Green synthesis of three-dimensional magnesium ferrite/titanium dioxide/reduced graphene from Garcinia mangostana extract for crystal violet photodegradation and antibacterial activity

In this study,three-dimensional porous magnesium ferrite/titanium dioxide/reduced graphene oxide(Mg Fe_2O_(4)-GM/TiO_(2)/rGO(MGTG))was successfully synthesized via green and hydrothermal-supported co-precipitation methods using the extract of Garcinia mangostana(G.mangostana)as a reducing agent.The characterization results indicate the successful formation of the nano/micro Mg Fe_(2)O_(4)(MFO)and TiO_(2) on the structure of the reduced graphene oxide(rGO),which can also act as efficient support,alleviating the agglomeration of the nano/micro MFO and TiO_(2).The synergic effects of the adsorption and photodegradation activity of the material were investigated according to the removal of crystal violet(CV)under ultraviolet light.The effects of catalyst dosage,CV concentration,and p H on the CV removal efficiency of the MGTG were also investigated.According to the results,the CV photodegradation of the MGTG-200 corresponded to the pseudo-first-order kinetic model.The reusability of the material after 10 cycles also showed a removal efficiency of 92%.This happened because the materials can easily be recollected using external magnets.In addition,according to the effects of different free radicals·O_(2)^(-),h^(+),and·OH on the photodegradation process,the photocatalysis mechanism of the MGTG was also thoroughly suggested.The antibacterial efficiency of the MGTG was also evaluated according to the inhibition of the Gram-positive bacteria strain Staphylococcus aureus(S.aureus).Concurrently,the antibacterial mechanism of the fabricated material was also proposed.These results confirm that the prepared material can be potentially employed in a wide range of applications,including wastewater treatment and antibacterial activity.

山竹皮氧杂蒽酮超声辅助植物油提取工艺优化及其抗氧化和抑菌能力研究

使用中心复合设计对超声波辅助植物油提取山竹皮氧杂蒽酮工艺进行优化,并研究山竹皮提取物在植物油中的抗氧化能力和抑菌能力。结果:超声波辅助植物油提取山竹皮氧杂蒽酮工艺中最终采用大豆油作为提取溶剂,最佳提取工艺为超声时间2 h、料液比1∶25 g/mL、水浴时间35 min;山竹皮氧杂蒽酮提取物在植物油中具有显著的抗氧化能力和一定抑菌效果,其对枯草芽孢杆菌的抑菌效果最佳。

Antibiofilm activity of a-mangostin extracted from Garcinia mangostana L. against Staphylococcus aureus

Objective: To isolate a-mangostin(AMG) from the peels of mangosteen(Garcinia mangostana L.), grown in Vietnam, and to investigate antibiofilm activity of this compound against three Staphylococcus aureus(S. aureus) strains, one of which was methicillin-resistant S. aureus(MRSA) and the other two strains were methicillinsensitive S. aureus(MSSA).Methods: AMG in n-hexane fraction was isolated on a silica gel column and chemically analyzed by HPLC and NMR. The antibiofilm activity of this compound was investigated by using a 96-well plate model for the formation of biofilms. Biofilm biomass was quantified using crystal violet. The viability of cells was observed under confocal microscopy using LIVE/DEAD Bac Light stains. Biofilm composition was determined using specific chemical and enzyme tests for polysaccharide, protein and DNA. Membranedamaging activity was assayed by measuring the hemolysis of human red blood cells in presence of AMG.Results: The results indicated that the isolated AMG, with a purity that exceeded 98%,had minimal inhibitory concentrations in the range of 4.6–9.2 mmol/L for the three strains tested. Interestingly, the MSSA strains were more sensitive to AMG than the MRSA strain. Minimal bactericidal concentrations were 2-fold higher than the minimal inhibitory concentration values for the three strains, indicating that AMG was a bactericidal compound. AMG also prevented biofilm formation effectively, albeit that again the MRSA strain was the most resistant. Interestingly, biofilms of the MRSA strain contained protein as a main component of the extracellular matrix, whereas this was polysaccharide in the MSSA strains. This might relate to the resistance of the MRSA 252 strain to AMG.Assays using human red blood cells indicated that AMG caused significant membrane damage with 50% of cell lysis occurred at concentration of about 36 mmol/L.Conclusions: Our results provide evidence that the isolated AMG has inhibitory activity against biofilm formation by S. aureus, including MRSA. Thus, isolated AMG proposes a high potential to develop a novel phytopharmaceutical for the treatment of MRSA.

Antimalarial activity and toxicity of Garcinia mangostana Linn.

Objective:To investigate the antimalarial activity and toxicity of the crude ethanolic extract of its pericarp both in vitro and in vim.Methods:The antimalarial activity of Gareinja mangostana(G.mangostana)Linn.extract against 3D7 and Kl Plasmodium falciparum(P.falciparum)clone were assessed using SYBR green I-based assay.A 4-day suppressive test of Plasmodium berghei{P.berghei)infected mouse was performed to investigate in vivo antimalarial activity.Results:The in vitro antimalarial activity was seleclive(SI>5?and classified as weak and good lo moderate activity against both 3D7 and K1 P.falciparum,clones with median IC_(50)(range)values of 11.12(10.94-11.29)and 7.54(6.80-7.68)μg/mL,respectively.The extract was considered nontoxic to mice.The maximum tolerated doses for acute and subacute toxicity in mice were 5 000and 2 000 mg/kg,respectively.Median(range)parasite density on day 4 of the negative control group(25%Tween-80),mice treated with 250,500,1000,and 2 000 mg/kg body weight of the extract,and 10 mg/kg body weight of chloroquine for 14 d were 12.8(12.2-13.7),11.4(9.49-13.8),11.6(9.9-12.5),11.7(10.6-12.8),10.9(9.4-11.6)and 0(0-0)%respectively.Parasite density on day 4in the control group treated with Tween-80 was higher than the groups treated with chloroquine and all dose levels of the extract.Conclusions:G.mangostana linn,showed weak antimalarial activity of the extract both in vitro and in vivo could be due to limitation of absorption of the active compounds.

Proteomics analysis of antimalarial targets of Garcinia mangostana Linn.

Objective:To investigate possible protein targets for antimalarial activity of Garcina mangostana Linn.(G.mangostana)(pericarp)in 3D7 Plasmodium falciparum clone using 2-dimensional electrophoresis and liquid chromatography mass-spectrometry(LC/MS/MS).Methods:3D7 Plasmodium falciparum was exposed to the crude ethanolic extract of G.mangostana Linn.(pericarp)at the concentrations of 12μg/mL(1C_(50)level:concentration that inhibits parasite growth by 50%)and 30μg/mL(1C_(90)level:concentration that inhibits parasite growth by 90%)for 12 h.Parasite proteins were separated by 2-dimensional electrophoresis and identified by LC/MS/MS.Results:At the IC_(50)concentration,about 82%of the expressed parasite proteins were matched with the control(non-exposed),while at the IC_(90)concentration,only 15%matched proteins were found.The selected protein spots from parasite exposed to the plant extract at the concentration of 12μg/mL were identified as eneymes that play role in glycolysis pathway,i.e.,phosphoglyeerate mutase putative,L-lactate dehydrogenase/glyceraldehyde-3-phosphate dehydrogenase,and fruetose-bisphosphate aldolase/phosphoglyeerate kinase.The proteosome was found in parasite exposed to 30μg/mL of the extract.Conclusions:Results suggest that proteins involved in the glycolysis pathway may be the targets for antimalarial activity of G.mangostana Linn.(pericarp).

Larvicidal activity of the pericarp extract of Garcinia mangostana against dengue vector Aedes aegypti in Sri Lanka

Objective:To assess the larvicidal activity of mangosteen(Garcinia mangostana)against larval stages of Aedes aegypti mosquitoes.Methods:A crude extract was prepared in ethanol from powdered mangosteen pericarps.A concentration gradient(0.01-4.92 g/L)was prepared from the stock solution.Seven batches of 25 third instar larvae of Aedes aegypti were used for larval bioassays.Larval mortality rates were observed after one and 24 hours.Cholesterol and total lipid contents in 20 randomly selected dead larvae at each trial were assessed by colorimetric method.The experimental setup was repeated five times.The General Linear Model and Probit analysis were used to evaluate the relationship of mortality with cholesterol level,total lipid level and cholesterol to total lipid ratio.Results:The percentage mortalities significantly varied with different concentrations(F_(7,32)=385.737;P<0.001).The LC50 and LC99 values were(0.041±0.006)g/L and(10.616±1.758)g/L,respectively after 24 hours.There was no mortality recorded within the one-hour exposure time.Only the cholesterol content(F_(5,24)=173.245;P<0.001)in larvae exposed to different concentrations denoted a significantly decreasing trend within 24-hour exposure.Larvae that were exposed to the lowest concentration(0.55 g/L)showed a higher cholesterol level(22.67±1.33)μg.Conclusions:The Garcinia mangostana extract acts as an effective sterol carrier protein inhibitor that inhibits cholesterol uptake in Aedes aegypti mosquitoes.Hence,it could be explored for use as a key source for the development of an environment-friendly plant-based larvicide.

山竹壳多酚类物质提取纯化方法和生物活性研究进展

山竹作为一种药食同源的水果,以鲜食为主,其食用后产生的大量果壳被丢弃,造成资源浪费以及环境污染。山竹壳质量约占山竹鲜果的60%,含有丰富的氧杂蒽酮类、黄酮类等多酚类物质,且这些多酚类物质具有抗氧化、抗菌、抗癌等生物活性。该文从山竹壳多酚类物质的提取、纯化方法及生物活性三方面进行综述,为山竹壳功能活性的开发提供参考。

山竹皮单宁提取与纯化工艺

以山竹(Garcinia mangostana L.)皮为原料,采用乙醇为提取溶剂,用溶剂萃取法提取山竹皮单宁;采用大孔树脂吸附法分离纯化山竹皮中的单宁,得到山竹皮中单宁最佳的提取工艺与分离纯化条件。结果表明,以提取率为考核指标,由单因素、正交试验结果确定提取山竹皮单宁的最佳工艺条件为50%乙醇、料液比1∶225、提取温度65℃、提取时间50 min,山竹皮中单宁的提取率可达10.78%。从5种大孔树脂中筛选出吸附和洗脱效果较好的ADS-21、HPD826大孔树脂,根据静态、动态吸附,静态、动态洗脱试验结果,得出ADS-21大孔树脂为分离纯化山竹皮中单宁的最佳树脂,洗脱溶剂适宜用75%乙醇。

山竹果壳中红色素的提取及其应用研究

本文研究了山竹果壳红色素的提取条件和应用结果表明,采用0.108%HCl-95%乙醇作为提取剂,按1:8(质量:体积)的投料比,在常温下浸提10h,山竹红色素有较高的提取率。将山竹果壳红色素应用于饮料和白酒着色,表现出良好的稳定性。

多酚对鸡肉氧化脂肪诱导蛋白质变性的影响

为了探索茶多酚对冷鲜鸡氧化脂肪诱导蛋白质发生变性的抑制作用,以三黄胡须鸡为原料,利用不同氧化时间下制备的氧化脂肪与提取的冷鲜鸡肌原纤维蛋白制备模拟反应体系。在该体系中加入0.1%茶多酚,测定4℃条件下模拟体系中肌原纤维蛋白变性指标,分析茶多酚对冷鲜鸡氧化脂肪诱导蛋白质发生变性的抑制作用。结果表明:不同程度氧化的脂肪与蛋白质建立的模拟体系中,肌原纤维蛋白氧化变性程度显著差异。在加入茶多酚的模拟体系和未加茶多酚的模拟体系中,茶多酚的模拟体系中与肌原纤维蛋白氧化有关的羰基含量、表面疏水性都发生显著的变化,而总巯基含量的降低也有明显的减少。说明茶多酚对氧化脂肪诱导蛋白质发生氧化变性产生了抑制作用。

山竹果壳色素的稳定性及抑菌活性研究

研究从山竹果壳中提取的色素在不同条件下的稳定性及抑菌活性。将山竹果壳色素用不同的pH、温度和不同浓度的金属离子、氧化剂、还原剂、常用防腐剂处理。结果显示:山竹果壳色素在pH<6时较稳定;温度大于80℃后增色效应增强;各种金属离子对其影响较小;山竹果壳色素易被氧化、还原;高浓度的防腐剂对其稳定性有较大影响。抑菌实验显示,山竹果壳提取液对霉菌、细菌、酵母菌都有较强的抑菌效果,随着色素质量浓度的提高抑制作用随之增强。其抑菌效果依次为藤黄球菌>八叠球菌>枯草芽孢杆菌>啤酒酵母>根霉>痢疾杆菌>大肠杆菌。实验显示,该色素具有较好的稳定性和抑菌活性,可作为天然植物色素应用于食品、饮料添加剂和制药等行业。

山竺果壳的化学成分(英文)

从山竺（Garcinia mangostana）果壳中分离得到6个化合物，通过MS，1D NMR以及与文献对照鉴定它们为4个[口山]酮类化合物：α-rnangostin（1），β-mangostin（2），γ-mangostin（3），5，9-dihydroxy-8-methoxy-2，2-dimethyl-7-（3-methylbut-2-envl）-2H，6H-pyrano-[3，2-b]-xanthen-6-one（4），以及表儿茶素（epicatechin，5）和一个双苄类化合物egonol（6）。其中化合物5和化合物6为首次从该植物中分离得到。对化合物1～5进行抗HIV-1 RT活性筛选结果表明，化合物2和化合物5在浓度200μg/ml的条件下，其对HIV-1 RT抑制率分别为41．97％和47．72％；同一实验结果显示化合物1，3和4没有抑制HIV-1 RT作用。

山竹壳中原花青素提取 分级及抗氧化活性的研究

从提取溶剂及提取条件等方面对山竹壳中原花青素提取工艺进行优化研究。通过提取溶剂、提取温度、提取时间、料液比、乙醇溶液酸碱度5个单因素试验,采用响应面分析法,分析乙醇溶液酸碱度、浸提时间、浸提温度和料液比之间的交互作用以及对原花青素提取率的影响,建立数学模型,得出最佳工艺条件为乙醇浓度的体积分数为60%,浸提温度60℃,浸提时间66min,料液比1∶19,乙醇溶液的酸碱度为3.7,原花青素提取率质量分数为5.94%。同时采用不同有机溶剂分级山竹壳提取液,测定不同溶剂相自由基的清除率。

山竹果皮中抗氧化活性物质的提取分离

将山竹果皮95%乙醇提取物用溶剂萃取法分成4个不同的组分;采用体外抗氧化模型测定4个组分的抗氧化能力;并对该4个组分分别测定总黄酮、总酚的含量;用大孔吸附树脂D101纯化分离正丁醇相;并测定正丁醇相纯化前后抗氧化活性、总黄酮和总酚含量的变化。结果表明:正丁醇相表现出较强的抗氧化活性;而且该相中总黄酮和总酚的含量也较其他几相高;用D101大孔吸附树脂纯化正丁醇相后抗氧化活性及总黄酮、总酚含量都有显著的提升。

催陈方式对山竹果酒理化特性和香气成分的影响

采用加热、微波和超声波等催陈方法对山竹果酒进行处理,考察不同催陈方式对山竹果酒各理化指标(总酯、总酸、色度)的影响,并通过顶空固相微萃取-GC-MS方法对挥发性香气成分进行了分析,探讨了催陈方式对香气成分的影响。结果表明:加热和微波处理有利于果酒总酯含量的提高,最大值达到2.97 g/L,加热处理的果酒色度比原果酒色度升高了53.3%,微波处理有利于果酒酸度的降低,原果酒的总酸含量由2.21 g/L降低至1.72 g/L。香气成分表明:三种催陈方式对果酒品质和香气都有所改善,山竹果酒经加热处理后,醇类物质降低了11.89%,脂类物质含量升高了11.28%,并生成了2-甲基丁酸乙酯等新物质。经微波处理后的醇类物质含量略有降低,脂类物质含量略有升高,而超声处理后醇类物质含量由原来的84.61%降低了7.42%,脂类物质含量由原来的15.3%升高了7.1%,并生成乙酸己酯、松油醇、乙酸苯乙酯等新物质,对香气成分有较大的改善。

莽吉柿中几种双苯吡酮和蒽醌类成分的分离与鉴定

对莽吉柿(Pericarpium Garciniae Mangostanae)85%乙醇提取物进一步分离,得到8个双苯吡酮类化合物和1个蒽酮类化合物,经理化性质和NMR及MS谱学数据鉴定分别为α-倒捻子素-3,6-二乙酸酯(α-mangostin-3,6-diyl diacetate,Ⅰ)、1,5,8-三羟基-3-甲氧基-2,4-双-(3-甲基丁-2-烯)双苯吡酮(8-hydroxycud-raxanthone G,Ⅱ)、1,3-二羟基-6,7-二甲氧基-2,8-双-(3-甲基丁-2-烯基)双苯吡酮(Cowaxanthone B,Ⅲ)、1,6-二羟基-3,5-二甲氧基-2-(3-甲基丁-2-烯基)双苯吡酮(Cowaxanthone A,Ⅳ)、1,5-二羟基-4-(3-甲基丁-2-烯基)-6′,6′-二甲基吡喃[2′,3′:3,2]双苯吡酮(trapezifolixanthone,Ⅴ)、1,6-二羟基-6′,6′-二甲基吡喃[2′,3′:7,8]-6″,6″-二甲基吡喃[2″,3″:3,2]双苯吡酮(brasilixanthone B,Ⅵ)、1,3,5-三羟基-2-(3-甲基丁-2-烯)-4-(1,1-二甲基-2-烯丙基)双苯吡酮(Allanxanthone A,Ⅶ)、1,3,8-三羟基-5-甲氧基-2,4-双-(3-甲基丁-2-烯)双苯吡酮(2,4-di-(3-methylbut-2-enyl)-1,3,8-trihydroxy-5-methoxyxanthone,Ⅷ)、1,4,8-三羟基-6-甲基-3-甲氧基-9,10-蒽酮(1,4,8-trihydroxy-6-methyl-3-methoxy-9,10-anthraquinone,Ⅸ)。其中化合物Ⅰ、Ⅴ、Ⅵ、Ⅶ、Ⅸ为首次从藤黄属植物中分离得到,化合物Ⅱ、Ⅲ、Ⅳ、Ⅷ为首次从该植物中分离得到。

莽吉柿果皮中几种氧杂蒽酮的分离与鉴定

对莽吉柿果皮的85%乙醇提取物进一步分离,得到5个氧杂蒽酮类化合物,经理化性质和NMR及MS数据鉴定,分别为1,6-二羟基-6′,6′-二甲基-4′,5′-二氢吡喃[2′,3′:7,8]-6″,6″-二甲基-4″,5″-二氢吡喃[2″,3″:1,2]氧杂蒽酮(isonormangostin,Ⅰ)、1,3,6,7-四羟基-2,5,8-三-(3-甲基丁-2-烯基)氧杂蒽酮(garcinoneE,Ⅱ)、1,3,6-三羟基-7-甲氧基-2,5,8-三-(3-甲基丁-2-烯)氧杂蒽酮(7-O-methylgarcinone E,Ⅲ)、1,6-二羟基-7-甲氧基-8-(3-羟基3-甲基丁基)-6′,6′-二甲基-4′,5′-二氢吡喃[2′,3′:3,2]氧杂蒽酮[1,6-dihydroxy-7-methoxy-8-(3-hydroxy-3-methylbutyl)-6′,6′-dimethyl-4′,5′-dihydropyrano[2′,3′:3,2]xanthone,Ⅳ]、1,6-二羟基-7-甲氧基-8-(3-甲基丁-2-烯)-6′,6′-二甲基-4′,5′-二氢吡喃[2′,3′:3,2]氧杂蒽酮(3-isomangostin,Ⅴ)。其中化合物Ⅱ、Ⅳ为首次从该植物中分离得到。

微波-表面活性剂协同提取山竹外衣色素

研究了微波-表面活性剂协同提取法(MAME)提取山竹外衣色素的工艺条件与过程。考察了提取剂中表面活性剂类型和含量、提取液pH、微波提取功率、时间、浸泡固液质量比和时间对色素提取率的影响,实验结果表明:pH=1时,以w(聚氧乙烯十二酸失水山梨醇单酯)=0.08%的乙醇溶液〔φ(CH3CH2OH)=70%〕为提取剂,山竹外衣按m(山竹外衣)∶m(提取剂)=1∶263浸泡于提取剂中5 m in、微波功率800 W下提取25 s,色素提取率为96.26%。该法一次提取率是传统溶剂法的1.78倍,提取时间是溶剂法的1/240,聚氧乙烯十二酸失水山梨醇单酯对色素提取有增溶作用。

膜分离技术提取山竺红色素的工艺优化

以山竺果皮为原料,对山竺红色素提取、纯化工艺进行研究。采用正交试验研究山竺红色素的提取条件,结果表明最佳提取工艺条件为浸提温度50℃、浸提时间120min、料液比1:8(g/mL)。应用膜分离技术对山竺红色素提取液进行除杂纯化,研究微滤预处理、操作压差和膜面流速对超滤膜通量的影响,确定超滤最佳纯化工艺为操作压差0.12MPa、膜面流速2500L/h。超滤液经蒸发、干燥可得到纯度较高的山竺红色素,其色价达22.15,为未经超滤提取色素色价的3.5倍。

山竹果皮植物多酚及其抗氧化活性研究

以山竹果皮为原料,分析山竹果皮中植物多酚的类型及含量,并对其抗氧化活性进行研究。研究结果表明,山竹果皮中含有缩合类植物多酚、水解类植物多酚和黄酮等多种多酚类物质。其中,总酚、原花青素以及总黄酮的含量分别为15·5%±1·9%、8·56%±1·40%和6·52%±2·14%。山竹果皮提取液经大孔树脂纯化后,40%乙醇洗脱相的抗氧化活性最强,对DPPH自由基、羟基自由基以及超氧阴离子的清除能力IC50值分别为32·5±0·5、55·1±0·7、25·3±0·6μg/mL。