薄壳山核桃酚类代谢物研究进展

薄壳山核桃(Caryaillinoensis)富含酚类代谢物,具有显著的抗氧化活性。近年来,我国薄壳山核桃产业快速发展,种植面积迅速扩大。明确薄壳山核桃中的酚类代谢物组成及保健功效对于促进健康产业发展具有重要意义。迄今为止,从薄壳山核桃中已检测出酚类代谢物67个,其中包括单宁36个、类黄酮22个、酚酸9个,水解后检测出酚类代谢物苷元34个。该文主要对薄壳山核桃酚类代谢物的组成、提取方法、含量、药理活性及与采后贮藏特性的关系进行综述,以期为今后深入研究薄壳山核桃酚类代谢物与其生理活性的关系及挖掘薄壳山核桃酚类代谢物的保健价值提供依据。     

薄壳山核桃根系水浸提液对2种作物种子萌发及幼苗生长的影响

为探讨薄壳山核桃根系水浸提液对小麦、大豆的影响,采用蒸馏水浸提法收集薄壳山核桃根系化感物质,并运用室内生物测定法检测不同浓度(0.025、0.05和0.1 g·mL~(-1))根系水浸提液对小麦、大豆种子萌发和幼苗生长的影响。结果表明:各浓度处理的根系水浸提液对小麦、大豆萌发及幼苗生长的化感抑制作用较为显著,且具有显著的浓度效应(浓度低抑制作用弱,浓度高抑制作用强);薄壳山核桃根系水浸提液对小麦、大豆种子发芽率、发芽指数、发芽势和活力指数的抑制作用分别依次为:活力指数发芽势发芽指数发芽率和活力指数发芽势发芽率发芽指数;薄壳山核桃根系水浸提液各浓度处理对小麦、大豆幼苗根长、苗高、鲜质量和干质量的化感效应均为:根长苗高鲜质量干质量,其中薄壳山核桃根系水浸提液对2种受体植物幼苗根长均有显著的抑制作用,而对幼苗干、鲜质量的影响则因受体植物种类的不同而不同;薄壳山核桃根系水浸提液对2种受体植物的综合化感效应顺序为:小麦大豆;生长7 d的幼苗体内,SOD活性降低,MDA含量、POD活性和CAT活性与对照相比均随浓度的增加而增加。综合分析认为:小麦对薄壳山核桃根系水浸提液更为敏感。     

利用SSR构建薄壳山核桃主要品种的分子身份证北大核心CSCD

薄壳山核桃是著名的干果和木本油料树种,当前存在“同名异物、同物异名”现象影响产业发展。本研究在薄壳山核桃基因组中筛选到80个简单重复序列(SSR),利用8个品种的基因组DNA,对80对SSR引物进行筛选,初筛到23对目标条带清晰、检测结果稳定的引物,发现它们分布于13条染色体上。进一步在Pawnee、Mahan、Stuart等36个常用品种中开展基因分型,共检测到70个等位位点;其中18对引物具有遗传多态性,检测到的等位基因数介于2~8,多态性信息含量(PIC)介于0.03~0.72。聚类分析发现,各个样本按照遗传背景聚类,不同品种之间遗传距离介于0.026~0.636,同一品种的不同来源个体之间遗传距离介于0~0.0127。按PIC值从大到小的顺序,依次增加引物的数量,直至能够区分每个品种,发现最少可使用Ciz91、Ciz85、Ciz81、Ciz140和Ciz107等5个标记实现所有品种的有效区分,进而将这组引物确定为核心引物组。最后,使用核心引物组分别构建每个品种特异的分子指纹图谱、分子身份证条形码和二维码。本研究结果为薄壳山核桃品种鉴别、种苗纯度检测、品种追溯等提供了理论基础。     

薄壳山核桃花粉离体萌发和花粉管生长特性研究

以6年生薄壳山核桃优良品种‘金华’的新鲜花粉为试材,采用离体培养法,研究了不同复水时间、不同培养基组分、不同培养温度及培养时间对薄壳山核桃花粉萌发和花粉管生长的影响。结果显示:(1)薄壳山核桃花粉萌发试验前进行4h复水处理可显著提高萌发率,萌发率可达51.78%,为对照(2.51%)的20.68倍。(2)蔗糖、H3BO3、Ca(NO3)2·4H2O在一定浓度范围内均具有促进花粉萌发和花粉管生长的作用,但浓度过高则起抑制作用。(3)正交试验结果经实验验证表明,薄壳山核桃花粉萌发和花粉管生长的最适培养基为20%蔗糖+0.02%~0.03%H3BO3+0.05%Ca(NO3)2·4H2O,最佳培养条件为25℃下恒温培养24h,此时的花粉萌发率高达74.46%,花粉管平均长度为258.84μm。     

植物生长调节剂对薄壳山核桃品种‘波尼’枝条生长和叶片碳氮代谢物积累的影响

以5年生薄壳山核桃品种‘波尼’(Carya illinoinensis‘Pawnee’)幼树为实验材料,根据L_9(3~3)正交试验设计进行3因子(包括植物生长调节剂的种类、质量浓度和喷施次数)3水平(植物生长调节剂分别为GA_3、PP_(333)和6-BA,植物生长调节剂质量浓度分别为100、200和300 mg·L~(-1),植物生长调节剂喷施次数分别为1、2和3)叶面喷施实验,研究不同处理对薄壳山核桃品种‘波尼’枝条生长和叶片碳氮代谢物积累的影响。结果表明:GA_3处理组薄壳山核桃品种‘波尼’枝条长度较CK(对照,蒸馏水喷施3次)组显著增加,其中,T2(200 mg·L~(-1)GA_3喷施2次)处理组的枝条长度最大,较CK组增加了35.7%;PP_(333)处理组的枝条粗度总体上较CK组显著增加,其中,T5(200mg·L~(-1)PP_(333)喷施1次)处理组的枝条粗度最大,较CK组增加了23.8%。处理后30~90 d,所有处理组薄壳山核桃品种‘波尼’枝条叶片中可溶性糖含量均呈逐渐升高的变化趋势,而叶片中淀粉和可溶性蛋白质含量以及C/N比总体上呈先升高后降低的变化趋势。PP_(333)和6-BA处理组叶片中可溶性糖、淀粉和可溶性蛋白质含量以及C/N比总体上显著高于CK组,其中,T5和T6(300 mg·L~(-1)PP_(333)喷施2次)处理组对叶片中可溶性糖和淀粉含量以及C/N比的促进效果较佳,而T4(100 mg·L~(-1)PP_(333)喷施3次)和T8(200 mg·L~(-1)6-BA喷施3次)处理组对叶片中可溶性蛋白质含量的促进效果较佳。极差分析结果表明:植物生长调节剂种类对薄壳山核桃品种‘波尼’枝条长度、叶片中可溶性糖和淀粉含量以及叶片C/N比的影响最大,植物生长调节剂喷施次数对枝条粗度和叶片中可溶性蛋白质含量的影响最大。研究结果显示:叶面喷施200 mg·L~(-1)GA_3对薄壳山核桃品种‘波尼’枝条伸长的促进效果最佳,喷施200 mg·L~(-1)PP_(333)对枝条增粗及叶片碳氮代谢物积累的促进效果最佳。     

激素浸种对薄壳山核桃种子萌发的影响及其种子吸胀过程中SOD和POD活性变化

薄壳山核桃﹝Carya illinoinensis ( Wangenh.) K. Koch﹞为胡桃科( Juglandaceae)山核桃属( Carya Nutt.)植物,又名美国山核桃、长山核桃,是世界上著名的经济树种之一[1-2]。目前,主要采用本砧嫁接的方法培育薄壳山核桃良种嫁接苗,而培育优质实生苗作为砧木是该技术的关键环节之一,因此,了解其种子萌发特性极为重要。目前,对薄壳山核桃种子萌发特性的研究主要集中在植物激素催芽方面[3-5],而有关激素催芽过程中的适宜浸泡天数、种子吸胀过程中相关的酶活性变化等问题尚不明确。     

莲属植物类黄酮代谢产物的研究进展

莲属(Nelumbo)植物既可药用也可食用, 其中荷叶、藕节、莲子、莲子心、莲房和莲须等皆可入药, 但药效各不相同。迄今为止, 从莲的各组织中共检测出类黄酮多达61个, 包括8个花青素苷、2个黄酮醇、29个黄酮醇苷、1个黄酮、16个黄酮苷(内含13个碳苷黄酮)和5个黄烷醇。该文对莲各组织中所含类黄酮的检测方法、组成、含量及药理等方面的研究进展进行了综述。迄今的研究结果表明, 莲中含有丰富的类黄酮化合物, 且具广泛的药理活性(如抗氧化、抗菌、抗HIV、抗动脉粥样化、提高免疫力和减肥降脂等)。这些资料不仅对今后深入研究莲各部位的类黄酮代谢物及其与药效的关系有重要意义, 而且对保健食品和中药的研发也具有重要的参考价值。     

基于广泛靶向代谢组学的竹黄活性成分分析

竹黄是我国一种重要的药用真菌,在医学、农业、食品等方面应用广泛且前景可观。为深入挖掘竹黄中有药理活性的有效化学成分,了解其在生长发育过程中不同时期代谢物的变化规律,利用广泛靶向代谢组学技术检测了竹黄子座不同发育时期的代谢物,找出差异代谢物并进行代谢通路分析。从竹黄子座中共检测出612种代谢物,前期和中期特有27种代谢物。黄酮类、奎宁酸、香豆素等具有良好生物活性的化合物首次在竹黄中被检测到。筛选出的差异代谢物主要是脂质、氨基酸、核苷酸、黄酮类、萜类、有机酸等物质,其中黄酮和氨基酸类化合物占主要地位。通过对代谢通路富集分析,获得6条具有显著意义的代谢途径。黄酮类化合物被认为是除竹红菌素外与竹黄药效有重要联系的化合物。本研究为竹黄药用机理及有效成分深入研究提供了一定的理论基础,为竹黄有效成分的代谢途径解析提供参考。     

不同生长阶段欧李叶片酚类物质含量及其抗氧化性

以4年生‘蒙原’欧李为试验材料,对不同生长阶段欧李叶片中多酚类物质(总酚、总黄酮、原花青素、花青素、黄酮醇)含量及其抗氧化活性(总抗氧化活性、铁离子还原力、DPPH·清除率、·OH清除率)进行了比较分析,为欧李叶片的进一步研究和开发利用提供理论依据。结果表明：(1)欧李叶片各酚类物质含量随着生长期均表现为先增加后降低的变化规律,并均于果实着色膨大期达到最大。(2)各酚类物质的抗氧化活性均表现出与各酚类物质类似的变化规律,除个别有差异外,基本也均于果实着色膨大期达到最高。(3)在果实着色膨大期,欧李叶片各酚类物质含量及其抗氧化活性均表现为总酚最高,总黄酮和原花青素次之,黄酮醇和花青素最低。研究发现,欧李叶片各酚类物质含量与其抗氧化活性存在着明显的协同变化关系,抗氧化活性随着各酚类物质含量的增加或降低而升高或降低;除原花青素和花青素外,着色膨大期是欧李叶片酚类物质含量积累高峰期,同时也是总抗氧化力最高的时期。     

慢性疲劳综合征中学生运动前后尿液差异代谢物的比较

目的：探讨慢性疲劳综合征（CFS）中学生运动前后尿液的差异代谢物及其代谢通路特征,阐述慢性疲劳综合征的代谢机制。方法：依据美国疾病预防控制中心关于CFS的筛选标准,选取8名17~19岁男性CFS中学生作为受试对象,同时选择来自同一学校的8名同龄、同性别健康中学生作为对照组。受试者进行一次改良的哈佛台阶运动（上下台阶30次/min,持续3 min）,采集运动前后的尿液,以液相-质谱联用（LC-MS）法检测其差异代谢物;采用多维统计法对所检测到的代谢物进行主成分分析（PAC）和正交偏最小二乘判别分析（OPLS-DA）;通过MetPA数据库分析与差异代谢物相关的代谢通路。结果：与对照组相比较,运动前CFS组筛选出肌酸、吲哚乙醛、植物鞘氨醇和焦谷氨酸4个差异代谢物,其含量均显著下降（P<0.05或P<0.01）;运动后CFS组检测出11个差异代谢物,依次是壬二酸、甲基腺苷、乙酰肉碱、癸酸、皮质酮、肌酸、左炔诺孕酮、泛酸、焦谷氨酸、黄嘌呤核苷和黄尿酸,其中除甲基腺苷和肌酸比对照组显著升高（P<0.05）外,其他9个差异代谢物均较对照组显著降低（P<0.05或P<0.01）。将上述15个差异代谢物分别输入MetPA数据库进行代谢通路权重得分分析,结果显示,运动前CFS组只检测出精氨酸-脯氨酸代谢通路紊乱,标记代谢物为肌酸;而运动后检测出精氨酸-脯氨酸代谢、泛酸与辅酶A生物合成、类固醇激素生物合成3条代谢通路存在障碍,标记代谢物依次是：肌酸、泛酸和皮质酮。结论：运动干预前,CFS中学生的精氨酸-脯氨酸代谢通路紊乱被检出;施加运动后,又检测出其类固醇激素生物合成代谢通路与泛酸和辅酶A代谢通路也存在代谢紊乱情况。     

Microbial metabolism of dietary phenolic compounds in the colon

Plant foods contain substantial amounts of phenolic compounds. Dietary interventions with phenolic supplementation show that phenolic compounds are transformed into phenolic acids or lactone structures by intestinal microbiota. The colon is the main site of microbial fermentation. The metabolites circulate in plasma and are excreted via urine. The entero-hepatic circulation ensures that their residence time in plasma is extended compared to that of their parent compounds. Thus these metabolites may exert systemic effects, which however have not been studied adequately. In particular the health implications of microbial metabolites of flavonoids, mostly phenolic acids, are unknown. This review aims to elucidate the microbial metabolism of most of the phenolic classes: flavonoids, isoflavonoids, lignans, phenolic acids and tannins. Some examples of biological activity studies of flavonoid and lignan metabolites are given. Biological significance of enterolactone, a mammalian plant lignan metabolite, has been studied quite extensively, but convincing evidence of the health benefits of the diverse pool of microbial metabolites is still scarce. Hopefully, novel tools in systems biology and the constant search for biomarkers will elucidate the role of the phenolic metabolome in health and in the prevention of chronic diseases. In conclusion, the colon is not only an excretion route, but also an active site of metabolism and deserves further attention from the scientific community.     

Chemical composition and nutritional function of olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.): a review

The olive (Olea europaea L.) is a widely-distributed plant that originated in the Mediterranean region. Its fruit is commonly used to produce olive oil, table olives, and other by-products. The main nutrient of the olive fruit is fat, predominantly monounsaturated fatty acids (MUFA). Olives are also rich in carbohydrates, vitamins, and minerals. Increasing numbers of investigations show that the health benefits of the ‘Mediterranean diet’ are associated with lower incidences of chronic degenerative diseases and higher life expectancy. These benefits have been attributed to the dietary consumption of olive oil. Furthermore, epidemiological data suggest that phenolic components and other antioxidants in olive oil are responsible for some of these benefits. Remarkably, these minor components play significant roles in reducing the incidences of atherosclerosis, cardiovascular disease, neurodegenerative diseases, and certain types of cancer. We reviewed the main olive products and the nutritional composition of olive oil focusing on fatty acids, phenolic compounds, and other antioxidants. We also discuss the chief chemical constituents relevant to the biological activity of olive oil, the metabolism and bioavailability of olive oil phenolic compounds, and the antioxidant activity of metabolites. Finally, we outline recent advances, potential applications, and limitations of developments in the olive oil industry, aiming to provide a theoretical basis for further research and to broaden the prospect of its application to healthy diets.     

Benefits of polyphenols on gut microbiota and implications in human health

The biological properties of dietary polyphenols are greatly dependent on their bioavailability that, in turn, is largely influenced by their degree of polymerization. The gut microbiota play a key role in modulating the production, bioavailability and, thus, the biological activities of phenolic metabolites, particularly after the intake of food containing high-molecular-weight polyphenols. In addition, evidence is emerging on the activity of dietary polyphenols on the modulation of the colonic microbial population composition or activity. However, although the great range of health-promoting activities of dietary polyphenols has been widely investigated, their effect on the modulation of the gut ecology and the two-way relationship “polyphenols ? microbiota” are still poorly understood.Only a few studies have examined the impact of dietary polyphenols on the human gut microbiota, and most were focused on single polyphenol molecules and selected bacterial populations. This review focuses on the reciprocal interactions between the gut microbiota and polyphenols, the mechanisms of action and the consequences of these interactions on human health.     

Identification of Antioxidant Capacity -Related QTLs in Brassica oleracea

Brassica vegetables possess high levels of antioxidant metabolites associated with beneficial health effects including vitamins, carotenoids, anthocyanins, soluble sugars and phenolics. Until now, no reports have been documented on the genetic basis of the antioxidant activity (AA) in Brassicas and the content of metabolites with AA like phenolics, anthocyanins and carotenoids. For this reason, this study aimed to: (1) study the relationship among different electron transfer (ET) methods for measuring AA, (2) study the relationship between these methods and phenolic, carotenoid and anthocyanin content, and (3) find QTLs of AA measured with ET assays and for phenolic, carotenoid and anthocyanin contents in leaves and flower buds in a DH population of B. oleracea as an early step in order to identify genes related to these traits. Low correlation coefficients among different methods for measuring AA suggest that it is necessary to employ more than one method at the same time. A total of 19 QTLs were detected for all traits. For AA methods, seven QTLs were found in leaves and six QTLs were found in flower buds. Meanwhile, for the content of metabolites with AA, two QTLs were found in leaves and four QTLs were found in flower buds. AA of the mapping population is related to phenolic compounds but also to carotenoid content. Three genomic regions determined variation for more than one ET method measuring AA. After the syntenic analysis with A. thaliana, several candidate genes related to phenylpropanoid biosynthesis are proposed for the QTLs found.     

Regulation, evolution, and functionality of flavonoids in cereal crops

Flavonoids are plant secondary metabolites that contribute to the adaptation of plants to environmental stresses, including resistance to abiotic and biotic stress. Flavonoids are also beneficial for human health and depress the progression of some chronic diseases. The biosynthesis of flavonoids, which belong to a large family of phenolic compounds, is a complex metabolic process with many pathways that produce different metabolites, controlled by key enzymes. There is limited knowledge about the composition, biosynthesis and regulation of flavonoids in cereals. Improved understanding of the accumulation of flavonoids in cereal grains would help to improve human nutrition through these staple foods. The biosynthesis of flavonoids, scope for altering the flavonoid composition in cereal crops and benefits for human nutrition are reviewed here.     

基于代谢组学的功能性蛹虫草成分研究

对功能性蛹虫草、野生蛹虫草、柞蚕蛹虫草及冬虫夏草的代谢组学进行非靶向成分比较分析,并对功能性蛹虫草的常见生物活性成分进行定量分析。结果表明,功能性蛹虫草共检测出代谢产物成分2 213种,占成分总量的72.67%,其特有成分497种,与冬虫夏草、柞蚕蛹虫草和野生蛹虫草相比具有显著的成分优势。除目前已经报导的部分成分外,还含有丰富的特殊性代谢产物,如灵芝酸、茯苓新酸、人参皂苷、仙茅皂苷、苦玄参苷、黄芪皂苷、金铁锁环肽、王不留行环肽、甾醇、丹酚酸等。常规成分定量分析表明功能性蛹虫草子实体中虫草素和喷司他丁含量均较高,麦角甾醇、SOD酶、维生素E含量均显著高于对照组。大量药物活性物质在蛹虫草代谢产物成分体系中得到表达,对于揭示蛹虫草保健价值的物质基础具有重要意义。     

A review of dietary stilbenes: sources and bioavailability

Stilbenes are a class of phenolic metabolites found in various edible plants, such as grapevine, berries and peanuts. Their bioactivitiy and their potential benefits for human health have been the subject of several studies. Among all identified stilbenes, resveratrol has been particularly studied and results from literature showed that it presents several biological activities, including antioxidant, anti-inflammatory and antiproliferative effects. Likewise, some researches focused on other stilbenes and highlighted similar biological activity for those compounds. However, stilbenes present a high diversity in their phenolic structures (various chemical substituents and polymerization) which is a determining factor of their absorption and metabolism rates. Consequently, this could affect the effectiveness of stilbenes in vivo. In this context, an evaluation of the bioavailability and metabolism of stilbenes is necessary to move forward with pharmacological and clinical studies. Hence, this review aims to present recently obtained data and results concerning stilbenes sources and bioavailability, as a contribution to the valorization of the role of dietary stilbenes in the human diet.     

肠道微生物与血清素互作研究进展

肠道微生物在肠道稳态和大脑健康中发挥着举足轻重的作用.血清素是大脑的一种重要的单胺类神经递质,90％以上在结肠肠嗜铬细胞中由色氨酸代谢转化而来,在机体发挥广泛作用.近年来的研究表明,血清素对机体发挥的作用可能受到肠道微生物影响.肠道中某些微生物具有产生血清素的能力,同时,微生物群及其代谢产物(如丁酸)能通过影响色氨酸羟...     

Human metabolic pathways of dietary flavonoids and cinnamates

Flavonoids and cinnamates are widespread phenolic secondary metabolites synthesized by plants for defensive purposes. Many foods and beverages contain high levels of phenolic compounds. Certain phenolics in the diet are particularly bioactive and have pronounced effects on mammalian cells. These effects, together with epidemiological studies and animal models, have led to the hypothesis that dietary phenolics contribute to the health benefits of a diet rich in fruit and vegetables. This paper examines the biochemistry of the uptake and metabolic route of two groups of plant phenolics, the flavonols and hydroxycinnamates.     

Extraction and analysis of polyphenols: recent trends

In recent years, there has been an increasing interest in diets rich in fruits and vegetables and this is mostly due to their presumed role in the prevention of various degenerative diseases, such as cancer and cardiovascular diseases. This is mainly due to the presence of bioactive compounds, such as polyphenols, carotenoids, among others. Polyphenols are one of the main classes of secondary metabolites derived from plants offering several health benefits resulting in their use as functional foods. Prior to the use of these polyphenols in specific applications, such as food, pharmaceutical, and the cosmetic industries, they need to be extracted from the natural matrices, then analyzed and characterized. The development of an efficient procedure for the extraction, proper analysis, and characterization of phenolic compounds from different sources is a challenging task due to the structural diversity of phenolic compounds, a complex matrix, and their interaction with other cellular components. In this light, this review discusses different methods of extraction, analysis, and the structural characterization of polyphenolic compounds.