Antibacterial activity of the extracts from the fruit rinds of Garcinia cowa and Garcinia pedunculata against food borne pathogens and spoilage bacteria

The crude hexane and chloroform extracts from the fruit rinds of Garcinia cowa and Garcinia pedunculata were studied for their antibacterial activity against some foodborne pathogens and spoilage bacteria such as Bacillus cereus, Bacillus coagulans, Bacillus subtilis, Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentrations (MICs) of the extracts determined by the agar dilution method were ranging from 15 to 500 μg/ml and 300 to 1250 μg/ml for G. cowa and G. pedunculata, respectively. However, the hexane and chloroform extracts from the fruit rinds of G. cowa exhibited marked inhibitory effect against all the test organisms and were more effective than that of G. pedunculata extracts. The antibacterial activity of all the extracts was more pronounced against the tested Gram-positive bacteria than the tested Gram-negative bacterium. Furthermore, this study is the first report on the in vitro antibacterial activity of extracts from the fruit rinds of G. cowa and G. pedunculata.     

Immunomodulatory and anticancer activities of phenolics from Garcinia mangostana fruit pericarp

The methanolic extract of Garciniamangostana fruit pericarp was partitioned into butanol and water fractions in this work. Three major phenolics were purified and identified as P₁ [1,3,6,7-tetrahydroxy-2,8-(3-methyl-2-butenyl) xanthone], P₂ [1,3,6-trihydroxy-7-methoxy-2,8-(3-methyl-2-butenyl) xanthone] and P₃ (epicatechin). Strong antioxidant activities were detected for P₁–P₃. In vitro cell proliferation trials indicated that P₁ and P₃ exhibited good immunomodulatory activities when 7.5 μg/ml was used. Furthermore, P₁ and P₃ showed good cytotoxicities against human breast cancer cells (MCF-7) and human colon cancer cells (LOVO). P₁ exhibited the maximal cytotoxicity of 73.06% against MCF-7 cells and of 46.27% against LOVO cells when 62.5 μg/ml was used. The cytotoxicities of P₁, P₂, P₃ and paclitaxel against normal embryonic lung fibroblast cells (HELF) were in a decreasing order: paclitaxel > P₃ > P₁ > P_2. These results suggested that P₁ and P₃ could be used as a potential anticancer agent.     

Phenolics from hull of Garcinia mangostana fruit and their antioxidant activities

The air-dried fruit hulls of Garcinia mangostana Linn. were extracted with 70% MeOH, and then partitioned into the n-BuOH fractions. Furthermore, three major phenolic components related to their antioxidant activities were purified by silica gel column chromatography and Sephadex LH-20 and then identified as P₁ (1,3,6,7-tetrahydroxy-2,8-(3-methyl-2-butenyl)), P₂ [1,3,6-trihydroxy-7-methoxy-2,8-(3-methyl-2-butenyl) xanthone] and P₃ (epicatechin) using UV–visible spectrophotometry, IR spectrophotometry and NMR spectroscopy, respectively. The antioxidant activities of three major phenolics were evaluated using different tests, including the free radical scavenging capability and total antioxidant activity in a linoleic acid peroxidation. These three phenolic compounds exhibited different antioxidant activities in these antioxidant tests. The hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capabilities and the activity against linoleic acid peroxidation of P₁ were greater than those of P₂ and P₃, while the superoxide anion radical scavenging activity of P₃ was greater than that of P₁, but was close to that of P₂ or α-tocopherol. An activity-guided isolation and purification process was used to identify the components showing the strong DPPH radical scavenging activity from G. mangostana Linn.     

Phenolic acid profiles of mangosteen fruits (Garcinia mangostana)

The composition of phenolic acids in various parts of mangosteen fruit (Garcinia mangostana) was determined by GC and MS. The total content of phenolic acids, identified by GC-FID ranged from 265.7 ± 12.7 (aril) to 5027.7 ± 188.0 (peel) mg per kg of dry matter of sample. Ten phenolic acids were identified in mangosteen fruit. Of these, protocatechuic acid was the major phenolic acid in the peel and rind, while p-hydroxybenzoic acid was the predominant phenolic acid in the aril. m-Hydroxybenzoic acid was detected only in the peel, while 3,4-dihydroxymandelic was present only in the rind. The phenolic acids liberated from esters and glycosidic bonds were the major fractions of phenolic acids in mangosteen fruit.     

Chemical analysis and preliminary toxicological evaluation of Garcinia mangostana seeds and seed oil

The chemical analysis and preliminary toxicological evaluation of Garcinia mangostana seeds and seed oil have been investigated in order to determine the possibility of using them for human and/or animal consumption. Proximate analysis showed that the seeds had high amount of carbohydrate and were rich in oil (21.68 ± 6.18%) but have a low protein content. The physical properties of the oil extracts showed the state to be liquid at room temperature (25 ± 1 °C) and the colour of the oil golden-orange. The specific gravity of the oil was 0.98 ± 0.01. Among the chemical properties of the oil extracts, acid value, saponification number, iodine value, percent free fatty acid and peroxide value compared well with those of conventional edible oils. The seed flour was found to be a good source of minerals. It contained considerable amounts of potassium (7071 mg/kg), magnesium (865 mg/kg) and calcium (454 mg/kg). Fatty acid composition of the seed oil indicated that the oil contained one essential fatty acids small proportions: linoleic acid (1.30%). The most prevalent fatty acids were palmitic acid (49.5%) and oleic acid (34.0%). Weanling albino rats appeared to suffer no toxicological effects when fed with G. mangostana seed oil in their diet for 8 weeks. Weekly monitoring of the rats showed good physical appearance and steady weight increase. Histological examination of sections of the heart, liver, kidney, spleen and lung revealed that the kidney of some of the rats had some degrees of pathology which included diffuse glomerular and tubular degeneration. No lesion was found in the heart and liver of the rats. The seed oil could be useful as an edible oil and for industrial applications.     

Flacourside,a new 4-oxo-2-cyclopentenylmethyl glucoside from the fruit juice of Flacourtia indica

A new glucoside ester, named flacourside, has been isolated together with known methyl 6-O-(E)-p-coumaroyl glucopyranoside and 6-O-(E)-p-coumaroyl glucopyranose from the n-butanol extract of fruit juice of the Flacourtia indica. The structure of flacourside has been determined to be 4-oxo-2-cyclopentenylmethyl 6-O-(E)-p-coumaroyl-β-d-glucopyranoside on the basis of spectroscopic studies.     

Extraction of cocoa butter alternative from kokum (Garcinia indica) kernel by three phase partitioning

Kokum kernel is a byproduct of agro-processing industry in India containing about 40–50% fat which has the potential as a worthy cocoa butter alternative (CBA). However, inefficient extraction techniques that are practiced at cottage level restrict its industrial applications. This work reports on the optimization of the technique of three phase partitioning (TPP) for efficient extraction of kokum kernel fat. The parameters of TPP were optimized with respect to ammonium sulphate concentration, ratio of slurry to t-butanol and pH of slurry. The optimized protocol resulted in maximum recovery of 95% (w/w) fat recovery within 2 h. The technique is economical and eco-friendly, and is promising for utilization of agro-processing waste in India to a product of commercial significance.     

Extraction and identification of anthocyanins from Smilax aspera L. berries

Anthocyanins, present in the berries of Smilax aspera L., a creeping shrub typical of the Mediterranean region, were extracted and identified for the first time. The pigments were extracted from the skin of the berries with of 0.1% HCl in methanol solution, purified on a C-18 solid-phase cartridge and characterized by means of HPLC-DAD-MS analysis. From spectral analysis before and after acid and alkaline hydrolysis, it was noted that pelargonidin 3-O-rutinoside represented about 83% of the total anthocyanin content in the skin of Smilax aspera berries. A low quantity of cyanidin 3-O-rutinoside (13%) was also found. The attractive colour and the great abundance of the plant in the south of Italy make Smilax aspera berries a new and very good source of natural pigments.     

Standardised Mangifera indica extract is an ideal antioxidant

The standardised ethanolic and aqueous extracts of Mangifera indica leaf were prepared and analysed for their free radicals scavenging activity. The IC₅₀ values using the DPPH assay were 0.17 ± 0.02 and 0.49 ± 0.4 mg/ml, respectively. Standardised ethanolic extracts of the M. indica leaf had a solid content of 9.1 ± 0.7%, mangiferin concentration of 73 ± 0.17 mg/g of dry weight of the extract, free radical scavenging activity (IC₅₀) of 0.17 ± 0.02 mg/ml and total phenolic content of 590 ± 48 mg/g of extract. The protection exhibited by these extracts against lipid peroxidation was superior to butylated hydroxytoluene (BHT) and commercial grape seed extract. These extracts at higher concentration did not exhibit pro-oxidant activities when compared to vitamin C. Our findings also show that the aqueous and ethanolic extracts of M. indica leaf protect NIH/3T3 cells from oxidant-induced cell death.     

Extraction optimisation of daphnoretin from root bark of Wikstroemia indica (L.) C.A. and its anti-tumour activity tests

The bark of Wikstroemia indica is rich in daphnoretin, which has strong antiviral and anti-tumour activities. In order to optimise the extraction conditions of daphnoretin from the bark of W. indica, various extraction parameters were chosen to identify their effects on daphnoretin extraction. Response surface methodology (RSM) was applied to obtain the optimal combination of these parameters. Results showed that the optimisation conditions for daphnoretin extraction were: ethanol concentration 67.44%, extraction time 49.44 min, temperature 60.19 °C and liquid–solid ratio 23.49:1. The maximum extraction of daphnoretin obtained experimentally was 2.18‰. The mathematical model developed was found to fit well with the experimental data. Further, four kinds of human cancer cell lines, HeLa, A549, CNE and HEp-2, were tested in vitro to explore the anti-tumour spectrum of daphnoretin. It was found for the first time that daphnoretin showed significant inhibition on the proliferation of CNE and HeLa cells.     

Volatile compounds of leaves and fruits of Mangifera indica var. coquinho (Anacardiaceae) obtained using solid phase microextraction and hydrodistillation

Volatile compounds present on fruits and leaves of Mangifera indica var. coquinho were investigated by headspace solid phase microextraction (HS-SPME) and hydrodistillation (HD). Conventional techniques, such as hydrodistillation, may impart chemical changes to the original oil composition being also time-consuming. On the other hand, HS-SPME provides solvent-less extractions, shorter extraction times and may supply complementary information about the composition of the compounds. The HS-SPME technique was previously evaluated by the comparative study among the fibres: commercial PDMS, NiTi-ZrO₂ and NiTi-ZrO₂-PDMS. The fibre NiTi-ZrO₂-PDMS showed better sensitivity and precision and was used on the extraction of components. The influence of several parameters like the time and temperature of extraction and desorption time were examined to obtain better efficiency. Fruits and leaves were analysed in mature and immature stages. The profiles corresponding to the volatile compounds detected by both techniques are discussed.     

Characterisation of esterolytic activity from two wild mushroom species, Amanita vaginata var. vaginata and Tricholoma terreum

Characterisation of esterase activities from the edible mushroom species, Amanita vaginata var. vaginata and Tricholoma terreum, were investigated. Native electrophoresis of the crude extracts prepared from both mushroom samples showed the presence of esterolytic activities. The extracts had the greatest activity in the presence of p-nitrophenyl butyrate (pNPB) as a substrate. pH and temperature optima were found to be 8.0 and 30 °C for both enzymes, respectively. V_max and K_m values were determined as 14.2 U/l and 71 μM for A. vaginata var. vaginata and 34.6 U/l and 9.6 μM for T. terreum, respectively. The pH-stability profile showed a stationary line between 3.0 and 10.0 for both enzymes. The esterolytic activities from the extracts were maintained between 10 and 40 °C for 4 h and started to decrease at 50 °C. The effects of EDTA, NaN₃, DTT and PMSF on the enzyme activity were also investigated.     

Characterisation and preliminary bioactivity determination of Berberis boliviana Lechler fruit anthocyanins

Berberis boliviana Lechler is a member of the Berberidaceae family that has a small edible red-purple berry. The plant is native to the Peruvian Andes and contains high amounts of anthocyanin pigments. The monomeric anthocyanin content, determined by a pH-differential method, was 7/100 g of seedless berries. Pigments were characterised by HPLC coupled to a photodiode array (PDA) and mass spectrophotometer (MS) detectors. Five aglycones and ten anthocyanins were found and identified as petunidin-3-glucoside (24.4%), delphinidin-3-glucoside (24.1%), malvidin-3-glucoside (22.1%), cyanidin-3-glucoside (10.2%), petunidin-3-rutinoside (7.15%), malvidin-3-rutinoside (4.9%), cyanidin-3-rutinoside (3.8%), delphinidin-3-rutinoside (2.6%), peonidin-3-glucoside (1.1%), and peonidin-3-rutinoside (0.9%).     

Antibacterial activities of Anisomeles indica constituents and their inhibition effect on Helicobacter pylori-induced inflammation in human gastric epithelial cells

The antibacterial activity of Anisomeles indica extract, and its isolated constituents against Helicobacter pylori growth were examined. Among tested, ethanol extract, pure constituents ovatodiolide (OVT) followed by acteoside, isoacteoside, and terniflorin showed potent antimicrobial activity. OVT demonstrated bactericide activity against H. pylori reference, as well as multidrug-resistant strains. On the other side, in vitroH. pylori-infection model revealed that OVT inhibited the H. pylori bacteria adhesion and invasion to human gastric epithelial (AGS) cells. In addition, OVT inhibited the H. pylori-induced inflammatory response by the reduced nuclear factor (NF)-κB activation and interleukin (IL)-8 expressions in H. pylori-infected AGS cells. Furthermore, OVT attenuated the cytotoxin-associated gene A (CagA) functions by reduced CagA translocation, phosphorylation, and caused hummingbird phenotype of AGS cells. These results indicate that OVT might be useful as food supplement or drug development for H. pylori complications.     

Study of the effect of ‘Ataulfo’ mango (Mangifera indica L.) intake on mammary carcinogenesis and antioxidant capacity in plasma of N-methyl-N-nitrosourea (MNU)-treated rats

The effect of ‘Ataulfo’ mango consumption on chemically induced mammary carcinogenesis and plasma antioxidant capacity in rats treated with N-methyl-N-nitrosourea (MNU) was studied. Mango was administered in the drinking water (0.02–0.06 g/mL) during both short-term and long-term (LT) periods to rats treated or not with MNU. Rats treated with MNU showed no differences in mammary carcinogenesis or in plasma antioxidant capacity measured by both ferric reducing/antioxidant power (FRAP) and total oxyradical scavenging capacity assays. However, in animals not treated with MNU but with a LT intake of mango the plasma antioxidant capacity as measured by the FRAP assay tended to increase in a dose-dependent manner. This suggests that mango consumption by healthy subjects may increase antioxidants in plasma.     

Identification and characterisation of anthocyanins in the antioxidant activity-containing fraction of Liriope platyphylla fruits

The objective of this study was to investigate antioxidant activities and anthocyanin profiles in the fruits of Liriope platyphylla, where these are considered functional substances in Korea. The acidic methanol extract of this species exhibited potent antioxidant activities, showing 83.9% DPPH scavenging activity and 92.5% ABTS scavenging activity at a concentration of 0.5 mg/ml. Moreover, anthocyanins were identified by reversed-phase C₁₈ column chromatography, NMR spectroscopy, and HPLC-DAD-ESI/MS analysis. Seven anthocyanins were characterised, including delphinidin-3-O-glucoside (1), delphinidin-3-O-rutinoside (2), cyanidin-3-O-glucoside (3), petunidin-3-O-glucoside (4), petunidin-3-O-rutinoside (5), malvidin-3-O-glucoside (6), and malvidin-3-O-rutinoside (7). Among these, petunidin-3-O-rutinoside (5) (7302.2 μg/g) and malvidin-3-O-rutinoside (7) (5776.1 μg/g) were the predominant anthocyanins, whereas the least prevalent anthocyanin was found to be cyanidin-3-O-glucoside (3) (64.9 μg/g). Therefore, our results suggest that strong antioxidant activities of the acidic methanol extract of L. platyphylla fruits are correlated with high anthocyanin contents, particularly the petunidin-3-O-rutinoside (5) and malvidin-3-O-rutinoside (7).     

Characterisation of anthocyanins in the black soybean (Glycine max L.) by HPLC-DAD-ESI/MS analysis

The aim of this study was to isolate and identify the anthocyanins in the black seed coated soybean (cv. Cheongja 3, Glycine max (L.) Merr.) using reverse phase C-18 open column chromatography and high-performance liquid chromatography (HPLC) with diode array detection and electro spray ionization/mass spectrometry (DAD-ESI/MS) analysis, respectively. Anthocyanins were extracted from the coat of black soybeans with 1% TFA in methanol, isolated by RP-C-18 column chromatography, and their structures elucidated by 1D and 2D NMR spectroscopy. The isolated anthocyanins were characterised as delphinidin-3-O-glucoside (3), cyanidin-3-O-glucoside (5), petunidin-3-O-glucoside (6), pelargonidin-3-O-glucoside (7) and cyanidin (9). Furthermore, four minor anthocyanins were detected and identified as catechin-cyanidin-3-O-glucoside (1), delphinidin-3-O-galactoside (2), cyanidin-3-O-galactoside (4), and peonidin-3-O-glucoside (8) based on the fragmentation patterns of HPLC-DAD-ESI/MS analysis.     

Effects of various solvents on the extraction of antioxidant phenolics from the leaves, seeds, veins and skins of Tamarindus indica L.

The effects of solvents, of varying polarities, on the extraction of antioxidant phenolics from the leaves, seeds, veins and skins of Tamarindus indica (T. indica) were studied. The efficiencies of the solvents for extraction of the antioxidant phenolics were in the order: methanol > ethyl acetate > hexane. Phenolic content ranged from 3.17 to 309 mg of gallic acid equivalents/g. Methanol leaf extract (MEL) had the highest phenolic content and was the most potent scavenger of DPPH and superoxide radicals. Methanol vein extract had the highest ferric reducing activity whereas methanol seed extract was the most potent ABTS radical-scavenger. A positive correlation existed between phenolic content and antioxidant activities of the plant parts. HPLC analyses of MEL revealed the presence of catechin, epicatechin, quercetin and isorhamnetin. Overall, methanol was the most effective solvent for extraction of antioxidant phenolics from T. indica. T. indica, particularly the leaf, can be a useful source of natural antioxidants.     

Characterisation of leucyl aminopeptidase from Solanum tuberosum tuber

Potato juice (a waste product from the starch industry) is a potential source of novel enzymes for food applications. For use in the production and improvement of food protein hydrolysates, commercially available exopeptidases, predominantly aminopeptidases, are recommended. The present study was performed to explore possible biotechnological interest of leucyl aminopeptidase (LAP) activity in the potato tuber. The LAP from potato tuber was purified and characterised. Specific LAP activity was increased 200-fold by purification of the crude extract. The purified enzyme had a pH optimum of 9.0 and temperature optimum of 45 °C. LAP hydrolysed leucine-, alanine- and lysine-p-nitroanilide to a similar degree. The most efficient inhibitor was 1,10-phenanthroline. Almost all divalent cations tested inhibited the enzyme activity, while Co²⁺ stimulated LAP activity by over 100%. The purified LAP had a molecular weight of 90 kDa with an isoelectric point of 5.45. Sodium dodecylsulfate–polyacrylamide gel electrophoresis revealed one band of 48 kDa.     

Changes in anthocyanins in arils of chitosan-coated pomegranate (Punica granatum L. cv. Rabbab-e-Neyriz) fruit during cold storage

Edible coatings as chitosan treatments (0%, 1% and 2%) were applied to ‘Rabbab-e-Neyriz’ pomegranate (Punica granatum L.). The effect of chitosan coating on individual anthocyanins and colour parameters of the juice during storage at 2 °C or 5 °C was examined. Six predominant anthocyanins were identified in the juice, with up to 935 mg/L total anthocyanins at the time of harvest. Cyanidin 3,5-diglucoside (402 mg/L) was the major pigment. The total anthocyanin content and chroma decreased with storage time in all applied treatments, although lightness and hue angle increased. These changes were reduced with chitosan treatments and at lower storage temperature (2 °C as compared to 5 °C). Based on the obtained results, the diglucoside anthocyanins were more stable than the monoglucosides. Chitosan coating followed by cold storage delayed anthocyanin degradation and prevented colour deterioration in the pomegranate arils.