The comparative study digestion and metabolism of nitrogen and purine derivatives in male, Thai, Swamp buffalo and Thai, Brahman cattle

Studies on in vivo digestion, rates of passages, metabolism of nitrogen, urinary purine derivative excretion and blood metabolites were carried out in Thai Brahman cattle and Thai swamp buffaloes (16 months old). The animals were fed mixed diets based on pineapple (Ananas comusus) waste silage containing urea‐N (NPN) and true protein from a concentrate (TP). The Brahman cattle (310 ± 15 kg) were heavier than the swamp buffaloes (195 ± 9.4 kg) and had higher dry matter (DM), organic matter (OM) and neutral detergent fiber (NDF) intakes when compared on the basis of their metabolic body weight (BW^0.75), but these intakes did not differ significantly when the diets of each animal species were compared. The total tract, apparent digestibilities of dry matter (DM) and organic matter (OM) were not significantly different between the animal species when comparing the two types of diets. The NDF digestibility was significantly (P < 0.01) decreased in both animal species when fed the TP diet, but was significantly (P < 0.01) greater in cattle than in swamp buffaloes. The passage rate digesta k₁ (P < 0.01) and the passage rate digesta k₂ (through the caecum and proximal colon) (P < 0.03) were significantly slower, and the total mean retention time (TMRT) (P < 0.01) was significantly longer in swamp buffaloes when compared to Brahman cattle, but the transit time (TT) showed no difference (P = 0.07) between the animal species or the diets. The N intakes were not different in both animal species and diets, but urine‐N was greater (P < 0.05) in Brahman cattle than that in swamp buffaloes. Urine N and digestibility of N were significantly (P < 0.04) higher in animals fed the NPN diet than those fed the TP diet. Urinary purine derivatives (PD) and the creatinine (Cr) excretion of swamp buffaloes were significantly (P < 0.01) lower than those in Brahman cattle. Plasma urea‐N (BUN) concentration was significantly (P < 0.01) higher in swamp buffaloes than that in Brahman cattle, but plasma glucose and insulin concentrations were significantly (P < 0.01) higher in Brahman cattle than in swamp buffaloes. The concentrations of non‐esterified fatty acids (NEFA) were not significantly (P > 0.05) different in animals fed different diets. The present study demonstrated that Brahman cattle were better in fiber digestibility than swamp buffaloes at utilizing pineapple waste silage with both N sources.     

恩诺沙星在凡纳滨对虾体内和体外肝微粒体中的代谢产物比较分析

采用超高效液相色谱-四级杆-飞行时间质谱(UPLC/Q-TOF MS)对恩诺沙星在凡纳滨对虾(Litopenaeus vannamei)体内和体外肝胰腺微粒体孵育下的代谢产物进行定性分析。体内试验为凡纳滨对虾口灌30 mg.kg-1恩诺沙星,24 h后采集血浆用于代谢产物分析。体外试验为在含有肝微粒体的NADPH体系中加入恩诺沙星(100μM)进行孵育,检测孵育液中的代谢产物;肝胰腺采集自未给药的凡纳滨对虾,超速离心法制备而得。凡纳滨对虾血淋巴中除以恩诺沙星原形药物为主外,还可检测到少量的N-去乙基代谢产物环丙沙星、环丙沙星哌嗪环开环代谢物及其同分异构体;而在肝胰腺微粒体体外孵育体系中除检测到原形药物外,只有少量的N-去乙基代谢物环丙沙星。无论是体内还是体外,代谢产物生成量都很少,但环丙沙星是主要代谢产物。推测恩诺沙星在凡纳滨对虾体内的代谢反应主要是脱乙基反应和加氢还原反应,而在体外肝胰腺微粒体恩诺沙星代谢的反应主要是脱乙基反应。     

UPLC-MS/MS法测定肠衣中四种硝基呋喃类代谢物残留量

采用超高效液相色谱-串联四极杆质谱,电喷雾电离(正离子模式),对肠衣中四种硝基呋喃类代谢物残留量进行定性定量。试样用甲醇、水脱脂去除部分杂质后,经Oasis HLB固相萃取小柱富集净化后,经Waters ACQUITY UPLCTMBEHC18色谱柱分离,以0.3%乙酸乙腈溶液和0.3%乙酸水溶液为流动相,梯度洗脱。在多反应监测模式下以保留时间和离子对(母离子和两个子离子)信息比较进行定性,以响应值高的子离子进行定量。该法的检出限为0.2~0.5μg/kg,加标回收率为86%~97%,相对标准偏差小于10%。     

红树内生菌代谢产物抑菌作用的初步观察

观察红树内生菌CⅢ-1代谢产物对金黄色葡萄球菌、表面葡萄球菌、大肠杆菌以及沙门氏菌等常见动物病原菌的抑菌效果。结果表明,CⅢ-1代谢产物对金黄色葡萄球菌、埃希氏大肠杆菌有较强的抑制作用,且抑菌活性随代谢产物浓度的增加而增加;金黄色葡萄球菌、表面葡萄球菌和埃希氏大肠杆菌对8倍浓缩的CⅢ-1代谢产物高度敏感,但沙门氏菌呈中度敏感。CⅢ-1浓缩样品与几种常用抗生素的抑菌效果相当。     

植物次生代谢产物对瘤胃发酵调控的研究进展

瘤胃发酵调控在反刍动物营养与饲料产品研究中占有重要地位.近年来大量研究证实,植物提取物中含有生物碱、皂苷、萜类、挥发精油等多种生物活性成分,具有抗菌、促生长、提高免疫力和抗氧化等功能,同时具有调控反刍动物瘤胃发酵模式,提高氮存留,减少甲烷排放的功能.因此,植物次生代谢产物作为反刍动物饲料添加剂研究和应用将成为研究的热点,对发展反刍动物绿色营养技术、提高饲料利用效率和保护环境起到积极作用.本文针对目前应用于反刍动物饲料添加剂的植物次生代谢产物的来源、种类、组成特性和应用做了综述,以期对今后我国该领域的研究和产品开发提供参考价值.     

氮磷钾对桔梗生长及次生代谢产物的影响

通过田间试验,采用氮、磷、钾三因素二次D 饱和最优设计研究了氮、磷、钾肥及其配比施肥对桔梗（Platycodon grandiflorum）生长及次生代谢产物的影响。试验结果表明,施肥能显著提高桔梗药材产量,氮、磷、钾元素对桔梗药材产量影响依次为氮>钾>磷。氮、磷、钾元素对桔梗总皂苷含量影响依次为氮>钾>磷,对桔梗植株多糖含量影响依次为磷>氮>钾;氮、磷对黄酮积累表现出一定负效应。依据桔梗药材产量及总皂苷含量提出桔梗合理施肥方案为N 150 kg·hm-2、P2O5 79.41 kg·hm-2、K2O 225 kg·hm-2。     

出芽短梗霉菌PA-2侵染对藜叶片代谢的影响

为探明出芽短梗霉菌Aureobasidium pullulans PA-2侵染对藜Chenopodium album叶片代谢影响,采用基于液相色谱-质谱联用技术(LC-MS)的代谢组学方法,对出芽短梗霉菌PA-2侵染藜叶片差异代谢产物进行分析.结果 表明,通过正交偏最小二乘法判别分析(OPLS-DA),PA-2孢子处理...     

Exploring the Mangrove Fruit: From the Phytochemicals to Functional Food Development and the Current Progress in the Middle East

Nowadays, the logarithmic production of existing well-known food materials is unable to keep up with the demand caused by the exponential growth of the human population in terms of the equality of access to food materials. Famous local food materials with treasury properties such as mangrove fruits are an excellent source to be listed as emerging food candidates with ethnomedicinal properties. Thus, this study reviews the nutrition content of several edible mangrove fruits and the innovation to improve the fruit into a highly economic food product. Within the mangrove fruit, the levels of primary metabolites such as carbohydrates, protein, and fat are acceptable for daily intake. The mangrove fruits, seeds, and endophytic fungi are rich in phenolic compounds, limonoids, and their derivatives as the compounds present a multitude of bioactivities such as antimicrobial, anticancer, and antioxidant. In the intermediary process, the flour of mangrove fruit stands as a supplementation for the existing flour with antidiabetic or antioxidant properties. The mangrove fruit is successfully transformed into many processed food products. However, limited fruits from species such as Bruguiera gymnorrhiza, Rhizophora mucronata, Sonneratia caseolaris, and Avicennia marina are commonly upgraded into traditional food, though many more species demonstrate ethnomedicinal properties. In the Middle East, A. marina is the dominant species, and the study of the phytochemicals and fruit development is limited. Therefore, studies on the development of mangrove fruits to functional for other mangrove species are demanding. The locally accepted mangrove fruit is coveted as an alternate food material to support the sustainable development goal of eliminating world hunger in sustainable ways.     

茶树对氮肥的吸收利用及氮肥对茶树代谢产物合成影响的研究进展

氮元素是茶树重要的矿质养分,是茶树正常生长发育和生理活动所必需的营养元素.茶树对氮肥的利用率不仅与茶树生长和生理特性有着密切的关系,还会影响茶叶的产量和品质.文章综述不同茶树品种对氮肥的吸收利用情况和氮肥对茶树代谢产物合成的影响,探讨氮元素对茶树生长和生理活动的影响及其与茶叶品质的关系,以期为进一步研究开发利用茶树氮肥...     

Targeted Large-Scale Genome Mining and Candidate Prioritization for Natural Product Discovery

Large-scale genome-mining analyses have identified an enormous number of cryptic biosynthetic gene clusters (BGCs) as a great source of novel bioactive natural products. Given the sheer number of natural product (NP) candidates, effective strategies and computational methods are keys to choosing appropriate BGCs for further NP characterization and production. This review discusses genomics-based approaches for prioritizing candidate BGCs extracted from large-scale genomic data, by highlighting studies that have successfully produced compounds with high chemical novelty, novel biosynthesis pathway, and potent bioactivities. We group these studies based on their BGC-prioritization logics: detecting presence of resistance genes, use of phylogenomics analysis as a guide, and targeting for specific chemical structures. We also briefly comment on the different bioinformatics tools used in the field and examine practical considerations when employing a large-scale genome mining study.