Enhanced anaerobic degradation of thiobencarb using a horizontal-flow anaerobic immobilized biomass bioreactor.

Thiobencarb is a herbicide globally used in the agricultural sector, and its extensive application leads to severe environmental pollution. In this study, the thiobencarb supplementation caused a significant shift in the bacterial community in the sediment slurry. An analysis of the degradation metabolites of microorganisms from the sediment indicated that deschlorothiobencarb, S-4-chlorobenzyl ethylthiocarbamate, 4-chlorobenzyl mercaptan, 4-chlorobenzyl alcohol, 4-chlorobenzoic acid and chlorobenzene were the main intermediates. The degradation rates were significantly enhanced using a horizontal-flow anaerobic reactor with immobilized cells in polyurethane foam. The degradation rates at 2.6, 12.9 and 25.6 mg L-1 concentrations by suspended microorganisms from the sediment in the mineral medium supplemented with glucose were 0.085 ± 0.000, 0.383 ± 0.010 and 0.500 ± 0.045 mg day-1, respectively. The corresponding data for degradation in the reactor were 2.54 ± 0.03, 11.69 ± 0.72 and 18.58 ± 1.83 mg day-1 at the sixth operation period. Moreover, COD removal efficiencies were >90% achieved in the reactor. The proposed method facilitates degradation using a horizontal-flow anaerobic immobilized biomass bioreactor. Moreover, this study reveals the degradation of metabolites of thiobencarb under anaerobic conditions.

Dithiocarbamate prodrugs activated by prostate specific antigen to target prostate cancer.

Disulfiram in conjunction with copper has been shown to be a potent anticancer agent. However, disulfiram's therapeutic potential in prostate cancer is hindered by off-target effects due to its reactive and nucleophilic thiol-containing component, diethyldithiocarbamate (DTC). To minimize undesirable reactivity, we have strategically blocked the thiol moiety in DTC with a cleavable p-aminobenzyl (pAB) group linked to peptide substrates recognized by prostate specific antigen (PSA). Here we report the synthesis and evaluation in cancer cell models of two PSA-activatable prodrugs: HPD (Ac-HSSKLQL-pAB-DTC and RPD (RSSYYSL-pAB-DTC). In vitro exposure to PSA was found to trigger activation of HPD and RPD to release diethyldithiocarbamate, and both prodrugs were found to induce toxicity in prostate cancer cells, with HPD showing the most promising selectivity. With copper supplementation, the IC50 of HPD was 1.4 µM in PSA-expressing LNCaP cells, and 11 µM in PC3 cells that do not express PSA. These studies demonstrate the utility of using peptide recognition handles to direct the activity of dithiocarbamate prodrugs for selective cytotoxicity of cancer cells.

Simultaneous determination of cartap and its metabolite in tea using hydrophilic interaction chromatography tandem mass spectrometry and the combination of dispersive solid phase extraction and solid phase extraction.

Risk assessment of cartap residue in tea should include the exposure of cartap and its metabolite due to rapid degradation of cartap into nereistoxin. Herein, a reliable method for determination of cartap and nereistoxin in tea was developed by hydrophilic interaction chromatography tandem mass spectrometry. Target compounds were extracted with water containing 1% formic acid and 5 mM ammonium formate. The use of dichloromethane effectively removed caffeine. Tea extracts were cleaned up by dispersive adsorbents of octadecylsilane and strong anion exchanger, then further purified using hydrophilic lipophilic balanced solid phase extraction cartridge. Isotopic internal standard was employed to calibrate the loss of analytes during sample preparation and compensate matrix effects. Method validation illustrated excellent linearity, with correlation coefficients (R2) higher than 0.999. Satisfactory recoveries of target compounds spiked in green tea, black tea and oolong tea ranged from 87.6% to 119.9% with intra- and inter-day precisions below 20%. Limits of quantification of cartap and nereistoxin were 10.0 µg kg-1, and limits of detection were 2.0 µg kg-1 for cartap and 4.0 µg kg-1 for nereistoxin. The developed method was applied to determine cartap and nereistoxin in thirty tea samples.

Potential Angiotensin Converting Enzyme Inhibitors from Moringa oleifera.

BACKGROUND: Hypertension is the chronic medical condition and it affected billions of people worldwide. Natural medicines are the main alternatives to treatment for a majority of people suffering from hypertension. Niazicin-A, Niazimin-A, and Niaziminin-B compounds from Moringa oleifera ethanolic leave extract were reported to have potent antihypertensive activity. OBJECTIVE: These compounds were targeted with Angiotensin-converting enzyme [ACE] which is one of the main regulatory enzymes of the renin-angiotensin system. METHODS: Protein-ligand docking of these compounds with [ACE] [both domain N and C] was conceded out through Autodock vina and visualization was done by chimera. Pharmacokinetics study of these compounds was predicted by ADME-Toxicity Prediction. RESULTS: Niazicin-A, Niazimin-A, and Niaziminin-B showed high binding affinity with ACE and partially blocked the active sites of the enzyme. Niazicin-A, Niazimin-A and Niaziminin-B showed the estimated free binding energy of -7.6kcal/mol kcal/mol, -8.8kcal/mol and -8.0kcal/mol respectively with C-domain of ACE and -7.9kcal/mol, -8.5kcal/mol and -7.7kcal/mol respectively with N-domain of ACE. The compounds showed better binding energy with angiotensinconverting enzyme in comparison to Captopril -5.5kcal/mol and -5.6kcal/mol and Enalapril [standard] -8.4kcal/mol and -7.5kcal/mol with C and N domain, respectively. CONCLUSION: Computationally, the selected bioactive molecules have shown better binding energy to known standard drugs which have been already known for inhibition of ACE and can further act as a pharmacophore for in vitro and in vivo studies in the development of alternative medicine.

Alcohol-fermented soybean increases the expression of receptor-interacting protein 2 and IκB kinase ß in mouse peritoneal macrophages.

Soybean is a useful component of traditional Korean medicine with well-documented health-promoting effects. We investigated the effects of alcohol-fermented soybean (AFS) on immune function. When AFS treatment was used in combination with recombinant interferon-γ (rIFN-γ), there was a marked cooperative induction of nitric oxide (NO) and tumor necrosis factor (TNF)-α production in mouse peritoneal macrophages. AFS increased the expression of inducible NO synthase mRNA and protein in rIFN-γ-primed macrophages. Treating macrophages with pyrrolidine dithiocarbamate, an inhibitor of nuclear factor-κB (NF-κB), decreased the synergistic effects of AFS. In addition, AFS in combination with rIFN-γ increased the phosphorylation of p38 and c-Jun N-terminal kinase (JNK) but not extracellular signal-regulated kinase. However, AFS had no effect on phosphorylation of mitogen-activated protein kinases by itself. The p38 inhibitor SB203580 or the JNK inhibitor SP600125 inhibited the AFS-induced NO and TNF-α production. When AFS was used in combination with rIFN-γ, there was a co-operative activation of NF-κB and receptor-interacting protein 2 (Rip2)/IκB kinase (IKK)-ß. Our results indicate that AFS increases the production of NO and TNF-α through the activation of Rip2/IKK-ß in rIFN-γ-primed macrophages.

Toward the control of Leptosphaeria maculans: design, syntheses, biological activity, and metabolism of potential detoxification inhibitors of the crucifer phytoalexin brassinin.

Brassinin (1), a crucial plant defense produced by crucifers, is detoxified by the phytopathogenic fungus Leptosphaeria maculans (Phoma lingam) to indole-3-carboxaldehyde using a putative brassinin oxidase. Potential inhibitors of brassinin detoxification were designed by replacement of its dithiocarbamate group (toxophore) with carbamate, dithiocarbonate, urea, thiourea, sulfamide, sulfonamide, dithiocarbazate, amide, and ester functional groups. In addition, the indolyl moiety was substituted for naphthalenyl and phenyl. The syntheses and chemical characterization of these potential detoxification inhibitors, along with their antifungal and cytotoxic activity, as well as screening using cultures of L. maculans are reported. Overall, three types of interaction were observed in cultures of L. maculans co-incubated with the potential inhibitors and brassinin: (1) a decrease on the rate of brassinin detoxification due to the strong inhibitory activity of the compound on fungal growth, (2) a decrease on the rate of brassinin detoxification due to the inhibitory activity of the compound on the putative brassinin oxidase, and (3) a low to no detectable effect on the rate of brassinin detoxification. A noticeable decrease in the rate of brassinin detoxification was observed in the presence of N'-methylbrassinin, methyl N-methyl-N-(naphthalen-2-ylmethyl) dithiocarbamate, tryptophol dithiocarbonate, and methyl 3-phenyldithiocarbazate. Tryptophol dithiocarbonate appeared to be the best inhibitor among the designed compounds, representing the first inhibitor of brassinin detoxification and potentially the first selective protecting agent of oilseed crucifers against L. maculans infestation.

Detoxification of the cruciferous phytoalexin brassinin in Sclerotinia sclerotiorum requires an inducible glucosyltransferase.

The phytoalexins, brassinin, 1-methoxybrassinin and cyclobrassinin, were metabolized by the stem rot fungus Sclerotinia sclerotiorum into their corresponding glucosyl derivatives displaying no detectable antifungal activity. Importantly, co-incubation of S. sclerotiorum with camalexins, various phytoalexin analogs, and brassinin indicated that a synthetic camalexin derivative could slow down substantially the rate of brassinin detoxification. Furthermore, inducible brassinin glucosyltransferase (BGT) activity was detected in crude cell-free extracts of S. sclerotiorum. BGT activity was induced by the phytoalexin camalexin, and the brassinin analogs methyl tryptamine dithiocarbamate and methyl 1-methyltryptamine dithiocarbamate. The overall results suggest that the fungus S. sclerotiorum in its continuous adaptation and co-evolution with brassinin producing plants, has acquired efficient glucosyltransferase(s) that can disarm some of the most active plant chemical defenses.

Tryptophan-derived sulfur-containing phytoalexins--a general overview.

Phytoalexins are low molecular weight antimicrobial compounds that are synthesized and accumulated in plants after their exposure to pathogenic microorganisms (bacteria, fungi, viruses and protozoans). They are extensively studied now as promising antifungal, potentially anticancer and plant diseases controlling agents. The article pertains to a group of indole-derived phytoalexins--brassinins, containing at least one sulfur atom in the side chain or in the ring(s), isolated from the cruciferous plants. Up today more than 20 compounds, closely related biogenetically, but exhibiting diversified biological activity have been identified. The survey summerises most promising recent results pertaining practical application of brassinins and camalexins.

Chemical defenses of crucifers: elicitation and metabolism of phytoalexins and indole-3-acetonitrile in brown mustard and turnip.

The metabolism of the cruciferous phytoalexins brassinin and cyclobrassinin, and the related compounds indole-3-carboxaldehyde, glucobrassicin, and indole-3-acetaldoxime was investigated in various plant tissues of Brassica juncea and B. rapa. Metabolic studies with brassinin showed that stems of B. juncea metabolized radiolabeled brassinin to indole-3-acetic acid, via indole-3-carboxaldehyde, a detoxification pathway similar to that followed by the "blackleg" fungus (Phoma lingam/Leptosphaeria maculans). In addition, it was established that tetradeuterated brassinin was incorporated into the phytoalexin brassilexin in B. juncea and B. rapa. On the other hand, the tetradeuterated indole glucosinolate glucobrassicin was not incorporated into brassinin, although the chemical structures of brassinins and indole glucosinolates suggest an interconnected biogenesis. Importantly, tetradeuterated indole-3-acetaldoxime was an efficient precursor of phytoalexins brassinin, brassilexin, and spirobrassinin. Elicitation experiments in tissues of Brassica juncea and B. rapa showed that indole-3-acetonitrile was an inducible metabolite produced in leaves and stems of B. juncea but not in B. rapa. Indole-3-acetonitrile displayed antifungal activity similar to that of brassilexin, was metabolized by the blackleg fungus at slower rates than brassinin, cyclobrassinin, or brassilexin, and appeared to be involved in defense responses of B. juncea.

The cruciferous phytoalexins brassinin and cyclobrassinin are intermediates in the biosynthesis of brassilexin.

Following feeding experiments with the tetradeuterated cruciferous phytoalexins brassinin (5b) and cyclobrassinin (6b), leaves of Brassica carinata were elicited with the blackleg causing fungus Phoma lingam and incubated. Spectroscopic and HPLC analyses indicated that both brassinin (5a) and cyclobrassinin (6a) were incorporated into the cruciferous phytoalexin brassilexin (7a).

[Antimicrobial action of potential isothiocyanate forming substances 7th communication (author's transl)]. / Die antimikrobielle Wirkung von potentiellen Isothiocyanat-Bildnern

A number of (N-aryl-dithiocarbamino)-alkanecarbonic acids bearing halogen substituents and related compounds are described which may be considered potential isothicyanate forming substances. The in vitro fungistatic activity of these compounds was investigated and the results obtained compared with those of captan and thiram. It was demonstrated that the halogen substituted (N-aryl)-dithiocarbamino)-alkanecarbonic acids exert an intensive fungistatic effect with a wide spectrum of activity and that the most active of them are equal to captan and thiram.