173 publications from this institution
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Significant research interest has been devoted to organoselenium compounds due to their diverse biological activities, particularly their antioxidant properties, which mimic those of glutathione peroxidase (GPx) enzymes. While previous reviews have explored the broad spectrum of organoselenium chemistry and their applications, this review focuses specifically on aminic organoselenium compounds as next-generation GPx mimics and radical-trapping antioxidants. This work presents a comprehensive analysis of their catalytic mechanisms and structure-activity relationships (SAR) and the methodologies employed to evaluate their antioxidant efficacy. Unlike earlier reviews, this work emphasizes the critical role of aminic moieties in enhancing GPx-like activity and dual functionalities (peroxide decomposition and radical quenching). Key topics include the design principles of aminic organoselenium compounds, their performance relative to classical antioxidants like ebselen and α-tocopherol, and their promising use in developing treatments for conditions linked to oxidative stress. By consolidating advancements from the past two decades, this review connects existing research areas and suggests valuable pathways for future studies in developing multifunctional organoselenium antioxidants.
The synthesis of a variety of aromatic amines carrying an ortho-alkyltelluro group is described. The new antioxidants quenched lipidperoxyl radicals much more efficiently than α-tocopherol and were regenerable by aqueous-phase N-acetylcysteine in a two-phase peroxidation system. The inhibition time for diaryl amine 9 b was four-fold longer than recorded with α-tocopherol. Thiol consumption in the aqueous phase was found to correlate inversely to the inhibition time and the availability of thiol is the limiting factor for the duration of antioxidant protection. The proposed mechanism for quenching of peroxyl radicals involves O-atom transfer from peroxyl to Te followed by H-atom transfer from amine to alkoxyl radical in a solvent cage.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Tramadol, a weak opioid agonist with effects on adrenergic and serotonergic neurotransmission, is used to treat conditions varying from postoperative to chronic malignant pain. Additionally, selective serotonin reuptake inhibitors (SSRIs) are used as adjuvants or prophylactics for the associated residual pain component. The present work evaluates, by isobolographic analysis, the interaction between a combination of racemic (±) tramadol, an opioid agonist, and fluoxetine, an SSRI, using a chemical analgesiometric test (abdominal writhing). Intraperitoneal administration of both tramadol (0.5–20 mg/kg) and fluoxetine (5–40 mg/kg) produced dose‐dependent antinociception. Co‐administration of fixed ratios of ED 50 fractions of fluoxetine and tramadol resulted in an additive effect. However, the least dose of fluoxetine (2.1 mg/kg) and tramadol (0.21 mg/kg) used in fixed ratios for antinociceptive effect individually showed antidepressant activity in a modified Porsolt forced swim test. The interaction studies in the writhing test suggested that such combinations might be devoid of any additional advantage over the individual drug regimen in acute cases of pain with co‐morbidity of depression. Further, the nature of interaction for such combinations in chronic pain models needs further assessment. Drug Dev. Res. 61:79‐85, 2004. © 2004 Wiley‐Liss, Inc.
A new series of silicon(IV) complexes have been synthesized by adopting classical thermal- and microwave-irradiated techniques. The complexes are prepared by the reaction of dimethyldichlorosilane and triphenylchlorosilane with the sodium salts of 1-(1-(2-oxo-2H-chromen-3-yl)ethylidene)thiosemicarbazide and 1-(1-(2-oxo-2H-chromen-3-yl)ethylidene)semicabazide in 1:1 and/or 1:2 molar ratios. Characterization of the ligands as well as of the silicon complexes has been carried out on the basis of elemental analysis, melting point determinations, molecular weight determinations, infrared, 1H NMR, 13C NMR, 29Si NMR, and electronic and mass spectral studies. Spectral studies confirm ligands to be monofunctional bidentate and trigonal bipyramidal and octahedral environments around silicon ions. The newly synthesized ligands and their complexes have been screened for antimicrobial, minimum inhibitory concentration, and pesticidal activities. The results obtained from bioassays indicate that this class of compounds can be utilized for the design of new substances with pesticidal activity and promising antimicrobial activity.
Based on the traditional 77 Se NMR spectroscopy investigation, a catalytic cycle for the formation of N -thiophenyl ebselenamine 12 involving diselenide 9 , selenenyl sulfide 10 and ebselenamine 7a was reported by the reaction of azo-bis-ebselen 8 with PhSH and H 2 O 2 . The signals detected in the 77 Se NMR spectrum corresponding to 7a , 10 and 12 were directly isolated from the NMR mixture. Mechanistic investigation for the formation of N -thiophenyl ebselenamine 12 was confirmed from an independent reaction of diselenide 9 and PhSSPh in the presence of H 2 O 2 . This was further supported by another diselenide 19 containing p -tolyl group with equimolar amount of H 2 O 2 and PhSH in an independent experiment followed by the 77 Se NMR spectroscopy, yielding similar observations. These results, which illustrated diselenide has been observed as the main precursor in the formation of all intermediates. The new novel selenium antioxidants quenched lipidperoxyl radicals much more efficiently than α-tocopherol and were regenerable by the aqueous ascorbic acid in a two-phase (chlorobenzene/water) azo-initiated peroxidation system. The notable benefit of the organoselenium biology, the novel ebselenamine analogues and their corresponding selenenyl sulfides were found to mimic the activity of the glutathione peroxidase enzymes better than ebselen in the coupled reductase assay.
Osteoporotic Vertebral compression fracture occurs in approximately 20% of individuals over 70 years of age.A significant majority of fractures approx 60% to 75% occur around the thoracolumbar region.The fractures can result in persistent pain, inability to perform daily activities, and a marked decrease in the quality of life.Reduction of pain and stabilization of vertebrae and prevention of deformity are the goals of treatment in vertebral compression fracture.The purpose of this technical note is to demonstrate the usefulness of minimal invasive cement augmented screw vertebroplasty along with short segment fixation at junctional vertebral compression fracture and its intraoperative effectiveness in preventing devastating complications.
Very strong and weak IHBs in curcumin.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The syntheses of selenenate/seleninate esters and related derivatives by aromatic nucleophilic substitution (S N Ar) reactions of 2‐bromo‐3‐nitrobenzylalcohol ( 13 ) and 2‐bromo‐3‐nitrobenzaldehyde ( 17 ) with Na 2 Se 2 / n BuSeNa are described. The reaction of 13 with Na 2 Se 2 at room temperature afforded 7‐nitro‐1,2‐benzisoselenole(3 H) ( 15 ) instead of the desired diaryl diselenide 14 . Oxidation of selenenate ester 15 with hydrogen peroxide afforded the corresponding selenium(IV) derivative, 7‐nitro‐1,2‐benzisoselenole(3 H) selenium oxide ( 18 ). 2‐(Butylselanyl)‐3‐nitrobenzaldehyde ( 19 ) was synthesized by treating compound 17 with in situ generated n BuSeNa. The bromination reaction of selenide 19 did not afford the expected arylselenenyl bromide 20 , instead, it resulted in the formation of the unexpected 7‐nitro‐1,2‐benzisoselenol(3 H)‐3‐ol ( 21 ) and 3,3′‐oxybis(7‐nitro‐1,2‐benzisoselenole(3 H)) ( 22 ), respectively. The facile formation of heterocycles 21 and 22 is rationalized in terms of the aromatic ring strain in selenenyl bromide 20 . The presence of intramolecular secondary Se⋅⋅⋅O interactions in esters 15 , 18 , 21 , 22 , and selenenic anhydride 29 has been confirmed by single‐crystal X‐ray diffraction studies as well as computational studies. The presence of an intramolecular Se⋅⋅⋅O interaction in esters 4b , 8 , 15 , 18 , 21 , and 22 has been further proved by natural bond orbital (NBO) and atoms in molecules (AIM) calculations. Glutathione peroxidase‐like (GPx) antioxidant activities of 15 , 18 , 21 , 22 , and related heterocycles such as 7‐nitro‐1,2‐benzisoselenol(2 H)‐3‐one selenium oxide ( 4b ), 7‐nitro‐1,2‐benzisoselenol(2 H)‐3‐one ( 8 ), and 29 have been determined by the coupled reductase assay.
