Novel NARC-G1 garlic: comparative allicin quantification with morpho-biochemical & genetic profiling.

Garlic (Allium sativum) is an important cash food crop, and the biotechnology industry has considerable interest in the plant because of its medicinal importance. These medicinal properties are attributed to organosulphur compounds as the accumulation of these compounds varies according to genotype, locality, light quality, and cultivation practices. In this study, we compared a newly developed garlic variety NARC-G1 by National Agricultural Research Centre (NARC), Islamabad, Pakistan with three different garlic cultivars and highlighted the distinctive attributes like phenotypic characteristics, the content of allicin, elemental profile, and gene polymorphism. Phenotypic analysis showed NARC-G1 has significantly higher bulb weight (66.36g ± 18.58), single clove weight (5.87g ± 1.041), and clove width (17.41mm ± 0.95) which directly correlates to the size of the garlic. The analytical analysis showed the highest allicin content (4.82 ± 0.001) in NARC-G1. Genotyping of the alliinase in all four cultivars showed indels in the gene resulting in distinguishable changes in organosulphur compounds' profile. NARC-G1 is unique from other garlic cultivars and could be the best choice for mass production with proper cultivation and irrigation management. Moreover, for Pakistan NARC-G1 could be a potential contender to earn the industrial benefits with inland cultivation instead of importing garlic alleviating the economic burden.

Modulation of Allicin-Free Garlic on Gut Microbiome.

The allicin diallyldisulfid-S-oxide, a major garlic organosulfur compound (OSC) in crushed garlic (Allium sativum L.), possesses antibacterial effects, and influences gut bacteria. In this study, we made allicin-free garlic (AFG) extract and investigated its effects on gut microbiome. C57BL/6N male mice were randomly divided into 6 groups and fed normal diet (ND) and high-fat diet (HFD) supplemented with or without AFG in concentrations of 1% and 5% for 11 weeks. The genomic DNAs of feces were used to identify the gut microbiome by sequencing 16S rRNA genes. The results revealed that the ratio of p-Firmicutes to p-Bacteroidetes increased by aging and HFD was reduced by AFG. In particular, the f-Lachnospiraceae, g-Akkermansia, and g-Lactobacillus decreased by aging and HFD was enhanced by AFG. The g-Dorea increased by aging and HFD decreased by AFG. In addition, the ratio of glutamic-pyruvic transaminase to glutamic-oxaloacetic transaminase (GPT/GOT) in serum was significantly increased in the HFD group and decreased by AFG. In summary, our data demonstrated that dietary intervention with AFG is a potential way to balance the gut microbiome disturbed by a high-fat diet.

Resistance and clonal selection among Allium sativum L. germplasm resources to Delia antiqua M. and its correlation with allicin content.

BACKGROUND: Garlic is the second largest allium crop after onion and is grown all over the world. The onion maggot (Delia antiqua M.) is a pest that seriously affects the yield and quality of garlic. Cultural controls and insecticides have several potential problems, including pesticide residue and development of resistance. Screening resistant varieties is an ideal alternative method. RESULTS: The resistance of 213 accessions of garlic clones against onion maggot was identified. The results showed that the pest index was between 5.56% and 91.11%, with classification into six groups by cluster analysis: HR (highly resistant), R (resistant), MR (moderately resistant), MS (moderately susceptible), S (susceptible) and HS (highly susceptible). Among these accessions, 9 and 30 were HR and R to onion maggot, respectively. Comparing the resistances of seven pairs of accessions between the original accessions and their progenies showed that single bulb clonal selection could be an effective way to improve allicin content, onion maggot resistance and most morphological traits. The relationship between allicin content and resistance was investigated, and a significant positive relationship was found. Accessions with a high content of allicin have great potential as resistant accessions. CONCLUSION: This study showed significant differences among garlic germplasm in their response to Delia antiqua M. Some accessions were highly resistant and tolerant. Utilization of these accessions will help minimize environmental pollution, preserve agro-ecosystems and biodiversity, and make management processes more economical. Furthermore, these accessions could be used in breeding programs to develop new maggot-resistant onion cultivars. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effect of pre-storage removal of different parts of the scape top on the biochemical changes of two garlic cultivars during controlled atmosphere storage.

BACKGROUND: This study highlights the effect of removing different plant parts on the biochemical changes in the garlic scape of cultivars G064 and G025 during controlled atmosphere storage (O2 = 2%-5%, CO2 = 3%-6%) at temperature = 0 ± 0.5 °C, Relative Humidity (RH) RH = 85%-95%, for 168 day. Total polyphenols (TP), total flavonoids (TF), the concentration of allicin, ethylene production and the antioxidant potential were evaluated and analyzed by using four different assays. Statistically significant differences were observed between different treatments. RESULTS: Total polyphenols, allicin concentration, and ethylene production were the highest in G064, while the total flavonoid concentration was the highest in G025. Removing the top resulted in the highest levels of total polyphenols, total flavonoids, allicin, and ethylene in both cultivars. The antioxidant capacity was also significantly higher when the top was removed than with other treatments in both cultivars. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity (HRSC), ferric ion reducing antioxidant power (FRAP) and metal-chelating capacity (MCC) were higher in cultivar G064 compared to G025. CONCLUSION: Overall, the results suggest that the removing the tops of the scapes of G025 and G064 is the best treatment to maintain these biochemical changes. © 2018 Society of Chemical Industry.

Development and characterization of sandwich-type enzyme-linked aptamer assay for the detection of rongalite in food.

Rongalite is an essentially strong carcinogen, which due to its properties as a bleaching and brightening, is illegally added to the food processing. In this study, a sandwich-type enzyme-linked aptamer assay (ELAA) is developed by using a rongalite-specific aptamer G02 modified fluorescein amidite (FAM) as a capture probe and aptamer C01 modified biotin as a signal element. In the presence of rongalite, the aptamer G02-rongalite-aptamer C01 complex is produced, and the absorbance value can be subsequently measured. The sandwich-type ELAA was shown to detect rongalite with high specificity and affinity, with a KD value of 19.91 ±â€¯1.321 nM. In addition, the standard curve was established, with the limit of quantification (LOQ) for rongalite at 10 ng mL-1. By calculating the slope of the standard curve and the standard deviation of the blank values, the method detection limit (MDL) was 0.572 ng mL-1. Additionally, the accuracy of the sandwich-type ELAA was demonstrated in real food samples. Compared with high-pressure liquid chromatography (HPLC) assay, the sandwich-type ELAA can detect rongalite directly, and it has great advantages in pre-treatment, operation technique and cost. In short, our data suggest that the sandwich-type ELAA may be applicable as a molecular detection technique for rongalite.

Application of Direct Analysis in Real Time-High Resolution Mass Spectrometry to Investigations of Induced Plant Chemical Defense Mechanisms-Revelation of Negative Feedback Inhibition of an Alliinase.

Several plants of agricultural and medicinal importance utilize defense chemistry that involves deployment of highly labile, reactive, and lachrymatory organosulfur molecules. However, this chemistry is difficult to investigate because the compounds are often short-lived and prone to degradation under the conditions required for analysis by common analytical techniques. This issue has complicated efforts to study the defense chemistry of plants that exploit the use of sulfur in their defense arsenals. This work illustrates how direct analysis in real time-high resolution mass spectrometry (DART-HRMS) can be used to track organosulfur defense compound chemistry under mild conditions. Petiveria alliacea was used as a model plant that exploits the enzyme alliinase to generate induced organosulfur compounds in response to herbivory. Tracking of the organosulfur compounds it produces and quantifying them by DART-HRMS using isotopically labeled analogues revealed a feedback inhibition loop through which the activities of the alliinase are stymied shortly after their activation. The results show that the downstream thiosulfinate products petivericin (100 µM) and pyruvate (8.4 mM) inhibit alliinase activity by 60% and 29%, respectively, after 1 h, and a mixture of the two inhibited alliinase activity by 65%. By 2 h, alliinase activity in the presence of these alliinase-derived products had ceased completely. Because thiosulfinate, pyruvate, and lachrymatory sulfine compounds are produced via the same alliinase-derived sulfenic acid intermediate, the inhibition of alliinase activity by increasing concentrations of downstream products shows how production of these defense compounds is modulated in real time in response to a tissue breach. These findings provide a framework within which heretofore unexplained phenomena observed in the defense chemistry of P. alliacea, onion, garlic, and other plants can be explained, as well as an approach by which to track labile compounds and enzymatic activity by DART-HRMS.

Resistance of Garlic Cultivars to Bradysia odoriphaga and Its Correlation with Garlic Thiosulfinates.

Garlic, a widely cultivated global vegetable crop, is threatened by the underground pest Bradysia odoriphaga in China. Previous reports indicated that garlic essential oil, of which the dominant components are sulfides or thiosulfinates, exhibits insecticidal activity against pests. However, it is unclear whether the resistance of garlic to B. odoriphaga is related to thiosulfinates. Here, we compared the resistance of 10 garlic cultivars at various growth stages to B. odoriphaga by field investigation and indoor life-table data collection. Furthermore, the relationship between thiosulfinates content and resistance, as well as the toxicity of garlic oil and allicin against B. odoriphaga larvae was determined. Field surveys demonstrated that the garlic cultivars Qixian and Cangshan possessed the highest resistance, while Siliuban and Yishui were the most sensitive. When reared on Qixian, B. odoriphaga larval survival and fecundity declined by 26.2% and 17.7% respectively, but the development time was prolonged by 2.8 d compared with Siliuban. A positive correlation was detected between thiosulfinates content and resistance. Furthermore, garlic oil and allicin exhibited strong insecticidal activity. We screened out 2 pest-resistant cultivars, for which thiosulfinate content was highest. Additionally, the insecticidal activity displayed by sulfides and allcin suggests their potential for exploitation as botanical insecticides.

Boiling enriches the linear polysulfides and the hydrogen sulfide-releasing activity of garlic.

Garlic is rich in polysulfides, and some of them can be H2S donors. This study was conducted to explore the effect of cooking on garlic's organopolysulfides and H2S-releasing activity. Garlic bulbs were crushed and boiled for a period ranging from 3 to 30min and the solvent extracts were analyzed by GC-MS/FID and HPLC. A cell-based assay was used to measure the H2S-releasing activity of the extracts. Results showed that the amounts of allyl polysulfides increased in crushed garlic boiled for 6-10min; however, prolonging the thermal treatment to 20 or 30min decreased their concentrations. Data of the H2S-releasing activity, expressed as diallyl trisulfide equivalents (DATS-E), parallel this trend, being significantly higher at 6 and 10min boiling. Our results showed enhancement of H2S-releasing activity upon moderate boiling, suggesting that shorter cooking time may maximize its health benefits as a dietary source of natural H2S donors.

Selective Gas-Phase Ion/Ion Reactions: Enabling Disulfide Mapping via Oxidation and Cleavage of Disulfide Bonds in Intermolecularly-Linked Polypeptide Ions.

The selective gas-phase oxidation of disulfide bonds to their thiosulfinate form using ion/ion reactions and subsequent cleavage is demonstrated here. Oxidizing reagent anions are observed to attach to all polypeptides, regardless of amino acid composition. Direct proton transfer yielding a charge-reduced peptide is also frequently observed. Activation of the ion/ion complex between an oxidizing reagent anion and a disulfide-containing peptide cation results in oxygen transfer from the reagent anion to the peptide cation to form the [M+H+O](+) species. This thiosulfinate derivative can undergo one of several rearrangements that result in cleavage of the disulfide bond. Species containing an intermolecular disulfide bond undergo separation of the two chains upon activation. Further activation can be used to generate more sequence information from each chain. These oxidation ion/ion reactions have been used to illustrate the identification of S-glutathionylated and S-cysteinylated peptides, in which low molecular weight thiols are attached to cysteine residues in peptides via disulfide bonds. The oxidation chemistry effectively labels peptide ions with readily oxidized groups, such as disulfide bonds. This enables a screening approach for the identification of disulfide-linked peptides in a disulfide mapping application involving enzymatic digestion. The mixtures of ions generated by tryptic and peptic digestions of lysozyme and insulin, respectively, without prior separation or isolation were subjected both to oxidation and proton transfer ion/ion chemistry to illustrate the identification of peptides in the mixtures with readily oxidized groups.

Biochemical Characterization and Antimicrobial and Antifungal Activity of Two Endemic Varieties of Garlic (Allium sativum L.) of the Campania Region, Southern Italy.

Extracts of the bulbs of the two endemic varieties "Rosato" and "Caposele" of Allium sativum of the Campania region, Southern Italy, were analyzed. The phenolic content, ascorbic acid, allicin content, and in vitro antimicrobial and antifungal activity were determined. Ultra performance liquid chromatography with diode array detector performed polyphenol profile. The polyphenolic extracts showed antioxidant activity (EC50) lower than 120 mg. The amount of ascorbic acid and allicin in the two extracts was similar. Polyphenol extract exhibited antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and (only by the extract of Rosato) against Bacillus cereus. The extract of Caposele was more effective in inhibiting the growth of Aspergillus versicolor and Penicillum citrinum. On the other hand, the extract of Rosato was effective against Penicillium expansum.

A Chemical Approach for the Detection of Protein Sulfinylation.

Protein sulfinic acids are formed by the reaction of reactive oxygen species with protein thiols. Sulfinic acid formation has long been considered an irreversible state of oxidation and is associated with high cellular oxidative stress. Increasing evidence, however, indicates that cysteine is oxidized to sulfinic acid in cells to a greater extent, and is more controlled, than first thought. The discovery of sulfiredoxin has demonstrated that cysteine sulfinic acid can be reversed, pointing to a vast array of potential implications for redox biology. Identification of the site of protein sulfinylation is crucial in clarifying the physiological and pathological effects of post-translational modifications. Currently, the only methods for detection of sulfinic acids involve mass spectroscopy and the use of specific antibodies. However, these methodologies are not suitable for proteomic studies. Herein, we report the first probe for detection of protein sulfinylation, NO-Bio, which combines a C-nitroso warhead for rapid labeling of sulfinic acid with a biotin handle. Based on this new tool, we developed a selective two-step approach. In the first, a sulfhydryl-reactive compound is introduced to selectively block free cysteine residues. Thereafter, the sample is treated with NO-Bio to label sulfinic acids. This new technology represents a rapid, selective, and general technology for sulfinic acid detection in biological samples. As proof of our concept, we also evaluated protein sulfinylation levels in various human lung tumor tissue lysates. Our preliminary results suggest that cancer tissues generally have higher levels of sulfinylation in comparison to matched normal tissues. A new ability to monitor protein sulfinylation directly should greatly expand the impact of sulfinic acid as a post-translational modification.

Capillary electrophoresis with mass spectrometric detection for separation of S-nitrosoglutathione and its decomposition products: a deeper insight into the decomposition pathways.

S-Nitrosoglutathione (GSNO) is a very important biomolecule that has crucial functions in many physiological and physiopathological processes. GSNO acts as NO donor and is a candidate for future medicines. This work describes, for the first time, the separation and the detection of GSNO and its decomposition products using capillary electrophoresis coupled to mass spectrometry (CE-MS). The separation was performed in slightly alkaline medium (pH 8.5) under positive-ionization MS detection. The identification of three byproducts of GSNO was formally performed for the first time: oxidized glutathione (GSSG), glutathione sulfinic acid (GSO2H), and glutathione sulfonic acid (GSO3H). GSO2H and GSO3H are known to have important biological activity, including inhibition of the glutathione transferase family of enzymes which are responsible for the elimination of many mutagenic, carcinogenic, and pharmacologically active molecules. We observed, after the ageing of GSNO in the solid state, that the proportion of both GSSG and GSO3H increases whereas that of GSO2H decreases. These results enabled us to propose an oxidation scheme explaining the formation of such products.

Evaluation of sorbent materials for the sampling and analysis of phosphine, sulfuryl fluoride and methyl bromide in air.

Phosphine (PH3), sulfuryl fluoride (SO2F2) and methyl bromide (CH3Br) are highly toxic chemical substances commonly used for fumigation, i.e., pest control with gaseous pesticides. Residues of fumigation agents constitute a health risk for workers affected, and therefore accurate methods for air sampling and analysis are needed. In this study, three commercial adsorbent tubes; Carbosieve SIII™, Air Toxics™ and Tenax TA™, were evaluated for sampling these highly volatile chemicals in air and their subsequent analysis by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). The breakthrough volume (BTV) of each fumigant was experimentally determined on the different adsorbents at concentrations at or above their permissible exposure limits, using a method based on frontal chromatography of generated fumigant atmospheres. Carbosieve SIII™, a molecular sieve possessing a very high specific area, proved to be a better adsorbent than both Air Toxics™ and Tenax TA™, resulting in at least a 4-fold increase of the BTV50%. BTV50% for Carbosieve SIII™ at 20°C was measured as 4.7L/g, 5.5L/g and 126L/g for phosphine, sulfuryl fluoride and methyl bromide, respectively, implying safe sampling volumes of 1.9L, 2.2L and 50L, respectively, for a commercial tube packed with 800mg Carbosieve SIII™. The temperature dependence of BTV was strong for Carbosieve SIII™, showing a reduction of 3-5%/°C in breakthrough volume within the range -20 to 40°C. Furthermore, although Carbosieve SIII™ reportedly has a higher affinity for water than most other adsorbents, relative humidity had only a moderate influence on the retention capacity of phosphine. Overall, the applicability of Carbosieve SIII™ adsorbent sampling in combination with TD-GC-MS analysis was demonstrated for highly volatile fumigants.

Influence of pH, concentration and light on stability of allicin in garlic (Allium sativum L.) aqueous extract as measured by UPLC.

BACKGROUND: Garlic is one of the most important bulb vegetables and is mainly used as a spice or flavoring agent for foods. It is also cultivated for its medicinal properties, attributable to sulfur compounds, of which allicin is the most important. However, the stability of allicin in garlic extract is not well understood. In this study, using UPLC, the stability of allicin extracted in water from garlic was evaluated in phosphate buffer at different temperatures under light and dark conditions. RESULTS: At room temperature, allicin in aqueous extract was most stable at pH 5-6 but degraded quickly at lower or higher pH. It began to degrade within 0.5 h and was not detectable after 2 h when the pH was higher than 11 or lower than 1.5. It degraded quickly when the temperature was higher than 40 °C and especially higher than 70 °C. At room temperature, allicin in water could be stored for 5 days without obvious degradation. Higher concentrations of allicin in solution were somewhat more stable than low concentrations. CONCLUSION: Allicin extract was sensitive to pH and temperature of storage but not to light. Higher-concentration allicin solution was more stable.

Garlic revisited: antimicrobial activity of allicin-containing garlic extracts against Burkholderia cepacia complex.

The antimicrobial activities of garlic and other plant alliums are primarily based on allicin, a thiosulphinate present in crushed garlic bulbs. We set out to determine if pure allicin and aqueous garlic extracts (AGE) exhibit antimicrobial properties against the Burkholderia cepacia complex (Bcc), the major bacterial phytopathogen for alliums and an intrinsically multiresistant and life-threatening human pathogen. We prepared an AGE from commercial garlic bulbs and used HPLC to quantify the amount of allicin therein using an aqueous allicin standard (AAS). Initially we determined the minimum inhibitory concentrations (MICs) of the AGE against 38 Bcc isolates; these MICs ranged from 0.5 to 3% (v/v). The antimicrobial activity of pure allicin (AAS) was confirmed by MIC and minimum bactericidal concentration (MBC) assays against a smaller panel of five Bcc isolates; these included three representative strains of the most clinically important species, B. cenocepacia. Time kill assays, in the presence of ten times MIC, showed that the bactericidal activity of AGE and AAS against B. cenocepacia C6433 correlated with the concentration of allicin. We also used protein mass spectrometry analysis to begin to investigate the possible molecular mechanisms of allicin with a recombinant form of a thiol-dependent peroxiredoxin (BCP, Prx) from B. cenocepacia. This revealed that AAS and AGE modifies an essential BCP catalytic cysteine residue and suggests a role for allicin as a general electrophilic reagent that targets protein thiols. To our knowledge, we report the first evidence that allicin and allicin-containing garlic extracts possess inhibitory and bactericidal activities against the Bcc. Present therapeutic options against these life-threatening pathogens are limited; thus, allicin-containing compounds merit investigation as adjuncts to existing antibiotics.

Investigating lignin key features in maize lignocelluloses using infrared spectroscopy.

Lignins and their cross-linking to hemicelluloses detrimentally affect the cellulose-to-ethanol conversion of grass lignocelluloses. Screening appropriate grass cell walls and their compositional changes during the various steps of the process calls for a high-throughput analytical technique. Such a performance can be fulfilled by Fourier transform mid-infrared (FT-MIR) spectroscopy. In the present paper, a set of maize cell walls from mature stems were selected, including brown midrib samples. Lignin fractions were isolated by mild acidolysis to obtain a set of purified maize lignin standards. The lignin content and the percentage of lignin-derived p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) thioacidolysis monomers were determined. In addition, the composition of cell wall polysaccharides, as well as the amount of ester-linked p-coumaric (CA) and ferulic (FA) acids, was measured by wet chemistry. Partial least square (PLS) analyses were applied to infrared and chemical data of cell walls. The resulting models showed a good predictive ability with regard to the lignin content, to the frequency of S (or G) thioacidolysis monomers, and to the level of ester-linked CA of maize cell walls. The loading plots and regression coefficients revealed relevant infrared absorption bands.

Jack bean urease inhibition by crude juices of Allium and Brassica plants. Determination of thiosulfinates.

The aim of this study was the elucidation of the inhibitory influence of Allium (garlic, onion, leek) and Brassica (cabbage, Brussels sprouts) plants juices, on jack bean urease activity. Concentrations of thiosulfinates, the compounds responsible for the inhibition, were determined in studied materials. The kinetics and mechanism of the inhibitions were investigated. Biphasic, time-dependent courses of the inhibition reactions were observed for all tested Allium and Brussels sprouts from Brassica. The cabbage material caused the monophasic course of the inhibition. In the presence of dithiothreitol, a total reactivation of the inhibited urease proceeded for the tested plants except for the onion. The onion juice modified urease, regained only half of the initial activity. The irreversible contribution was related to the presence of 1-propanethial-S-oxide, cepaenes and zwiebelanes formed in the onion juice. It was found that the thermal processing of the plant juices, results in the decrease of thiosulfinates concentration, as well as the efficiency of urease inhibition.

Garlic extracts prevent oxidative stress, hypertrophy and apoptosis in cardiomyocytes: a role for nitric oxide and hydrogen sulfide.

BACKGROUND: In ancient times, plants were recognized for their medicinal properties. Later, the arrival of synthetic drugs pushed it to the backstage. However, from being merely used for food, plants are now been widely explored for their therapeutic value. The current study explores the potential of skin and flesh extracts from a hard-necked Rocambole variety of purple garlic in preventing cardiomyocyte hypertrophy and cell death. METHODS: Norepinephrine (NE) was used to induce hypertrophy in adult rat cardiomyocytes pretreated with garlic skin and flesh extracts. Cell death was measured as ratio of rod to round shaped cardiomyocytes. Fluorescent probes were used to measure apoptosis and oxidative stress in cardiomyocytes treated with and without extracts and NE. Pharmacological blockade of nitric oxide (NO) and hydrogen sulfide (H2S) were used to elucidate the mechanism of action of garlic extracts. Garlic extract samples were also tested for alliin and allicin concentrations. RESULTS: Exposure of cardiomyocytes to NE induced an increase in cell size and cell death; this increase was significantly prevented upon treatment with garlic skin and flesh extracts. Norepinephrine increased apoptosis and oxidative stress in cardiomyocytes which was prevented upon pretreatment with skin and flesh extracts; NO, and H2S blockers significantly inhibited this beneficial effect. Allicin and alliin concentration were significantly higher in garlic flesh extract when compared to the skin extract. CONCLUSION: These results suggest that both skin and flesh garlic extracts are effective in preventing NE induced cardiomyocyte hypertrophy and cell death. Reduction in oxidative stress may also play an important role in the anti-hypertrophic and anti-apoptotic properties of garlic extracts. These beneficial effects may in part be mediated by NO and H2S.

Effect of processing and cooking conditions on onion (Allium cepa L.) induced antiplatelet activity and thiosulfinate content.

Allium vegetables serve as sources of antiplatelet agents that may contribute to the prevention of cardiovascular disease. However, onion and garlic, the major Allium species, are usually cooked before consumption. Here, we examined the effect of cooking on onion in vitro antiplatelet activity (IVAA). Two different cooking systems (convection oven and microwaves) and several time-temperature variables were tested on whole bulbs, quarters of bulbs, and completely crushed bulbs, monitoring the degradation of sulfur antiplatelet compounds (e.g., thiosulfinates) by analysis of pyruvate levels. Although heating was, in general, detrimental for onion IVAA, the extent of this effect varied greatly, from unaffected antiplatelet activity (AA) (i.e., similar to raw onion) to a complete lost of activity, depending upon the manner in which onions were prepared prior to heating, the cooking method, and the intensity of the heat treatment. "Whole", "quarters", and "crushed" onions lost their IVAA after 30, 20, and 10 min of oven heating, respectively. The longer retainment of AA in intact bulbs was attributed to a later alliinase inactivation. Proaggregatory effects observed in samples subjected to the most intense oven and microwave heat treatments suggest that extensively cooked onions may stimulate rather than inhibit platelet aggregation. The efficacy of Allium species as antiplatelet agents, as affected by preparation and cooking conditions, is discussed.

Determination and dynamics of ethylicin residues in cotton-field ecosystem.

In this work, we developed an efficient method to determine the ethylicin content in soil, cotton plant and cotton seed, and we also studied the fate of ethylicin in the cotton field ecosystem. The residual ethylicin was analyzed by GC-ECD. The limit of quantification was 0.005 mg/kg for soil, 0.01 mg/kg for the plant and cotton seed. The kinetics study of ethylicin residue showed that the ethylicin concentration in plant and soil can be regressively quantified as C = 1.0762e(-0.2529t) and C = 0.5535e(-0.1333t), representing a half-live of 2.7 and 5.2 days, respectively. As a conclusion, a dosage of 354 g a.i. ha(-1) was recommended, which could be considered as safe to human beings and animals.