热风干燥法对刺梨果活性成分影响的研究

目的：采用热风干燥法干燥刺梨鲜果,分析干燥前后对刺梨主要活性成分（维生素C、总多酚、总黄酮、没食子酸、儿茶素和鞣花酸）的影响,以及测定其有害重金属含量。结果：刺梨鲜果经60 ℃热风干燥后,总黄酮含量基本不变,总多酚和维生素C含量有减少;多酚类化合物儿茶素含量减少,没食子酸和鞣花酸含量则增加;刺梨干果中维生素C含量仍然高（7.2%）;干果中总多酚96.18 mg/g、总黄酮1.97 mg/g、儿茶素4.94 mg/g、没食子酸0.30 mg/g、鞣花酸1.70 mg/g。有害重金属限量符合国家标准GB 2762—2017的规定。结论：热风干燥的工艺方法使刺梨中活性成分含量变化,但不影响干刺梨的应用品质,是加工干燥刺梨鲜果的方便、快捷、性价比合适的方式,适合规模化应用。     

DPPH-HPLC-QTOF-MS/MS快速筛选和鉴定杜仲黑茶中抗氧化活性成分

建立DPPH-HPLC-QTOF-MS/MS方法快速筛选、鉴定和测定杜仲黑茶中抗氧化活性成分。杜仲黑茶提取物与DPPH自由基反应30 min后,9个抗氧化活性成分的HPLC峰消失或峰面积明显减少,结合QTOF-MS/MS谱图及与标准品对照,确定抗氧化活性成分为:没食子酸,新绿原酸、原儿茶酸、绿原酸、咖啡酸、表没食子儿茶素没食子酸酯、槲皮素-3-O-桑布双糖苷、芦丁和异槲皮苷。并建立HPLC法同时测定9个抗氧化活性成分的含量。所建立的方法无须繁琐的分离纯化过程,可快速、灵敏、准确、高通量筛选复杂体系中的抗氧化活性成分,并为杜仲黑茶的质量控制提供科学依据。     

秦岭南麓萱草属植物花蕾中酚类物质比较分析

目的：为了对秦岭南麓野生萱草资源进行保护和开发利用。方法：从已收集的野生萱草属植物中选取具有代表性的种质材料，以黄花菜栽培种‘沙苑花’为对照，利用高效液相色谱法和紫外分光光度计对萱草属植物花蕾中酚酸类和黄酮类化合物进行检测和分析。结果：对7种酚酸类物质检测表明，野生材料的绿原酸、丁香酸、香草酸、对香豆酸、阿魏酸含量较栽培种低；但没食子酸和香豆酸的含量较栽培种高，其中野生‘萱草’的没食子酸和香豆酸含量分别是栽培种的1.57倍和1.59倍。在黄酮类物质中，野生材料的儿茶素含量低于栽培种；野生‘大苞萱草’的总黄酮和芦丁含量较栽培种低；但野生材料的槲皮素含量均高于栽培种，其中野生‘萱草’和‘大苞萱草’的平均含量分别是栽培种的1.99倍和2.56倍。结论：在秦岭南麓萱草属植物中，野生材料的没食子酸、香豆酸、总黄酮、槲皮素含量高于栽培种，且绿原酸、总黄酮和儿茶素含量明显高于其他地区的萱草材料，故应加强对该地区野生萱草属植物资源的调查收集和开发利用，这将对丰富萱草资源多样性和营养品质改良具有重要意义。     

遮光对刺梨果实和叶片中维生素C与糖含量以及相关酶活性的影响

为探究光照强度减弱对不同发育期的刺梨(Rosa roxburghii Tratt.)果实和叶片中维生素C与糖含量及相关酶活性的影响,以‘贵农5号’刺梨扦插苗为材料,采用遮阳网设置光强减弱20%、40%、60%的3个遮光处理,以自然光照强度为对照(CK),分析不同光照强度条件下刺梨果实和叶片中维生素C含量及相关酶活性以及糖含量的变化。结果表明：(1)光照强度减弱后,不同发育期的刺梨果实和叶片中维生素C含量均显著降低,对照及3个处理间的果实维生素C含量的差异在快速膨大期均达到显著水平。(2)随着光照强度的减弱,刺梨果实和叶片中L 半乳糖 1,4 内酯脱氢酶(GalLDH)、单脱氢抗坏血酸还原酶(MDHAR)和脱氢抗坏血酸还原酶(DHAR)活性均降低,而抗坏血酸氧化酶(AAO)和抗坏血酸过氧化物酶(APX)活性均增强,尤其是果实中MDHAR活性在快速膨大期迅速大幅增强。(3)刺梨果实和叶片中可溶性糖、蔗糖、葡萄糖、果糖含量随光照强度减弱而降低,但果实中葡萄糖含量在快速膨大期增加尤为迅速。(4)果实中维生素C含量与叶片中蔗糖、葡萄糖含量在不同发育期均呈极显著正相关关系,快速膨大期果实中GalLDH、MDHAR活性与维生素C含量呈极显著正相关关系且相关系数均达到最大值,而其APX活性与维生素C含量呈极显著负相关关系且相关系数达到最大值。研究认为,光照强度通过调控刺梨果实中维生素C合成及相关代谢关键酶的活性与叶片中光合产物的含量最终影响果实中维生素C的积累量;弱光环境不利于刺梨果实和叶片中维生素C及糖的积累,其影响在果实快速膨大期尤为明显;良好的光照是保证刺梨果实优良品质的基本条件。     

云南普洱茶原料晒青毛茶的化学成分

从云南临沧地区生产普洱茶的原料晒青毛茶中分离到 2 1个化合物 ,通过波谱分析分别鉴定为 :(- )表儿茶素、 (- )表没食子儿茶素、 (- )表没食子儿茶素 - 3-O -没食子酸酯、 (- )表儿茶素 - 3-O -没食子酸酯、 (- )表阿福豆素 - 3-O -没食子酸酯、 ( )儿茶素、 (± )没食子儿茶素、槲皮素、槲皮素 - 3-O - β -D -葡萄吡喃糖甙、芦丁、山奈酚、山奈酚 - 3-O - β -D -葡萄吡喃糖甙、山奈酚 - 3-O -芦丁糖甙、小木麻黄素 (strictinin)、 1,6 -O -二没食子酰基 - β -D -葡萄吡喃糖、茶倍素、绿原酸、 3α ,5α -二羟基 - 4 -α -O -咖啡酰基金鸡纳酸、松柏醇甙、没食子酸和咖啡因     

金荞麦果实中有效成分的分析

采用HPLC法对金荞麦果实中的有效成分进行了分析,结果表明:金荞麦果实中含有芦丁、槲皮素和表儿茶素等有效成分,其中主要以芦丁为主,槲皮素、表儿茶素等含量甚微.金荞麦果实中的有效成分主要集中在种子部分,果皮中则不合或含量甚微.     

几种茶叶生化成分及其抗氧化活性分析

目的：比较白茶与绿茶、红茶生化成分的差异,探讨生化成分与抗氧化活性的关系。方法：以寿眉、安吉白茶及白琳工夫分别为白茶、绿茶、红茶代表,分析茶叶成分,测定茶汤抗氧化活性,并对二者进行相关性分析。结果：总黄酮含量与年份呈正相关关系,而咖啡碱则相对稳定;白茶茶多酚及儿茶素含量均低于绿茶,但其酯型儿茶素所占比重显著高于绿茶,且游离氨基酸、茶氨酸及总黄酮含量也显著高于其他两种茶类;EGC所占比重与酯型儿茶素均与茶汤抗氧化活性有较强的相关性。结论：白茶与其他茶在成分和抗氧化性上均有显著差异;EGCG与抗氧化活性相关性最强。     

宁夏枸杞‘中科绿川1号’果实和叶片的主要成分分析

以国家林业局审定的宁夏枸杞新品种‘中科绿川1号’为实验材料,研究不同月份采集的枸杞叶片芦丁含量,以及果实总黄酮、总多糖、总类胡萝卜素、玉米黄素双棕榈酸酯的含量变化。结果显示,叶片芦丁含量在枸杞盛果期较低,抽条期较高;果实总黄酮、总类胡萝卜素、玉米黄素双棕榈酸酯的含量在头茬果中含量较高,盛果期果实含量较低;果实总多糖可能与果实量呈负相关;褐化果(俗称"油果")总黄酮含量与正常果差异不大,可用作提取枸杞黄酮类物质的原材料。研究结果可为枸杞果实分级、成分提取提供新思路。     

小檗果实中酚类化合物含量测定及其抗氧化活性研究

本试验采用UV法和HPLC法测定小檗果实中酚类化合物的含量,通过DPPH自由基清除率对酚类化合物进行抗氧化活性研究。UV法测得小檗果实总酚含量为3.858 mg/g,HPLC法测得小檗果实中绿原酸、芦丁、槲皮素、山奈酚平均含量分别为0.980 22%、0.006 23%、0.000 44%、0.001 51%;测得DPPH自由基清除率K为85.59%。HPLC法分析速度快,重复性好,能较准确测定小檗果实中总酚含量,且其中酚类化合物具有较强的抗氧化活性,小檗果实可作为天然抗氧化原料开发应用研究。     

绿茶,乌龙茶,红茶中的主要组成和酚类化全物抑制脂肪氧合酶…

绿茶、乌龙茶和红茶中含有多种抑制脂肪氧合酶及抗油脂自动氧化的有效成分。实验结果表明,其中以表没食子儿茶素没食子酸酯（ＥＧＣＧ）的抗氧化活性最强,延缓猪油自动氧化诱导期为５５．５小时,比无添加抗氧化成分的延长１１倍,抑制脂肪氧合酶活性的ＩＣ５０值为１０．０μｍｏｌ／Ｌ。茶黄素单酯－２Ｂ（ＴＦＭ－２Ｂ）和茶黄素双酯（ＴＦＤ）比ＥＧＣＧ抑制脂肪氧合酶活性的效果更强,其ＩＣ５０值分别为０．５７和０．２３α     

Densitometric Quantification and Optimization of Polyphenols in Phyllanthus maderaspatensis by HPTLC

Quantifying and optimizing the polyphenol content of Phyllanthus maderaspatensis was accomplished using a single-solvent HPTLC system. Analyzing hydroalcoholic extracts for kaempferol, rutin, ellagic acid, quercetin, catechin, and gallic acid, we simultaneously quantified and optimized their concentration. In the experiment, the methanol to water ratio (%), temperature (°C), and time of extraction (min) were all optimized using a Box-Behnken statistical design. Kaempferol, rutin, ellagic acid, quercetin, catechin, and gallic acid were among the dependent variables analyzed. In the HPTLC separation, silica gel 60F254 plates were used, and toluene, ethyl acetate, and formic acid (5:4:1) made up the mobile phase. For kaempferol, rutin, ellagic acid, quercetin, catechin, and gallic acid, densitometric measurements were carried out using the absorbance mode at 254 nm. Hydroalcoholic extract of P. maderaspatensis contains rutin (0.344), catechin (2.62), gallic acid (0.93), ellagic acid (0.172), quercetin (0.0108) and kaempferol (0.06). Further, it may be affected by more than one factor at a time, resulting in a varying degree of reaction. A negative correlation was found between X1 (extraction time (min)) and X2 (temperature), as well as X1 and X3 (solvent ratios). Taking these characteristics into consideration, the method outlined here is a validated HPTLC method for measuring kaempferol, rutin, ellagic acid, quercetin, catechin, and gallic acid.     

A Comparative Study on Polyphenolic Composition of Berries from the Tibetan Plateau by UPLC‐Q‐Orbitrap MS System

Five traditional medicinal food from the Tibetan plateau including Nitraria tangutorum Bobrov (NT), Hippophae rhamnoides L. (HR), Lycium ruthenicum Murray (LR), Lycium barbarum L. (LB) and Rubus corchorifolius L.f. (RC) are rich in phenolic compounds. However, the detailed studies about the phenolic compounds remain scarce. Therefore, we established a rapid method for the simultaneous identification and quantification of the phenolic compounds from berries via Ultra Performance Liquid Chromatography‐Quadruple‐Orbitrap MS system (UPLC‐Q‐Orbitrap MS). This method was verified from many aspects including detection limit, quantification limit, precision, repeatability, stability, average recovery rate and recovery range, and then was used to analyze the phenolic compounds in these five species of berries. Finally, a total of 21 phenolic compounds were directly identified by comparing the retention time and exact mass, of which 14 compounds were identified by us for the first time in berries from the Tibetan plateau, including one flavonoid aglycone (myricetin), 11 phenolic acids (gallic acid, protocatechuate, chlorogenic acid, vanillic acid, caffeic acid, syringic acid, p‐coumaric acid, ferulic acid, 2‐hydroxybenzeneacetic acid and ellagic acid), one flavanol (catechin) and one dihydrochalcone flavonoid (phloretin). Quantitative results showed that rutin, myricetin, quercetin and kaempferol were the main flavonoids. Moreover, a variety of phenolic acid compounds were also detected in most of the berries from the Tibetan plateau. Among these compounds, the contents of protocatechuate and chlorogenic acid were high, and high levels of catechin and phloretin were also detected in these plateau berries.     

Structure‐Activity Relationships Analysis of Monomeric and Polymeric Polyphenols (Quercetin,Rutin and Catechin) Obtained by Various Polymerization Methods

Plant polyphenols, especially flavonoids, are active and pro‐health substances found in fruits and vegetables. Quercetin and its glycoside rutin are representatives of flavonoids, commonly found in plant products. Catechins found in large quantities in tea are also a well‐known group of natural polyphenols. These compounds are based on the structure of flavan‐3‐ol, which is why the number, positions and types of substitutions affect the scavenging of radicals and other properties. Despite some inconsistent evidence, several structure?activity relationships of monomeric flavonoids are well established in vitro. However, the relationships between the activity and other properties of the polymeric forms of flavonoids and their structures are poorly understood so far. The aim of this article is to compare the data on polymerization of quercetin, rutin and catechin, as well as to systematize knowledge about the structure?activity relationship of the polymeric forms of these compounds.     

A reevaluation of the peroxynitrite scavenging activity of some dietary phenolics

Peroxynitrite is implicated in many diseases. Hence, there is considerable interest in potential therapeutic peroxynitrite scavengers. Diet-derived phenolics have been claimed to be powerful peroxynitrite scavengers. However, the reactivity of peroxynitrite can be significantly modified by bicarbonate and this has not been considered in evaluations of the scavenging activity of phenols. Bicarbonate (25 mM) significantly decreased the ability of several phenolic compounds (caffeic acid, o- and p-coumaric acid, gallic acid, ferulic acid) but not others (catechin and epicatechin) to inhibit peroxynitrite-mediated tyrosine nitration. Bicarbonate (25 mM) also decreased the ability of catechin, epicatechin, quercetin and ferulic acid but not chlorogenic acid, gallic acid, caffeic acid and o-coumaric acid to inhibit peroxynitrite-mediated alpha(1)-antiproteinase inactivation. These results show that physiological concentrations of bicarbonate substantially modify the ability of dietary phenolics to prevent peroxynitrite-mediated reactions. When assessing compounds for peroxynitrite scavenging, experiments should be conducted in the presence of bicarbonate to avoid misleading results.     

Effect of irrigation on yield parameters and antioxidant profiles of processing cherry tomato

A two-year (2010 and 2011) open field experiment was conducted to study the effect of drip irrigation and seasonal variation on the yield parameters and main bioactive components, carotenoids (mainly all trans, cis lycopene, and β-carotene), polyphenols (chlorogenic acid, caffeic acid, gallic acid, quercetin, rutin, naringin, etc.), and tocopherols of processing Strombolino F1 cherry tomatoes. The irrigated plants (STI) gave a higher marketable yield (61% and 101% respectively), and rain fed plants showed a yield loss. Water supply had a strong positive (R²=0.98) effect on marketable yield in 2011, but weak (R²=0.69) in 2010. In both years, the antioxidant concentration (all carotenoids, total polyphenols, tocopherols) showed a decrease with irrigation. Water supply affected the composition of carotenoids to a considerable extent. The optimum water supply treatment gave a lower proportion of lycopene than the rain fed control (STC) treatment. We observed significant negative correlation between rutin concentration and irrigation. The α-tocopherol concentration was significantly higher in STC treatments. Irrigation negatively influenced antioxidant concentrations of cherry tomato fruits, but higher yield could account for the concentration loss of individual fruits by higher antioxidant production per unit area.     

Chemical Characterization and Multidirectional Biological Effects of Different Solvent Extracts of Arum elongatum: in Vitro and in Silico Approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS⁺⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.     

Phytochemical profiling and antioxidant potential of Daphne mucronata Royle and action against paracetamol-induced hepatotoxicity and nephrotoxicity in rabbits

The paracetamol-induced injuries of liver and kidneys in animals are mostly used to screen out the hepato and nephroprotective effect of extract or other therapeutic agents. In the present study total phenolic and flavonoid contents, in vitro antioxidant, and in vivo hepato/nephroprotective (on paracetamol-induced intoxication in experimental rabbits) potentials of the Daphne mucronata leaves methanolic extract were determined. For the identification of possible phytochemicals, HPLC (high performance liquid chromatography) analysis was carried out and a total of eight phenolic compounds; malic acid, gallic acid, chlorogenic acid, epigallocatechin gallate, quercetin, morin, ellagic acid, and rutin were identified. D. mucronata extract at doses of 250 and 500 mg/kg body weight were given for eight days to paracetamol intoxicated rabbits and the observed results were compared with standard Silymarin. The level of liver enzymes like aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, serum triglyceride, serum cholesterol, serum bilirubin, and kidneys biomarkers like serum urea, uric acid, and creatinine, as well as lipid peroxidation malondialdehyde contents were increased while the antioxidant enzymes like reduced glutathione and total antioxidant capacity were decreased. Furthermore, histopathological analysis of the liver and kidney tissues of control and treated groups also confirmed the hepatoprotective and nephroprotective effect of the D. mucronata which was most probably due to its high antioxidant phenolic and flavonoid phytoconstituents.     

HPLC同时测定大叶冬青叶中10种多酚成分的含量及抗氧化活性研究

建立HPLC同时测定大叶冬青叶中新绿原酸、绿原酸、隐绿原酸、咖啡酸、对羟基肉桂酸、芦丁、异槲皮苷、异绿原酸B、异绿原酸A和异绿原酸C 10种多酚类化合物的定量分析方法,研究不同产地及不同采收时期大叶冬青叶中10种多酚类化合物的含量差异及其抗氧化活性。采用HPLC测定大叶冬青叶50%甲醇提取液中10种多酚类成分的含量,并选用DPPH法对其抗氧化活性进行初步探索。结果表明,10种多酚类化合物分离效果较好,标准曲线在检测范围内具有良好的线性(r>0.999 5),平均加样回收率在96.58%～112.03%,RSD<4%(n=6)。大叶冬青叶50%甲醇提取液抗氧活性良好。本实验建立的方法快速、准确、重复性好,可用于同时测定大叶冬青叶中新绿原酸、绿原酸、隐绿原酸、咖啡酸、对羟基肉桂酸、芦丁、异槲皮苷、异绿原酸B、异绿原酸A、异绿原酸C 10种成分的含量;不同产地、不同采收时期大叶冬青叶中10种多酚类化合物含量存在一定差异;不同来源大叶冬青叶50%甲醇提取液抗氧化能力具有明显差异。     

Phenolic Compounds and Antioxidant Activity of Different Organs of Potentilla fruticosa L. from Two Main Production Areas of China

This report compared the phenolic compounds and antioxidant activity of the leaves, flowers, and stems of Potentilla fruticosa L. collected from two main production areas of P. R. China (Taibai Mountains and the Qinghai Huzhu Northern Mountains). The results indicated that there were significant differences in the phenol contents and antioxidant activities among the different organs and between the two productions. High‐performance liquid‐chromatography analysis indicated that hyperoside, (+)‐catechin, ellagic acid, and rutin were the primary compounds in leaves and flowers; for stems, the content of six phenolic compounds, from two productions, were the lowest. The 1,1‐diphenyl‐2‐picryl hydrazyl (DPPH), 2,2‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) di‐ammonium salt (ABTS), ferric reducing power (FRAP), lipid peroxidation assays, and microbial test system (MTS) were used to evaluate the antioxidant activity. The results demonstrated that the leaves from two productions exhibited powerful antioxidant activity than other organs, which did not significantly differ from that of the positive control (rutin), followed by the flowers and stems. The correlation between the content of phytochemicals and the antioxidant activities of different organs showed that the total phenol, tannin, hyperoside, and (+)‐catechin contents may influence the antioxidant activity, and these compounds can be used as markers for the quality control of P. fruticosa.     

Antimicrobial activity of Amazon Astrocaryum aculeatum extracts and its association to oxidative metabolism

Several compounds present in fruits as polyphenols are able to kill or inhibit the growth of microorganisms. These proprieties are relevant mainly in tropical areas, as Amazonian region where infectious are highly prevalent. Therefore, this study investigated the antimicrobial activity of tucumã Amazonian fruit against 37 microorganisms. The potential role of oxidative metabolism imbalance was also studied as causal mechanism of antimicrobial activity. The results showed antibacterial effect of pulp and peel tucumã hydro-alcoholic extracts on three Gram-positive bacteria (Enterococcus faecalis, Bacillus cereus, Listeria monocytogenes) and antifungal effect against Candida albicans. The antimicrobial contribution of main chemical compounds (quercetin, rutin, β-carotene and gallic, caffeic and chlorogenic acids) found in tucumã extracts was also investigated showing an inhibitory effect depending of the organism mainly by quercetin in bacteria and rutin in C. albicans. Analysis of kinetic of DNA releasing in extracellular medium by fluorescence using DNA Pico Green assay^® and reactive oxygen species production (ROS) showed potential oxidative imbalance contribution on tucumã inhibitory effect. In B. cereus and C. albicans this effect was clear since after 24 h the ROS levels were higher when compared to negative control group. In conclusion, tucumã extracts present antimicrobial activity to four microorganisms that have large problems of drug resistance, and the possible mechanism of action of this Amazon fruit is related to REDOX imbalance.