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1.
L ‐3,4‐dihydroxyphenylalanine (L‐DOPA) is a well‐recognized therapeutic compound to Parkinson's disease. Tyrosine is a precursor for the biosynthesis of L‐DOPA, both of which are widely found in traditional medicinal material, Mucuna pruriens. In this paper, we described a validated novel analytical method based on microchip capillary electrophoresis with pulsed electrochemical detection for the simultaneous measurement of L‐DOPA and tyrosine in M. pruriens. This protocol adopted end‐channel amperometric detection using platinum disk electrode on a homemade glass/polydimethylsiloxane electrophoresis microchip. The background buffer consisted of 10 mM borate (pH 9.5) and 0.02 mM cetyltrimethylammonium bromide, which can produce an effective resolution for the two analytes. In the optimal condition, sufficient electrophoretic separation and sensitive detection for the target analytes can be realized within 60 s. Both tyrosine and L‐DOPA yielded linear response in the concentration range of 5.0–400 μM (R2 > 0.99), and the LOD were 0.79 and 1.1 μM, respectively. The accuracy and precision of the established method were favorable. The present method shows several merits such as facile apparatus, high speed, low cost and minimal pollution, and provides a means for the pharmacologically active ingredients assay in M. pruriens.  相似文献   

2.
Biosynthesis of metallic silver nanoparticles (AgNPs) has gained much interest and offers an attractive alternate to physical and chemical approaches. In recent year several safe, easy, cost-effective, reproducible, and environmentally friendly synthesis approaches for silver nanoparticles have been developed. In this research work, a simple, cheap, and unexplored method was applied on green synthesis of AgNPs using secondary metabolites extracted from Bixa orellana seeds. The seeds are rich of flavonoids and phenolic compounds which presumably responsible for the fast reduction and stabilization of silver ion into silver nanoparticles. The biosynthesis process is very likely to be able to reduce silver ions under simple physiological conditions. The surface plasmon resonance (SPR) that was appeared at 420 nm in UV–vis spectrum, had confirmed the formation of AgNPs. Moreover, the functional groups in secondary metabolite that act as reducing, capping and stabilizing agents for silver nanoparticles, are identified by Fourier transform infrared (FTIR) spectra. An X-ray diffraction analysis generated four peaks for Bixa orellana seed extract mediated AgNPs positioned at 2θ angles of 38.1°, 44.2°, 64.6°, and 77.5° corresponding to crystal planes (1 1 1), (2 0 0), (2 2 0), and (3 1 1). Field emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM) images confirmed the formation of nanosized silver particles. The z-average of the synthesized particles measured by dynamic light scattering (DLS) was found to be 92.9 nm. AgNPs synthesized exhibited remarkable antioxidant activity, antibacterial and antiproliferative activity against human breast (MCF-7) cell line. On the basis of our results, we conclude that biologically synthesized AgNPs exhibited favorable characteristics and have the potential to be used in biomedical fields.  相似文献   

3.
Abstract

The objective of this study was to compare the antioxidant activity and cytotoxicity of Durio zibethinus M. (Durian) leaf extract from two extraction methods. Ultrasound-assisted extraction and Accelerated-solvent extraction were used to produce crude extract. The results revealed that UAE achieved 3× higher in total phenolic content in the leaf extract compared to ASE. DPPH radical scavenging activity was 4.6× higher in leaf extract from ASE. No significant differences reported in ferric reducing power, and total flavonoid content of the leaf extract between the two methods. Cytotoxicity via MTT assay demonstrated no significant differences in cell viability upon exposure to the leaf extract from both methods. This suggested that they were appropriate in producing Durio zibethinus M. leaf extract for end use application in food related product. Both ensured similar level of safety in Durio zibethinus M. leaf extract as a new potential ingredient for the food industry.  相似文献   

4.
In this study, essential oils from Voacanga africana seeds at different extraction stages were investigated. In the chemical composition analysis, 27 compounds representing 86.69–95.03% of the total essential oils were identified and quantified. The main constituents in essential oils were terpenoids, alcohols and fatty acids accounting for 15.03–24.36%, 21.57–34.43% and 33.06–57.37%, respectively. Moreover, the analysis also revealed that essential oils from different extraction stages possessed different chemical compositions. In the antioxidant evaluation, all analysed oils showed similar antioxidant behaviours, and the concentrations of essential oils providing 50% inhibition of DPPH-scavenging activity (IC50) were about 25 mg/mL. In the antimicrobial experiments, essential oils from different extraction stages exhibited different antimicrobial activities. The antimicrobial activity of oils was affected by extraction stages. By controlling extraction stages, it is promising to obtain essential oils with desired antimicrobial activities.  相似文献   

5.
The influence of natural, hot-air and infrared drying on chemical composition and bioactivity of lemon peel essential oil are investigated in this study. The results showed that drying resulted in losses or increases of some components or production of some new substances, but the d-limonene (59.52–70.01%) was found as the main component of essential oil. Drying brought about decreases in the yield, antioxidant and antibacterial activity of essential oil. However, the natural drying had little effect, while the hot-air and infrared drying resulted in significant decreases in these parameters, especially at the higher temperature. The yield was the lowest under hot-air drying (60 °C) and decreased by 78%, while infrared drying (60 °C) sample exhibited the lowest antioxidant and antibacterial activities. Infrared drying was easier to lead to the decrease in bioactivity than hot-air drying at the same temperature. These results provided the theoretical basis for drying lemon peel.  相似文献   

6.
Salvia miltiorrhiza Bge. is a traditional Chinese medicine applied in the treatment of various diseases in clinical practice. In the course of its processing, S. miltiorrhiza Bge. is usually processed by sweating. This study employed 10‐component contents determination coupled with high‐performance liquid chromatography (HPLC) fingerprint and antioxidant activity to investigate the effect of sweating on S. miltiorrhiza Bge. so as to evaluate the quality of S. miltiorrhiza Bge. The HPLC method was performed using C18 and 0.05% phosphoric acid aqueous solution–acetonitrile with a gradient elution system. It was validated for linearity, precision, repeatability, stability and recovery. Similarity analysis, principal components analysis and antioxidant activity assays were used to compare sweated S. miltiorrhiza Bge. (SSM) and nonsweated S. miltiorrhiza Bge. (NSSM). SSM and NSSM showed good similarities in HPLC fingerprint (>0.9), but principal components analysis could classify the HPLC fingerprint and 10‐component quantitation analysis. Meanwhile, the antioxidant activity of SSM was significantly higher than that of NSSM (p < 0.01). The results of this study indicated that sweating could alter the content of chemical constituents in S. miltiorrhiza Bge., and could also improve its antioxidant activity. In addition, the method not only affords a viable strategy for comparing SSM and NSSM and assessing the quality of S. miltiorrhiza Bge., but also provides a reference for other herbal medicine that suffers from sweating.  相似文献   

7.
Danshen tablet, which consists of Salviae Miltiorrhizae Radix et Rhizoma, Notoginseng Radix et Rhizoma and Borneolum syntheticum , has been widely used in the therapy of cardiovascular disease. The aim of this study was to develop comprehensive evaluation methods for the quality control of Danshen tablet. First, five‐wavelength fusion fingerprint was established to avoid one‐sidedness of a single wavelength. Then, the ultraviolet spectrum fingerprint was applied to reflect the information of unsaturated bond and conjugated system of chemical substances in Danshen tablet. The similarity analyses of these two fingerprints were performed by systematic quantified fingerprint method in terms of qualitative and quantitative aspects. After that, the evaluation results of high‐performance liquid chromatography and ultraviolet fingerprints were integrated by the mean algorithm, which could reduce the error caused by single method. The integrated evaluation results showed that 30 batches of samples were classified into seven grades. Finally, the fingerprint–efficacy relationship was established using an on‐line antioxidant system and partial least‐squares model to explore the connection between chemical components and antioxidant activities. The methods established in this paper were found suitable for the analysis of Danshen tablet.  相似文献   

8.
Various dietary polyphenolics have been found to show an inhibitory effect on xanthine oxidase (XO) which mediates oxidative stress-originated diseases because of its ability to generate reactive oxygen species (ROS), including superoxide anion radical (O2) and hydrogen peroxide. XO activity has usually been determined by following the rate of uric acid formation from xanthine-xanthine oxidase (X-XO) system using the classical XO activity assay (UV-method) at 295 nm. Since some polyphenolics have strong absorption from the UV to visible region, XO-inhibitory activity of polyphenolics was alternatively determined without interference by directly measuring the formation of uric acid and hydrogen peroxide using the modified CUPRAC (cupric reducing antioxidant capacity) spectrophotometric method at 450 nm. The CUPRAC absorbance of the incubation solution due to the reduction of Cu(II)-neocuproine reagent by the products of the X-XO system decreased in the presence of polyphenolics, the difference being proportional to the XO inhibition ability of the tested compound. The structure-activity relationship revealed that the flavones and flavonols with a 7-hydroxyl group such as apigenin, luteolin, kaempferol, quercetin, and myricetin inhibited XO-inhibitory activity at low concentrations (IC50 values from 1.46 to 1.90 μM), while the flavan-3-ols and naringin were less inhibitory. The findings of the developed method for quercetin and catechin in the presence of catalase were statistically alike with those of HPLC. In addition to polyphenolics, five kinds of herbs were evaluated for their XO-inhibitory activity using the developed method. The proposed spectrophotometric method was practical, low-cost, rapid, and could reliably assay uric acid and hydrogen peroxide in the presence of polyphenols (flavonoids, simple phenolic acids and hydroxycinnamic acids), and less open to interferences by UV-absorbing substances.  相似文献   

9.
Lianqiao Baidu pills are widely used herbal medicinal preparation that were analyzed to develop a quality consistency technique. The characteristic fingerprints of 28 batches of Lianqiao Baidu pill samples were established at five wavelengths and simultaneously assessed by using a limited‐ratio quantified fingerprint method using 15 marker compounds. The principal component analysis and fingerprinting results were compared, and the qualitative classification of the samples by principal component analysis agreed with their quantitative evaluation by the limited‐ratio quantified fingerprint method. Furthermore, the antioxidant activities of the samples were surveyed and determined using a 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging approach. A relationship between the common peaks in the fingerprints and the antioxidant activities was established using a partial least squares model. The relationship can be used both to determine the antioxidant activities of the Lianqiao Baidu pill preparations in vitro and as a reference for the selection of active constituents for sample quality classification. The classification results for the samples based on principal component analysis agreed with the quantitative evaluation by the limited‐ratio quantified fingerprint method, which demonstrated that the method can be applied to the holistic quality control of traditional Chinese medicine and herbal preparations.  相似文献   

10.
《印度化学会志》2021,98(11):100201
Microwave assisted hydro-distillation (MAHD) and conventional hydro-distillation (HD) techniques were compared in the extraction of essential oils from Amomum subulatum seeds. The time required for MAHD method (70 ​min) is lesser than that for HD method (4 ​h). There is a slight increase in the yield of extracted oil in MAHD method (3.35%) compared to HD (3%). Gas chromatography–mass spectrometry GC-MS results show that MAHD extracted essential oil was wealthier in oxygenated compounds. 1, 8-Cineole was found to be a major compound in case of both the essential oil, followed by α-pinene. In MAHD the percentage of the major oxygenated monoterpene (1, 8- cineol) slightly increases from 88% to 89% as compared to hydrodistillation. Contrarily to this, the percentage of monoterpene hydrocarbon was decreased in MAHD than HD extracted oil. MAHD and HD extracted oils show good antibacterial activities against gram-negative and gram-positive bacteria. MAHD extracted oil shows better antibacterial activity than HD extracted against both gram positive and gram-negative bacteria. 2, 2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging antioxidant activities show that MAHD extract has better inhibition percentage than HD extract, and the half-maximal inhibitory concentration IC50 value of MAHD was less than HD extracted oil.  相似文献   

11.
Green chemistry of nanomaterials from synthesis to diverse biomedical applications is a discussion of town in the current scientific scenario. In this work, Ocimum basilicum leaves extract was utilized as the reducing agent in the synthesis of ZnO nanoparticles. Green synthesized ZnO NPs mediated via Ocimum basilicum extract were decorated on the reduced graphene oxide (RGO) sheet by the simple one-step method. The prepared green synthesized RGO-ZnO nanocomposites (NCs) were characterized via the X-ray diffractometer. The average crystallite size of ZnO was 25 nm which confirmed the wurtzite hexagonal structure of ZnO. The scanning Electron Microscopy technique confirmed the spherical morphology of particle size of 31 nm. Further, Fourier Transform Infrared Spectroscopy confirms the Zn-O bond stretching in the RGO-ZnO NCs. Antioxidant activity of the green synthesized Ocimum basilicum ZnO NPs and RGO-ZnO NCs were performed by DPPH scavenging activities and found the dose-dependent. RGO-ZnO effectively inhibited the α-amylase and α-glucosidase for in vitro antidiabetic activities. Moreover, RGO-ZnO NCs showed the antibacterial potential with increasing concentration against the gram-positive (Cocci) and gram-negative (E. coli) bacterial strains. In Photocatalytic activity, the ZnO NPs and RGO-ZnO NCs were utilized as the catalyst and degraded the Rh-B dye 91.4% and 96.7% under UV–visible light. Overall, RGO-ZnO NCs showed better results in antibacterial, antidiabetic activity as well as photocatalytic activity against the pure ZnO NPs. Hence, RGO-ZnO nanocomposites have demonstrated the opportunity to be an entrancing material for photocatalysis and biological studies.  相似文献   

12.
Acetone extract of faba bean (Vicia faba L.) was found to be highest total phenol and flavonoid content among all extracts. Antioxidant activity for inhibition percentage (free radical scavenging activity) had 86.47% for acetone extract, and 97.36% for ascorbic acid respectively. IC50 value of ascorbic acid and acetone extact were found to be 9 μg/mL ± 0.20 and 30 μg/mL ± 0.21. Faba bean seeds had catechin, epicatechin, gallic acid and ellagic acid which on molecular docking study revealed that it binds effectively with xanthine oxidase by binding energy of –7.78, –6.11, –6.39, –5.78 kcal/mol respectively compared to allopurinol drug having binding energy of –4.94 kcal/mol. Gallic acid, ellagic acid, catechin, epicatechin (polyphenols) and allopurinol bind other than catalytic residues (Glu-1261) of xanthine oxidase. In vitro and in silico analysis recommended that mode of enzyme inhibition was mixed type.  相似文献   

13.
The tunable ZnO nanorods (NRs) are produced due to the phytochemicals present in Cycas pschannae leaves which act as reducing and stabilizing agents. The confirmations of the ZnO NRs were validated using different characterization techniques: X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer, Emmett and Teller (BET), scanning electron microscopy–Energy Dispersive X-Ray Analysis (EDX), UV–visible spectroscopy, Raman spectroscopy, and transmission electron microscopy. The ZnO NRs show unique surface area and low particle size. Photocatalytic activity was measured and found to be 50.75% at low concentrations and 78.33% at high concentrations. The antioxidant activity of the ZnO NRs also showed promising results for their use in free radical scavenging. In vitro toxicity studies using zebrafish embryos was performed to evaluate the toxic nature of it and the obtained result confirmed its non-toxic nature. In addition, ZnO anticancer potential was verified using the A549 lung cancer cell line. Cytotoxic assessments of ZnO NRs were performed via 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), and neutral red uptake assays to examine the cell death cycle on the A549 lung cancer cell. Dose-dependent apoptosis and necrosis were confirmed by Lactate dehydrogenase (LDH) assay. It was also confirmed that ZnO NRs induce Reactive oxygen species (ROS) and apoptosis inside cancer (A549) cells via different intrinsic gene expression. Thus, based on this research it is evident that an effective ecofriendly, nontoxic potential anticancer drug can be synthesized using C. pschannae leaf extract.  相似文献   

14.
Hydrodistillation (HD), simultaneous distillation solvent extraction (SDE), microwave-assisted hydrodistillation (MWHD), and supercritical fluid (CO2) extraction (SFE) were employed to isolate volatile secondary metabolites from fresh leaves and stems of Colombian Lippia alba (Mill.) N.E. Brown. Kovàts indices, mass spectra or standard compounds were used to identify around 40 components in the various volatile fractions. Carvone (40-57%) was the most abundant component, followed by limonene (24-37%), bicyclosesquiphellandrene (5-22%), piperitenone (1-2%), piperitone (ca. 1.0%), and beta-bourbonene (0.6-1.5%), in the HD, SDE, MWHD, and SFE volatile fractions. Static headspace (S-HS), simultaneous purge and trap in solvent (CH2Cl2) (P&T), and headspace solid-phase microextraction (HS-SPME) were used to sample volatiles from fresh L. alba stems and leaves. The main components isolated from the headspace of the fresh plant material were limonene (27-77%), carvone (14-30%), piperitone (0.3-0.5%), piperitenone (ca. 0.4%), and beta-bourbonene (0.5-6.5%). The in vitro antioxidant activity of L. alba essential oil, obtained by hydrodistillation was evaluated by determination of hexanal, the main carbonyl compound released by linoleic acid subjected to peroxidation (1 mm Fe2+, 37 degrees C, 12 h), and by quantification of this acid as its methyl ester. Under the same conditions, L. alba HD-essential oil and Vitamin E exhibited similar antioxidant effects.  相似文献   

15.
Secondary metabolites from the sawmill waste Picea abies bark were extracted using an innovative two-step extraction that includes a first step with supercritical CO2 (SCO2) and a second step using green solvents, namely ethanol, water, and water ethanol mixture. Maceration (M), ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE) techniques were applied in the second step. A total of nineteen extract were obtained and yield were compared. Bark extracts were characterized by LC-DAD-MSn and classes of compounds were quantified as abietane derivatives, piceasides, flavonoids, and phenolics to compare different extractions. Obtained extracts were studied by in vitro assay to evaluate potential pharmaceutical, nutraceutical and cosmetic uses assessing the antioxidant activity as well as the inhibitory activity on target enzymes. Results show that the “smart extraction chain” is advantageous in term of yield of extraction and phytoconstituent concentration. SCO2 extract, presenting a unique composition with a large amount of abietane derivatives, exerted the best activity for amylase inhibition compared to the other extracts.  相似文献   

16.
In this work, a general and novel separation technique gas‐assisted three‐liquid‐phase extraction was established and applied in separating and concentrating isoflavonoids from the actual sample of puerariae extract by one step. For the gas‐assisted three‐liquid‐phase extraction method, optimal conditions were selected: polyethylene glycol 2000 and ethyl acetate as the flotation solvent, pH 5, (NH4)2SO4 concentration 350 g/L in aqueous phase, N2 flow rate 30 mL/min, flotation time 50 min, and flotation twice. Five isoflavonoids compounds puerarin, 3′‐methoxydaidzin, puerarinxyloside, daidzin and daidzein were separated with recoveries of 82, 84, 80, 88 and 89%, respectively. The separated products were purified by preparative high‐performance liquid chromatography, and the purity of the final products was >96%. The established general gas‐assisted three‐liquid‐phase extraction was used to separate anthraquinones from Cassiae Semen under the optimal conditions, and the recoveries were >75%. The experimental results showed that the established gas‐assisted three‐liquid‐phase extraction method is a general technique for separating active compounds from herb extract.  相似文献   

17.
A simple and green sodium dodecyl sulfate‐synergistic microwave‐assisted extraction method was developed to extract and determine the iridoids, phenylpropanoids, and lignans in Eucommiae Cortex followed by ultra‐high‐performance liquid chromatography with photodiode array detection. The biodegradable solution (sodium dodecyl sulfate) was used as a promising alternative to organic solvents. The response surface methodology provided the optimum extraction conditions (2 mg/mL sodium dodecyl sulfate, 1100 W microwave power, and 6 min extraction time). The recoveries of three types of components ranged from 95.0 to 105% (RSDs < 5%). The intra‐ and inter‐day precision and accuracy were less than 3.40% and within the range of 97.1‐105%, respectively. Compared with other extraction methods, this newly established method was more efficient and environmental friendly. The results demonstrated that sodium dodecyl sulfate‐synergistic microwave‐assisted extraction followed by ultra‐high‐performance liquid chromatography with photodiode array method was applicable for the simultaneous extraction and determination of these three types of compounds for quality evaluation of Eucommiae Cortex.  相似文献   

18.
An improved analytical method was developed for the simultaneous quantification of several plant growth regulators and fungicides (carbendazim, pyrimethanil, metalaxyl, triadimefon, paclobutrazol, thiophanate, prochloraz, dimethomorph, difenoconazole, (4‐chlorophenoxy)‐acetic acid, (2,4‐dichlorophenoxy)‐acetic acid, thiadiazuron, forchlorfenuron and gibberellins) in fruits followed by ultra high performance liquid chromatography with tandem mass spectrometry. Samples were extracted and purified using a modified QuEChERS method. Different extraction solvents and sorbents in the QuEChERS method were compared. Optimum results were followed by the addition of 1% acetic acid in acetonitrile; C18 sorbent was added due to the acidic nature of several pesticides. The recoveries of the pesticides were in the range 73.7–118.4%, with relative standard deviations lower than 16.63%. Limits of detection ranged from 0.1–1.0 μg/kg. The method presented here is simple, rapid, sensitive and can be applied to large‐scale monitoring programs to screen the presences of pesticides in fruits.  相似文献   

19.
In this study, a hydrophilic deep eutectic solvent was synthesized as a carrier and disperser of magnetic nanoparticles based on ferrofluid and used to develop the dispersive micro‐solid‐phase extraction method. Ethylene glycol/tetramethylammonium chloride deep eutectic solvent and SiO2@Fe3O4 were used to provide the highly stable ferrofluid with strong sorbing properties without any additional stabilizer, which was employed to extract and determine morin in apple and grape juices, diluted and acidic extract of dried onion, and green tea infusion samples. The dispersibility of SiO2@Fe3O4 and prevention of its aggregation in the sample solution were improved using the deep eutectic solvent‐based ferrofluid. Also, it facilitated the fast injection of sorbent into the sample solution that led to an increase of the contact surface between the sorbent and analyte, and reduction of the extraction time and consumption of the sorbent. The important experimental parameters influencing the extraction efficiency of morin were examined. Under the optimal conditions, a linear calibration curve was obtained in the range of 3–500 µg/L with a determination coefficient of 0.9994. The limits of detection and quantification were of 0.91 and 2.98 µg/L, respectively. While an extraction recovery of 97.7% with relative standard deviation of 3.8% (interday) was obtained via three replicated measurements on a 30 µg/L of morin standard solution, the enrichment factor was 39.1. Finally, this method was successfully used to extract and preconcentrate morin in various samples, followed with their determination by high‐performance liquid chromatography with ultraviolet detection.  相似文献   

20.
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