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.

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.

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.

从泰国进境山竹上截获藤黄树链蚧Asterolecanium garciniae(Hemiptera:Asterolecaniidae)

本研究描述了藤黄树链蚧Asterolecanium garciniae的田间形态特征和显微形态特征;给出了结构测量值;提供了生态照片、显微照片和显微绘图;评述了与近似种A.javae、A.russellae和A.sumatrae的区别;提供了寄主和分布,首次报道了新的分布地曼谷;藤黄树链蚧为我国口岸首次截获,该研究结果可为链蚧的检疫鉴定及该种蚧虫的截获鉴定提供参考。

RP-HPLC-UVD法测定莽吉柿中α-倒捻子素的含量

[目的]建立一种测定莽吉柿(Garcinia mangostana L.)中α-倒捻子素(alpha-mangostin)含量的方法。[方法]采用反相高效液相色谱-紫外检测法(RP-HPLC-UVD)测定。色谱条件:迪马公司DiamonsilTMC18色谱柱(250.0mm×4.6mm,5.0μm);流动相,甲醇-水(83∶17);流速,1.0ml/min;柱温,25℃;紫外检测波长,317nm。[结果]在选定的色谱条件下,反相高效液相色谱-紫外检测法符合精密度、准确度和线性(R2>0.999)的基本要求,加样回收率为98.9%,RSD为1.87%。3批莽吉柿样品中α-倒捻子素含量分别为36.4、37.3、38.5mg/g,平均含量为37.4mg/g。[结论]该方法简便,准确,灵敏度高,重现性好,可用于莽吉柿中α-倒捻子素含量的测定。

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。

莽吉柿提取物对宫颈癌Hela细胞凋亡的影响

目的研究莽吉柿提取物对宫颈癌Hela细胞凋亡的影响。方法使用不同浓度0.75、1.25、2.5、5μg/mL的莽吉柿提取物处理体外培养Hela细胞,CCK-8检测试剂盒检测其对宫颈癌细胞增殖的影响;流式细胞术检测细胞凋亡和细胞活性氧(ROS)表达水平;Western Blot检测磷酸化的细胞外调节蛋白激酶(p-ERK1/2)、B淋巴细胞瘤-2蛋白(Bcl-2)和Bcl-2相关X蛋白(BAX)表达水平。结果莽吉柿提取物对宫颈癌细胞的增殖具有显著的抑制作用(P<0.05),IC50为1.63μg/mL。流式细胞术检测发现,莽吉柿提取物处理组(2.5μg/mL和5μg/mL)的Hela细胞的凋亡率显著高于对照组[(4.19±0.24)%、(14.03±0.21)%比(3.30±0.10)%,P均<0.05]。莽吉柿提取物处理组的ROS含量显著高于对照组,为对照组的3.05倍,P<0.05。荧光显微镜结果显示莽吉柿提取物处理组的ROS荧光强度显著升高。Western Blot检测发现,莽吉柿提取物处理组(2.5μg/mL和5μg/mL)宫颈癌Hela细胞p-ERK1/2蛋白表达量显著低于对照组,分别为对照组的54%和25%;Bcl-2蛋白表达量显著低于对照组,分别为对照组的76%和67%;BAX蛋白表达量显著高于对照组,分别为对照组的1.11倍和1.45倍(P均<0.05)。结论莽吉柿提取物对宫颈癌细胞的影响可能是通过诱导细胞氧化损伤,调控肿瘤细胞MAPK/ERK1/2信号通路和凋亡相关蛋白,进而诱导细胞发生凋亡,抑制肿瘤细胞的增殖。

RP—HPLC法测定山竹果壳中a—Mangostin的含量

建立高效液相色谱法测定山竹果壳中a—Mangostin的含量。色谱条件：色谱柱为Diamonsil C18（250mm×4．6mm，5μm）；流动相为乙腈-pH3．0磷酸水溶液（70：30）；流速1．0mL／min；检测波长240nm；柱温25℃；进样20山。线性范围内0．02—0．10mg／mL（r=0．9998），加样平均回收率为98．25％，RSD为0．74％（n=6）。本方法准确度高、重现性好，操作快速简捷，可以作为山竹果壳中a—Mangostin含量的检测方法。

Gc-Ms Analysis and Antibacterial Activity of Mangosteen Leaf Extracts against Plant Pathogenic Bacteria

The potential of Garcinia mangostana as a biological control agent against plant pathogenic bacteria which decrease the quality and volume of crop production worldwide was assessed. Mangosteen leaves were extracted by maceration using chloroform, n-hexane, and methanol. For the in vitro antibacterial activity, two dissimilar species of plant pathogenic bacteria: Pseudomonas syringe pv. tomato and Xanthomonas oryzae pv. oryzae were acquired. Four different concentrations, 12.5, 25, 50, and 100 mg/ml were obtained through the cup-plate agar diffusion technique. Streptomycin sulphate at 30 μg/ml concentration was set as the positive control, whereas every respective solvent used in the leaf extraction was set as the negative control. The results have shown that, only methanol extract demonstrated antibacterial activity when tested on the plant pathogenic bacteria. The highest diameter of inhibition zones was observed in X. oryzae pv. oryzae, at all range of concentrations, followed by P. syringae pv. tomato. The least methanol extract concentration utilised in determination of minimum inhibitory concentration (MIC) assay was at 1.562 mg/ml, inhibiting X. oryzae pv. oryzae, followed by P. syringe pv. tomato at a concentration 3.125 mg/ml. Antibacterial impacts of the most effectual extract of mangosteen crude were supported by the existence of chemical components identified by GC-MS. Cycloartenol, Caryophyllene, Docosane, Phenol, 4,4-Methylenebis (2,6-di-tert-butylphenol) and Chromium were noted as key compounds in the mangosteen leaf extract, which were perhaps causing the antibacterial activity.

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。

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。

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。

超声波辅助提取山竹果皮中的原花青素

文中研究了山竹果皮中原花青素的超声辅助提取工艺条件。通过单因素试验分析超声提取过程中超声功率、料液比、乙醇浓度、提取时间和温度等因素对原花青素提取率的影响,在此基础上,采用L9(34)正交试验优选出山竹果皮中原花青素提取的最佳条件。结果表明:各因素对原花青素提取率的影响大小顺序为乙醇浓度(B)>温度(C)>料液比(A)>时间(D);最佳工艺条件为料液比为1∶30,乙醇体积分数60%,提取温度50℃,提取时间45 min,此条件下山竹果皮中原花青素的提取率为15.61%。

山竹果皮提取物抗氧化活性的研究

研究了山竹果皮乙醇提取物的抗氧化活性。实验以富含α-亚麻酸的蚕蛹油为底物,采用烘箱法探讨山竹果皮乙醇提取物对蚕蛹油的抗氧化作用及与其它物质的协同抗氧化效果。实验结果表明,山竹果皮乙醇提取物对蚕蛹油有较好的抗氧化作用,其抗氧化能力随着提取物用量增加而增强,但其抗氧化效果不如维生素C;将山竹果皮乙醇提取物与维生素C、维生素E复配后,抗氧化能力显著改善,蚕蛹油氧化诱导期从20d提高至160d,表现出很明显的协同抗氧化作用。