Anti-fertility effects of fractions from Carica papaya (Pawpaw) Linn. methanol root extract in male Wistar rats

The methanol root extracts of Carica papaya (Pawpaw) are used in eastern Nigeria for the treatment of malaria, hepatitis and jaundice. The aim of this study was to investigate the effects of the fractions isolated from C. papaya methanol root extract on fertility in male Wistar rats using sperm counts, percentage defective sperm cells (morphology), biochemical and hormonal assays as biomarkers. The roots of C. papaya were extracted using 80% methanol for 72 h. Oral acute toxicity study was done with the crude extract for 24 h. The extract was fractionated by column chromatography using petroleum ether, chloroform, ethyl acetate and methanol. The petroleum ether fraction was further fractionated on preparative TLC using ethyl acetate–methanol solvent systems to isolate CPFE 1, CPFE 2 and CPFM 1. The 3 fractions (75 mg/kg) were used to treat male Wistar rats orally for 60 days. Animals were euthanized and testes collected, homogenized and used for sperm count and motility. Plasma and serum were used to assay biochemical parameters including aspartate aminotransferase (AST), blood urea nitrogen (BUN), total bilirubin (TB), alkaline phosphatase (ALP), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), triglycerides, hormones (LH and FSH). Histopathological study of the testes, kidney, heart and liver were conducted. Acute toxicity result showed that C. papaya root extract produced no mortalities at the dose of 2000 mg/kg but induced CNS-related symptoms as well as diuresis. The fractions significantly (P < 0.01) produced decreases in sperm counts and increased the percentage of defective sperm cells. There were significant (P < 0.05) increases in aspartate aminotransferase (AST) and blood urea nitrogen (BUN). Histopathological studies showed mild kidney and cardiac hyperaemia, slight hepatic degeneration and severe necrosis of the germinal epithelium of the testes. This study calls for some level of caution in the use of these roots and its extracts/fractions in traditional medicine for treating diseases. On the other hand, it could be a good source of drug for birth control.     

Evaluation of the safety and antioxidant activities of Crocus sativus and Propolis ethanolic extracts

The possible toxicological effects and in vitro antioxidant activity of the ethanolic extracts of Crocus sativus and Propolis were investigated. Both extracts did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. In the sub-chronic study; the tested extracts did not produce any significant change in liver and kidney functions of rats, following oral administration for 8 successive weeks at doses of 500 mg/kg b.wt. of each. Propolis showed remarkable in vitro antioxidant activity at concentrations of (40–100 mg/ml). In contrast, the ethanolic extract of C. sativus ethanolic extract showed weak antioxidant activity in concentrations of (1–10 mg/ml) while at concentrations of (20–100 mg/ml) failed to exhibit any antioxidant activity. It was concluded that: both extracts were non-toxic, as they did not cause any mortalities or signs of toxicity in mice when administered orally at doses up to 5 g/kg b.wt. Daily oral administration of C. sativus, Propolis ethanolic extracts alone or in combination for 8 successive weeks to rats was quiet safe and didn't cause any toxic changes in liver and kidney. Antioxidant study showed that Propolis ethanolic extract was a more potent antioxidant than C. sativus extract.     

Gamma irradiation improves the antioxidant activity of Aloe vera (Aloe barbadensis miller) extracts

Aloe has been widely used in food products, pharmaceuticals, and cosmetics because of its aromatic and therapeutic properties. In the present study, the ethanolic extracts of aloe gel were gamma-irradiated from 10 to 100 kGy. After gamma irradiation, the color of the ethanolic extracts of aloe gel changed to red; this color persisted up to 40 kGy but disappeared above 50 kGy. Liquid chromatography/mass spectrometry analysis demonstrated the production of a new, unknown compound (m/z=132) after gamma irradiation of the ethanolic extracts of aloe gel. The amount of this unknown compound increased with increasing irradiation up to 80 kGy, and it was degraded at 100 kGy. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by the 1,1-diphenyl-2-picrylhydrazyl-radical scavenging capacity. The antioxidant activity of aloe extract was dramatically increased from 53.9% in the non-irradiated sample to 92.8% in the sample irradiated at 40 kGy. This strong antioxidant activity was retained even at 100 kGy. These results indicate that gamma irradiation of aloe extract can enhance its antioxidant activity through the formation of a new compound. Based on these results, increased antioxidant activity of aloe extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.     

Vasodilator Effect of Ethanolic Extract of Mulberry Leaves (Morus alba L.) in Rat and Rabbit

The effects of ethanolic extracts of Mulberry Leaves (Morus alba L.) on nitric oxide (NO) serum level in rat and diameter of blood vessels in rabbit ear were investigated. NO level of ethanolic extract of mulberry leaves at dose of 100 mg/kg bw rats gave significant difference compared to negative control (P<0,05) at minute 30 after extract administration (4,51 ± 4,31 μM). Ethanolic extract of mulberry leaves at dose of 200 mg/kg bw had no significant difference in NO serum level. However, ethanolic extract of mulberry leaves at dose of 400 mg/kg bw rats increased NO serum level significantly compared to negative control (P<0,05) at minute 0, 10, 30, 60, and 90 after extract administration. The maximum serum level of NO of 400 mg/kg bw mulberry extract was 4,62 ± 3,05 μM, and it is the highest among other groups. Therefore this dose was choosen for vasodilatation assay in rabbit. Observation on blood vessels diameter in rabbit ears showed that ethanolic extract of mulberry leaves were able to dilatate the big vessels and small vessels of rabbit ears significantly compared to negative control (P<0,05) at minute 60 after extract administration. In conclusion, ethanolic extract of mulberry leaves at dose of 400 mg/kg bw rats or 202.67 mg/kg bw rabbits has a vasodilator effect, probably due to an increase of NO serum level.     

Gas Chromatography-Mass Spectroscopic,high performance liquid chromatographic and In-silico characterization of antimicrobial and antioxidant constituents of Rhus longipes (Engl)

Rhus longipes is one of those underutilized plant species with inherent values. Therefore, we conducted a phytochemical study and investigated the antioxidant and antimicrobial potentials of the plant extracts. Aqueous and ethanol extract was subjected to phytochemical analysis. Gas chromatography-mass spectroscopy was performed to identify the volatile compounds while high performance liquid chromatography was done to identify the phenolic and flavonoids in the ethanol extract. Bioactivity and molecular docking analysis was also done for the identification of the bioactive constituents. Tannins, flavonoids, phenolics, terpenoids, steroids, alkaloids, and saponins were identified both in the ethanol and in aqueous extracts of R. longipes. The extracts and ascorbic acid exhibited radical inhibition in a concentration dependent manner. The IC₅₀ values; 3.23, 4.13, 70.75 µg/mL (ABTS), 200.82, 103.63, 390.83 µg/mL (DPPH), 10.06, 93.46, 253.26 µg/mL (O₂), and 99.77, 109.23, 446.34 µg/mL (NO) for ascorbic acid, ethanol and aqueous extract respectively showed that ethanol extract exhibited better radical inhibition than the aqueous extract. 4-hydroxybenzoic and 4-hydroxycoumarin were the most abundant phenolics in the extract. The ethanol extract of R. longipes demonstrated broad-spectrum antibacterial activity with inhibition zone of 25.5 mm against S. aureus, 27.5 mm against E. coli, and 20.5 mm against P. aeruginosa. The identified phytochemicals demonstrated inhibitory potentials against bacterial glucosamine 6-phosphate synthase, penicillin-binding protein 3, DNA gyrase and β-lactamase. It is evident that R. longipes have some antioxidant and antibacterial properties and the plant contain important phytochemicals with ability to retard food oxidation and deterioration and thus could be annexed for various industrial and medicinal purposes.     

The Potential of Dewa Leaves (Gynura Pseudochina (L) D.C) and Temu Ireng Rhizomes (Curcuma aeruginosa Roxb.) as Medicinal Herbs for Dengue Fever Treatment

There are a lot of natural resources that potentially used as herbal medicines in Indonesia. Some of the herbs, like Dewa leaves (Gynura pseudochina (L) D.C) and temu ireng rhizome (Curcuma aeruginosa Roxb.), were ussually used to increase number of thrombocytes in dengue patient. This current study was to determine the potential of dewa leaves (Gynura pseudochina (L) D.C) and temu ireng rhizome (Curcuma aeruginosa Roxb.) against the number of trombocytes, erythrocytes, and hematocrits level on male white rats (Rattus novergicus) by using Heparin Induction. Dosages of the extracts were 250 mg/kg BW and 500 mg/kg BW used for both dewa leaves and temu ireng rhizome. Extracts were given orally to the tested animals for seven continuous days. The number of trombocytes, erythrocytes, and hematocrites level were examine at day 7 using sysmex XE-5000 hematology analyzer. The result showed that the rat groups which were treated with dewa leaves extract at 500 mg/kgBW; temu ireng Rhizomes extract at 250 mg/kgBW and 500 mg/kgBW dosages had significant differences (α = 0.05) on number of thrombocytes. The percentages of thrombocytes number enhancement for temu ireng rhizomes extract 500 mg/kgBW, temu ireng rhizomes extract 250 mg/kgBW, dewa leaves extract 500 mg/kgBW were 26.98%, 24.48%, 19.44% respectively. The rats group which were treated with temu ireng Rhizomes extract at 500 mg/kgBW, dewa leaves extract at 250 mg/kgBW and 500 mg/kgBW had significant differences (α = 0.05) on erythrocytes number and hematocrits level enhancement. The percentages of erythrocytes number enhancement for dewa leaves extract at dose of 500 mg/kgBW and 250 mg/kgBW, temu ireng rhizomes extract 500 mg/kgBW were 9.59%, 9.11%, 9.02% respectively. The highest percentages of hematocrits level enhancement was given by dewa leaves extract at dose of 500 mg/kgBW (10,97%), suggesting that the extracts treatment would not trigger plasma leakage. Thus, dewa leaves extract at 500 mg/kgBW; temu ireng rhizomes extract at 250 mg/kgBW and 500 mg/kgBW dosages are potential as candidates to be medicinal herbs to increase numbers of thrombocytes on dengue fever treatment     

Determination of the changes of antifungal properties of Satureja hortensis,Thymus vulgaris and Thymbra spicata exposed to gamma irradiation

In this research, changes in the antifungal activity of the extract of Satureja hortensis, Thymus vulgaris and Thymbra spicata exposed to gamma irradiation against two aflatoxigenic moulds Aspergillus parasiticus NRRL 2999 and 465 were investigated. The samples of dry plant leaf powder were irradiated with doses of 1.2, 3.0, 5.1 kGy. While the antifungal activity of S. hortensis with 0 and 1.2 kGy dose irradiation against A. parasiticus NRRL 2999 was found to be similar, it decreased with 3.0 and 5.1 kGy irradiation doses (P<0.05). On the contrary, antifungal activity of T. spicata increased until 3.0 kGy and then it decreased with 5.1 kGy irradiation dose (P<0.05). For T. vulgaris, an increase of irradiation dose resulted in a decrease of antifungal activity against aflatoxigenic moulds. This research shows that antifungal properties of some spices can be changed by gamma irradiation.     

Chemical composition and biological potential of seed oil and leaf extracts of Henophyton deserti Coss. & Durieu

Henophyton deserti was characterized in respect to its chemical composition, antioxidant potential and antimicrobial activity. Fourteen compounds were identified by LC/MS, GC/MS, and GC in leaf and seed extracts. Total flavonoids ranged between 45.66 and 181.2 mg QE g^?1 and 2.03 and 38.95 mg QE g^?1 dry weight (dw) in leaf and seed polar extracts, respectively. Rutin, Kaempferol 3-rutinoside, Diosmetin 7-O-Glucoside, and Acacetin 7-O-Glucoside flavonoids were tentatively identified in this plant. The profile of seed fatty acids revealed oleic acid (C18:1, 27%), linoleic acid (C18:2, 12%) and linolenic acid (C18:3, 17%). The highest antioxidant activities of 85.2% and 67.5% were obtained with methanol and ethyl acetate leaf extracts. All H. deserti extracts were active against at least one of the tested bacteria, leaf ethyl acetate extract showed the lowest MIC of 0.156 mg ml^?1. Only seed ethyl acetate extract showed antifungal activity with a MIC of 2.5 mg ml^?1.     

Antimicrobial and anti-inflammatory activities of Piper porphyrophyllum (Fam. Piperaceae)

The crude extracts and isolated compounds of Piper porphyrophyllum (Piperaceae) were evaluated for antibacterial and anti-inflammatory activities. The ethyl acetate extract and 3′,4′,5,7-tetramethoxyflavone exhibited the highest activity against Staphylococcus aureus giving values of MIC = 62.5 and 250 μg/mL, respectively. 5-Hydroxy-7-methoxyflavanone and 4′,5-dihydroxy-3′,7-dimethoxyflavone were active against Pseudomonas aeruginosa, both with MIC value 125 μg/mL. The hexane extract and 4′,5-dihydroxy-3′,7-dimethoxyflavone gave the highest anti-inflammatory activity in in vitro quantitative lipoxygenase inhibition assay with inhibitory activity of (IE) 99.72% and 91.81%, respectively.     

Analgetic Activity of Papaya (Carica papaya L.) Leaves Extract

The analgetic activity of Carica papaya leaves (CPL) extracts (n-hexane, ethyl acetate, ethanol) was investigated in mice model using acetic acid induced pain (Siegmund method). Experimental animals were divided into 11 groups and received n-hexane, ethyl acetate, and ethanol extracts at doses of 0.175, 0.35, 0.70 mg/kg bw orally; CMC-Na 0.5% (control group); 50 mg/ kg bw of aspirin. The results showed that all extracts at the doses of 0.175, 0.35 and 0.70 mg/kg bw gave significant analgetic activity (p<0.05) compared to control group. Ethanol extract of CPL dose of 0.70 mg/kg bw showed the best analgetic activity that was comparable to aspirin.     

(Liquid + liquid) phase equilibria of 1-alkyl-3-methylimidazolium methylsulfate with alcohols,or ethers,or ketones

Solubilities of binary mixtures that contain a room-temperature ionic liquid and an organic solvent – namely, 1,3-dimethylimidazolium methylsulfate, [mmim][CH₃SO₄], or 1-butyl-3-methylimidazolium methylsulfate, [bmim][CH₃SO₄] with an alcohol (hexan-1-ol, or octan-1-ol, or nonan-1-ol, or decan-1-ol), or an ether (dipropyl ether, or dibutyl ether, or methyl-1,1-dimethylethyl ether, or methyl-1,1-dimethylpropyl ether), or a ketone (pentan-2-one, or pentan-3-one, or hexan-2-one, or heptan-4-one, or cyclopentanone) – have been measured by a visual method from T = 270 K to the boiling temperature of the solvent. The (liquid + liquid) equilibria curves were predicted by the COSMO-RS method. For [bmim][CH₃SO₄], the COSMO-RS predictions correspond better with experimental results than do the predictions for [mmim][CH₃SO₄].Complete miscibility has been observed in the systems of [mmim][CH₃SO₄] with water and with alcohols ranging from methanol to octan-1-ol and that of [bmim][CH₃SO₄] with water and with alcohols ranging from methanol to decan-1-ol at the temperature T = 310 K.     

A calorimetric study of plant–plant and plant–soil interactions of extracts from Ixorhea tschudiana

The effect of the CHCl₃ and MeOH extracts from aerial parts from the Northwestern Argentina endemic species Ixorhea tschudiana Fenzl. on germination of the dicot tomato and the monoct onion and on soil microbial activity was studied by calorimetric and calorespirometric experiments. The CHCl₃ extract inhibited seedling growth of tomato which increased with increasing concentrations. Seeds imbibed with 250 mg dm^?3 extract germinated 24 h later than control and those imbibed with 100 and 500 mg dm^?3 extract. This was reflected in the calculated low specific seedling growth rate (p_SGΔH_B) as determined from calorespirometric experiments. On the other hand, seedlings obtained in 500 mg dm^?3 extract showed shorter and thicker hairy roots than control with significantly higher p_SGΔH_B. Probably, the extract induces inhibition of water uptake by seedling roots. Germination was reduced 50% in onion seeds imbibed with 500 mg dm^?3 CHCl₃ extract which apparently is due to higher rate of imbibition during the first stages as determined for calorimetry. On the other hand, 83 and 250 mg kg^?1 of the MeOH and CHCl₃ extract seem to selectively inhibit the growth of certain microorganisms and to enhance the activity of soil actinomycetes. Two actinobacteria were isolated from soil treated with these concentrations of both extracts: Kocuria sp. and Kocuria rosea; this latter species is known as a keratinolytic agent and seems to degrade complex carbon compounds of the soil and those incorporated by the MeOH extract. Both Kocuria specie seem to be beneficial for the soil converting substrate into biomass and thus I. tschudiana could be used as a soil phytoremediator.     

Green synthesis of silver nanoparticles using olive leaf extract and its antibacterial activity

The silver nanoparticles (AgNPs) synthesized using hot water olive leaf extracts (OLE) as reducing and stabilizing agent are reported and evaluated for antibacterial activity against drug resistant bacterial isolates. The effect of extract concentration, contact time, pH and temperature on the reaction rate and the shape of the Ag nanoparticles are investigated. The data revealed that the rate of formation of the nanosilver increased significantly in the basic medium with increasing temperature. The nature of AgNPs synthesized was analyzed by UV–vis spectroscopy, X-ray diffraction, scanning electron microscopy and thermal gravimetric analysis (TGA). The silver nanoparticles were with an average size of 20–25 nm and mostly spherical. The antibacterial potential of synthesized AgNPs was compared with that of aqueous OLE by well diffusion method. The AgNPs at 0.03–0.07 mg/ml concentration significantly inhibited bacterial growth against multi drug resistant Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli). This study revealed that the aqueous olive leaf extract has no effect at the concentrations used for preparation of the Ag nanoparticles. Thus AgNPs showed broad spectrum antibacterial activity at lower concentration and may be a good alternative therapeutic approach in future.     

Pharmacological activity of 2% aqueous acetic acid extract of Alhagi maurorum roots

A 2% aqueous acetic acid extract of Alhagi maurorum powdered roots was examined for its pharmacological activity and showed the following results: (1) Administration of the extract intraperitoneally into mice decreased the body temperature in a dose dependent manner. The decreases ranged from 2.5 to 7.3 °C. (2) Treatment of the frog rectus abdominis muscle with the extract in doses of 4 mg/ml bathing fluid did not antagonize Acetyl Coline (ACh) induced contraction. (3) Intraperitoneal administration of the extract into the anaesthetized rats decreased the heart rate by 10%. In addition, the extract depressed the force of contraction of the heart by 66.7%, thus, the extract seemed to be cardiac and a myocardial depressant. (4) The extract induced relaxations of the guinea-pig ureter and suppressed histamine-induced spasms. It seemed to possess a spasmolytic action and a ureter relaxing action that can enhance getting rid of renal stones and relieve of the accompanying pain. (5) The extract did not possess the property of enhancing dissolution of oxalate calculi.     

Enantioselective enzymatic resolution of racemic alcohols by lipases in green organic solvents

The effects of two eco-friendly solvents, 2-methyltetrahydrofuran (MeTHF) and cyclopentyl methyl ether (CPME), on the enzyme activity and enantioselectivity of Novozym 435, Candida rugosa lipase (CRL), Porcine pancreas lipase (PPL), Lipase AK, Lipase PS, and Lipozyme, a series of commercial lipases, in the enantioselective transesterfications of racemic menthol, racemic sulcatol and racemic α-cyclogeraniol were studied. Vinyl acetate was chosen as the acyl donor and the reactions were carried out at water activity 0.06. The activity of lipases in CPME was similar to that observed in other largely employed organic solvents [toluene and tert-butyl methyl ether (MTBE)], and was slightly lower in MeTHF. However, for most of the lipases tested, the enantioselectivity was higher in the eco-friendly solvents. Lipase AK exhibited a high enantioselectivity (E = 232) for the resolution of racemic menthol but the reaction rate was low. Lipase formulation (the enzyme was frozen and lyophilized in potassium phosphate buffer without and with 5% (w/v) of sucrose, d-mannitol, or methoxy poly(ethylene glycol)) was tested with this lipase in order to improve its activity, which increased up to 4.5 times, compared to the untreated enzyme. CALB was found to be a useful biocatalyst for the resolution of racemic sulcatol, where high activity and enantioselectivity were obtained (E ≥ 1000). For the resolution of the racemic primary alcohol α-cyclogeraniol, most of the lipases tested were active but not enantioselective, except lipase PS which displayed a moderate enantioselectivity (E = 19). The effect of the presence of a low percentage of two ionic liquids (ILs) 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BMIM][TFSI]) (5% (v/v)) and 1-Butyl-3-methylimidazoliumtetrafluoroborate ([BMIM][BF4]) (1% (v/v)) in the medium was also investigated. Only in the case of CRL the ILs slightly increased the enantioselectivity from E = 91 to E = 103 and E = 120 for [BMIM][TFSI] and [BMIM][BF4], respectively. However, in all cases ILs caused a decrease of enzyme activity.     

Enzymatic Extract Fractionation of (Cymbopogon winterianus Jowitt) Citronella through Supercritical Carbon dioxide (SC-CO2)

Cymbopogon winterianus Jowitt or citronella is said to be an insect repellant and usually planted in the yard in the Philippines. In this study enzymatic extracts of citronella were fractionated using supercritical carbon dioxide extraction to have different oil extracts in three different parameters, 10 megapascal (10 MPa), 20 megapascal (20 MPa) and 30 megapascal (30 MPa) at constant temperature at 40° Celsius. The highest oil yield is at 20 MPa with an average of 10.21 for three trials of extraction, followed by 10 MPa and 30 MPa with 4.89 and 2.15. Oil extract at 10 MPa was subjected to gas chromatography- mass spectrometry (GC-MS) and found four components in which 2-methyl-5-(1-methylethyl)bicycle hexan 2-ol or trans sabinene hydrate and 4-methanol-o-Menth-8-ene or elemol was the major compounds. The pure crude enzymatic extract, 20 MPa and 30 MPa supercritical carbon dioxide extracts were subjected to fatty acid profiling, twelve free fatty acid were found at pure crude enzymatic extract, while nine free fatty acid were found at 20 MPa and 30 MPa supercritical carbon dioxide extracts. Lauric (C12) is consistently highest in terms of weight by weight in three extracts that were subjected to free fatty acid profiling. This study can be used as basis for agricultural applications in food and pharmaceutical since there is no thorough study of the fractionation of enzymatic extract of citronella.     

Anti-inflammatory and anti-oxidant activities of Mallotus oppositifolius (Geisel) methanol leaf extracts

The methanol leaf extract of Mallotus oppositifolius was evaluated for anti-inflammatory activity in rats and mice using acute and chronic anti-inflammatory models with acetylsalicylate acid (aspirin) as the reference drug. The antioxidant activity was done in vitro using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-hydrazyl (DPPH) spectrophotometric assays. The extract dose dependently and significantly reduced paw edema volume in rats induced by carrageenan (p < 0.01), decreased croton oil-induced ear inflammation (p < 0.05), inhibited cotton pellet-induced granuloma in mice and reduced the rat paw thickness in formalin-induced arthritis.     

Self-aggregation of liquids from biomass in aqueous solution

Aggregation of several chemicals from biomass: furfural derived compounds (furfural, 5-methylfurfural, furfuryl alcohol and tetrahydrofurfuryl alcohol), lactate derived compounds (methyl lactate, ethyl lactate and butyl lactate), acrylate derived compound (methyl acrylate) and levulinate compounds (methyl levulinate, ethyl levulinate and butyl levulinate) in aqueous solution has been characterised at T = 298.15 K through density, ρ, speed of sound, u, and isentropic compressibilities, κ_S, measurements. In addition the standard Gibbs free energies of aggregation have been also calculated. Furthermore, in order to deepen insight the behaviour of these chemicals in aqueous solution, the solubility of these compounds has been measured at T = 298.15 K.     

Enthalpies of solution of dl-α-alanyl-dl-α-asparagine in aqueous alcohols at 298.15 K

The enthalpies of solution of dl-α-alanyl-dl-α-asparagine (AlaAsn) were measured in aqueous methanol, ethanol, 1-propanol and 2-propanol with an alcohol mole-fraction content x₂ (from 0 to 0.4) at 298.15 K. The experimental results were used to calculate the enthalpies of transfer of AlaAsn from water to these mixtures as well as the enthalpy coefficients of pair-wise interactions (h_xy) between AlaAsn and alcohol molecules in water, according to the McMillan–Mayer's model. The h_xy values were found to be positive and increasing in a series methanol < ethanol < 1-propanol < 2-propanol.     

The role of gamma irradiation on the extraction of phenolic compounds in onion (Allium cepa L.)

The effect of gamma irradiation on the content of total phenolic compounds, especially quercetin (Q), in onion (Allium cepa L.) skin was investigated. Onion skin extracts contained two predominant flavonoid compounds, Q and quercetin-4′-glucoside (Q4′G). After 10 kGy gamma irradiation, the yield of Q in the extracts increased significantly from 36.8 to 153.9 μg/ml of the extract, and the Q4′G content decreased slightly from 165.0 to 134.1 μg/ml. In addition, the total phenolic compound content also increased after irradiation at 10 kGy, from 228.0 μg/g of fresh weight to 346.6 μg/g; negligible changes (237.1–256.7 μg/g) occurred at doses of up to 5 kGy. As we expected, radical-scavenging activity was enhanced remarkably (by 88.8%) in the 10 kGy irradiated sample. A dose-dependent increase in the peak intensity of the electron paramagnetic resonance (EPR) spectra was observed in all irradiated samples, with a maximum increase at 10 kGy. The intensity relative to that of the control was 0.15, and it increased to 1.10 in 10 kGy irradiated samples. The optimum gamma irradiation dose, which is sufficient to break the chemical or physical bonds and release soluble phenols of low molecular weight in onion skin, is about 10 kGy.