Construction of AFLP Molecular Marking System in Mangifera indica L.

[Objective ] The study aimed to construct the AFLP molecular marking system in Mangifera indica. [ Method ] Four varieties of Mangifera indica were used to explore new ways for high-quality DNA, and AFLP analysis of 31 varieties of Mangifera indica was carried out to detect the varietal genetic diversity. [ Result] 14 pairs of primers with stronger polymorphism, better banding patterns and higher resolution were screened out from 64 pairs of selective amplification primers. Then they were used to analyse the fingerprint of 31 varieties of Mangifera indica, the results showed that the ratio of polymorphic bands amplificated by the 14 pairs of primers reached 97% in 31 varieties of Mangifera.[ Conclusion] It was suggested that AFLP was suitable for detecting the polymorphism of Mangifera indica resources.

水分胁迫对芒果(Mangifera indica L.)幼叶细胞活性氧伤害的影响

对芒果进行水分干旱胁迫处理 .结果表明 ,水分胁迫使芒果幼叶的相对含水量 RWC( relative water content)和叶水势 ΨT 下降 .芒果幼叶的超氧离子 O- 2.产生速率随水分胁迫处理强度加大而增加 .丙二醛 MDA( malondialdehyde)含量的变化趋势与 O- 2.产生速率的变化趋势相似 ,超氧歧化酶 SOD( superoxide dismutace) ,过氧化物酶 POD( peroxidase)和过氧化氢酶 CAT( catalase)的活性水平也与 O- 2.的变化相一致 ,细胞相对质膜透性加大 .说明芒果幼叶的水分胁迫损伤 ,是由 O- 2.引发的膜脂过氧化 ,致使 MDA含量增加 。

Occurrence Regularity of Fruit Physiological Disease Spongy Tissue in Zihua Mango(Mangifera indica L.)

[ Objective ] The aim was to study the occurrence regularity of fruit physiological disease spongy tissue in Zihua mango （Mangifera indica L. ）. [ Meth. od] Main features of disease symptoms of Zihua mango fruit spongy tissue were investigated from 2002 to 2005 ,and the correlation between the incidence of Zihua mango fruit spongy tissue and its external factors （ fruit maturity, fruit size and fruit yield per plant） was analyzed comprehensively. [Result] The main features of disease symptoms appeared depressed cavity in the middle or lower part of fruit, forming spongy-like cavity. Immature fruits basically had no incidence. The dis- ease began to appear before 10 d of maturity. The disease incidence rate had extremely positive correlation with fruit weight, fruit vertical diameter or cross diame- ter. [ Conclusion] The research provides reference for field diagnoses, identification, preharvest and postharvest uninjurous test of fruit physiological disease suonaw tissue.

Molecular Cloning and Sequence Analysis of C4H Gene of Mangifera indica L.

Cinnamate-4-hydroxylase( C4H) is a key enzyme in phenylpropanoid pathway in plants. Its activity and abundance directly affect the biosynthesis of flavonoids and aromatic compounds. In this study,degenerate primers were designed according to previously reported C4 H gene sequences to clone C4H cDNA sequence with 3'and 5'RACE-PCR from mango( Mangifera indica L). The full-length cD NA of M. indica C4H is 1 680 bp long. Its open reading frame( ORF)is 1 518 bp,encoding a protein of 505 amino acids with a predicted molecular weight of 58. 08 kDa. The isoelectric point of the predicted protein is 9. 52. Functional prediction showed that this gene is mainly located in mitochondria. In addition,the tertiary structure of the protein was built using SWISS-MODEL,and the results showed that the protein has three possible conformations. Phylogenetic analysis based on C4H protein sequences revealed that M. indica has a close genetic relationship with olive( Canarium album) and cocoa( Theobroma cacao). By analyzing the expression level of C4H gene in three colored mango cultivars,we found that that the expression level of C4 H gene in Guifei( with red peel) was the highest,and that in Guiqi( with green peel) was the lowest. The results provide a theoretical basis for studying the molecular mechanism of anthocyanin biosynthesis and C4H's impact on the color of mango fruit.

Antioxidant and antiglycation properties of two mango(Mangifera indica L.) cultivars from Senegal

Objective: To evaluate the total phenolic contents, antioxidant and antiglycation activities of leaves, barks, roots and kernels from two cultivars of Mangifera indica(Anacardiaceae). Methods: Total phenolic contents were determined by using Folin-Ciocalteu's method. The antioxidant activities were assessed by three different protocols including DPPH, oxygen radical absorbance capacity and iron(Ⅱ) chelation assays. In addition, in vitro bovine serum albumin/D-ribose assay was chosen to evaluate the antiglycation properties of the extracts. Results: All the investigated extracts were found to contain high level of total phenols as well as potent antioxidant activities. Kernel extracts showed the highest total phenol contents and DPPH radical scavenging activities whereas higher oxygen radical absorbance capacity values were observed for leave, root and bark extracts. Besides, extracts from leaves, roots and barks from both cultivars exhibited potent inhibitory effects against the formation of advanced glycation end products, with IC_(50) values lower than the standard positive control aminoguanidine. Conclusions: The potent antiglycation and antioxidative activities of these two Mangifera indica cultivars suggest a possible role in targeting aging, diabetic complications and oxidative stress related diseases.

Evaluation of Acute Toxicity, Antioxidant and Antibacterial Potential of Leaves Extracts from Two Anacardiaceae’s Species: Lannea microcarpa Engl. &K. Krause and Mangifera indica L.

Background: Leaves of Mangifera indica L or Lannea microcarpa Engl. & K. Krause are used in traditional medicine in Burkina Faso to treat bacterial, parasitic or metabolic diseases. Objective: The aim of this study is to evaluate the acute general toxicity, antioxidant potential and antibacterial activitiy of leave’s aqueous extracts from Lannea microcarpa Engl. and K. Krause and Mangifera indica L. The use of these plants in traditional medicine motivated our choice to lead scientific studies. Methods: The aqueous decoction of the leaves is the form of use recommended by traditional healers. We used the same type of extracts for studies. Acute toxicity was studied in NMRI strain mice, with the dose of 2000 mg/kg body weight, for each plant species. The antioxidant activity is evaluated by the method of reduction of radical DPPH. The phytochemical compounds were detected with specific reagent: Alcaloids with Dragendorff’s reagent, Flavonoids with ammonia (NH4OH), Polyphenols and tannins are revelated by ferric chloride (FeCl3). Saponosides were revelated by their foaming power property. Bacterial inhibiting activity is tested by measuring the diameters’ inhibition of extracts on reference strains. Results: The aqueous extracts were not toxic at the maximum dose of 2000 mg/kg body weight, for each plant species. The extracts showed an antioxidant activity with an IC50, 20 μg/ml for Lannea microcarpa and 18 μg/ml for Mangifera indica. The extracts showed no bacterial activity on three strains of bacteria tested: Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The phytochemicals we have identified are for L. microcarpa: tannins and phenolics compounds, triterpenes, saponosides. We identified in M. indica’s extracts: tannins and phenolics compounds, triterpenes, saponosides and flavonoids.

Anti-inflammatory effects of Mangifera indica L.extract in a model of colitis

AIM:To investigate the effect of aqueous extract from Mangifera indica L.(MIE)on dextran sulfate sodium (DSS)-induced colitis in rats.METHODS:MIE(150 mg/kg)was administered in two different protocols:(1)rectally,over 7 d at the same time as DSS administration;and(2)once daily over 14 d (by oral gavage,7 d before starting DSS,and rectally for 7 d during DSS administration).General observations of clinical signs were performed.Anti-inflammatory activity of MIE was assessed by myeloperoxidase(MPO)activity. Colonic lipid peroxidation was determined by measuring the levels of thiobarbituric acid reactive substances (TBARS).Reduced glutathione(GSH)levels,expression of inflammatory related mediators[inducible isoforms of nitric oxide synthase(iNOS)and cyclooxygenase (COX)-2,respectively]and cytokines[tumor necrosis factor(TNF)-αand TNF receptors 1 and 2]in colonic tissue were also assessed.Interleukin(IL)-6 and TNF-α serum levels were also measured. RESULTS:The results demonstrated that MIE has anti-inflammatory properties by improvement of clinical signs,reduction of ulceration and reduced MPO activity when administered before DSS.In addition,administration of MIE for 14 d resulted in an increase in GSH and reduction of TBARS levels and iNOS,COX-2, TNF-αand TNF R-2 expression in colonic tissue,and a decrease in IL-6 and TNF-αserum levels. CONCLUSION:MIE has anti-inflammatory activity in a DSS-induced rat colitis model and preventive administration(prior to DSS)seems to be a more effective protocol.

Unripe Fruit Extracts of <i>Mangifera indica L.</i>Protect against AGEs Formation, Melanogenesis and UVA-Induced Cell Damage

In this study, we explored the effects of unripe fruit extracts of Mangifera indica L. on the anti-aging activity in skin cells. Mangifera indica L. is a popular economical and medicinal plant with numerous health-beneficial properties. The aqueous extracts of unripe fruit of Mangifera indica L. were obtained and subjected to HPLC and NMR analyses for the identification of bioactive compounds. The anti-glycation effect of Mango unripe fruit extracts was monitored by in vitro model system of AGEs (Advanced glycation end products) formation. Mango unripe fruit extracts significantly inhibited the AGEs formation in a dose-dependent manner. Meanwhile, Mango unripe fruit extracts possessed a comparable efficiency to commercialized Kojic acids in the inhibition of melanogenesis in B16-F10 melanoma cells. The UVA-induced cell damages can be prevented and repaired by Mango unripe fruit extracts in skin fibroblast CCD-966SK. Compared to the untreated control, Mango unripe fruit extracts significantly increased the cell viability while being applied before (36%) or after (43%) UVA irradiation. These results verified the potential application of Mango unripe fruit extracts in the skin protection and recovery from UVA irradiation, as well as the suppression of AGEs formation and melanogenesis.

Management of Chenopodium album L. through the Allelopathic Effect of Mangifera indica L.

Chenopodium album is an invasive weed in wheat fields in Egypt. The present study indicated the potentials for utilization of MILAE （Mangifera indica leaves aqueous extract） at different concentrations （5%, 10%, 15% and 25%） to suppress the germination and growth of C. album in Petri dish experiment Results indicated that predictable degrees of inhibition in C album germination and growth rate of seedlings were accompanied with the increase in the concentration of MILAE. PL （Plumule） and RL （radicle） lengths of C. album were negatively affected as the concentration of MILAE increased and the effect was prominent at 25% extract concentration. This study recommended the use of MILAE as strong phytotoxic potential allelochemicals. an alternative bioherbicides, since its leaves extract possess

Preliminary investigation on the antibacterial activity of mango(Mangifera indica L:Anacardiaceae) seed kernel

Objective:To evaluate the antibacterial activity of the methanolic extract of mango(Mangifera indica L) seed kernel.Methods:Chokanan mango seed kernel and seed kernels from assorted mango varieties were collected,cleaned,dried and powered.Crude methanolic extracts of mango seed kernel were analyzed for the phytochemical constituents.The free radical scavenging activity was determined by 2,2-Diphenyl-1-picrylhydrazyl(DPPH) assay.Antibacterial activity was evaluated by disc diffusion assay with three medically important bacterial pathogens such as methicillin resistant Staphylococcus aureus(S.aureus)(MRSA),Escherichia coli(E.coli) and Vibrio vulnificus(V.vulnificus).Results:Qualitative phytochemical analysis indicated the presence of important phytochemical compounds such as glycosides,saponins,flavanoids, tannins and alkaloids.There was no significant difference in the phytochemical content between the single and assorted mango seed kernels.However,the free radical scavenging study indicated that the assorted mango kernels showed slighdy higher activity than the single species(P【0.05). The crude methanolic extract of mango seed kernel at a concentration of 100 mg/mL is found to have potential antimicrobial activity against MRSA and E.coli compared to V.vulnificus. Study on the antibacterial activity also indicated that there was no significant difference in the antibacterial activity of the single and assorted mango seed kernel extracts.Conclusions:The present study conclusively demonstrates the free radical scavenging activity and antibacterial activities of mango seed kernel.In addition,the results also indicated that there is no significant difference in the phytochemical content and biological activity of mango kernels from single and assorted mango varieties.

Phenolic composition and inhibitory activity of Mangifera indica and Mucuna urens seeds extracts against key enzymes linked to the pathology and complications of type 2 diabetes

Objective:To investigate the phenolic compounds composition and the inhibitory activity of Mangifera indica(M.indica) and Mucuna urens(M.urens) seeds extracts against some key enzymes(-amylase,-glucosidasc and aldose reductase) implicated in the pathology and complications of type 2 diabetes in vitro.Methods:Reverse phase chromatographic quantification of the major flavonoids and phenolic acids in the seeds extracts was carried out using high performance liquid chromatography coupled with diode array detection.The inhibitory activities of the seeds extracts against-amylase and-glucosidase were estimated using soluble starch and p-nitrophenylglucopyranosidc as their respective substrates.Inhibition of aldose reductase activity by the extracts was assayed using partially purified lens homogenate of normal male rat as source of enzyme;inhibition of Fe^(2+)-induced lipid peroxidation by extracts was tested in rat pancreas homogenate.Results:The chromatography result revealed that extracts of both seeds had appreciable levels of some major flavonoids and phenolic acids of pharmacological importance,including gallic acid,chlorogenic acid,caffeic acid,ellagic acid,catechin,rutin,quercitrin.quercetin and kaempferol.Extracts of both seeds effectively inhibited-amylase,-glucosidase and aldose reductase activities in a dose-dependent manner,having inhibitory preference for these enzymes in the order of aldose reductase>-glucosidase>-amylase.With lower half-maximal inhibitory concentrations(IC50)against-amylase,-glucosidase,and aldose reductase,M.indica had stronger inhibitory potency against these enzymes than M.urens.Extracts of both seeds also inhibited Fe2+-induced lipid peroxidation in a dose-dependent pattern,with M.indica being more potent than M.urens.Conclusions:The results obtained provide support for a possible use of M.indica and M.urens seeds in managing hyperglycemia and preventing the complications associated with it in type 2diabetes.

Anti-oxidant and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica

Objective:To evaluate the anti-oxidani and anti-inflammatory activity of leaf extracts and fractions of Mangifera indica in in vitro conditions.Methods:In vitro DPPH radical scavenging activity and lipoxygenase（LOX） inhibition assays were used to evaluate the anti-oxidant and anti-inflammatory activities respectively.Methanolic extract（MEMI）,successive water extract （SWMI） and ethyl acetate fraction（EMEMI）,n-butanol fraction（BMEMI） and water soluble fraction （WMEMI） of methanolic extract were evaluated along with respective reference standards. Results:In in ritro DPPH radical scavenging activity,the MEMI,EMEMI and BMEMI have offered significant antioxidant activity with IC50 values of 13.37.3.55 and 14.19μig/mL respectively.Gallic acid,a reference standard showed significant antioxidant activity with IC? value of 1.88 and found to be more potent compared to all the extracts and fractions.In m vitro LOX inhibition assay,the MEMI,EMEMI and BMEMI have showed significant inhibition of LOX enzyme activity with IC50 values of 96.71.63.21 and 107.44μg/mL respectively.While,reference drug Indometlhacin also offered significant inhibtion against LOX enzyme activity with IC50 of 57.75.Furthermore,MEMI was found to more potent than SWMI and among the fractions EMEMI was found to possess more potent antioxidant and anti-inflammatory activity.Conclusions:These findings suggest that the MEMI and F.MEMT possess potent anti-oxidani and anti-inflammatory activities in in vitro conditions.

Phytochemical screening and evaluation of cytotoxic and hypoglycemic properties of Mangifera indica peels

Objective: To investigate the presence of different phytoconstituents in Mangifera indica(M. indica) peel and evaluate its cytotoxicity to Artemia salina and hypoglycemic potential in Swiss albino mice.Methods: The methanolic extract of M. indica peel was used to determine the presence of phytoconstituents. Brine shrimp lethality bioassay method was followed to determine the cytotoxic potential of plant extract. In the case of hypoglycemic activity, oral administration of extract at 200 and 400 mg/kg and standard glibenclamide at 10 mg/kg was done, followed by determining the percentage of reduction of plasma glucose from the initial level.Results: The methanolic extract of M. indica peel showed the presence of flavonoid,saponin, steroid, tannins, terpenoids, glycosides and alkaloids. In brine shrimp lethality bioassay, the LC_(50) of the extract and standard vincristine sulfate was found to be 2.04 and0.41 mg/mL, respectively. After 90 and 150 min, the methanolic extract at 200 and 400 mg/kg showed prominent plasma glucose reduction of 13.95%, 22.48% and 14.16%,26.18% respectively compared to standard glibenclamide showing 14.90% and 20.67% plasma glucose reduction.Conclusions: This current research affirms prominent cytotoxic and moderate hypoglycemic potential of M. indica peel. Further bioactivity guided isolation of phytoconstituents and investigation on higher animals can lead to development of new drug molecules.

Antidiarrhoeal efficacy of Mangifera indica seed kernel on Swiss albino mice

Objective:To examine the antidiarrhoeal activity of alcoholic and aqueous seed kernel extract of Mangifera indica(M.indica) on castor oil-induced diarrhoeul activity in Swiss albino mice.Methods:Mango seed kernels were processed and extracted using alcohol and water. Antidiarrhoeal activity of the extracts were assessed using intestinal motility and faecal score methods.Results:Aqueous and alcoholic extracts of M.indica significantly reduced intestinal motility and faecal score in Swiss albino mice.Conclusions:The present study shows the traditional claim on the use of M.indica seed kernel for treating diarrhoea in Southern parts of India.

Anti-enteric bacterial activity and phytochemical analysis of the seed kernel extract of Mangifera indica Linnaeus against Shigella dysenteriae(Shiga,corrig.) Castellani and Chalmers

Objective:To evaluate the phytochemical and anti-bacterial efficacy of the seed kernel extract of Mangifera indica(M.indica) against the enteropathogen,Shigella dysenteriae(S.dysenteriae), isolated from the diarrhoeal stool specimens.Methods:The preliminary phytochemical screening was performed by the standard methods as described by Harborne.Cold extraction method was employed to extract the bioactive compounds from mango seed kernel.Disc diffusion method was adopted to screen antibacterial activity.Minimum inhibitory concentration(MIC) was evaluated by agar dilution method.The crude extracts were partially purified by thin layer chromatography(TLC) and the fractions were analyzed by high performance thin layer chromatography(HFTLC) to identify the bioactive compounds.Results:Phytochemical scrutiny of M.indica indicated the presence of phytochemical constituents such as alkaloids,gums, flavanoids,phenols,saponins,steroids,tannins and xanthoproteins.Antibacterial activity was observed in two crude extracts and various fractions viz.hexane,benzene,chlor of orm,methanol and water.MIC of methanol fraction was found to be(95±11.8)μg/mL.MIC of other fractions ranged from 130-380μg/mL Conclusions:The present study confirmed that each crude extracts and fractions of M.indica have significant antimicrobial activity against the isolated pathogen 5. dyserUeriae.The antibacterial activity may be due to the phytochemical constituents of the mango seed kernel.The phytochemical tannin could be the reason for its antibacterial activity.

Molecular characterization, expression and function analysis of eukaryotic translation initiation factor(eIF1A) in Mangifera indica

Eukaryotic translation initiation factor 1A(eIF1A)functions as an important regulatory factor of protein synthesis and plays a crucial role in responses to abiotic stresses in plants.However,little is known about the eIF1A gene involved in fruit development and stress response of mango.In this study,the MieIF1A-b gene was isolated from Mangifera indica,and contains a 435-bp open reading frame,which encodes a putative protein of 144 amino acids(GenBank accession number:KP676599).The predicted MieIF1A-b protein had a molecular weight of 16.39 kDa with a pI of 4.6.Sequence homology analysis showed that MieIF1A-b shared high homology with Elaeis guineensis,Manihot esculenta,and Populus trichocarpa,with 96 and 95%identity,respectively.Quantitative reverse transcriptative PCR(qRT-PCR)analyses indicated that MieIF1A-b was expressed in all tested tissues,and had the highest expression level in fruit 80 d after flowering.The expression of MieIF1A-b was obviously regulated by NaCl and H2O2 treatments in leaves.Functional analysis indicated that the overexpression of MieIF1A-b in transgenic Arabidopsis thaliana enhanced the growth,phenotype and salinity tolerance compared with wild-type(WT)plants.The results indicated that MieIF1A-b may be correlated with the control of fruit development and salt adaptation,and it was a candidate gene for abiotic stress in mango.

Antimicrobial Activities of Seed Extracts of Mango (<i>Mangifera indica</i>L.)

Mangifera indica L. is a species of mango in the Anacardiaceae family. It is found in the wild in tropical regions and cultivated varieties have been introduced to other warm regions of the world. This present study aimed to investigate the in vitro antimicrobial activities of methanol and ethanol extracts of mango seed against 25 representatives gram positive, gram negative, acid fast bacteria and fungi. Mango fruit seed were extracted by Soxhlet using methanol and ethanol as solvents. The extracts were tested against the microorganisms using disc diffusion method at different concentrations: 5 mg/mL, 3.75 mg/mL, 3.125 mg/mL, 2.5 mg/mL, 1.875 mg/mL and 1.25 mg/mL). In vitro antibacterial activities of methanol and ethanol extracts of mango bulb showed inhibitions to tested organisms with variable inhibition zones. Except one organism (Rhodococcus equi), no resistance among the tested strains was shown. The mean zone of inhibition produced ranged between 5 mmand18 mmwith18 mm/Mycobacterium smegmatis showed the highest zone of inhibition. In most test strains comparable zones of inhibitions were noted for both methanol and ethanol extract. Candida albicans and Aspergilllus niger were both inhibited by the extracts. The methanol and ethanol extracts of mango seed showed good inhibitory effects against almost all tested strains. The inhibition zones produced by mango extract were less than those produced by standard positive control drug. This could be due to low diffusion rate of mango extract in agarose medium, a thing needed to be further investigated. The products are potential new antimicrobial therapy in the ethnopharmacology domain.

Chemosystematics Studies on Six Varieties of <i>Mangifera indica</i>L.

Taxonomic investigation was carried out on six (6) varieties of Mangifera indica (Julie, Broken, Peter, Kerosene, Opioro and Big fibre) using chemosystematics evidence. Extracts obtained from the leaf of each variety were phyto-chemically screened and quantified. Gravimetric and spectroscopic approaches were adopted in the quantification of active principles common to all the six varieties. Binary matrices computed from qualitative assessment were analysed to yield a dendrogram using the Average Linkage Method. Quantitative values were subjected to appropriate descriptive and inferential statistical analysis. All varieties possessed alkaloid except Big-fibre. Peter and Kerosene varieties lacked saponin, an active principle present in other varieties. Anthraquinone was present in all except in Julie and Opioro. Five out of the six varieties lacked phlobatannin. All varieties had tannin, steroid, flavonoid and reducing sugar. Tannin was lowest in Big-fibre (0.43%) but highest in Opioro (2.41%). Steroid ranged from 3.8% in Opioro to 9.0% in Julie with a standard deviation of 1.84. Julie variety recording the lowest composition in flavonoid (0.01%) and reducing sugar (0.04%) components was notable. Comparison of the mean values of phytochemicals has shown a statistically significant difference (p = 0.0005) with a large F-value (18.244). Using the LSD mean separation, steroid was the most remarkable phytochemical contributing to the significant differences. Dendrogram revealed very close relationship between Julie and Opioro varieties. The remaining four were divergent and distinct although Broken and Peter varieties arose from the same ancestral lineage with Julie and Opioro. However, Big-fibre and Kerosene varieties were clearly different from rest belonging to a different phylogenetic ancestor. With these remarkable differences, they ought to be given special taxonomic and systematic review for appropriate nomenclatural assignment. The six varieties of Mangifera indica investigated are thus clearly partitioned and therefore recommended to be circumscribed. This approach is maiden, and considered innovative as it is employed in this study for the first time in the taxonomy of Mangifera.

Comparative Analyses of the Efficacy of Dry and Fresh <i>Mangifera indica</i>Ethanolic Extracts on <i>E. coli</i>and <i>S. aureus</i>

Background: The need to identify and characterize new antimicrobial agents is important due to the increasing development of resistance by microorganisms to the existing antimicrobial agents. Aim: This study examined the efficacies of Mangifera indica on Escherichia coli and Staphylococcus aureus. Method: Three parts (leaf [L], root [R], and bark [B]) of the plant were analyzed. The extraction of the samples was performed by aseptically grinding the samples, dissolving in absolute ethanol, and filtering through whatman filter paper. The efficacy of the extracts bothsingle and combined was determined using agar well diffusion assay with gentamycin [10 μl] (E. coli) and vancomycin [30 μl] (S. aureus) as control antibiotics. Results: The higher concentration (C2 = 3.0 g/ml) showed more antibacterial effectiveness than the lower concentration (C1 = 1.5 g/ml) against both bacterial isolates with significant differences (P < 0.05) in all extracts except for single extracts (E. coli dry leaf extract;fresh bark extract), double extracts (S. aureus: dry and fresh leaf extracts) and triple extract (E. coli and S. aureus dry extracts). For the single extracts the bacteria has the following significant results: E. coli L (dry 6.3 ± 2.5 mm, fresh 14.7 ± 0.6 mm, P = 0.0050), R (dry 11.3 ± 1.5 mm, fresh 7.3 ± 1.5 mm, P = 0.0327);for S. aureus L (dry 7.0 ± 1.7 mm, fresh 11.0 ± 1.0 mm, P = 0.0257), R (dry 7.0 ± 2.0 mm, fresh 11.7 ± 1.5 mm, P = 0.0325), and B (dry 5.0 ± 1.0 mm, fresh 16.0 ± 1.0 mm, P = 0.0002). For the double extracts the bacteria has the following significant results: E. coli L + R (dry 15.7 ± 2.3 mm, fresh 1.7 ± 1.5 mm, P = 0.0070), R + B (dry 18.7 ± 1.5 mm, fresh 9.7 ± 1.5 mm, P = 0.0020), and L + B (dry 9.7 ± 1.5 mm, fresh 6.3 ± 0.6 mm, P = 0.0241);S. aureus L + R (dry 14.7 ± 1.5 mm, fresh 7.0 ± 1.0 mm, P = 0.0019), R + B (dry 15.3 ± 1.5 mm, fresh 11.7 ± 1.5 mm, P = 0.0424). For the triple extracts, the fresh leaves showed significantly higher levels of efficacy than the dry for both E. coli L + R + B (P = 0.0101) and S. aureus (P = 0.0307). The fresh extracts showed higher levels of efficacy than dry extracts against both bacteria for all the single and three combined conditions. Conclusions: Fresh extracts show better efficacies against E. coli while dry extracts show greater efficacies against S. aureus for both single and triple combined extracts. The reverse is true for double combined extracts.

优化QuEChERS法联合UPLC-MS/MS测定马兰草中35种农药的残留

目的建立优化的QuEChERS提取方法结合超高效液相色谱-串联质谱(UPLC-MS/MS)测定马兰草中35种农药残留的方法。方法13批次马兰草样品净化前处理后,采用QuEChERS提取方法,以乙腈作为提取溶剂、经亲水亲油平衡材料(HLB SPE)固相萃取柱净化,选择waters Xbridge C18色谱柱(10 cm×2.1 mm,2.6μm)、0.1%甲酸溶液(含5 mmol/L甲酸铵)-乙腈为流动相,柱温40℃、流速0.3 mL/min,应用超高效液相色谱-串联质谱法(UPLC-MS/MS)在多反应监测模式(MRM)下扫描,采用基质标准曲线法对马兰草中35种目标农药进行定量分析。结果所检35种农药在0.77~155.38μg/L浓度范围内线性关系良好,相关系数均大于0.9938;方法加标回收率为71.3%~108.7%,相对标准偏差(RSD)为1.7%~6.7%,检测限范围为0.77~7.77μg/L,1批样品中检出甲拌磷。结论本研究建立的方法具有操作简便、灵敏度高及可靠性强等特点,适用于马兰草中多种农药残留的检测。