Enzyme inhibitory and antioxidant activity of Melia azedarach L. naturalized in Anatolia and its phenolic acid and fatty acid composition

In the present study, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and tyrosinase inhibitory and antioxidant activities of the fruit and leaf extracts of Melia azedarach L. (Meliaceae) of Turkish origin were evaluated. Enzyme inhibitory activity of the extracts was tested in vitro using ELISA microplate reader. Antioxidant activity of the extracts was tested using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelation, and ferric-reducing antioxidant power (FRAP) assays. Phenolic composition of the extracts was elucidated by high performance liquid chromatography (HPLC) and fatty acid compositions of the fatty oils of the fruits and leaves were elucidated by gas chromatography-mass spectrometry (GC-MS). The ethyl acetate extract from the leaves showed the highest inhibition against AChE (33.63 ± 1.40%) and BChE (92.89 ± 3.05%). The methanol extract from the leaves exerted the best antioxidant activity in DPPH radical scavenging and FRAP assays, while the ethyl acetate extracts of the fruits and leaves had the most notable effect in metal-chelation assay.     

Assessment of dermal wound healing and in vitro antioxidant properties of Avena sativa L.

Avena sativa L. (Poaceae) has been reported to have traditional utilization against skin diseases and inflammation. Therefore, in this study, the n-hexane, ethyl acetate, ethanol, and water extracts of A. sativa were investigated for their wound healing and antioxidant activities. Total phenol and flavonoid contents of the extracts were established spectrophotometrically. For the wound healing activity, linear incision and circular excision models on rats and mice were evaluated with a standard ointment Madecassol^®. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Significant wound healing activity was observed with the ointment formulation of the ethanol extract at 1% concentration. The histopathological examination results also supported the outcome of both linear incision and circular excision wound models. All of the extracts exerted low antioxidant activity in the applied assays. The present study provides a scientific evidence for the traditional usage of A. sativa in the management of wound healing.     

Preparation and evaluation of antioxidant capacity of Jackfruit (Artocarpus heterophyllus Lam.) wine and its protective role against radiation induced DNA damage

Jackfruit is an underutilized edible fruit in the tropics and subtropics. The aim of this study was to produce wine from jackfruit pulp and to evaluate the total phenolic and flavonoid contents and antioxidant properties of the wine. The ability of scavenging free radicals was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant assay (FRAP), N, N-dimethyl-p-phenylendiamine (DMPD) and nitric oxide (NO) scavenging assays. Experimental results indicated that jackfruit wine was effective in DPPH radical scavenging (69.44 ± 0.34%), FRAP (0.358 optical density value, O.D.), DMPD (78.45 ± 0.05%) and NO (62.46 ± 0.45%) capacity. By the analysis of the high performance liquid chromatography coupled to diode array detector (HPLC-DAD), two phenolic compounds namely gallic acid and protocatechuic acid were identified. The jackfruit wine was also able to protect H₂O₂ + UV radiation and γ-radiation (100 Gy) induced DNA damage in pBR322 plasmid DNA. The antioxidant and DNA damage protecting properties of jackfruit wine confirmed health benefits when consumed and could become a valuable source of antioxidant rich neutraceuticals. Additionally, the wine could be a commercially valuable by-product for the jackfruit growers.     

Potential of extracts of the tropical plant Balanites aegyptiaca (L) Del. (Balanitaceae) to control the mealy bug, Maconellicoccus hirsutus (Homoptera: Pseudococcidae)

The effects of extracts of different parts of the perennial tropical plant Balanites aegyptiaca (L) Del., including various solvent extracts of roots, methanol extracts from leaves, fruits, flowers and roots, partially purified saponins obtained from its roots and a standard saponin were studied on the life cycle (adult longevity, number of eggs, crawlers, adults, weight of adults and % wax content) of a laboratory-reared parthenogenic line of the mealy bug, Maconellicoccus hirsutus (Homoptera: Pseudococcidae). Extracts derived from various parts of B. aegyptiaca (leaves, fruits, flowers, and roots in methanol) affected the life cycle of M. hirsutus with a methanol root extract being the most effective at a concentration of 500 μg ml⁻¹. Partially purified saponin of B. aegyptiaca and the commercial bark saponin extract (Sigma) from Quillaja saponaria at a concentration of 500 μg ml⁻¹ were effective in reducing the longevity of M. hirsutus. Significant reductions in oviposition by M. hirsutus were found for all the extracts at a concentration of 500 μg ml⁻¹. Extracts also affected the number of emerging crawlers, number of adults as well as the weight and wax content of emerging adults. These studies suggest that B. aegyptiaca plant extracts and saponins can be useful botanical insecticides for the protection of crops from mealy bugs.     

Optimization of extraction conditions of antioxidants from sunflower shells (Helianthus annuus L.) before and after enzymatic treatment

The effects of three independent variables: solvent polarity, temperature and extraction time on the antioxidant capacity, total phenolic content and phenolic acid composition in extracts obtained from sunflower shells before and after enzymatic treatment were studied. Response surface methodology based on three-level, three-variable Box-Behnken design was used for optimization of extraction parameters and evaluation of their effect on antioxidant capacity and total phenolic content in shell extracts.The average antioxidant capacities of extracts from sunflower shells without enzymatic treatment (368.1-1574.4 μmol TE/100 g) were higher than those for cellulolytic and pectolytic enzymes-treated shells (222.7-1419.0 and 270.7-1570.7 μmol TE/100 g, respectively). The content of total phenolic compounds ranged between 58.2-341.2 mg CGA/100 g, 26.7-277.3 mg CGA/100 g and 51.4-301.5 mg CGA/100 g for extracts obtained from shells without enzyme and treated with cellulolytic and pectolytic enzymes, respectively. Total phenolic content (TPC) in the studied shell extracts correlated significantly (p < 0.0001) positively with their antioxidant capacity determined by the ferric reducing antioxidant power (FRAP) method (r = 0.9275). Results of FRAP, TPC and phenolic acid composition in the studied shell extracts depend on the extraction conditions (solvent polarity, temperature, time), but they are independent on the addition of enzyme solutions. The antioxidant capacity and total phenolic content in the resulting extracts increased with a line in extraction temperature and solvent polarity.     

Effects of crude seed extracts of Annona atemoya and Annona squamosa L. against the cabbage looper, Trichoplusia ni in the laboratory and greenhouse

Antifeedant, growth inhibitory and toxic effects of crude seed extracts of Annona squamosa and Annona atemoya from Fazenda Viveiro Bona, Parasisópolis – Minas Gerais, Brazil, were evaluated against the cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae) using different bioassays. Crude methanolic seed extracts deterred feeding of third instar T. ni larvae in a leaf disc choice bioassay. A. squamosa was ∼10 times more active as a feeding deterrent than A. atemoya (DC₅₀ = 2.3 mg/ml vs. 20.1 mg/ml). A. squamosa was ∼three times more active as a growth inhibitor than A. atemoya (EC₅₀ = 38.0 ppm vs. 117.0 ppm). Methanolic seed extracts of A. squamosa and A. atemoya were toxic to third instar T. ni larvae both through topical and oral application. A. squamosa was more toxic through feeding (LC₅₀ = 167.5 ppm vs. 382.4 ppm) whereas, A. atemoya exerted greater toxicity via topical application (LC₅₀ = 301.3 μg/larva vs. 197.7 μg/larva). Both A. squamosa and A. atemoya extracts reduced leaf area consumption and larval growth in a greenhouse experiment. Our results indicate that both A. squamosa and A. atemoya have potential for development as botanical insecticides, especially for local use in Brazil.     

Efficacy of medicinal plant extracts against Formosan subterranean termite, Coptotermes formosanus

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is among the most devastating termite pests. Natural products derived from plant extracts were tested in a discovery programme for effective, environment friendly termite control agents. Screening for anti-termitic activity of plant extracts with some known medicinal attributes could lead to the discovery of new agents for termite control. The aim of this study was to investigate the anti-termitic activity of crude leaf hexane, ethyl acetate, acetone and methanol extracts of Andrographis lineata Wallich ex Nees. (Acanthaceae), Andrographis paniculata (Burm.f.) Wall. ex Nees. (Acanthaceae), Argemone mexicana L. (Papaveraceae), Aristolochia bracteolata Lam. (Aristolochiaceae), Datura metel L. (Solanaceae), Eclipta prostrata L. (Asteraceae), Sesbania grandiflora (L.) Pers. (Fibaceae) and Tagetes erecta L. (Compositae) against C. formosanus. An impregnated filter paper no-choice bioassay method was followed. All the crude extracts showed anti-termitic activity in a dose-dependent manner and exhibited a significant activity after 24 h and 48 h of exposure; the highest termite mortality was found in leaf hexane extract of A. bracteolata, ethyl acetate extract of A. paniculata, D. metel, E. prostrata, methanol extract of A. lineata and D. metel after 24 h (LD₅₀ = 363, 371, 298, 292, 358 and 317 ppm; LD₉₀ = 1433, 1659, 1308, 1538, 1703 and 1469 ppm), respectively. The hexane extract of T. erecta, acetone extract of A. mexicana, methanol extract of S. grandiflora and T. erecta showed activity after 48 h (LD₅₀ = 245, 253, 289, 409 ppm; LD₉₀ = 1378, 1511, 1508 and 2425 ppm), respectively. Among the natural products tested, may provide a renewable source of safe natural wood preservatives. These findings corroborate traditional insecticidal application of selected plants and the results can be extended for the control of termites. The primary objective of the present study was to identify novel, natural chemotypes from biologically active crude plant extracts that may be useful as part of termite treatment regimens in their natural form or as synthons for structure-activity studies in the future. The results reported here open the possibility of further investigations of efficacy on their anti-termitic properties of natural product extracts.     

Arbutus unedo L. leaves as source of phytochemicals with bioactive properties

In recent years the strawberry tree (Arbutus unedo L.) is being gradually replaced by other species with higher economic value. With the ultimate goal of selecting superior genotypes, the present work was initiated to study the antioxidant and antimicrobial activities, and total phenolic content in 19 different genotypes of A. unedo leaves from the Trás-os-Montes region of Portugal.The genotype Bragança 1 contains higher total phenolic content (215.0 mg GAE/g_extract) whereas the Vila Boa 4 genotype shows lower total phenolic content (148.0 mg GAE/g_extract). In both methods tested to evaluate the antioxidant activity, Vila Verde and Donai displayed the highest antioxidant capacity (EC₅₀ values of 0.088 and 0.090 mg/mL, respectively, for DPPH; EC₅₀ values of 0.233 and 0.245 mg/mL, respectively, for reducing power assay) while Vila Boa 2 reported the lowest antioxidant potential (EC₅₀ values of 0.142 and 0.378 mg/mL, respectively, in DPPH and reducing power methods). Linear negative correlations were established between the total phenol contents and the EC₅₀ values for both of the antioxidant activity methods tested. Preliminary assays for antimicrobial potential showed that extracts from A. unedo leaves display antibacterial activity, with MIC values of 1 and 5 mg/mL for some Gram-positive and Gram-negative bacteria, respectively. Taken together, the results suggest that A. unedo leaves are a potential source of natural compounds with valuable bioactive properties that could be explored by the pharmaceutical, chemical and food industries.     

Chemical profiling and biological screening of Thymus lotocephalus extracts obtained by supercritical fluid extraction and hydrodistillation

Essential oil and extracts from the aerial parts of Thymus lotocephalus were obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE) in two different collectors, respectively. SFE was conducted at 40 °C and a working pressure of 12 or 18 MPa. The chemical profiles were determined using GC-FID and GC-IT-MS. Oxygen-containing monoterpenes were the primary constituents in the essential oil and SFE extracts collected in the second separator, while the extracts obtained in the first separator were predominantly oxygen-containing sesquiterpenes. A large number of compounds were identified by hydrodistillation and, in contrast, the highest extraction yields were obtained using SFE. Linalool (10.43 ± 1.63%) was the main component in essential oil, whereas camphor (7.91 ± 0.84%) and cis-linalool oxide (7.25 ± 1.45%) were the major compounds in the extracts-2nd separator obtained at pressures of 12 and 18 MPa, respectively. Caryophyllene oxide was the primary constituent identified in the extracts-1st separator (4.34 ± 0.51 and 4.41 ± 1.25% obtained at 12 and 18 MPa, respectively). The antioxidant activity was assessed by ORAC and DPPH assays, and the anti-cholinesterase activity was evaluated in vitro using Ellman's method. The essential oil and SFE extracts (first separator) of T. lotocephalus possessed antioxidant activity and strongly inhibited cholinesterases. We also demonstrated that the acetylcholinesterase and butyrylcholinesterase inhibitory activities of the essential oil could be attributed to 1,8-cineole and caryophyllene oxide, respectively.     

Distillation waste water can modify peppermint (Mentha ×piperita L.) oil composition

We evaluated the effects of foliar sprays made of residual distillation waters from 13 species containing essential oil (Melissa officinalis, Mentha arvensis, M. gracilis, M. ×piperita, M. spicata, Monarda citriodora, Nepeta mussinii, Porophyllum ruderale, Rosmarinus officinalis, Salvia officinalis, Satureja montana, Tagetes lucida, and Thymus vulgaris), hot water extracts from two alkaloid-containing species (Glaucium flavum, Datura innoxia), and three plant hormones (methyl jasmonate, gibberellic acid, and salicylic acid) on growth, productivity, and essential oil content and composition (α-pinene, β-pinene, sabinene, myrcene, l-limonene, 1,8-cineole, l-menthone, menthofuran, d-isomenthone, menthyl acetate, neo-menthol, b-caryophyllene, l-menthol, pulegone, germacrene-d, and piperitone) of peppermint (Mentha ×piperita L.) ‘Black Mitcham’. The results showed significant effects of the treatments on plant height and weight, essential oil content and yield, and essential oil composition. Cluster analysis indicated similarities between the effects of plant hormones and some extracts on peppermint oil composition. None of the distillation waters had strong in vitro antimicrobial activity. The results indicated that residual distillation water of some plant species may influence monoterpene synthesis and accumulation in peppermint and hence may be used for targeted modification of peppermint essential oil composition.     

Chemical composition of the essential oil and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss.

This study was conducted to evaluate the essential oil composition and antioxidant activity of methanolic extracts from fruits and flowers of Hypericum lydium Boiss., a wild growing species of the Turkish flora. The antioxidant activities were determined through several biochemical assays. Both extracts showed an inhibitory effect against the formation of TBARS in a phosphatidylcholine liposome model system, moderate scavenging effect on DPPH and superoxide radicals, prominent reducing power and inhibitory effect on deoxyribose degradation in both the nonsite and site-specific assay, but a greater hydroxyl radical scavenging activity was observed in the non-site specific assay, suggesting that the extracts were better at scavenging hydroxyl radicals than at chelating iron. Correlation analysis indicated that there was a linear relationship between antioxidant potency, free-radical scavenging activity, reducing power and the content of flavonoids of fruits and flowers extracts. The essential oils obtained by hydrodistillation were analyzed by GC and GC-MS. In total forty-three compounds were identified. The most abundant components were monoterpenes hydrocarbons represented principally by α-pinene. The tested oil showed no antioxidant activity.     

Antioxidant activity and phenolic composition of the medicinal and edible halophyte Mesembryanthemum edule L.

Mesembryanthemum edule L. (sourfig, Aizoaceae) has long been used as food and in traditional medicine. This study was intended to characterize the antioxidant properties and the phenolic compounds of M. edule leaf, stem and root. The approach consisted to evaluate these organs for their antioxidant activities through several in vitro tests, to determine tissue contents in total phenolics, flavonoids and proanthocyanidins and to establish the phenolic composition through RP-HPLC analysis. All studied organs showed a high antioxidant activity as compared to positive control BHT, with maximal efficiency for stems followed by leaves and roots. The highest polyphenolic levels were found in stems and leaves (86.5 and 68.7 mg GAE g⁻¹ DW, respectively), suggesting that their strong antioxidant activity could be attributed to these phytochemicals. The HPLC analysis revealed that the main phenolic compounds were quercitrin and avicularin (1.4 and 1.15 mg g⁻¹ DW, respectively) in the leaves, while catechin and procyanidin B2 (1.66 and 1.54 mg g⁻¹ DW, respectively) were the most abundant phenolics in the stems. Overall, the strong antioxidant activity and richness of M. edule aerial tissues suggest that it could be advantageously used as a functional or nutraceutical food, to prevent or moderate oxidative stress-related diseases.     

Antioxidant, antibacterial, and antiviral effects of Lactuca sativa extracts

Antioxidant, antibacterial and antiviral effects of aqueous and methanol extracts of Lactuca sativa var longifolia leaves were investigated. The antioxidant activity was evaluated using the DPPH assay. The effect of the extracts against 5 Gram-positive and 6 Gram-negative bacteria was tested. The antiviral activity was determined against human cytomegalovirus (HCMV) strain AD-169 (ATCC Ref. VR 538) and coxsackie B virus type 3 (CoxB-3) using a cytopathic effect (CPE) reduction assay. The methanol extract had the highest total phenolic contents (235.31 mg CE/g extract). It exhibited a significantly (p < 0.05) greater hydroxyl radical-scavenging activity (IC₅₀ = 3.5 μg/ml) than the aqueous extract (4.1 μg/ml). It was also the most effective extract with the lowest MIC (2.5 mg/ml) against all Gram negative and Gram positive bacteria. Methanol and aqueous extracts exhibited antiviral activity against HCMV and Cox-B3 viruses with IC₅₀ of 200 μg/ml.     

In vitro plant regeneration from decapitated embryonic axes of Clitoria ternatea L.—An important medicinal plant

In vitro clonal propagation of Clitoria ternatea has been achieved by employing decapitated embryonic axes (DEAs) explants. The explants induced multiple shoots on cytokinin-containing medium. Several cytokinins [6-benzylaminopurine (BAP), 6-furfuryl aminopurine (KIN) and thidiazuron (TDZ)] were assayed. The best response was achieved with 2 mg l⁻¹ BAP in which 100% of cultures produced 6.0 ± 0.14 shoots per explant. MS + 1 mg l⁻¹ gibberellic acid (GA₃) was the most suitable for shoot elongation. Regenerated shoots were rooted in half-strength Murashige and Skoog (MS) medium with 0.2 mg l⁻¹ indole-3-butyric acid (IBA). Plantlets were successfully acclimatized and established in soil, and they were morphologically indistinguishable from the source plant. The plantlets attained maturity and flowered normally. The efficient regeneration protocol reported here provides an important method of micropropagation of this plant. Furthermore, this protocol may be used for genetic transformation of this valuable medicinal plant for its further improvement.     

Feeding perturbation and toxic activity of five Chrysanthemum species crude extracts against Spodoptera littoralis (Boisduval) (Lepidoptera; Noctuidae)

The effect of the whole methanol extracts of five Chrysanthemum species on feeding and performance of Spodoptera littoralis (Boisduval) larvae has been investigated in vitro. The extracts exhibited an anti-feeding and phagostimulating activities against cotton leafworm larvae when applied either on leaf discs or incorporated into an artificial diet. Under chosen conditions, the antifeedant index calculated over 24 h for sixth instar larvae significantly varied from 78.55 for Chrysanthemum segetum L. to −44.18 for Chrysanthemum fuscatum Desf. at the dose of 1000 ppm. Toxicity of the extracts was manifested by a high mortality, reduced growth rates, and low weight gain by larvae fed on diets containing 1000–10,000 ppm of the extract. Anyone of the larvae treated with Chrysanthemum macrotum (D.R.) Ball. leaves crude extract survived to pupation at the two higher concentrations. The time to pupation increased for Chrysanthemum grandiflorum flowers crude extract from 11.40 ± 0.93 to 28.93 ± 10.92 days as the extract concentration in the diet increased from 0 to 10,000 ppm. The ingestion of crude extract by the third instar larvae reduced significantly the consumption, growth and utilisation of the ingested and digested food, and reduced digestibility.     

Supercritical carbon dioxide (SC-CO2) extraction of Nigella sativa L. oil using full factorial design

In this study, Nigella sativa L. oil was extracted using supercritical carbon dioxide with full factorial design to determine the best extraction condition (pressure, temperature and dynamic extraction time) for obtaining an extract with high yield, antioxidant activity and thymoquinone (TQ) quantity. The maximum thymoquinone content in the highest overall yield was achieved through SC-CO₂ extraction condition of 150 bar, 40 °C, 120 min with the value of 4.09 mg/ml. The highest SC-CO₂ extraction yield was 23.20% which obtained through extraction condition of 350 bar, 60 °C and 120 min. The extraction conducted at 350 bar, 50 °C, 60 min showed the lowest IC₅₀ value (highest antioxidant activity) of 2.59 mg/ml using DPPH radical scavenging activity method. Fatty acid composition of the extracted oil with highest radical scavenging activity was obtained by gas chromatographic analysis.     

Fatty acid composition and oxidation stability of hemp (Cannabis sativa L.) seed oil extracted by supercritical carbon dioxide

Supercritical carbon dioxide (SC-CO₂) was employed to extract oil from hemp (Cannabis sativa L.) seeds. For ground seeds, the supercritical extraction was carried out at temperatures of 40, 60 and 80 °C and pressures of 300 and 400 bar. Different solvent-ratios were applied. Supercritical CO₂ extractions were compared with a conventional technique, n-hexane in Soxhlet. The extraction yields, fatty acid composition of the oil and oxidation stability were determined. The seed samples used in this work contained 81% PUFAs, of which 59.6% was linoleic acid (ω-6), 3.4% γ-linolenic (ω-3), and 18% α-linolenic (ω-6). The highest oil yield from seeds was 22%, corresponding to 72% recovery, at 300 bar and 40 °C and at 400 bar and 80 °C. The highest oxidation stability corresponding to 2.16 mM Eq Vit E was obtained at 300 bar and 80 °C.     

Microscopy techniques and image analysis for evaluation of some chemical and physical properties and morphological features for seeds of the castor oil plant (Ricinus communis)

Ricinus communis seed is a source of protein and oil with a high potential to use as animal's feedstock and biodiesel production. However, the oil yield and the extraction efficiency depend on the process conditions applied, as well as on the physical, chemical and structural properties of the seed, which have not been fully investigated. Hence, the objective of this study was to evaluate some chemical and physical properties of R. communis seed as well as to describe and quantify the macro and microstructure of this raw material by microscopy techniques and image analysis. Chemical analysis confirmed the seeds’ high contents of protein (28.48 ± 0.25%) and fat (51 ± 0.31%). On the other hand, the values of geometric mean diameter (8.95 ± 0.05 mm), bulk density (538 ± 11 kg/m³), and true density (1458 ± 27 kg/m³), among others, were higher than the ones reported about similar oils seeds. Microstructural studies showed that the endosperm cells presented an ovoid shape, as obtained from the aspect ratio results (AR = 1.28 ± 0.17), and a cell density of 570 ± 10 cell/mm², resulting in a porous structure, while the embryo cells had a cell density of 4903 ± 2 cell/mm², and an AR of 2.41 ± 0.48, related to a more compact structure (rectangular form) in this part of the seed. Regarding to lipids bodies (lb), they were only visible in the endosperm cells, showing a circular shape (AR = 1.16 ± 0.1), and a mean cell density of 9.57 ± 2.40 lipid bodies/μm², associated to protein as observed by the mineral presence (K, P, Mg and S) as determined by the energy dispersive X-ray analysis. Microscopy techniques and images analysis were efficient tools for the characterization of macro and microstructure of seeds and the data obtained integrate numerical information that could be useful for thermal and mechanical processing of R. communis seed, as well as for the design process equipment.     

Enzymatic epoxidation of Sapindus mukorossi seed oil by perstearic acid optimized using response surface methodology

As a novel renewable resource, Sapindus mukorossi seed oil (SMSO) with an iodine value of 84.86 g/100 g, and containing 51.0 ± 0.9% oleic acid (18:1), 6.6 ± 0.6% linoleic acid (18:2), 1.1 ± 0.3% linolenic acid (18:3), and 23.1 ± 0.9% eicosanoic acid (20:1), was epoxidized using hydrogen peroxide as oxygen donor and stearic acid as active oxygen carrier in the presence of immobilized Candida antarctica lipase B. The effect of the amount of stearic acid on the enzymatic epoxidation was investigated. Response surface methodology (RSM) was used to study and optimize the effects of variables (reaction temperature, enzyme load, mole ratio of H₂O₂/CC-bonds, and reaction time) on the epoxy oxygen group content (EOC) of epoxidized SMSO. Results showed that stearic acid as active oxygen carrier could enhance the enzymatic epoxidation of SMSO. The variables of reaction temperature and enzyme load were the most significant in the process. A two second-order model was satisfactorily fitted the data (R² = 0.9723) with non-significant lack of fit. The optimum EOC of epoxidized SMSO was 4.6 ± 0.3% under the conditions of 50.0 °C, 7.0 h, 2.00% (relative to the weight of SMSO) enzyme load, and 4:1 mole ratio of H₂O₂/CC-bonds.     

Bioactive properties and chemical constituents of methanolic extract and its fractions from Jatropha curcas oil

The present work is designed to evaluate the bioactive properties of the crude methanolic extract of Jatropha curcas oil and its solvent fractions. The crude methanolic extract obtained was fractionated using a hydrophilic lipophilic balanced (HLB) cartridge and then eluted with different solvents in the order of hexane (F1), dichloromethane (F2), chloroform (F3), ethyl acetate (F4) and methanol (F5), respectively. Total phenolic content of the crude methanolic extract and its fractions was in the range of 0.19-4.5 mg/g as gallic acid equivalent. Antioxidant activity of the crude methanolic extract and its fractions were determined by two complementary test methods, namely, phenanthroline method and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. All samples demonstrated weak antioxidant activity (150-851 μmol Fe/100 g of the extract and IC₅₀ of 1.05-13.5 mg/mL). When compared to butylated hydroxytoluene (BHT), a reference synthetic antioxidant, both showed weaker antioxidative potential. The evaluation of antimicrobial activity of the extracts was performed using a disc diffusion method and a micro-well dilution method against six economic plant disease bacteria. The results showed that all extracts possessed strong to moderate antibacterial activity with varying degrees of growth inhibition against the test bacteria. The minimum inhibitory concentrations (MIC) were in the range of 14.92-428.6 μg/mL. In addition, the chemical constituents in each fraction of the extract were subjected to analyze by gas chromatography-mass spectrometry (GC-MS). The eleven constituents were identified. Among them, 2,4-di-tert-butylphenol, methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and linoleic acid may be the main cause of its strong antibacterial activity. Therefore, this oil present in the methanolic extract had great potential as effective antibacterial sources.