Determination of ethylene-bis-dithiocarbamates and their degradation product ethylenethiourea in dry herbs by UHPLC-MS/MS.

Dithiocarbamates are a class of fungicides widely used in many countries. In this study, methods for determining the ethylene-bis-dithiocarbamate (EBDC) subclass, and their degradation product ethylenethiourea (ETU) were validated by UHPLC-MS/MS in different types of dry herbs, which can be used as food and/or medicinal purposes. Mancozeb was used in the validation of the EBDC method, where it was initially complexed with EDTA, derivatized, extracted with dimethyl sulfate in acetonitrile, magnesium sulfate (MgSO4), and sodium chloride (NaCl), and then purified using primary secondary amine (PSA). In the ETU method, L-cysteine hydrochloride monohydrate was added to the samples before extraction with acetonitrile, MgSO4, and NaCl, followed by purification with PSA. A pesticide-free blend of seven herbs (boldo, artichoke, "espinheira-santa", cat's claw, senna, chamomile, and cascara buckthorn) comprising distinct parts of the plants (leaves, bark, flowers and/or stems) was used as a control for method validation. Recoveries ranged from 79 to 113% for EBDC and 81 to 109% for ETU. Repeatability and intermediate precision were <20% for both methods. The limit of quantification was 0.03 mg kg-1 for EBDC (0.02 mg kg-1 of CS2) and ETU. The limit of detection (LOD) was set at 1/3 of the LOQ (0.01 mg kg-1 for both analytes). In total, 103 samples of 33 different dry herbs were analyzed, of which 19.4% were positive for EBDC (≥LOD), but no ETU residues were found in any of the analyzed samples. Given the absence of registered dithiocarbamates for use in the investigated herbs in Brazil, the positive results suggest potential illegal pesticide use or cross-contamination, especially considering the low concentrations detected in most samples. Although exposure to EBDC through the consumption of medicinal herbs from positive samples did not indicate a health risk to consumers, these plants must be monitored to prevent illicit pesticide usage, particularly when the herbs are intended for therapeutic purposes.

Synthesis, Molecular Docking and Biological Evaluation of 2- Mercaptomidazoles using Solid Phase Synthesis.

BACKGROUND: With the increasing resistance and side effects caused due to antifungal agents there is an urgent need for the new potent antifungal agents with low toxicity profile. Imidazoles have been used against fungal infections since long time. Further, our previous studies demonstrated that mercaptoimidazoles possessed good antifungal potency. AIM AND OBJECTIVE: This study was aimed to study the antifungal potency of new series of 2- mercaptoimidazoles. MATERIALS AND METHODS: Eighteen new 2-mercaptoimidazoles containing substituted phenyl group were synthesized and structures of the synthesized compounds were characterized by spectral studies. The synthesized compounds were screened for their antifungal potency. Compound 2-(1-(3-hydroxyphenyl)-2- mercapto-1H-imidazol-4-yl)phenol was found to be the most potent compound among all synthesized compounds against tested fungal strains. Moreover, all the synthesized compounds were further subjected to molecular docking study for the inhibition of enzyme 14α-demethylase. RESULTS: The in-silico molecular docking study results showed that all the synthesized compounds have minimum binding energy and good affinity for the active site and may be considered as good inhibitor of 14α-demethylase. CONCLUSION: 2-mercaptoimidazoles may be used as potential lead molecules as 14α-demethylase inhibitors.

Oxidation of ethylenethiourea in water via ozone enhanced by UV-C: identification of transformation products.

Ethylenethiourea (ETU) is a toxic degradation product of one class of fungicide which is largely employed in the world, the ethylenebisdithiocarbamates. In this study, ETU was degraded by ozonation enhanced by UV-C light irradiation (O3/UV-C) in aqueous medium. Degradation experiments were conducted at natural pH (6.8) and neutral pH (7.0, buffered). ETU was promptly eliminated from the reactive medium during ozonation in the presence and absence of light. Within the first few minutes of reaction conducted in natural pH, the pH decreased quickly from 6.8 to 3.0. Results show that ETU mineralization occurs only in the reaction conducted in neutral pH and that it takes place in a higher rate when enhanced by UV-C irradiation. Main intermediates formed during the O3/UV-C experiments in different conditions tested were also investigated and three different degradation mechanisms were proposed considering the occurrence of direct and indirect ozone reactions. At pH 7, ethylene urea (EU) was quickly generated and degraded. Meanwhile, at natural pH, besides EU, other compounds originated from the electrophilic attack of ozone to the sulfur atom present in the contaminant molecule were also identified during reaction and EU was detected within 60 min of reaction. Results showed that ozonation enhanced by UV-C promotes a faster reaction than the same system in the absence of light, and investigation of the toxicity is recommended.

Molecular Modelling Studies of 1,4-Diaryl-2-Mercaptoimidazole Derivatives for Antimicrobial Potency.

BACKGROUND: Imidazoles are considered as potent antimicrobial agents. In view of this 2-mercaptoimidazoles were synthesized and evaluated for antimicrobial study. METHODS: Some new 2-mercaptoimidazoles 4a-r were synthesized using substituted aniline and substituted phenacyl bromides in the presence of anhydrous sodium carbonate or potassium carbonate and potassium thiocyanate under solvent-free conditions catalyzed by eco-friendly ptoluene sulfonic acid. RESULTS: The structure of compounds was evaluated on the basis of Infrared spectroscopy (IR), 1HNMR (proton nuclear magnetic resonance) and mass spectral studies. These novel compounds were screened for in-vitro antibacterial and antifungal potency against Staphyllococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Further, the study was rationalized by molecular modeling studies. All the compounds were subjected to molecular modeling studies for inhibition of enzyme 14α-demethylase. CONCLUSIONS: The compounds were found to be effective in inhibiting the growth of pathogens. The in-silico results depicted that, all the synthesized compounds have minimum binding energy and good affinity towards the active site and thus can be considered as good inhibitors of 14α- demethylase enzyme.

Design of anti-thyroid drugs: Binding studies and structure determination of the complex of lactoperoxidase with 2-mercaptoimidazole at 2.30 Å resolution.

Lactoperoxidase (LPO) belongs to mammalian heme peroxidase superfamily, which also includes myeloperoxidase (MPO), eosinophil peroxidase (EPO), and thyroid peroxidase (TPO). LPO catalyzes the oxidation of a number of substrates including thiocyanate while TPO catalyzes the biosynthesis of thyroid hormones. LPO is also been shown to catalyze the biosynthesis of thyroid hormones indicating similar functional and structural properties. The binding studies showed that 2-mercaptoimidazole (MZY) bound to LPO with a dissociation constant of 0.63 µM. The inhibition studies showed that the value of IC50 was 17 µM. The crystal structure of the complex of LPO with MZY showed that MZY bound to LPO in the substrate-binding site on the distal heme side. MZY was oriented in the substrate-binding site in such a way that the sulfur atom is at a distance of 2.58 Å from the heme iron. Previously, a similar compound, 3-amino-1,2,4-triazole (amitrole) was also shown to bind to LPO in the substrate-binding site on the distal heme side. The amino nitrogen atom of amitrole occupied the same position as that of sulfur atom in the present structure indicating a similar mode of binding. Recently, the structure of the complex of LPO with a potent antithyroid drug, 1-methylimidazole-2-thiol (methimazole, MMZ) was also determined. It showed that MMZ bound to LPO in the substrate-binding site on the distal heme side with 2 orientations. The position of methyl group was same in the 2 orientations while the positions of sulfur atom differed indicating a higher preference for a methyl group.

Variable coordination and C-S bond cleavage activity of N-substituted imidazolidine-2-thiones towards copper: synthesis, spectroscopy, structures, ESI-mass and antimicrobial studies.

An equimolar reaction of copper(i) iodide with N-ethyl-imidazolidine-2-thione (l-Et) in acetonitrile formed black prismatic crystals over a period of three weeks. The X-ray structure determination of black crystals revealed that the thio-ligand l-Et has transformed into a new thio-ligand, 1-ethyl-3-(1-ethyl-4,5-dihydro-1H-imidazol-2-yl)imidazolidine-2-thione (l-NEt), through C-S rupture/C-N bond formation which was coordinated in the unusual 2D polymer, {(CuII(κ2-N,S-l-NEt)2)·(CuI4)·(CuI2)}n1. An ESR spectrum supported the presence of divalent CuII in the polymer. In contrast, reaction of copper(i) iodide with N-phenyl-imidazolidine-2-thione (l-Ph) in 1 : 1 molar ratio yielded a polymer, [-Cu(µ-I)2Cu(µ-S-l-Ph)2Cu-]n2, with alternate Cu2I2 and Cu2S2 cores. Further, a series of reactions of copper(i) halides with N-substituted imidazolidine-2-thiones, namely, l-R in 1 : 2 metal to ligand molar ratio (M : L) in acetonitrile have yielded different type of complexes: trigonal planar {CuX(κ1-S-l-R)2, R, X : Et, I, 4; Me, I, 5; Bun, I,6; Me, Br,7; Bun, Br, 8; Me, Cl, 9; Prn, Cl, 10; Ph, Cl, 11}, dinuclear [Cu2Br2(µ-S-l-Ph)2(κ1-S-l-Ph)2] 12, tetranuclear, [Cu4I2(µ-I)2(µ-S-l-Ph)4(κ1-S-l-Ph)2] 3 and hexanuclear [Cu6Cl6(µ-S-l-Bun)6] 13. All these complexes have been characterized using analytical data, IR and proton NMR spectroscopy, ESI-mass studies and single crystal X-ray crystallography. The antimicrobial activity of these complexes has been investigated against Gram positive bacteria, namely, Staphylococcus aureus (MTCC740), methicillin resistant Staphylococcus aureus (MRSA), Gram negative bacteria, Klebsiella pneumoniae (MTCC109), Salmonella typhimurium (MTCC741) and Candida albicans (MTCC227)- a yeast. It is significant to add that among various complexes tested for cytotoxicity toward living cells, 4, 5, 8, 9 and 10 complexes were toxic, while complex 12 was non-toxic.

Effects of hydrochemistry variables on the half-life of mancozeb and on the hazard index associated to the sum of mancozeb and ethylenethiourea.

Mancozeb is a dithiocarbamate non-systemic agricultural fungicide with multi-site, protective action. It helps to control many fungal diseases in a wide range of field crops, fruits, nuts, vegetables, and ornamental plants. We have investigated the stability profiles of mancozeb in aqueous solutions to determine the effect of pH, temperature and light on the degradation process of mancozeb. In addition, the toxicological risk for humans associated with the joint intake of mancoze7b and its final degradation product, ethylenethiourea (ETU), was calculated and modelled as a function of the experimental conditions. Stability study results showed a very low stability profile of mancozeb in all the aqueous solutions with rapid degradation that varied with experimental conditions. The process followed first order kinetics. The study of the degradation kinetics showed a significant effect of pH*temperature interaction on the degradation process. The results also expressed that light has a greater impact on the stability of mancozeb and the formation of ETU. The current study concludes that mancozeb is unstable in aqueous solutions, particularly at an acid pH, in addition to presenting both severe light and lower temperature sensitivity. The toxicological risk associated with mancozeb degradation increases with time and temperature, being higher at basic pH and in absence of light.

Molecular Modeling Investigation of Some New 2-mercaptoimidazoles.

BACKGROUND: Docking study has become an important and interesting tool for the investigation of drug- receptor interaction. Computational methodologies have become a crucial component in the drug discovery programs which involves identification of target and lead along with their ADME and pharmacokinetic studies so as to obtain a potent lead. OBJECTIVE: Synthesis and Molecular modeling investigation of some new 2-mercaptoimidazoles. METHOD: New 2- mercaptoimidazoles were synthesized via solid phase synthesis and were characterized by spectral studies i.e IR, 1NMR, Mass spectra and LC-MS. Compounds were screened for their antimicrobial potency via agar well diffusion assay against three bacterial strains and two fungal strains. Compounds were subjected to molecular docking studies for rationalization of their mode of action. RESULTS: 18 new imidazole derivatives having mercapto group (4a-r) were synthesized via solid phase synthesis and were characterized by spectral studies i.e IR, 1NMR, Mass spectra and LC-MS. All the compounds were found to possess promising antimicrobial potency. However, compounds 4j and 4k were found to be the most potent compounds of the series against al the tested strains. The in silcio molecular modeling study results indicated that all the compounds exhibited good affinity towards the active site and thus may be considered as good inhibitors of enzyme 14α.-demethylase. CONCLUSION: Thus, it may be concluded that the compounds are good inhibitors of enzyme 14α.- demethylase and may be further investigated to obtain antimicrobial lead.

A Selective Imidazoline-2-thione-Bearing Two-Photon Fluorescent Probe for Hypochlorous Acid in Mitochondria.

Hypochlorite (OCl(-)) plays a key role in the immune system and is involved in various diseases. Accordingly, direct detection of endogenous OCl(-) at the subcellular level is important for understanding inflammation and cellular apoptosis. In the current study, a two-photon fluorescent off/on probe (PNIS) bearing imidazoline-2-thione as an OCl(-) recognition unit and triphenylphosphine (TPP) as a mitochondrial-targeting group was synthesized and examined for its ability to image mitochondrial OCl(-) in situ. This probe, based on the specific reaction between imidazoline-2-thione and OCl(-), displayed a selective fluorescent off/on response to OCl(-) with the various reactive oxygen species in a physiological medium. PNIS was successfully applied to image of endogenously produced mitochondrial OCl(-) in live RAW 264.7 cells via two-photon microscopy.

Ozonation and peroxone oxidation of ethylenethiourea in water: operational parameter optimization and by-product identification.

The objective of this work was to study the degradation and mineralization of ethylenethiourea (ETU) in water by ozonation at different pH values and in the presence of hydrogen peroxide. Degradation experiments were performed using an initial ETU concentration of 50 ppm for 180 min with a gas flux of 0.25 dm(3) min(-1) and an O3 production rate of 12.1 mg min(-1). Degradation of by-products was monitored by direct injection electrospray ionization mass spectrometry (ESI-MS), ETU concentration was determined by HPLC-UV, and its mineralization was detected by total organic carbon (TOC) analysis. Optimum degradation of ETU in water was observed at pH = 11, whereas at pH = 3, the degradation of ETU was slowest, indicating that the reaction occurred through different mechanisms. The additional effects of hydroxyl radicals formed at the highest pH can be used to explain the results obtained in this study. Peroxone experiments were carried out in the presence of 400 and 800 mg L(-1) H2O2; the degradation of ETU was faster at 400 mg L(-1) H2O2. This was attributed to the scavenging effect of the excess H2O2. ETU treatment by ozonation produced several by-products of degradation such as ethylene urea and 2-imidazoline.

Base-mediated hydroamination of propargylamine: a regioselective intramolecular 5-exo-dig cycloisomerization en route to imidazole-2-thione.

An intramolecular transition-metal-free base-mediated hydroamination of propargylamine with isothiocyanates has been achieved. This atom-economical, regioselective intramolecular 5-exo-dig cycloisomerization was utilized for the one-pot synthesis of diversely substituted imidazole-2-thione and spiro-cyclic imidazolidine-2-thione. The reaction goes to completion at room temperature via propargylthiourea and 65-97% isolated yields were obtained.

Degradation of ethylenethiourea pesticide metabolite from water by photocatalytic processes.

In this study, photocatalytic (photo-Fenton and H2O2/UV) and dark Fenton processes were used to remove ethylenethiourea (ETU) from water. The experiments were conducted in a photo-reactor with an 80 W mercury vapor lamp. The mineralization of ETU was determined by total organic carbon analysis, and ETU degradation was qualitatively monitored by the reduction of UV absorbance at 232 nm. A higher mineralization efficiency was obtained by using the photo-peroxidation process (UV/H2O2). Approximately 77% of ETU was mineralized within 120 min of the reaction using [H2O2]0 = 400 mg L(-1). The photo-Fenton process mineralized 70% of the ETU with [H2O2]0 = 800 mg L(-1) and [Fe(2+)] = 400 mg L(-1), and there is evidence that hydrogen peroxide was the limiting reagent in the reaction because it was rapidly consumed. Moreover, increasing the concentration of H2O2 from 800 mg L(-1) to 1200 mg L(-1) did not enhance the degradation of ETU. Kinetics studies revealed that the pseudo-second-order model best fit the experimental conditions. The k values for the UV/H2O2 and photo-Fenton processes were determined to be 6.2 × 10(-4) mg L(-1) min(-1) and 7.7 × 10(-4) mg L(-1) min(-1), respectively. The mineralization of ETU in the absence of hydrogen peroxide has led to the conclusion that ETU transformation products are susceptible to photolysis by UV light. These are promising results for further research. The processes that were investigated can be used to remove pesticide metabolites from drinking water sources and wastewater in developing countries.

Combined determination and confirmation of ethylenethiourea and propylenethiourea residues in fruits at low levels of detection.

In this work, a new method for the determination of ethylenethiourea (ETU) and propylenethiourea (PTU) in fruits and vegetables is presented. Different extraction and purification techniques, including matrix solid phase dispersion (MSPD) and solid-liquid extraction (SLE), followed by a clean-up step by solid phase extraction (SPE), were compared. The determination of ETU and PTU was performed by high performance liquid chromatography with diode array detection (HPLC/DAD) or by gas chromatography with mass spectrometry detection (GC/MS). The effect of several parameters on the extraction, separation and detection was studied. The proposed method based on solid-liquid extraction with acetonitrile, clean-up with Envicarb II/PSA cartridges and subsequent analysis by HPLC/DAD was characterised and applied to the analysis of fruits and vegetables from different countries. Analytes recoveries were between 71% and 94% with relative standard deviations (RSDs) ranging from 8% to 9.5%. Quantification limits obtained for ETU and PTU with the HPLC/DAD method were 7 and 16 µg kg⁻¹ in strawberries (fresh weight), respectively. For apples, they were 11 and 25 µg kg⁻¹, respectively.

Exploring the pH dependent SERS spectra of 2-mercaptoimidazole molecule adsorbed on silver nanocolloids in the light of Albrecht's "A" term and Herzberg-Teller charge transfer contribution.

The pH dependent surface-enhanced Raman scattering (SERS) spectra of biologically and industrially significant, 2-mercaptoimidazole (2-MI) molecule at 1.0×10(-10)M concentration have been investigated. The pH dependent SERS spectra are compared with the corresponding normal Raman spectra (NRS) of the molecule. The vibrational analyses of the pH dependent NRS spectra of the molecule reveal that in the acidic pH medium, the cationic form of the molecule is preponderant, while in the neutral pH, the existence of the cationic, normal, ylidic, and anionic forms of the molecule are all prevalent. However, in the alkaline pH medium, the anionic form of the molecule is estimated to be dominant. The SERS spectral analyses suggest the predominant adsorption of the cationic and the normal forms of the molecule on the nanocolloidal silver surface at acidic pH of the medium. However, at neutral pH, the cationic and/or normal, ylidic forms of the molecule take active part in the adsorption process, while considerable interactions of the normal, ylidic and/or anionic forms of the molecule with the nanocolloidal silver surface are presaged at alkaline pH of the medium. The genesis of selective enhancements of the Raman bands in the SERS spectra of the molecule recorded at various pH values of the medium has been unveiled from the view of the Albretcht's "A" and Herzberg-Teller (HT) charge transfer (CT) contribution.

Synthesis and antidiabetic activity of 2,4-thiazolidindione, imidazolidinedione and 2-thioxo-imidazolidine-4-one derivatives bearing 6-methyl chromonyl pharmacophore.

Numerous compounds have been prepared in order to improve the pharmacological profile of insulinotropic activities. In the present paper, we report the synthesis and the in vitro insulin releasing activity of the 6-methyl-chromonyl-2,4-thiazolidinediones (IIIa-c, IVa-c, Va-c). Compounds IIIb, IIIc, IVa-c, Va and Vc (at lower concentration; 0.001 mg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose. In this series, the most potent compound is IVa having methyl group at N3 position of TZD ring.

Genesis of enhanced Raman bands in SERS spectra of 2-mercaptoimidazole: FTIR, Raman, DFT, and SERS.

The surface enhanced Raman scattering (SERS) spectra of biologically and industrially significant, 2-mercaptoimidazole (2-MI) molecule have been investigated. The SERS spectra of the molecule at different concentrations of the adsorbate are compared with its Fourier transform infrared (FTIR) and normal Raman spectra (NRS) in varied environments. The optimized molecular structures and vibrational wavenumbers of the various forms (ca. cationic, neutral, ylidic, anionic) of the molecule have been estimated from the density functional theory (DFT). The vibrational signatures of the molecule have been assigned for the first time from the potential energy distributions (PEDs). The analyses of the Raman vibrational signatures reveal the coexistence of all the different forms of the molecule in the solid state and in aqueous solution. Concentration dependent SERS spectra of the molecule at neutral pH of the medium together with the multivariate data analyses techniques also suggest the concomitance of all the probable forms of the molecule in the surface adsorbed state. The genesis of selective enhancements of the Raman bands in the SERS spectra emanating from the cationic, neutral, ylidic and anionic forms of the molecule have been divulged from the view of the Albretcht's "A" and Herzberg-Teller (HT) charge transfer (CT) contribution.

Kinetic and thermodynamic investigation of mancozeb degradation in tomato homogenate during thermal processing.

BACKGROUND: The kinetic and thermodynamic parameters of mancozeb degradation in tomato homogenates under the conditions prevailing in the manufacture of tomato products (at 60-100 °C for 0-60 min) were investigated. A gas chromatography-mass spectrometry method was used to analyse residual mancozeb in tomato homogenate. Ethylenethiourea (ETU), the main toxic degradation product of mancozeb, was measured by high-performance liquid chromatography (HPLC)-with photodiode array detector (PDA). RESULTS: The degradation of mancozeb and the formation of ETU in tomato homogenates were adequately described as first-order kinetics. Dependence of the rate constant followed the Arrhenius relationship. Apparent activation energies, temperature coefficients, half time and time to reduce to 90% of the initial value of mancozeb were calculated as kinetic parameters. The thermodynamic parameters of mancozeb were also described as Δg(d) = - 2.440 and 7.074 kJ mol⁻¹; Δh(d) = - 32.555 and - 42.767 kJ mol⁻¹; Δs(d) = - 0.090 and - 0.150 kJ mol⁻¹ K⁻¹; K(e) = 0.414 and 9.797 L g⁻¹ for 333 and 373 K respectively. CONCLUSION: Current findings may shed light on the reduction of mancozeb residue and its toxic degradation product during thermal processing of tomatoes and may also be valuable in awareness and prevention of potential risks from dietary exposure.

Experimental studies on ozonation of ethylenethiourea.

The experimental study on ozonation of ethylenethiourea (ETU) is conducted. The reaction of gas-phase ETU with 0.63 x 10(-6) mol/L ozone is carried out in a 200-L reaction chamber. The secondary organic aerosol (SOA) resulted from the ozonation of gas-phase ETU is observed with a scanning mobility particle size (SMPS). The rapid exponential growth of SOA reveals that the atmospheric lifetime of ETU vapor towards ozone reaction is less than four days. The ozonation of dry ETU particles, ETU-contained water droplets and ETU aqueous solution is investigated with a vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS). The formation of 2-imidazoline is observed in the ozonation of dry ETU particles and ETU-contained water droplets. The formation of 2-imidazoline and ethylenerea is observed in the ozonation of ETU aqueous solution.

Experimental and computational approach to the rational monitoring of hydrogen-bonding interaction of 2-Imidazolidinethione with DNA and guanine.

The hydrogen-bonding interaction of 2-Imidazolidinethione with DNA and guanine has been investigated using UV/vis, circular dichroism, differential pulse voltammetry and ab initio chemical mechanic quantum procedures. The bonding constant of 2-Imidazolidinethione with DNA was measured by UV/vis spectroscopy and is estimated to be 1.4x10(3). In order to prove of hydrogen-bonding formation, the bonding constants of 2-Imidazolidinethione with guanine in Tris-HCl buffer and binary mixture of buffer-acetonitrile were measured. In addition, density functional theory calculations, using ab initio methodology at the 6-31+G(d,p) level and simulating the effect of solvents on interaction by mean of the Cosmo Polarizable Continuum Model (CPCM), were performed on the single and complex of 2-Imidazolidinethione and guanine molecules. However, we concluded that 2-Imidazolidinethione interacted with N(3) of guanine in minor groove of DNA.

Rhenium(I) tricarbonyl complexes with poly(azolyl)borates generated in situ from an organometallic precursor containing the B-H...Re coordination motif.

Complex fac-[Re(kappa(3)-H(mu-H)(2)B(tim(Me)))(CO)(3)] (1) reacts with protic azoles, like 2-mercapto-1-methylimidazole (tim(Me)H), 2-mercaptobenzothiazole (bztH), or pyrazoles (pz*H), to afford fac-[Re(kappa(3)-H(mu-H)B(tim(Me))(2)(CO)(3)] (2), fac-[Re(kappa(3)-H(mu-H)B(tim(Me))(bzt))(CO)(3)] (3), fac-[Re(kappa(3)-H(mu-H)B(tim(Me))(pz))(CO)(3)] (4), fac-[Re(kappa(3)-HB(tim(Me))(pz)(2))(CO)(3)] (5), and fac-[Re(kappa(3)-H(mu-H)B(tim(Me))(3,5-Me(2)-4-EtOOCCH(2)pz))(CO)(3)] (6). Complexes 2-6 are stabilized by tridentate poly(azolyl)borates generated in situ, and their formation involves most probably a metal-assisted process which is considerably faster for the pyrazole derivatives. The characterization of the novel complexes, 3-6, has been done by common analytical techniques, including single crystal X-ray diffraction analysis. The solid state structures confirmed the presence of hybrid heteroscopionates, presenting (kappa(3)-H, S, S'), (kappa(3)-H, S, N), or (kappa(3)-S, N, N) binding motifs. Multinuclear ((1)H, (13)C, and (11)B) NMR studies have also shown that the coordination mode found in the solid state is retained in solution.