Nitrogen Atom Of Ring Research Articles

Improving visible light-driven CO2 conversion to high calorific fuels over sustainable highly crystalline and holey sulphur doped graphitic carbon nitrides

The effectiveness of CO2 reduction through g-C3N4 (CN) is considerably hindered by poor visible light absorption and the high rate of recombination of electron-hole (e−/h+) pairs. An effective method for increasing CO2 photoreduction efficiency is to incorporate non-metal components into the CN to modify its electronic properties and enhance its performance. This research presents the findings of our inquiry into sulfur-doped graphitic carbon nitrides (S–CN) for CO2 reduction through visible light. The XPS study reveals that the substitution of nitrogen atoms in the heptazine ring by sulfur (S) doping significantly influences the electronic configuration of CN, while the UV–visible absorbance spectra reveals that the CN band gap value 2.64 eV has reduced to 2.50 eV after S doping. Therefore, S–CN exhibits exceptional visible-light absorption, separation and migration of photoexcited e−/h+, corroborated by photoluminescence and transient photocurrent response experiments. Besides, S–CN demonstrated remarkable CO2 reduction capabilities without any cocatalyst or sacrificial agent, achieving CO/CH4 formation rates of 25/3 μmolg−1h−1, outperforming traditional CN. Our research highlights the relevance of impeding the e−/h+ recombination process to boost solar energy conversion output, suggesting potential for productive solar fuel generation using g-C3N4.

Structure-mutagenicity relationships on quinoline and indole analogues in the Ames test

BackgroundAlthough the in silico predictive ability of the Ames test results has recently made remarkable progress, there are still some chemical classes for which the predictive ability is not yet sufficient due to a lack of Ames test data. These classes include simple heterocyclic compounds. This study aimed to investigate the mutagenicity and structure-mutagenicity relationships for some heterocycles in the Ames test. In the present study, we selected 12 quinoline analogues containing one or two nitrogen atoms in the naphthalene ring and 12 indole analogues containing one to three nitrogen atoms in the indole ring, without any side moiety.ResultsThe Ames test was performed with five standard bacterial strains (TA100, TA1535, TA98, TA1537, and WP2uvrA) using the pre-incubation method with and without rat liver S9. Five quinoline and two indole analogues were mutagenic. Among the five quinoline analogues, four were mutagenic in the presence of S9 mix with TA100, whereas cinnoline was mutagenic in the absence of S9 mix with TA1537. Among the two indole analogues, indazole was mutagenic in the presence and absence of S9 mix with WP2uvrA and 4-azaindole was mutagenic in the absence of S9 mix with TA1537. The mechanisms underlying the induction of mutagenesis appear to differ between quinoline and indole analogues. In addition, we performed in silico analysis of the mutagenicity of all these analogues using DEREK Nexus 6.1.1 (Lhasa Limited) and GT_EXPERT from CASE Ultra 1.8.0.5 (MultiCASE Inc.) as knowledge-based models and GT1_BMUT from CASE Ultra 1.8.0.5 (MultiCASE Inc.) as a statistical-based model. The knowledge-based model showed low sensitivity for both the quinoline and indole analogues (DEREK Nexus and GT_EXPERT: 20% for quinolines and 0% for indoles). Conversely, the statistical model showed high sensitivity (100% for both quinolines and indoles) and low specificity (43% for quinolines and 10% for indoles).ConclusionBased on the Ames test results, we proposed structural alerts noting that quinoline analogues were mutagenic when they had nitrogens in any of the positions 2, 5, 7, or 8 in addition to 1, and indole analogues were mutagenic when they had nitrogens at positions 2 or 4 in addition to 1.

DFT Study on the His-Tag Binding Affinity of Metal Ions in Modeled Hexacationic Metal Complexes.

Histidine oligomers (His-tags) are commonly used as affinity tags in recombinant protein purification to enable in vitro experimental studies, including biochemical and biophysical assays and structure determination. His-tags enable protein purification by specifically and efficiently coordinating bivalent metal ions present in the purification resins, such as Cu2+, Zn2+, and Ni2+. Although His-tags, combined with Ni2+-based resins, are widely used due to their biophysical properties and commercial availability, the structure and nature of the metal cation coordination have remained unclear. In this study, the chemical structure of metal-coordinating His-tags was modeled to elucidate the metal preferences for better binding and to determine the structural changes that occur upon metal coordination. 6His-tag is a string of 6 histidine residues usually coordinated to bivalent metal ions (M2+), such as Ni2+, Zn2+, and Cu2+, through the nitrogen atoms of the imidazole rings. The metals complete their octahedral coordination shell with the lone pair of electrons of the oxygen atoms of the resin to which they are attached to. The resin was modeled as an oxalaldehyde group with the closed formula of (OCH)4. The geometry optimizations were carried out using the DFT method at the B3LYP/6-31g (d, p) level and in implicit water using the IEFPCM solvent model. The impact of Ni2+, Zn2+, and Cu2+ metals on the resin binding ability of 6His-tags was tested by adding amino acids to the N-terminus of metal-coordinated hexahistidine chains. The activity of the metals as electron donors or acceptors to the coordination bonds that they form was estimated by calculating the NBO energies. The complexation enthalpies of metal-bearing resin with hexahistidine, naked or having an amino acid tail, were calculated. Our results showed that Ni2+ has the highest affinity for the recombinant 6His-tag.

Mechanism of TMB Discoloration Catalyzed by Layered CoNi@CN Nanozymes: Application Based on Smart Phone for Resorcinol Detection

Comprehensive SummaryReal‐time on‐site monitoring of resorcinol (RS) concentrations is crucial for detecting hazardous levels, enabling prompt response measures to mitigate potential environmental and health risks. In this study, we developed an innovative method using CoNi@CN‐2 nanozymes to activate peroxymonosulfate (PMS) for oxidizing 3,3',5,5'‐tetramethylbenzidine (TMB). Our results show that the formation of Ni2+ through the oxidation of Ni0 on the CoNi@CN‐2 surface significantly enhances the electron‐donating capacity of Co0. The catalytic reaction of TMB is mediated by redox active species (SO4•−, •O2−, •OH and 1O2). RS drives colorimetry by transferring electrons to the benzene ring and specific nitrogen atoms in ox‐TMB, reducing ox‐TMB to TMB. Furthermore, the colorimetric assay shows a robust linear correlation between RS concentration and absorbance (Abs), described by Abs = –0.44[RS] + 0.886 (0—200 μmol/L, R2 = 0.983). Also, we introduce a novel smartphone‐integrated autonomous detection software that can analyze RS concentration and grayscale values (GSV), yielding GSV = 0.327[RS] + 63.601 (0—200 μmol/L, R2 = 0.990) with a detection limit of 5.29 μmol/L. Additionally, excess PMS leads to ROS attacking specific sites in ox‐TMB, forming secondary oxidation products. This study has enabled rapid and accurate detection of RS, making a significant contribution to environmental safety and protection.

Investigation of the Synthesis and Energetic Properties of an ANTA-Based Energetic Plasticizer.

Energetic plasticizers are being sought for their use in energetic formulations when combined with explosives. An energetic plasticizer based on the insensitive highly explosive 3-amino-5-nitro-l,2,4-triazole (ANTA) was synthesized and characterized by spectroscopy, X-ray crystallography, thermal analyses, and safety testing. Lastly, density functional theory calculations were employed to examine the observed selectivity among the three nucleophilic ring nitrogen atoms of ANTA toward electrophiles such as ANTA acrylate; this selectivity was found to be a combination of steric, electronic, and hydrogen bonding effects.

Synthetic Protocols, Structural Activity Relationship, and Biological Activity of Piperazine and its Derivatives.

The versatile basic structure of piperazine allows for the development and production of newer bioactive molecules that can be used to treat a wide range of diseases. Piperazine derivatives are unique and can easily be modified for the desired pharmacological activity. The two opposing nitrogen atoms in a six-membered piperazine ring offer a large polar surface area, relative structural rigidity, and more acceptors and donors of hydrogen bonds. These properties frequently result in greater water solubility, oral bioavailability, and ADME characteristics, as well as improved target affinity and specificity. Various synthetic protocols have been reported for piperazine and its derivatives. In this review, we focused on recently published synthetic protocols for the synthesis of the piperazine and its derivatives. The structure-activity relationship concerning different biological activities of various piperazine-containing drugs was also highlighted to provide a good understanding to researchers for future research on piperazines.

The Study of Reaction of Hexafluoro‐1,4‐Napthoquinone With Substituted 5‐Aminopyrazoles

ABSTRACTFor the first time, the interaction of perfluoro‐1,4‐naphthoquinone with various 5‐aminopyrazoles was investigated. It was shown that three types of products can be obtained depending on the structure of starting aminopyrazole. For all examples, the substitution of one fluorine atom in quinone moiety was observed. Wherein, in most cases, the starting aminopyrazoles act as a C‐nucleophile leading to 2‐(5‐aminopyrazol‐4‐yl)‐3,5,6,7,8‐pentafluoronaphthalene‐1,4‐diones. At the same time substrates unsubstituted at ring nitrogen atom regiospecifically react at aminogroup resulting in the formation of 2,5,6,7,8‐pentafluoro‐3‐((pyrazol‐5‐yl)amino)naphthalene‐1,4‐diones. Besides that, the absence of steric hindrance in the pyrazole unit allowed us to direct the process at nitrogen atom in Position 2 and synthesize zwitter‐ionic 3‐(5‐aminopyrazol‐2‐ium‐2‐yl)‐5,6,7,8‐tetrafluoro‐1,4‐dioxo‐1,4‐dihydronaphthalen‐2‐olates. The structures of two types of obtained products were confirmed by x‐ray analysis.

Cheminformatics approaches to predict the bioactivity and to discover the pharmacophoric traits crucial to block NF-κB

Many human disorders include NF-kB signaling pathways, making IKK a therapeutic target in cancer treatment. Inflammatory illnesses and cancer are examples. COVID-19 is one of several triggers that stimulate NF-kB signaling. The activation of the NF-kB pathway is necessary for COVID-19 to cease its development. To learn more about the mechanism and structural features essential to IKK inhibition (IC50), molecular modeling studies have been undertaken on experimentally reported 503. QSAR analysis explores certain reported and hidden structural features critical for IKKβ inhibition. The OECD guidelines guided the construction of the QSAR model, which achieved all the endorsed threshold values for all validation parameters (R2tr:0.81, R2LMO:0.80, and R2ext:0.78). The present QSAR study shows that IKK inhibitory activity is linked to the following structural features: lipophilic hydrogen atoms within 2 A units of the molecule's center of mass; ring nitrogen atoms within one bond of planar nitrogen atoms; ring carbon atoms exactly four bonds from the non-ring nitrogen atoms; planar nitrogen atoms exactly four bonds from sp2 hybridized carbon atoms; and so on. Pharmacophore modeling highlighted QSAR-identified structural characteristics. To investigate binding, we docked all 503 molecules. The observation indicates that the QSAR and molecular docking/pharmacophore modeling findings are in agreement. Following this, we conducted 200 ns of molecular dynamics simulation to validate the molecular docking protocol. MMGBSA analysis determined the binding energy of the dock complex. Thus, the current study found unique pharmacophoric properties that may assist in optimizing lead/hit compounds for anti-IKKβ activity.

Developments of Pyrrolo[2,3-d]pyrimidines with Pharmaceutical Potential

: In terms of fused heterocyclic compounds, pyrrolopyrimidines, and their substituted analogs are among the most extensively explored scaffolds. Based on the location of the nitrogen atom in the pyrrole ring, pyrrolopyrimidines have different isomers. This study deals only with the pyrrolo[2,3-d]pyrimidine isomer. Several techniques are represented and discussed in this review for producing pyrrolo[2,3-d]pyrimidine derivatives. The first one is the cyclization of the pyrimidine ring on the pyrrole ring through the reaction of β-enaminonitrile, β-enaminoester or β-enaminoamide of the pyrrole ring with different bifunctional reagents such as formic acid, acetic acid, acetic anhydride, formamide, isothiocyanate, urea, thiourea, and carbon disulfide. The second technique includes cyclization of the pyrrole ring on the pyrimidine ring via the treatment of pyrimidine, aminopyrimidine, diamino-pyrimidine, or triamino-pyrimidine with different reagents such as nitroalkenes, alkynes, aldehydes, and acid chlorides. In addition, different reaction methodologies like one pot, two-step, and threestep synthetic methodologies were reported. The last technique for producing pyrrolo[2,3-d]pyrimidine derivatives is through miscellaneous reactions. This review also includes the interactions of pyrrolo[2,3- d]pyrimidines at different active centers of the pyrrole ring with different reagents to form N-alkylated, Nglycosylated, C-5, and C-6 adducts. Besides, the interactions on the pyrimidine ring to form chloro, hydrazino, and amino-imino derivatives were also discussed. The amino-imino derivatives are key intermediates for the preparation of tricyclic pyrrolotriazolopyrimidines. Finally, the pharmaceutical and biological properties of some pyrrolo[2,3-d]pyrimidine derivatives have also been mentioned. This information can be utilized to design novel diverse pyrrolopyrimidine derivatives for recent challenges in pharmaceutical and medical studies to develop the already existing drugs or discover new ones.

Purinyl N-directed aroylation of 6-arylpurine ribo- and 2'-deoxyribonucleosides, and mechanistic insights.

The purinyl ring contains four embedded nitrogen atoms of varying basicities. Selective utilization of these ring nitrogen atoms can lead to relatively facile remote functionalization, yielding modified purinyl motifs that are otherwise not easily obtained. Herein, we report previously undescribed N-directed aroylation of 6-arylpurine ribo and the more labile 2'-deoxyribonucleosides. Kinetic isotope analysis as well as reaction with a well-defined dimeric, palladated 9-benzyl 6-arylpurine provided evidence for N-directed cyclometallation as a key step, with a plausible rate-limiting C-H bond cleavage. Radical inhibition experiments indicate the likely intermediacy of aroyl radicals. The chemistry surmounts difficulties often posed in the functionalization of polynitrogenated and polyoxygenated nucleosidic structures that possess complex reactivities and a labile glycosidic bond that is more sensitive in the 2'-deoxy substrates.

Synthesis, X-ray Crystallography, Spectroscopic Characterizations, Density Functional Theory, and Hirshfeld Surface Analyses of a Novel (Carbonato) Picket Fence Iron(III) Complex.

An Fe(III)-carbonato six-coordinate picket fence porphyrin complex with the formula [K(2,2,2-crypt)][FeIII(TpivPP)(CO3)]·C6H5Cl·3H2O (I) has been synthesized and characterized by UV-Vis and FT-IR spectra. The structure of (carbonato)(α,α,α,α-tetrakis(o-pivalamidophenyl)porphinato)ferrate(III) was also established by XRD. The iron atom is hexa-coordinated by the four nitrogen atoms of the pyrrol rings and the two oxygen atoms of the CO32- group. Complex I, characterized as a ferric high-spin complex (S = 5/2), presented higher Fe-Np (2.105(6) Å) and Fe-PC (0.654(2) Å) distances. Both X-ray molecular structure and Hirshfeld surface analysis results show that the crystal packing of I is made by C-H⋯O and C-H⋯Cg weak intermolecular hydrogen interactions involving neighboring [FeIII(TpivPP)(CO3)]- ion complexes. Computational studies were carried out at DFT/B3LYP-D3/LanL2DZ to investigate the HOMO and LUMO molecular frontier orbitals and the reactivity within the studied compound. The stability of compound I was investigated by analyzing both intra- and inter-molecular interactions using the 2D and 3DHirshfeld surface (HS) analyses. Additionally, the frontier molecular orbital (FMO) calculations and the molecular electronic potential (MEP) analyses were conducted to determine the electron localizations, electrophilic, and nucleophilic regions, as well as charge transfer (ECT) within the studied system.

Comprehensive Review of Synthesis, Optical Properties and Applications of Heteroarylphosphonates and Their Derivatives.

This review focuses on optical properties of compounds in which at least one phosphonate group is directly attached to a heteroaromatic ring. Additionally, the synthesis and other applications of these compounds are addressed in this work. The influence of the phosphonate substituent on the properties of the described compounds is discussed and compared with other non-phosphorus substituents, with particular attention given to photophysical properties, such as UV-Vis absorption and emission, fluorescence quantum yield and fluorescence lifetime. Considering the presence of heteroatom, the collected material was divided into two parts, and a review of the literature of the last thirty years on heteroaryl phosphonates containing sulfur and nitrogen atoms in the aromatic ring was conducted.

Phenytoin from antiepileptic to covid-19: Synthesis, crystal structure, DFT, HSA, MEP and green biological study of phenytoin derivative as potential covid-19 drug candidates

That's an interesting point! Phenytoin's potential in reducing cognitive deficits during COVID-19 is indeed intriguing. Its established status as an approved antiepileptic medication could lend credibility to exploring its effects on cognitive function in COVID-19 patients. This dual functionality could provide a unique angle for research and potential therapeutic interventions. This study reports the synthesis, characterization and importance of a new phenytoin derivative PD, C23H24N4O5. A biological molecular modelling study using a computer-aided tool, which is a clean technique of PD compared to the approved Phenytoin anti-COVID-19 drugs, was achieved. Docking the three compounds into 7JQ0 of COVID-19 Mpro showed the potential capability of PD compared to Phenytoin and the inhibitor. Binding affinity, for example, was -7.3, -6.9 and -6.6 kcal/mol, respectively. Noticeably, PD interacted with 75 % of the essential functional Mpro amino acids, such as G143 and H164, M49, C145, M165 and E166, comparable to the standards used. Further interesting findings that predicted compound toxicity and drug-likeness also found that PD was less toxic and bio-available as a drug than Phenytoin and the inhibitor. Superposition of our ligand PD against Phenytoin and the Inhibitor docked into7JQ0 using the same parameters showed similar interactions in the amino acid cavity, enhancing the possibility of PD being an anti-COVID-19 drug. The free computer-aided methods were used to significantly speed up the initial stages of drug discovery by narrowing down potential candidates for further laboratory testing.This compound adopts an L-shaped conformation. The lone pairs on the ring nitrogen atoms participate in π bonding in the ring. In the crystal, a layer structure was generated by NH···N, NH···O and CH···O hydrogen bonds plus CH···π(ring) interactions. Theoretical studies of the compound were calculated using the density functional theory (DFT) method with a B3LYP 6–311++G(d,p) basis set. The geometrical parameters after optimization were compared with the experimental values. Molecular Electrostatic Potential (MEP) and Hirshfeld Surface Analysis (HSA) were studied to investigate intermolecular interactions. Frontier Molecular Orbitals (FMOs), which were Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO), were created, and the energy gap between these orbitals was calculated to understand the chemical stability of the molecule.

XPS Depth-Profiling Studies of Chlorophyll Binding to Poly(cysteine methacrylate) Scaffolds in Pigment-Polymer Antenna Complexes Using a Gas Cluster Ion Source.

X-ray photoelectron spectroscopy (XPS) depth-profiling with an argon gas cluster ion source (GCIS) was used to characterize the spatial distribution of chlorophyll a (Chl) within a poly(cysteine methacrylate) (PCysMA) brush grown by surface-initiated atom-transfer radical polymerization (ATRP) from a planar surface. The organization of Chl is controlled by adjusting the brush grafting density and polymerization time. For dense brushes, the C, N, S elemental composition remains constant throughout the 36 nm brush layer until the underlying gold substrate is approached. However, for either reduced density brushes (mean thickness ∼20 nm) or mushrooms grown with reduced grafting densities (mean thickness 6-9 nm), elemental intensities decrease continuously throughout the brush layer, because photoelectrons are less strongly attenuated for such systems. For all brushes, the fraction of positively charged nitrogen atoms (N+/N0) decreases with increasing depth. Chl binding causes a marked reduction in N+/N0 within the brushes and produces a new feature at 398.1 eV in the N1s core-line spectrum assigned to tetrapyrrole ring nitrogen atoms coordinated to Zn2+. For all grafting densities, the N/S atomic ratio remains approximately constant as a function of brush depth, which indicates a uniform distribution of Chl throughout the brush layer. However, a larger fraction of repeat units bound to Chl is observed at lower grafting densities, reflecting a progressive reduction in steric congestion that enables more uniform distribution of the bulky Chl units throughout the brush layer. In summary, XPS depth-profiling using a GCIS is a powerful tool for characterization of these complex materials.

Synthesis of Substituted 1,2,4-Triazole-3-Thione Nucleosides Using E. coli Purine Nucleoside Phosphorylase.

1,2,4-Triazole derivatives have a wide range of biological activities. The most well-known drug that contains 1,2,4-triazole as part of its structure is the nucleoside analogue ribavirin, an antiviral drug. Finding new nucleosides based on 1,2,4-triazole is a topical task. The aim of this study was to synthesize ribosides and deoxyribosides of 1,2,4-triazole-3-thione derivatives and test their antiviral activity against herpes simplex viruses. Three compounds from a series of synthesized mono- and disubstituted 1,2,4-triazole-3-thione derivatives were found to be substrates for E. coli purine nucleoside phosphorylase. Of six prepared nucleosides, the riboside and deoxyriboside of 3-phenacylthio-1,2,4-triazole were obtained at good yields. The yields of the disubstituted 1,2,4-triazol-3-thiones were low due to the effect of bulky substituents at the C3 and C5 positions on the selectivity of enzymatic glycosylation for one particular nitrogen atom in the triazole ring. The results of cytotoxic and antiviral studies on acyclovir-sensitive wild-type strain HSV-1/L2(TK+) and acyclovir-resistant strain (HSV-1/L2/RACV) in Vero E6 cell culture showed that the incorporation of a thiobutyl substituent into the C5 position of 3-phenyl-1,2,4-triazole results in a significant increase in the cytotoxicity of the base and antiviral activity. The highest antiviral activity was observed in the 3-phenacylthio-1-(β-D-ribofuranosyl)-1,2,4-triazole and 5-butylthio-1-(2-deoxy-β-D-ribofuranosyl)-3-phenyl-1,2,4-triazole nucleosides, with their selectivity indexes being significantly higher than that of ribavirin. It was also found that with the increasing lipophilicity of the nucleosides, the activity and toxicity of the tested compounds increased.

Probing the Adsorption Sites of 5‐amino‐2‐mercaptobenzimidazole Conformations on Colloidal Gold Nanoparticles Investigated by SERS and DFT

AbstractGold nanoparticles (AuNP) have shown great potential in biomedical applications due to their unique and tunable properties. Understanding the ligand conformation on AuNP has profound interest in nanoparticle research leading to a precise drug delivery system. Colloidal AuNPs were synthesized using trisodium citrate as reducing agent. Normal Raman spectrum (NRS) in solid and aqueous phase identifies that 5‐amino‐2‐mercaptobenzimidazole (5A2MBI) mainly exist as thione form. Surface enhanced Raman scattering (SERS) investigation of 5A2MBI depending on pH was performed to explore the adsorption mechanism of thiolate and thione conformations on AuNPs. Density functional theory (DFT) calculations were used to find the band assignments and molecular electrostatic potential (MEP) mapping to identify the electron rich site where metal can interact preferentially. Using SERS spectral analysis and DFT results, surface adsorption scheme was proposed. At basic pH, 5A2MBI adsorbs on AuNP as thiolate form bidentately via Sulfur and nitrogen atom of imidazole ring with tilted geometry. However, in acidic condition the thione form adsorbs on nanosurface with perpendicular orientation.

Crystal structure and Hirshfeld surface analysis of 6,6'-dimethyl-2,2'-bi-pyridine-1,1'-diium tetra-chlorido-cobaltate(II).

In the title mol-ecular salt, (C12H14N2)[CoCl4], the dihedral angle between the pyridine rings of the cation is 52.46 (9)° and the N-C-C-N torsion angle is -128.78 (14)°, indicating that the ring nitro-gen atoms are in anti-clinal conformation. The Cl-Co-Cl bond angles in the anion span the range 105.46 (3)-117.91 (2)°. In the extended structure, the cations and anions are linked by cation-to-anion N-H⋯Cl and C-H⋯Cl inter-actions, facilitating the formation of R 4 4(18) and R 4 4(20) ring motifs. Furthermore, the crystal structure features weak anion-to-cation Cl⋯π inter-actions [Cl⋯π = 3.4891 (12) and 3.5465 (12) Å]. Hirshfeld two-dimensional fingerprint plots revealed that the most significant inter-actions are Cl⋯H/H⋯Cl (45.5%), H⋯H (29.0%), Cl⋯C/C⋯Cl (7.8%), Cl⋯N/N⋯Cl (3.5%), Cl⋯Cl (1.4) and Co⋯H (1%) contacts.

Synthesis, antibacterial and antibiofilm activity of new 1,2,3,5-tetrazine derivatives from coupling reactions of diazonium salt of 2-amino-6-nitrobenzothiazole with diverse substituted 2-aminobenzothiazole derivatives.

The coupling reaction of diazonium ion of 2-amino-6-nitrobenzothiazole at 0-5 °C with distinctly substituted 2-aminobenzothiazole derivatives produced new 1,2,3,5-tetrazine derivatives. It was found that diazotized 2-amino-6-nitrobenzo[d]thiazol reacts with the ring nitrogen atom of varyingly substituted 2-aminobenzothiazole derivatives to yield tetrazine nucleus. The benzene ring of benzothiazole bearing electron donor group and annelated to the tetrazine was further substituted in situ by other 6-nitrobenzo[d]thiazol-2-yl) diazinyl to yield the final product. The structure of the prepared compounds was elucidated using their physical, elemental, and spectroscopic data. The synthesized compounds were tested for their antimicrobial and antibiofilm activities against Staphylococcus aureus and Escherichia coli bacteria. Two of the synthesis tetrazine derivatives exhibited interesting antibiofilm potential.

Emerging Aspects of Triazole in Organic Synthesis: Exploring its Potential as a Gelator.

Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) - commonly known as the "click reaction" - serves as the most effective and highly reliable tool for facile construction of simple to complex designs at the molecular level. It relates to the formation of carbon heteroatomic systems by joining or clicking small molecular pieces together with the help of various organic reactions such as cycloaddition, conjugate addition, ring-opening, etc. Such dynamic strategy results in the generation of triazole and its derivatives from azides and alkynes with three nitrogen atoms in the five-membered aromatic azole ring that often forms gel-assembled structures having gelating properties. These scaffolds have led to prominent applications in designing advanced soft materials, 3D printing, ion sensing, drug delivery, photonics, separation, and purification. In this review, we mainly emphasize the different mechanistic aspects of triazole formation, which includes the synthesis of sugar-based and non-sugar-based triazoles, and their gel applications reported in the literature for the past ten years, as well as the upcoming scope in different branches of applied sciences.

The medicinal chemistry of piperazines: A review.

The versatile basic structure of piperazine allows for the development and production of newer bioactive molecules that can be used to treat a wide range of diseases. Piperazine derivatives are unique and can easily be modified for the desired pharmacological activity. The two opposing nitrogen atoms in a six-membered piperazine ring offer a large polar surface area, relative structural rigidity, and more acceptors and donors of hydrogen bonds. These properties frequently result in greater water solubility, oral bioavailability, and ADME characteristics, as well as improved target affinity and specificity. Various synthetic protocols have been reported for piperazine and its derivatives. In this review, we focused on recently published synthetic protocols for the synthesis of the piperazine and its derivatives. The structure-activity relationship concerning different biological activities of various piperazine-containing drugs has also been highlighted to provide a good understanding to researchers for future research on piperazines.