

药用植物种植是我国中医药事业传承和快速发展的必要物质基础。近年来,随着规模化种植模式的推广,我国药用植物种植面积不断扩大,经济效益稳步提升。然而,药用植物病毒病的危害也日益凸显,严重降低了药用植物的产量和品质,对中医药临床疗效造成不利影响。本文对我国多种常见药用植物上已报道的病毒病的致病病原、典型症状、发生流行危害以及防控策略做了介绍和归纳总结。     

Biotransformation on the flavonolignan constituents of Silybi Fructus by an intestinal bacterial strain Eubacterium limosum ZL-II

Eubacterium limosum ZL-II is an anaerobic bacterium with demethylated activity, which was isolated from human intestinal bacteria in our previous work. In this study, the flavonolignan constituents of Silybi Fructus were biotransformed by E. limosum¹ ZL-II, producing four new transformation products — demethylisosilybin B (T1), demethylisosilybin A (T2), demethylsilybin B (T3) and demethylsilybin A (T4), among which T1 and T2 were new compounds. Their chemical structures were identified by ESI-TOF/MS, ¹H NMR, ¹³C NMR, HMBC and CD spectroscopic data. The bioassay results showed that the transformation products T1–T4 exhibited significant inhibitory activities on Alzheimer's amyloid-β 42 (Aβ₄₂²) aggregation with IC₅₀ values at 7.49 μM–10.46 μM, which were comparable with that of the positive control (epigallocatechin gallate, EGCG³, at 9.01 μM) and much lower than those of their parent compounds (at not less than 145.10 μM). The method of biotransformation by E. limosum ZL-II explored a way to develop the new and active lead compounds in Alzheimer's disease from Silybi Fructus. However, the transformation products T1–T4 exhibited decreased inhibitory activities against human tumor cell lines comparing with their parent compounds.     

富硒酵母对大鼠生产性能、脏器指数以及血常规指标的影响

将40只SD大鼠随机均分为4组(雌雄各半):对照组、低剂量组、中剂量组和高剂量组.对照组饲喂基础日粮,低剂量组、中剂量组和高剂最组分别饲喂含0.036%、0.144%和0.288%富硒酵母的日粮,持续28 d.在试验过程中,记录大鼠的增重和采食量,计算食物利用率.试验结束时,记录大鼠心脏、脾脏、肝脏、肾脏、睾丸、卵巢重量并计算脏器指数,试验结束时采取血液样本进行血常规指标测定.结果表明,高、中、低剂量组大鼠的食物利用率、心脏、脾脏、睾丸、卵巢指数以及血液常规指标与对照组相比均无显著差异(P>0.05);高剂鼍组大鼠的增重和采食量显著低于对照组(P<0.05),高剂量组大鼠的肾脏指数和肝脏指数显著高于对照组(P<0.05).低、中剂量富硒酵母日粮对大鼠的增重、采食量、肾脏、肝脏指数无明显影响;高剂量富硒酵母日粮对大鼠的增重、采食量、肾脏、肝脏指数有明显影响.     

Anti-Food Allergic Compounds from Penicillium griseofulvum MCCC 3A00225, a Deep-Sea-Derived Fungus

Ten new (1–10) and 26 known (11–36) compounds were isolated from Penicillium griseofulvum MCCC 3A00225, a deep sea-derived fungus. The structures of the new compounds were determined by detailed analysis of the NMR and HRESIMS spectroscopic data. The absolute configurations were established by X-ray crystallography, Marfey’s method, and the ICD method. All isolates were tested for in vitro anti-food allergic bioactivities in immunoglobulin (Ig) E-mediated rat basophilic leukemia (RBL)-2H3 cells. Compound 13 significantly decreased the degranulation release with an IC₅₀ value of 60.3 μM, compared to that of 91.6 μM of the positive control, loratadine.     

2ZLF-2甘薯裸苗复式移栽机设计与试验

为提高甘薯移栽水平,解决现有移栽机结构单一、缺少浇水部件的难题,研制了一款集精细化旋耕整地、起垄、移栽及浇水等功能为一体的甘薯裸苗复式移栽机。介绍了甘薯裸苗复式移栽机的基本结构、工作原理和相关参数等。田间试验结果表明,该机栽植频率为每行每人40株,漏栽率1.51%,栽植深度合格率93.1%,栽植株距合格率92.4%,均符合国家标准要求。     

重视生物安全，做好楼房养猪的病死猪无害化处理与利用

猪场的病死猪处理不当,极易引起疫病扩散、威胁食品安全及公共卫生安全。文章分析了楼房养猪背景下病死猪无害化处理的必要性,提供更高效环保的解决方案,为病死猪无害化处理和资源化利用找到新的途径。     

一例猪淋巴肉瘤的病理学诊断

通过尸体剖检和病理组织学对1例病猪进行了病理学诊断。大体剖检以两肾高度肿大,全身各部位的淋巴结显著肿大为主要特征,病理组织学观察,可见器官组织的正常结构破坏、消失,被大量分化不成熟的淋巴瘤细胞所替代。病理学诊断该病猪患淋巴肉瘤。