Aplysia sea hare assimilation of secondary metabolites from brown seaweed,Stypopodium zonale

JuvenileAplysia dactylomela were found feeding in abundance on the tropical brown algaStypopodium zonale, a seaweed previously shown to contain numerous unique terpene-quinone natural products. Lipid extracts of these herbivorous mollusks were shown by TLC and HPLC-NMR analyses to contain appreciable quantities of twoS. zonale metabolites as well as one new but closely related compound. Spectroscopic analyses of the new compound in concert with functional group modifications identified this new compound as 3-keto epitaondiol. A careful analysis of the seaweed extract failed to locate this ketone, and thus, it most likely represents anAplysia-biotransformed compound. This is the first clear reported observation of metabolite transfer between an alga of the phylum Phaeophyta and a sea hare.     

Physiological and behavioral effects of coniferyl benzoate on avian reproduction

Various plant secondary metabolites related to cinnamic acid are of interest because of their repellency to birds and their occurrence in ecologically important food items. Coniferyl benzoate (CB), a phenylpropanoid ester that occurs in quaking aspen (Populus tremuloides) is of particular ecological interest because of its effect on ruffed grouse (Bonasa umbellus) feeding behavior and its possible influence on the population dynamics of this bird. During detoxification processes, CB and other analogous compounds are metabolized into by-products, such as ferulic acid (FA), that can cause anti-reproductive effects. We tested whether consumption of CB produces antire-productive effects similar to FA using male and female Japanese quail (Coturnix coturnix) as avian models for ruffed grouse. The parameters we investigated included: the production, morphology, and development of eggs; reproductive characteristics influenced by estrogen; serum prolactin levels; and male reproductive behavior. Dietary CB did not produce antireproductive effects similar to FA at intake levels that Japanese quail and ruffed grouse would freely consume. Consumption of CB by Japanese quail significantly reduced egg production and body mass but did not affect male reproductive performance. Coniferyl benzoate's effect on egg production may be explained by lower energy acquisition and retention rather than endocrine changes per se. Contrary to previous reports, it is unlikely that FA, or similar compounds act directly as estrogen mimics or antagonists. Although, CB did reduce egg production in quail, it is unlikely that it would affect egg production in wild ruffed grouse. Detoxification costs and the effects of CB on nutrient utilization may explain why ruffed grouse avoid high dietary levels of CB.     

电喷雾串联质谱法分析阿托品在大

用液相色谱-电喷雾离子阱串联质谱(LC-ESIIT-MSn)联用法研究阿托品在大鼠肠内菌中的代谢,以阿托品优化色谱及质谱条件,总结其色谱及质谱行为规律。将阿托品与大鼠肠内菌体外厌氧温孵培养,与空白样品及阿托品标准品相比较,根据被测物的多级质谱数据,鉴定代谢物并阐述其结构。在温孵液中发现了阿托品的脱水及水解代谢产物,即脱水阿托品、托品和托品酸。该方法灵敏、快速、简单,适合于药物代谢分析。     

Steam radish sprout (Raphanus sativus L.): active substances,antioxidant activities and non-targeted metabolomics analysis

Various active substances, antioxidant activities and primary differential metabolite profiles were investigated to assess the nutritional quality of radish sprouts steamed for 0–300 s. The levels of flavonoids, total phenolic content and isothiocyanate in radish sprouts decreased with increased steaming time, and DPPH radical scavenging activity levels and superoxide dismutase levels also exhibited a downward trend (P < 0.05). By contrast, total phenolic acid, ferric-reducing antioxidant power and reducing power levels exhibited significant increases in the early short-term steaming process (P < 0.05). Steaming for 30 s promoted the accumulation of vitamin B₂, whereas, steaming for 300 s promoted the accumulation of phospholipids and myristic acid to a greater extent than steaming for 30 s. Overall, there was a partial non-decreased nutritional indicator in short-term steaming of radish sprouts, and a longer steaming time positively affected the differential metabolites.     

Milk metabolome reveals variations on enteric methane emissions from dairy cows fed a specific inhibitor of the methanogenesis pathway

Metabolome profiling in biological fluids is an interesting approach for exploring markers of methane emissions in ruminants. In this study, a multiplatform metabolomics approach was used for investigating changes in milk metabolic profiles related to methanogenesis in dairy cows. For this purpose, 25 primiparous Holstein cows at similar lactation stage were fed the same diet supplemented with (treated, n = 12) or without (control, n = 13) a specific antimethanogenic additive that reduced enteric methane production by 23% with no changes in intake, milk production, and health status. The study lasted 6 wk, with sampling and measures performed in wk 5 and 6. Milk samples were analyzed using 4 complementary analytical methods, including 2 untargeted (nuclear magnetic resonance and liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer) and 2 targeted (liquid chromatography-tandem mass spectrometry and gas chromatography coupled to a flame ionization detector) approaches. After filtration, variable selection and normalization data from each analytical platform were then analyzed using multivariate orthogonal partial least square discriminant analysis. All 4 analytical methods were able to differentiate cows from treated and control groups. Overall, 38 discriminant metabolites were identified, which affected 10 metabolic pathways including methane metabolism. Some of these metabolites such as dimethylsulfoxide, dimethylsulfone, and citramalic acid, detected by nuclear magnetic resonance or liquid chromatography-mass spectrometry methods, originated from the rumen microbiota or had a microbial-host animal co-metabolism that could be associated with methanogenesis. Also, discriminant milk fatty acids detected by targeted gas chromatography were mostly of ruminal microbial origin. Other metabolites and metabolic pathways significantly affected were associated with AA metabolism. These findings provide new insight on the potential role of milk metabolites as indicators of enteric methane modifications in dairy cows.     

豆腐果苷及其代谢产物时辰药动学研究

目的：研究不同时辰给药对豆腐果苷及其代谢产物药代动力学行为的影响。方法：建立并验证豆腐果苷及其3种Ⅰ相代谢产物高效液相色谱-质谱联用同时检测方法。分别在8∶00,14∶00及0∶00灌胃给予大鼠豆腐果苷50 mg/kg,眼底静脉丛采集血样,测得其血药浓度,对比在不同时间给药后原药及代谢产物的药物代谢动力学行为。结果：所建立的高效液相色谱串联质谱检测方法成功应用于灌胃给药后的大鼠血浆豆腐果苷及其3种代谢产物的同时检测。以AUC(0-t)做为吸收程度评价指标,原药、氧化产物、还原产物均为8∶00给药组>0∶00给药组>14∶00给药组;同一时间点原药与代谢产物比较,8∶00给药组、14∶00给药组、0∶00给药组均为：原药>还原产物>氧化产物。Cmax原药0∶00给药组>8∶00给药组>14∶00给药组,还原产物与氧化产物为8∶00给药组>14∶00给药组>0∶00给药组;Tmax原药与还原产物8∶00给药组>14∶00给药组>0∶00给药组,氧化产物8∶00给药组>0∶00给药组>14∶00给药组;以CLz/F为表征的清除情况,原药、还原产物与氧化产物均为14∶00给药组>0∶00给药组>8∶00给药组。 结论：本研究所选择的三个特定时间点,大鼠体内豆腐果苷原药及代谢产物在吸收与代谢过程显示出明显差异。8∶00给药吸收程度要大于其他两个时间点（P<0.01）,14∶00给药原药及代谢产物体内清除快于其他时间点（P<0.01）。     

葡萄籽提取物原花青素对肉兔抗氧化功能、脂质含量及血清代谢产物浓度的影响

研究葡萄籽提取物原花青素(grape seed proanthocyanidin extracts,GSPE)对肉兔抗氧化功能、脂质含量及血清代谢产物浓度的影响。采用单因子随机区组试验设计,选择128只60日龄、体重相近的健康新西兰兔,随机分为4组(1个对照组和3个试验组),每组32个重复,每个重复1只。对照组饲喂基础饲粮,3个试验组分别饲喂在基础饲粮中添加100、200及400 mg/kg GSPE的试验饲粮。试验期为39 d,其中预试期为6 d,正试期为33 d。结果表明:随饲粮中GSPE添加量升高,试验兔背最长肌、肝脏及血清总抗氧化能力、总超氧化物歧化酶与谷胱甘肽过氧化物酶活性均显著(P0.05)或极显著(P0.01)升高,而丙二醛浓度极显著(P0.01)降低;对照组试验兔背最长肌粗脂肪含量极显著(P0.01)高于200 mg/kg组和400 mg/kg组,而肝脏粗脂肪含量、血清三酰甘油与总胆固醇浓度均显著(P0.05)或极显著(P0.01)高于其余3组;对照组试验兔血清葡萄糖与尿素氮浓度均显著(P0.05)或极显著(P0.01)高于其余3组,而尿酸浓度显著(P0.05)或极显著(P0.01)低于200 mg/kg组和400 mg/kg组。研究结果提示:饲粮添加GSPE,可增强肉兔机体抗氧化功能,改善脂质、糖和氮代谢,且作用效果随添加量升高而增强。     

发酵乳─最新研究动向

有关发酵乳的研究,目前主要集中于新产品的开发和健康特性的研究。在对近１０年有关文献研究的基础上,介绍了发酵乳的种类,益生菌,乳酸菌的培养、代谢特性、遗传和生物技术,发酵剂的制作,健康特性研究及乳酸菌的安全性等。     

基于核磁共振代谢组学分析不同品种草莓的化学成分差异

目的采用基于核磁共振(nuclear magnetic resonance,NMR)的代谢组学方法对"丰香""久香""宁玉"和"甜查理"4个不同品种草莓进行指纹图谱比较和化学成分差异分析。方法采用主成分分析法综合评价4个不同品种草莓的整体分布状况;采用正交偏最小二乘判别分析法筛选并鉴别出引起不同草莓品种有所差异的潜在差异代谢物。结果研究发现,苹果酸在"丰香"草莓中含量最低,蔗糖含量则最高;蔗糖在"久香"草莓中的含量最低;丙氨酸、柠檬酸、天冬酰胺、D-葡萄糖和D-果糖在"宁玉"中含量最低;丙氨酸、苹果酸、柠檬酸、天冬氨酸和D-葡萄糖在"甜查理"中含量最高。结论基于NMR的代谢组学技术可以用于草莓品种的鉴别和化学成分的差异分析,并为草莓的品种溯源提供科学数据。     

红曲与核霉素

因红曲中含有桔霉素,将使我国的红曲出口受到很大影响。本文介绍了红曲中桔霉素的产生及合成途径;桔霉素的分子式、结构、物理和化学性质、毒性、抑菌性和检测方法等内容。