Imidazolium ionic-liquid-modified phenolic resin for solid-phase extraction of thidiazuron and forchlorfenuron from cucumbers.

An imidazolium ionic-liquid-modified phenolic resin (ILPR) was synthesized using 3-aminophenol as a functional monomer, glyoxylic acid as a green cross-linker, and polyethylene glycol 6000 as a porogen. The obtained ILPR showed better extraction of benzoylurea plant hormones thidiazuron and forchlorfenuron than the unmodified phenolic resin because the imidazolium IL provides more interaction modes with the analytes. ILPR, as a tailored adsorbent for solid-phase extraction, was coupled with high-performance liquid chromatography (ILPR‒SPE‒HPLC) for the simultaneous determination of thidiazuron and forchlorfenuron in cucumbers. Good linearity of the ILPR‒SPE‒HPLC method was obtained, ranging from 0.0100 to 5.00 µg g-1 with a correlation coefficient (r) ≥ 0.9999. The recoveries of spiked samples ranged from 91.4% to 100.7% with a relative standard deviation of ≤ 6.0%.

2,5-Disubstituted thiadiazoles as potent ß-glucuronidase inhibitors; Synthesis, in vitro and in silico studies.

Twenty-five thiadiazole derivatives 1-25 were synthesized from methyl 4-methoxybenzoate via hydrazide and thio-hydrazide intermediates, and evaluated for their potential against ß-glucuronidase enzyme. Most of the compounds including 1 (IC50 = 26.05 ±â€¯0.60 µM), 2 (IC50 = 42.53 ±â€¯0.80 µM), 4 (IC50 = 38.74 ±â€¯0.70 µM), 5 (IC50 = 9.30 ±â€¯0.29 µM), 6 (IC50 = 6.74 ±â€¯0.26 µM), 7 (IC50 = 18.40 ±â€¯0.66 µM), and 15 (IC50 = 18.10 ±â€¯0.53 µM) exhibited superior activity potential than the standard d-saccharic acid-1,4-lactone (IC50 = 48.4 ±â€¯1.25 µM). Molecular docking studies were conducted to correlate the in vitro results and to identify possible mode of interaction with enzyme active site.

A Novel Agonist of the TRIF Pathway Induces a Cellular State Refractory to Replication of Zika, Chikungunya, and Dengue Viruses.

The ongoing concurrent outbreaks of Zika, Chikungunya, and dengue viruses in Latin America and the Caribbean highlight the need for development of broad-spectrum antiviral treatments. The type I interferon (IFN) system has evolved in vertebrates to generate tissue responses that actively block replication of multiple known and potentially zoonotic viruses. As such, its control and activation through pharmacological agents may represent a novel therapeutic strategy for simultaneously impairing growth of multiple virus types and rendering host populations resistant to virus spread. In light of this strategy's potential, we undertook a screen to identify novel interferon-activating small molecules. Here, we describe 1-(2-fluorophenyl)-2-(5-isopropyl-1,3,4-thiadiazol-2-yl)-1,2-dihydrochromeno[2,3-c]pyrrole-3,9-dione, which we termed AV-C. Treatment of human cells with AV-C activates innate and interferon-associated responses that strongly inhibit replication of Zika, Chikungunya, and dengue viruses. By utilizing genome editing, we investigated the host proteins essential to AV-C-induced cellular states. This showed that the compound requires a TRIF-dependent signaling cascade that culminates in IFN regulatory factor 3 (IRF3)-dependent expression and secretion of type I interferon to elicit antiviral responses. The other canonical IRF3-terminal adaptor proteins STING and IPS-1/MAVS were dispensable for AV-C-induced phenotypes. However, our work revealed an important inhibitory role for IPS-1/MAVS, but not TRIF, in flavivirus replication, implying that TRIF-directed viral evasion may not occur. Additionally, we show that in response to AV-C, primary human peripheral blood mononuclear cells secrete proinflammatory cytokines that are linked with establishment of adaptive immunity to viral pathogens. Ultimately, synthetic innate immune activators such as AV-C may serve multiple therapeutic purposes, including direct antimicrobial responses and facilitation of pathogen-directed adaptive immunity.IMPORTANCE The type I interferon system is part of the innate immune response that has evolved in vertebrates as a first line of broad-spectrum immunological defense against an unknowable diversity of microbial, especially viral, pathogens. Here, we characterize a novel small molecule that artificially activates this response and in so doing generates a cellular state antagonistic to growth of currently emerging viruses: Zika virus, Chikungunya virus, and dengue virus. We also show that this molecule is capable of eliciting cellular responses that are predictive of establishment of adaptive immunity. As such, this agent may represent a powerful and multipronged therapeutic tool to combat emerging and other viral diseases.

Cytotoxic 1,3-Thiazole and 1,2,4-Thiadiazole Alkaloids from Penicillium oxalicum: Structural Elucidation and Total Synthesis.

Two new thiazole and thiadiazole alkaloids, penicilliumthiamine A and B (2 and 3), were isolated from the culture broth of Penicillium oxalicum, a fungus found in Acrida cinerea. Their structures were elucidated mainly by spectroscopic analysis, total synthesis and X-ray crystallographic analysis. Biological evaluations indicated that compound 1, 3a and 3 exhibit potent cytotoxicity against different cancer cell lines through inhibiting the phosphorylation of AKT/PKB (Ser 473), one of important cancer drugs target.

Reproduction of the Medicinal Plant Pelargonium sidoides via Somatic Embryogenesis.

The medicinal plant Pelargonium sidoides DC. (Geraniaceae) was traditionally used for the treatment of the common cold and cough in South Africa. Today an aequous-ethanolic root extract from this plant is approved for the treatment of acute bronchitis and is globally marketed also as an immunostimulant. The increasing demand of the plant material for the industrial production indicates the need of new effective methods for the propagation of P. sidoides. Here we report somatic embryogenesis and in vitro plantlet regeneration from somatic cells of inflorescence shoots and petioles of P. sidoides. A one-week cultivation of explants in media containing different concentrations of thidiazuron (1, 2.2, 3, and 4 mg/L) followed by a cultivation period without phytohormones resulted in the induction of somatic embryos within 2-4 weeks. After 2-4 months, the embryos generated roots and could be transferred into a greenhouse, where flower formation took place and the development of seeds occurred with high germination rates. The root umckalin concentration, determined by high-performance thin-layer chromatography, was comparable to that of seed-cultivated plants (100 ± 6 vs. 113 ± 10 µg umckalin/g dried roots). For the first time, direct somatic embryogenesis has been established as an appropriate cultivation method for P. sidoides plants used as raw material in the pharmaceutical industry. Moreover, genetically identical plants (chemical races) can be easily generated by this procedure.

Adaptive neuro-fuzzy inference system model for adsorption of 1,3,4-thiadiazole-2,5-dithiol onto gold nanoparticales-activated carbon.

In this research, a novel adsorbent gold nanoparticle loaded on activated carbon (Au-NP-AC) was synthesized by ultrasound energy as a low cost routing protocol. Subsequently, this novel material characterization and identification followed by different techniques such as scanning electron microscope(SEM), Brunauer-Emmett-Teller(BET) and transmission electron microscopy (TEM) analysis. Unique properties such as high BET surface area (>1229.55m(2)/g) and low pore size (<22.46Å) and average particle size lower than 48.8Å in addition to high reactive atoms and the presence of various functional groups make it possible for efficient removal of 1,3,4-thiadiazole-2,5-dithiol (TDDT). Generally, the influence of variables, including the amount of adsorbent, initial pollutant concentration, contact time on pollutants removal percentage has great effect on the removal percentage that their influence was optimized. The optimum parameters for adsorption of 1,3,4-thiadiazole-2, 5-dithiol onto gold nanoparticales-activated carbon were 0.02g adsorbent mass, 10mgL(-1) initial 1,3,4-thiadiazole-2,5-dithiol concentration, 30min contact time and pH 7. The Adaptive neuro-fuzzy inference system (ANFIS), and multiple linear regression (MLR) models, have been applied for prediction of removal of 1,3,4-thiadiazole-2,5-dithiol using gold nanoparticales-activated carbon (Au-NP-AC) in a batch study. The input data are included adsorbent dosage (g), contact time (min) and pollutant concentration (mg/l). The coefficient of determination (R(2)) and mean squared error (MSE) for the training data set of optimal ANFIS model were achieved to be 0.9951 and 0.00017, respectively. These results show that ANFIS model is capable of predicting adsorption of 1,3,4-thiadiazole-2,5-dithiol using Au-NP-AC with high accuracy in an easy, rapid and cost effective way.

Dispersive liquid-liquid microextraction for the determination of three cytokinin compounds in fruits and vegetables by liquid chromatography with time-of-flight mass spectrometry.

The paper presents a novel approach for the determination of three cytokinin compounds, thidiazuron (TDZ), 1,3-diphenylurea (1,3-DPU) and forchlorfenuron (CPPU), in fruit and vegetables samples using liquid chromatography with electrospray ionization and time-of-flight mass spectrometry (LC-ESI-TOFMS). Analytes were extracted from the sample matrix with ethanol, and the extract, after dilution with water, was submitted to dispersive liquid-liquid microextraction (DLLME). Once acetonitrile and 1,2-dichloroethane had been selected as extraction and disperser solvents, respectively, the influence of the following experimental parameters was studied using a Plackett-Burman design: volume of extraction and disperser solvents, sample mass and time and speed of centrifugation. The best analytical conditions were 250 µL 1,2-dichloroethane, 1.5 mL acetonitrile, 5 g sample mass, and centrifugation at 3000 rpm for 3 min. The optimized method provided DLs in the range 0.02-0.05 ng g(-1), depending on the compound. Satisfactory recovery values between 89 and 106% were obtained for spiked samples (kiwifruit, watermelon, grape and tomato) in the 0.2-1.0 ng g(-1) concentration range, depending on the compound. None of the target analytes was detected in any of the samples analyzed.

Photodegradation of etridiazole by UV radiation during drinking water treatment.

The photodegradation of etridiazole (ETZ) in water by UV radiation at 254 nm was investigated. Results indicate that the simulated first-order rate constants decreased with the increase of initial ETZ concentration (i.e., 5, 20 and 30 microM), and did not show any pH dependence within the range from 6.0 to 8.0. The quantum yield was 0.46+/-0.02 molE(-1) at pH 7.0. H(2)O(2) was generated at trace levels in the range from 0 to 1.0 microM during photodegradation of ETZ. Direct photodegradation was responsible for the decomposition of ETZ in distilled water by UV radiation. Three organic byproducts were identified: 5-ethoxy-3-dichloromethyl-1,2,4-thiadiazole, 5-ethoxy-1,2,4-thiadiazole-3-carboxylic acid and 5-ethoxy-3-hydroxyl-1,2,4-thiadiazole. About 90% of chloro mass in the initial ETZ was released as Cl(-) at the end of photodegradation. In contrast, the formation of sulfate and nitrate was insignificant. In general, ETZ decayed more quickly in groundwater than in sand-filtered or surface water. It is reasonably deduced that ETZ may not get removed effectively under a typical UV dose of 40 mJcm(-2) at most water treatment plants that employ UV radiation for disinfection.

Advanced treatment of benzothiazole contaminated waters: comparison of O3, AC, and O3/AC processes.

Benzothiazole (BT) is a toxic and poorly biodegradable contaminant, usually found in wastewater from rubber related applications. This compound could be effectively eliminated using advanced treatment processes. This paper compares experimental results on detoxification systems based on ozone oxidation, activated carbon adsorption, and simultaneous adsorption-oxidation using ozone in the presence of activated carbon. The effect of pH (2-11), and the presence of radical scavengers (tert-butyl alcohol and sodium carbonate) on process rates and removal efficiencies are assessed at laboratory scale. The experimental system consisted of a 1 L differential circular flow reactor and an ozone generator rated at 5 g O3/h. Results show that ozone oxidation combined with activated carbon adsorption increases the overall BT oxidation rate with respect to the ozonation process and activated carbon adsorption. In the presence of free radical scavenger, only a 44% reduction in BT removal rate is observed in the simultaneous treatment, as compared with 72% when ozonation treatment is used, suggesting that BT oxidation reactions mainly take place on the activated carbon surface.

Kinetic study of reactions between ozone and benzothiazole in water.

Benzothiazoles are frequently present in wastewater from rubber related applications, and may be found in surface and underground water bodies causing significant environmental impact. Cost effective treatment processes to deal with such contaminants are needed in both small and large-scale applications. These compounds are poorly biodegradable and could be removed by ozone oxidation before discharge to recipient water courses. Unfortunately, there is limited experimental data reported in the literature on such processes involving benzothiazoles. This article presents experimental data on ozone treatment of benzothiazole (BT), with a view to process design. The effects of pH and radical scavengers on process rate and removal efficiency were assessed at bench scale. Experimental results show that BT could be effectively removed using ozonisation, particularly at pH above 4. The presence of free radical scavengers drastically reduced the BT removal rate even at very low concentrations. Both direct and indirect reactions between ozone and BT were adequately described by second order kinetic schemes, with rate constants estimated at 20 degrees C: kD = 2.3 mol l(-1) s(-1) and kI = 6 x 10(9) mol l(-1) s(-1), respectively. The free radical mechanism accounted for 83-96% of BT removal rate within the pH range 2-9, at 20 degrees C.

Biotransformation of the antiviral agent 1,3,4-thiadiazol-2-ylcyanamide (LY217896) and characteristics of a mesoionic ribose metabolite.

The biotransformation of the antiinfluenza agent 1,3,4-thiadiazol-2-ylcyanamide (LY217896, I) was studied. In addition to a urea metabolite (II) formed by transformation of the cyanamide functionality, another highly polar metabolite was found in mouse urine and in BSC-1, MDCK, and other cell culture incubations of [14C]LY217896. Using 13C-labeled LY217896 together with NMR and MS techniques, this highly polar metabolite was identified as a ribose derivative (III), which apparently exists in a mesoionic form (i.e. positive and negative charges within the same ring system). It was also found that this ribose is formed from LY217896 and ribose-1-phosphate in a reaction catalyzed by the enzyme purine nucleoside phosphorylase, but that the reverse reaction (cleavage of the ribose) is not observed under the conditions used. When tested in vitro using the same assay as that used to measure the antiviral activity of LY217896, this ribose and the urea metabolite exhibit essentially no activity. The presence of a ribose has been implicated in the activity of antiviral compounds such as ribavirin and anticancer agents like 2-aminothiadiazole and tiazofurin, which are structurally similar to LY217896. These activities have been postulated to involve either mono- or triphosphorylated forms, or NAD-type analogs. Possible implications of the formation of this mesoionic ribose metabolite for the mechanism of antiviral activity of LY217896 are discussed.

High-performance liquid chromatographic separation, isolation and identification of 1,2,3-thiadiazole-5-carboxaldoxime glucuronide in rabbit urine.

Reversed-phase high-performance liquid chromatography was used to separate and isolate the glucuronic acid conjugate of 1,2,3-thiadiazole-5-carboxaldoxime from urine of rabbits after intravenous injection of the oxime. The conjugate was identified by gas chromatography-mass spectrometry as its trimethylsilylated methyl ester and by nuclear magnetic resonance spectrometry. Additional information was obtained from thin-layer chromatography and high-voltage paper electrophoresis.