Phytochemicals Mediated Synthesis of AuNPs from Citrullus colocynthis and Their Characterization

Engineered nanoparticles that have distinctive targeted characteristics with high potency are modernistic technological innovations. In the modern era of research, nanotechnology has assumed critical importance due to its vast applications in all fields of science. Biologically synthesized nanoparticles using plants are an alternative to conventional methods. In the present study, Citrullus colocynthis (bitter apple) was used for the synthesis of gold nanoparticles (AuNPs). UV-Vis’s spectroscopy, XRD, SEM and FTIR were performed to confirm the formation of AuNPs. UV-Vis’s spectra showed a characteristic peak at the range of 531.5–541.5 nm. XRD peaks at 2 θ = 38°, 44°, 64° and 77°, corresponding to 111, 200, 220 and 311 planes, confirmed the crystalline nature of AuNPs. Spherical AuNPs ranged mostly between 7 and 33 nm, and were measured using SEM. The FTIR analysis confirmed the presence of phytochemicals on the surface of AuNPs. Successful synthesis of AuNPs by seed extract of Citrullus colocynthis (bitter apple) as a capping and reducing agent represents the novelty of the present study.     

Purification and biochemical properties of SDS-stable low molecular weight alkaline serine protease from Citrullus colocynthis

A low molecular weight serine protease from seeds of Citrullus colocynthis was purified to electrophoretic homogeneity with high level of catalytic efficiency (22,945 M^?1 S^?1). The enzyme was a monomer with molecular mass of 25 kDa estimated by SDS–PAGE. The enzyme was highly active over a pH range of 6.5–9.0 and temperature range of 20–80 °C, with maximum activity at pH 7.5 and at 50 °C. The K_m and K_cat were 73 μg/mL and 67/s, respectively. The enzyme was strongly inhibited by PMSF, moderately by soybean trypsin inhibitor, indicating that the enzyme was a serine protease. The enzyme retained 86 and 73% of its activity in the presence of urea and DTT, respectively, and its activity was slightly enhanced in the presence of anionic detergent (SDS). Thus, the enzyme is a novel SDS-stable protease with high catalytic efficiency over wide ranges of pH and temperature which is commercially promising for various industrial applications.     

New Pentacyclic Cucurbitane Glucosides from the Fruits of Citrullus colocynthis Schrad.

Colocynthins A–C ( 1 – 3 , resp.), new pentacyclic cucurbitane type triterpene glucosides, have been isolated from the AcOEt‐soluble fraction of the fruits of Citrullus colocynthis, along with three known compounds, β‐sitosterol 3‐O‐β‐D ‐glucopyranoside, elaterinide, and bryoamaride. Their structures were determined on the basis of ¹H‐ and ¹³C‐NMR spectra, DEPT, and COSY, NOESY, HMQC, and HMBC experiments.     

Optimization of supercritical fluid extraction of geniposidic acid from plantain seeds using response surface methodology

The process parameters of supercritical CO₂ (SCCO₂) plus modifer for the extraction of geniposidic acid from plantain seeds were studied using a Box–Behnken design. The effects of independent variables, that is, ethanol concentration (0–70%, ethanol:water, v/v), extraction pressure (10–30 MPa), and temperature (50–80°C) on the yield of geniposidic acid were evaluated. Results indicated that the data could be well fitted to a second-order polynomial model. The effects of ethanol concentration and temperature, as well as the interaction between ethanol concentration and temperature were significant (p < 0.05). The yield (8.9 mg/g) of modified SCCO₂ extraction at optimal conditions was compared with that obtained by Soxhlet extraction or ultrasound assisted extraction.     

Polysaccharides of Fabaceae. II. Galactomannan from <Emphasis Type="Italic">Astragalus danicus</Emphasis> seeds

Galactomannan of molecular weight 472 kDa was isolated from Astragalus danicus Retz. (Fabaceae) seeds and consisted of galactose and mannose units in a 1:1.40 molar ratio. The main chain of the macromolecule was constructed of 1,4-β-D-mannopyranose units, 71% of which were substituted at C-6 by single α-D-galactopyranose units. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 255257, May-June, 2009.     

Characterization of urease derived from Citrullus lanatus (watermelon) seeds to estimate total Kjeldahl nitrogen in human urine

A urease extract prepared by decanting liquid from a suspension of finely ground Citrullus lanatus (watermelon) seeds was characterized and applied to dilute urine samples to demonstrate a low-cost field method to estimate total Kjeldahl nitrogen (TKN) concentrations in human urine. The extract exhibited a Michaelis-Menten constant, K_m, of 3.00 mM urea and a specific activity of up to 12.2 U/mg protein at an optimum pH of 8.1. A statistical F-test on 54 samples demonstrated that TKN can be estimated as the total ammonium-nitrogen recovered upon addition of urease in dilute fresh and stale urine samples. The total ammonium-nitrogen in urine samples determined after treatment with watermelon seed urease was consistent with that determined using traditional acid digestion techniques. The extract retained 85% of its initial capacity after three months of refrigeration. The effectiveness of this method to assay nitrogen in unbuffered urine samples will be useful in nitrogen analyses in nutrient recovery and urine or slurry storage contexts. Accordingly, this study is useful in understanding the kinetics of a plant-derived urease acting in dilute urine.     

正交试验结合响应面法优化诃子多糖提取工艺

采用正交试验结合响应面法优化诃子多糖的提取工艺,以诃子多糖的提取率为指标,以固液比、提取温度、提取时间和提取次数为因素,正交试验初步筛选工艺参数,响应面法做进一步优化.结果表明,多糖提取的最佳工艺条件为固液比1∶28,提取温度69℃,提取时间1h,提取次数3次,各项指标相对误差均小于2%,应用响应面法可减少诃子多糖提取时间.     

复合酶法提取大蒜多糖及其抗氧化活性研究

用复合酶法对大蒜多糖的提取工艺进行研究,并考察了不同浓度沉淀多糖的抗氧化活性;以多糖提取得率为指标,苯酚-硫酸法测定多糖的总糖含量,采用正交实验确定纤维素酶、木瓜蛋白酶和果胶酶的最佳配比,然后在单因素试验的基础上,采用正交实验优化复合酶提取大蒜多糖的最佳工艺;分别用羟基自由基(·OH)和1-二苯基-2-苦基肼基(DPP...     

In Vitro Cytotoxic Activity and Phytochemical Characterization (UPLC/T-TOF-MS/MS) of the Watermelon (Citrullus lanatus) Rind Extract

Reusing food waste is becoming popular in pharmaceutical industries. Watermelon (Citrullus lanatus) rind is commonly discarded as a major solid waste. Here, the in vitro cytotoxic potential of watermelon rind extracts was screened against a panel of human cancer cell lines. Cell cycle analysis was used to determine the induction of cell death, whereas annexin V-FITC binding, caspase-3, BAX, and BCL-2 mRNA expression levels were used to determine the degree of apoptosis. VEGF-promoting angiogenesis and cell migration were also evaluated. Moreover, the identification of phytoconstituents in the rind extract was achieved using UPLC/T-TOF-MS/MS, and a total of 45 bioactive compounds were detected, including phenolic acids, flavonoids aglycones, and their glycoside derivatives. The tested watermelon rind extracts suppressed cell proliferation in seven cancer cell lines in a concentration-dependent manner. The cytotoxicity of the rind aqueous extract (RAE) was higher compared with that of the other extracts. In addition to a substantial inhibitory effect on cell migration, the RAE triggered apoptosis in HCT116 and Hep2 cells by driving the accumulation of cells in the S phase and elevating the activity of caspase-3 and the BAX/BCL-2 ratio. Thus, a complete phytochemical and cytotoxic investigation of the Citrullus lanatus rind extract may identify its potential potency as an anticancer agent.     

黄芪多糖提取分离纯化工艺的优化研究

采用温浸法设计四因素三水平正交试验,对黄芪多糖最佳提取工艺进行了优化,结果表明:四因素对黄芪多糖提取的影响顺序为提取温度>提取次数>料液比>提取时间,提取最佳工艺为:料液比1∶6,提取时间90 min,提取温度100℃时提取3次;采用乙醇沉淀法设计三因素三水平正交实验对其最佳分离工艺进行研究,研究发现:三因素三水平对黄芪多糖分离影响顺序为乙醇浓度>乙醇加入量>沉淀时间,分离的最佳工艺为乙醇浓度为90%,加入量5倍体积,沉淀时间4 h;选用AB-8大孔吸附树脂和聚酰胺为吸附剂,不同浓度乙醇为洗脱剂对黄芪多糖最佳纯化工艺进行了探索,确定了最佳纯化工艺为:AB-8大孔吸附树脂吸附,30%乙醇洗脱.这些条件的确定为黄芪的大规模开发和应用奠定了基础.     

1H and 13C NMR signal assignment of cucurbitacin derivatives from Citrullus colocynthis (L.) Schrader and Ecballium elaterium L. (Cucurbitaceae)

2D NMR-derived 1H and 13C NMR signal assignments of six structurally closely related cucurbitacin derivatives are presented. The investigated 2-O-beta-D-glucopyranosylcucurbitacins I, J, K, and L were obtained from Citrullus colocynthis (L.) Schrader whereas the aglyca cucurbitacin E and I were isolated from Ecballium elaterium L.     

Optimization of extraction and quantification technique for phenolics content of garlic (Allium sativum): An application for comparative phytochemical evaluation based on cultivar origin

A range of conventional, i.e. maceration, percolation, ultrasonic assisted, Soxhlet and Soxtec extraction (STE), to advanced extraction techniques of accelerated solvent extraction (ASE) was utilized for the first time in order to optimize the extract yield and recovery of phenolics—gallic acid (GA), rutin (RT) and quercetin (QT)—quantified via ultra-high performance liquid chromatography with diode array detector (UHPLC–DAD). The effect of solvents (n-hexane, dichloromethane and methanol) and temperature (60, 80 and 100°C) upon extraction yield, phenolic content and antioxidant activity (DPPH, ABTS and DPPH) was studied, and the method was validated in commercial food samples from Saudi Arabia, China and India. A high extract yield with percentage recovery was observed for STE (1221.10 mg/5 g; 24.42%) and ASE techniques (91.50 mg/1 g; 9.15%) in methanol at 100°C. UHPLC–DAD showed retention times (min) of 0.67, 1.93 and 1.90 for GA, RT and QT, respectively in the shortest runtime of 3 min. The yield for phenolics was higher for STE/ASE (ppm): 15.27/15.29 (GA), 85.24/37.56 (RT) and 52.20/33.40 (QT), respectively. In terms of antioxidant activities, low IC₅₀ values (μg/ml) of 1.09/1.18 (DPPH), 2.11/5.32 (ABTS) and 4.35/7.88 (phenazine methosulfate–nicotinamide adenine dinucleotide) were observed for STE and ASE, respectively. Multivariate analysis for STE showed a significant (P = 0.000) correlation for extraction type vs. extract yield and phenolics content; however, there was no significance for antioxidant activities vs. extraction type. ASE showed a positive correlation for solvent vs. extraction yield, phenolics and antioxidant activity; however, there was no correlation for extraction yield and DPPH activity. Principal component analysis for STE showed a major variability (52.02%) for extraction yield and phenolics in PC1 followed by PC2 (38.30%) for antioxidant activities. For ASE, PC1 (48.68%) showed a positive correlation for solvent vs. extraction yield and phenolics while PC2 (33.12%) showed a positive correlation for temperature and antioxidant activities. STE and ASE were the optimized extraction techniques for the garlic food sample while a significant effect of solvent and temperature was observed upon extraction yield, phenolics and antioxidant activity.     

Optimization Extraction and Antioxidant Activity of Crude Polysaccharide from Chestnut Mushroom (Agrocybe aegerita) by Accelerated Solvent Extraction Combined with Response Surface Methodology (ASE-RSM)

The present work is conducted to investigate the optimal extraction technology of polysaccharide from chestnut mushroom (Agrocybe aegerita) using a new method based on accelerated solvent extraction combined with response surface methodology (ASE-RSM). The conventional reflux extraction (CRE) method and ultrasonic-assisted extraction (UAE) method were also carried out. Additionally, the in vitro antioxidant activities, including ABTS and DPPH assay, were evaluated. The RSM method, based on a three level and three variable Box–Behnken design (BBD), was developed to obtain the optimal combination of extraction conditions. In brief, the polysaccharide was optimally extracted with water as extraction solvent, extraction temperature of 71 °C, extraction time of 6.5 min, number of cycles of 3, and extraction pressure of 10 MPa. The 3D response surface plot and the contour plot derived from the mathematical models were applied to determine the optimal conditions. Under the above conditions, the experimental value of polysaccharide yield was 19.77 ± 0.12%, which is in close agreement with the value (19.81%) predicted by the model. These findings demonstrate that ASE-RSM produce much higher polysaccharide and consumed environmentally friendly extraction and solvent systems, have less extraction discrimination and shorter time and provide scientific basis for industrialization of polysaccharide extraction. Moreover, it was proved that the polysaccharide had the potential ability to scavenge ABTS and DPPH.     

Optimization of polysaccharides extraction from quince peels: partial characterization,antioxidant and antiproliferative properties

Abstract

In this study, Box-Behnken Design was used to optimize the ultrasonic extraction of polysaccharides from quince peels (QPPs) by ascorbic acid and the effect of extraction temperature, extraction time and pH was evaluated. Under optimized conditions of temperature 90?°C, 60?min sonication time and pH?=?3.26, the extraction yield, the galacturonic acid yield and the concentration of sample required to scavenge 50% of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS) values of QPPs were respectively 10.25%, 3.86% and 1.35?mg/mL. The QPPs extracted under optimum conditions was characterized by Fourier transform infrared spectroscopy (FTIR), Nuclear magnetic resonance (^1?H NMR) and Size exclusion chromatography (SEC/MALS/VD/DRI). The monosaccharide analysis revealed that arabinose was the most abundant, followed by galactose, glucose, mannose and xylose. Moreover, QPPs showed significant antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric- reducing antioxidant power (FRAP)) and reduced viability of human Caco-2 and murine B-16 cell lines in a dose-dependent manner. Hence QPPs could be used as antitumor agent in functional foods andpharmaceutical industries.     

Optimization of an Extraction Process to Obtain a Food-Grade Sulforaphane-Rich Extract from Broccoli (Brassica oleracea var. italica)

Sulforaphane (SFN) is a powerful health-promoting compound found in broccoli in the form of its inactive precursor, glucoraphanin (GFN). SFN formation occurs through the enzymatic hydrolysis of glucoraphanin by myrosinase under specific chemical conditions. Its incorporation in food formulations has been hindered by the thermal instability of SFN and low concentration in Brassicaceae. Then, extracting SFN from broccoli at a temperature below 40 °C appears as an option to recover and stabilize SFN, aiming at delivering it as a nutraceutical. We studied an eco-friendly extraction process to obtain an SFN-rich extract from broccoli. The effect of the broccoli mass/solvent ratio, ethanol concentration in the extractant solution, and extraction time on the recovery of SFN, GFN, phenolic compounds, and antioxidant activity were studied through a Box–Behnken design. The regression models explained more than 70% of the variability in the responses, adequately representing the system. The experimental factors differently affected the bioactive compound recovery and antioxidant activity of the extracts. The extraction conditions that allowed the highest recovery of bioactive compounds and antioxidant activity were identified and experimentally validated. The results may provide the basis for the design of a process to produce a sulforaphane-rich food supplement or nutraceutical by using a GRAS extractant.     

Optimization of extraction of total trans‐resveratrol from peanut seeds and its determination by HPLC

Resveratrol, a stilbene phytoalexin in plants, is believed to benefit human health. In this study, an optimized enzyme‐assisted method was developed to extract the total content of trans‐resveratrol (free or combined with glucose) in peanut seeds, followed by detection using high‐performance liquid chromatography. The extraction process was optimized by Box–Behnken design and response surface methodology. The optimized enzyme concentration, digestion time, pH, and temperature were 3.02 g/L, 57.06 min, 5.88, and 51.05°C, respectively. Validation tests indicated that the experimental yield of trans‐resveratrol was 0.183 ± 0.007 µg/g with a relative standard deviation of 3.87% (n = 5) under the optimal condition, which was closely agreed with the predicted value (0.182 µg/g). The recoveries obtained from the spiked samples were varied from 89.4 to 103.9%. Therefore, this study will provide a useful method for quantification of total trans‐resveratrol in peanut seeds.     

Isolation and structural characterization of a low-molecular-weight pectic polysaccharide SHPPB-1 isolated from sunflower heads

A novel low-molecular-weight pectic polysaccharide was isolated from sunflower heads that are a useless side product produced from sunflower oil processing. The low-molecular-weight pectic polysaccharide was purified by using an optimized four-step procedure and named as SHPPB-1. The molecular weight of SHPPB-1 is about 1.69× 10⁴ Da. Structure characterizations of SHPPB-1 by monosaccharide composition, methylation analysis, and Fourier transform infrared (FT-IR) spectroscopy showed that SHPPB-1 is consisted of 1,4-linked α-D-GalpA and 1,4-linked 2-OAc-5-COOMe-α-D-GalpA with rare α/β-D-Rhap, α/β-D-Manp, and α/β-D-GalpA. This was combined with NMR spectroscopic analysis to propose a structure of SHPPB-1 as: →4)-[α/β-D-monosaccharide-(1→3)]-α-D-GalpA-(1→4)-2-OAc-5-COOMe-α-D-GalpA-(1→ .     

Production,ultrasonic extraction,and characterization of poly (3‐hydroxybutyrate) (PHB) using Bacillus megaterium and Cupriavidus necator

Biodegradable polymer polyhydroxyalkanoates are one of the promising alternatives for conventional plastics. The present article focuses on a modified and novel method for the synthesis of poly (3‐hydroxybutyrate) (PHB) by two microorganisms, viz. Bacillus megaterium and Cupriavidus necator. These microbial cells were grown over fructose as a carbon source, and the produced PHB was recovered using ultrasound as well as solvent assisted extraction. The extracted PHB was characterized using FTIR, ¹H, and ¹³C NMR to observe the functional groups in the PHB molecule. The XRD characterization confirmed the partial crystalline nature of PHB, and the results of TGA, DTG, and DSC analysis attributed to the thermal stability of PHB. The major step of weight loss of PHB derived by B. megaterium and C. necator in TGA analysis was found to be 415°C and 289°C, respectively. These values were comparatively higher than standard PHB, for which it is 260°C. Similarly, the maximum degradation temperature for standard PHB is 236°C, whereas the maximum degradation temperature of PHB synthesized by B. megaterium and C. necator are 248°C and 277°C, respectively. This ascertains that the produced PHB has greater resistance to thermal degradation as compared with PHB standard. The melting point of synthesized PHBs were found to be 175°C to 176°C, which is similar to standard PHB. The glass transition temperature of the synthesized PHBs varies from –8°C to 6°C. The plausible reason behind the variances could be due to difference in crystallinity and molecular weight of polymer matrix. Nevertheless, thermal properties of PHB produced by B. megaterium and C. necator are found to be similar or much better than commercial PHB. The degree of crystallinity of synthesized PHBs are lower than previously reported literatures, which extends its range of applications.     

固相萃取人体血液中安定条件的统计学筛选与响应面优化

采用Plackett-Buman(P-B)法和中心复合设计(Central Composite Design,简称CCD)对影响固相萃取安定的6个因素进行筛选优化。P-B实验设计与统计学分析表明:pH、上样速度、洗脱液用量是影响回收率的3个关键因素。以回收率为响应目标,对3因素进行中心复合设计,并经响应面法优化分析得到影响回收率的二阶模型,确定了安定萃取实验的最优操作条件:pH10.20,上样速度0.67 mL/min,洗脱液用量2.60 mL,实测回收率达到91.26%。在0.10～10.00μg/mL的范围内本方法线性良好(R2>0.99),检测限为0.07μg/mL,日内和日间相对标准偏差(RSD)<10%,准确度(RE)<±6.0%。