不同方法提取胡椒花挥发油气质联用成分分析

采用水蒸气蒸馏、石油醚提取法提取胡椒花挥发油,考察不同提取方法对胡椒花挥发油化学成分的影响。用气相色谱-质谱联用技术(GC-MS)对2种挥发油中化学成分及其相对含量进行对比分析,结果表明,两种提取方法所得挥发油经GC-MS分析共鉴定出51种化学成分,共有成分有11种,含量最高的均为环己烷。石油醚提取挥发油成分单一,水蒸气蒸馏所得挥发油成分多样,以多种结构倍半萜烯为主。该研究为胡椒花挥发油的提取及其进一步开发利用提供依据。     

延胡索挥发油提取方法研究

比较研究延胡索挥发油的常规提取方法并对其进行成分分析。采用索式提取法、加热回流法及超声提取法提取延胡索样品中挥发油成分,使用GC-MS进行分析检测。研究结果表明:加热回流法最为适合延胡索挥发油提取。此外,三种方法提取出来的挥发油成分和含量上均有差异,说明提取方法不同会对延胡索挥发油组分构成及含量造成影响。     

两种不同提取方法所得莪术油的成分对比分析

利用气相色谱、气相色谱-质谱联用分析技术,对水蒸气蒸馏和超临界CO2萃取两种不同方法提取得到的莪术油化学成分进行分析鉴定,分别从中分离出60余和90余个组分,并确认了其中50多种化学成分,得到鉴定的组分峰面积占总馏出峰面积的90%以上。根据成分鉴定结果,对不同提取方法所得莪术油的主要化学成分进行比较分析。两种不同提取方法获得的莪术油组分不完全相同,含量也不尽相同,但主要化学成分基本一致,超临界CO2萃取的莪术油所含化学成分较多且相对分子质量较大的重组分较多。同时,对不同方法提取的莪术油中莪术醇等主要特征成分,采用薄层色谱、气相色谱、质谱进行分析测定。研究结果可为莪术油的开发与质量控制提供科学依据。     

延胡索挥发油提取方法研究

比较研究延胡索挥发油的常规提取方法并对其进行成分分析。采用索式提取法、加热回流法及超声提取法提取延胡索样品中挥发油成分,使用GC-MS进行分析检测。研究结果表明:加热回流法最为适合延胡索挥发油提取。此外,三种方法提取出来的挥发油成分和含量上均有差异,说明提取方法不同会对延胡索挥发油组分构成及含量造成影响。     

互花米草茎叶矿质元素提取潜力分析

外来入侵物种互花米草内含丰富的矿质成分,对其组织矿质成分的提取与表征是互花米草进行资源化利用的重要基础之一。本研究拟通过3种试验方法（榨汁不脱色法、双氧水脱色法、活性炭脱色法）提取互花米草矿质成分并比较分析,探究不同方法矿质成分的提取潜力。结果表明,互花米草K、Na、Ca、Mg等元素含量在3.74～101.1g/kg之间,具有较好的矿质成分提取潜力。双氧水脱色法得到的茎产品中矿质元素含量比其他两种方法得到的矿质元素含量高8.47%～35.31%,活性炭脱色法得到的叶片中矿质元素含量比其他两种方法得到的矿质元素高5.59%～23.48%,所以,提取茎中的互花米草矿质元素采用双氧水脱色法较为合适,但提取叶片中的矿质元素采用活性炭脱色法较为合适。     

不同方法提取胡椒叶挥发油GC-MS分析

分别采用水蒸气蒸馏、石油醚提取法提取胡椒叶挥发油,气相色谱-质谱联用技术(GC-MS)对2种挥发油中化学成分及其相对含量进行对比分析。结果发现,两种提取方法所得挥发油经GC-MS分析共鉴定出28种化学成分,共有成分14种,含量最高的均为环己烷。结论:该研究为胡椒叶挥发油的提取及其进一步开发利用提供依据。     

不同的萃取方式分析葫芦巴浸膏挥发性成分

为了明确葫芦巴浸膏中挥发性成分组成、含量及不同萃取方式对葫芦巴浸膏挥发性成分萃取效果的影响,分别采用固相微萃取(SPME)、溶剂萃取(LLE)和同时蒸馏萃取(SDE)对葫芦巴浸膏中挥发性成分进行提取,利用GC-MS技术对挥发性成分进行分析鉴定。3种萃取方法共鉴定出160种挥发性成分,其中固相微萃取(SPME)37种、溶剂萃取(LLE)66种、同时蒸馏萃取(SDE)113种,3种方式共有的16种,具有葫芦巴浸膏特征香味成分的葫芦巴内酯3种方式均能萃取出来,比较3种萃取方法可知:同时蒸馏萃取(SDE)和溶剂萃取(LLE)对葫芦巴浸膏中香味物质提取的更为全面,两种萃取方式共鉴定出151种。     

固相萃取与热脱附GC-MS对硫化胶中有机助剂分析的比较研究

本文分别采用溶剂抽提法和热脱附两种前处理方法对硫化胶中的有机助剂成分进行提取,并利用气相色谱-质谱联用仪(GC-MS)进行了研究分析。通过一系列不同胶种中有机助剂的分析效果的比较,以及综合两种方法各自的优缺点,对于一般的橡胶,可采用热脱附GC-MS法进行分析,而遇到含大量矿物油、烷烃油或(氯化)石蜡的橡胶时,建议采用抽提法经固相萃取提取分离后再进行GC-MS分析。     

不同提取方法对香荚兰挥发性成分的影响

分别采用冷法提取、热回流提取、超临界CO2萃取和超声波提取四种工艺提取香荚兰中挥发性成分,并利用气相色谱-质谱联用技术(GC-MS)对四种方法所得提取物中的挥发性成分进行对比分析。冷法提取物共检测出19种主要成分,热回流提取物检测出27种主要成分,超临界CO2萃取物共检测出24种主要成分,超声波提取物共检测出39种主要成分。超声波提取物中主要含有3-糠醛、苯甲醇、香草酸乙酯、香兰素等成分,其中香兰素含量达到85.06%,高于其他三种提取方法。结果表明超声波提取技术更适合于香荚兰的提取,为今后香荚兰的综合开发利用提供技术参考。     

GC/MS分析新疆玫瑰精油化学成分

利用GC/MS仪器分析法,对新疆本地种植的玫瑰采用水蒸气蒸馏法和溶剂提取法所得精油成分进行对比与分析,分别测得17种组分和12种组分。结果显示:两种精油成分差异较大;主体香气成分差异亦较大,水蒸气蒸馏法所得精油醇类化合物含量较高,溶剂提取法所得精油烯类化合物含量较高。     

植物一点红活性物质提取方法的研究

文章采用50%乙醇-水,70%乙醇-水,90%乙醇-水和无水乙醇等几种不同组成的溶剂对药物一点红分别进行超声波和索氏两种不同方法的提取,通过不同溶剂,不同提取时间所得到的提取物的质量变化,比较出两种方法对一点红活性物质的提取效果。结果显示,一点红活性物质的提取率随着萃取剂中乙醇浓度的升高而降低,而超声波提取法优于索氏提取法。     

印楝提取物对瓜绢螟的生物活性

在室内测定了印楝两种提取物（印楝乙酸乙酯萃取和CO2超临界萃取）对瓜绢螟的生物活性。两种提取物对瓜绢螟幼虫都具有较强的拒食作用、生长发育抑制作用,对成虫产卵忌避作用效果较好;对低龄幼虫有一定的毒杀活性,而对高龄幼虫活性很低。随着处理剂量增大,两种提取物作用效果显著增强,而同一剂量下CO2超临界萃取物活性高于乙酸乙酯萃取物。     

Antioxidant Capacity of Rapeseed Extracts Obtained by Conventional and Ultrasound‐Assisted Extraction

Ultrasound‐assisted extraction (UAE) and conventional solid–liquid extraction were applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacities (AC) of winter and spring rapeseed cultivars were determined by four different analytical methods: ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS). The average AC of the studied rapeseed cultivars ranged between 4.21–10.03 mmol Trolox (TE)/100 g, 7.82–10.61 mmol TE/100 g, 8.11–51.59 mmol TE/100 g, 22.48–43.13 mmol TE/100 g for FRAP, CUPRAC, DPPH and ABTS methods, respectively. There are positive correlations between total phenolics (TPC = 804–1625 mg sinapic acid (SA)/100 g) and AC of the studied rapeseed extracts (r = 0.2650–0.9931). Results of the principal component analysis (PCA) indicate that there are differences between the total amounts of antioxidants in rapeseed samples extracted by different extraction techniques. Rapeseed extracts obtained after 18 min of ultrasonication revealed the highest content of total antioxidants. The UAE is a very useful, efficient and rapid technique of oilseed samples preparation for determination of AC by different analytical methods.     

Comparison of Antioxidant Activity of Ethanolic Extracts of Propolis Obtained by Different Extraction Methods

The antioxidant activities of the ethanolic extracts of propolis obtained by different extraction methods (high hydrostatic pressure extraction, leaching at room temperature and heat reflux extraction) were investigated in relationship to their total polyphenol and flavonoid contents by two different assays, namely, the β‐carotene bleaching and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) free radical scavenging assay systems. The results showed that the ethanolic extracts of propolis obtained by high hydrostatic pressure extraction and leaching at room temperature had relatively strong antioxidant activities, which may be correlated with the total polyphenol and flavonoid contents. Antioxidant activities of ethanolic extracts of propolis obtained by high hydrostatic pressure extraction were the same as those of ethanolic extracts of propolis obtained by leaching at room temperature. Leaching at room temperature usually needs a few days, and can take even more than 7 d, while high hydrostatic pressure extraction needs only 1 min. These findings further illustrate that the high hydrostatic pressure extraction has a bright prospect for extracting flavonoids from propolis.     

Fruit Extract Mediated Green Synthesis of Metallic Nanoparticles: A New Avenue in Pomology Applications

Fruit extracts have natural bioactive molecules that are known to possess significant therapeutic potential. Traditionally, metallic nanoparticles were synthesized via chemical methods, in which the chemical act as the reducing agent. Later, these traditional metallic nanoparticles emerged as the biological risk, which prompted researchers to explore an eco-friendly approach. There are different eco-friendly methods employed for synthesizing these metallic nanoparticles via the usage of microbes and plants, primarily via fruit extract. These explorations have paved the way for using fruit extracts for developing nanoparticles, as they eliminate the usage of reducing and stabilizing agents. Metallic nanoparticles have gained significant attention, and are used for diverse biological applications. The present review discusses the potential activities of phytochemicals, and it intends to summarize the different metallic nanoparticles synthesized using fruit extracts and their associated pharmacological activities like anti-cancerous, antimicrobial, antioxidant and catalytic efficiency.     

Characterization of low molecular compounds in dashboard foils by extraction,preparative high performance liquid chromatography,and IR-spectroscopy

A procedure to obtain information concerning the low molecular weight compounds of dashboard foils is described. Solvent extracts of the foils were fractionated by preparative reversed or normal phase HPLC, respectively. The fractions were characterized by their infrared spectra. The benefits and the shortcomings of the two methods are discussed.     

Antioxidant activity of extracts from six different Sudanese plant materials

Methanolic extracts obtained by manual solvent extraction (MSE) and accelerated solvent extraction (ASE) of different Sudanese plant materials (Sclerocarya birrea leaves, Salvadora persica bark and leaves, Combretum hartmannianum leaves, Guiera senegalensis leaves and roots) were investigated for their antioxidant activity. There was no significant difference between the two extraction methods (p < 0.01) regarding the total amount of phenolic compounds expressed as gallic acid equivalents (GAE) (52.6–166.7 mg GAE/g total extractable compounds for MSE and 53.1–169.3 mg GAE/g for ASE). In comparison to a control without extract, the extracts were remarkably effective in the β‐carotene bleaching method, whereas the effectiveness was half or less in comparison to Trolox as standard antioxidant. Also using the 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) method antioxidant activity could be shown in comparison to a control, however, the extracts were less effective than Trolox. No significant difference was found between the two extraction methods. The increase of the peroxide value of sunflower oil during storage at 70°C was markedly lower after addition of the extracts in comparison to the control, but in the Rancimat test (120°C) the extracts showed only a small stabilization factor (F = 0.9–1.4) especially in comparison to Trolox (F = 5.8).     

Optimal fractionation and bioassay plans for isolation of synergistic chemicals: The subtractive-combination method

Studies of chemical ecology of an organism are founded on the isolation and identification of a semiochemical, often comprised of two or more synergistic compounds (each Synergist alone has little activity, but presented together they are bioactive). Chromatographie fractionation and bioassay methods of binary splitting, additive combination, and subtractive combination are compared for efficiency in isolating synergists. Formulas are derived for the latter two methods that calculate the expected number of bioassay tests required for isolation of from two to five synergists from biological extracts with any number of compounds, depending on the number of initial (major) Chromatographic fractions. A computer program based on the formulas demonstrates the superiority of the subtractive-combination method. Simulations with the program were used to determine the optimal number of initial fractions for the additive- and subtractive-combination methods when isolating two to five synergists from extracts of from 25 to 1200 compounds. Methods of bioassay, isolation, identification, and field testing of semiochemicals are discussed.     

Advanced methods for natural product drug discovery in the field of nutraceuticals

Advances in analytical methods and bioassay development have helped to push forward the research in natural products. In plant extracts and nutraceuticals, bioactive compounds are part of a complex mixture. The development of high-resolution methods related to HPLC for both chemical and biological profiling has significantly increased the efficiency of classical bioactivity-guided fractionation procedures. Furthermore, the level of sensitivity obtained by these methods give the possibility to work with few micrograms of compound. This represents a key advantage for rapid localisation of the biological activity and subsequent identification of the compounds of interest. The same methods are also used to study the extracts from a metabolomic view point. The possibility to study them as a whole can highlight synergetic effects, which are likely to occur in plant extracts and nutraceuticals. In this paper, the main trends are summarised and the developments made in our laboratory on profiling crude extracts with UHPLC-TOF-MS, natural product identification at the microgram level using microflow NMR and integration of these methods with biological evaluation are highlighted.     

Two‐Step Labeling of Endogenous Enzymatic Activities by Diels–Alder Ligation

A ligation strategy based on the Diels–Alder [4+2] cycloaddition for the two‐step activity‐based labeling of endogenously expressed enzymes in complex biological samples has been developed. A panel of four diene‐derivatized proteasome probes was synthesized, along with a dienophile‐functionalized BODIPY(TMR) tag. These probes were applied in a Diels–Alder labeling procedure that enabled us to label active proteasome β‐subunits selectively in cellular extracts and in living cells. We were also able to label the activity of cysteine proteases in cell extracts by utilizing a diene‐derivatized cathepsin probe. Importantly, the Diels–Alder strategy described here is fully orthogonal with respect to the Staudinger–Bertozzi ligation, as demonstrated by the independent labeling of different proteolytic activities by the two methods in a single experiment.