THE QUEST FOR STABLE BOROZENE CORE IN MAIN-GROUP CAPPED INVERSE SANDWICH COMPLEXES, [(HE)2B6H6]2- (E=B, Al, Ga, In, and Tl).

The ubiquitous chemistry of benzene led us to explore ways to stabilise analogous borozene, by capping them with appropriate groups. The mismatch in overlap of ring-cap fragment molecular orbitals in [(HB)2B6H6]2- is overcome by replacing the two BH caps with  higher congeners of boron. We calculated the relative energies of all the polyhedral structural candidates for [(HE)2B6H6]2- (E = Al-Tl) and found hexagonal bipyramid (HBP) to be more stable with Al-H caps. A global minimum search also gives HBP as the most stable structure for [Al2B6H8]2-. The capped B6H6 ring in [(HAl)2B6H6]2- has aromaticity comparable to that of benzene.

Pyrano[2,3-c]pyrazole fused spirooxindole-linked 1,2,3-triazoles as antioxidant agents: Exploring their utility in the development of antidiabetic drugs via inhibition of α-amylase and DPP4 activity.

Environment-benign, multicomponent synthetic methodologies are vital in modern pharmaceutical research and facilitates multi-targeted drug development via synergistic approach. Herein, we reported green and efficient synthesis of pyrano[2,3-c]pyrazole fused spirooxindole linked 1,2,3-triazoles using a tea waste supported copper catalyst (TWCu). The synthetic approach involves a one-pot, five-component reaction using N-propargylated isatin, hydrazine hydrate, ethyl acetoacetate, malononitrile/ethyl cyanoacetate and aryl azides as model substrates. Mechanistically, the reaction was found to proceed via in situ pyrazolone formation followed by Knoevenagel condensation, azide alkyne cycloaddition and Michael's addition reactions. The molecules were developed using structure-based drug design. The primary goal is to identifying anti-oxidant molecules with potential ability to modulate α-amylase and DPP4 (dipeptidyl-peptidase 4) activity. The anti-oxidant analysis, as determined via DPPH, suggested that the synthesized compounds, A6 and A10 possessed excellent anti-oxidant potential compared to butylated hydroxytoluene (BHT). In contrast, compounds A3, A5, A8, A9, A13, A15, and A18 were found to possess comparable anti-oxidant potential. Among these, A3 and A13 possessed potential α-amylase inhibitory activity compared to the acarbose, and A3 further emerged as dual inhibitors of both DPP4 and α-amylase with anti-oxidant potential. The relationship of functionalities on their anti-oxidant and enzymatic inhibition was explored in context to their SAR that was further corroborated using in silico techniques and enzyme kinetics.

Comprehensive laboratory diagnosis of Fanconi anaemia: comparison of cellular and molecular analysis.

BACKGROUND: Fanconi anaemia (FA) is a rare inherited bone marrow failure disease caused by germline pathogenic variants in any of the 22 genes involved in the FA-DNA interstrand crosslink (ICL) repair pathway. Accurate laboratory investigations are required for FA diagnosis for the clinical management of the patients. We performed chromosome breakage analysis (CBA), FANCD2 ubiquitination (FANCD2-Ub) analysis and exome sequencing of 142 Indian patients with FA and evaluated the efficiencies of these methods in FA diagnosis. METHODS: We performed CBA and FANCD2-Ub analysis in the blood cells and fibroblasts of patients with FA. Exome sequencing with improved bioinformatics to detect the single number variants and CNV was carried out for all the patients. Functional validation of the variants with unknown significance was done by lentiviral complementation assay. RESULTS: Our study showed that FANCD2-Ub analysis and CBA on peripheral blood cells could diagnose 97% and 91.5% of FA cases, respectively. Exome sequencing identified the FA genotypes consisting of 45 novel variants in 95.7% of the patients with FA. FANCA (60.2%), FANCL (19.8%) and FANCG (11.7%) were the most frequently mutated genes in the Indian population. A FANCL founder mutation c.1092G>A; p.K364=was identified at a very high frequency (~19%) in our patients. CONCLUSION: We performed a comprehensive analysis of the cellular and molecular tests for the accurate diagnosis of FA. A new algorithm for rapid and cost-effective molecular diagnosis for~90% of FA cases has been established.

Electro-organic synthesis of C-5 sulfenylated amino uracils: Optimization and exploring topoisomerase-I based anti-cancer profile.

Cancer is spreading worldwide and is one of the leading causes of death. The use of existing chemotherapeutic agents is frequently limited due to side effects. As a result, it is critical to investigate new agents for cancer treatment. In this context, we developed an electrochemical method for the synthesis of a series of thiol-linked pyrimidine derivatives (3a-3p) and explored their anti-cancer potential. The biological profile of the synthesized compounds was evaluated against breast (MDAMB-231 and MCF-7) and colorectal (HCT-116) cancer cell lines. 3b and 3d emerged to be the most potent agents, with IC50 values ranging between 0.98 to 2.45 µM. Target delineation studies followed by secondary anticancer parameters were evaluated for most potent compounds, 3b and 3d. The analysis revealed compounds possess DNA intercalation potential and selective inhibition towards human topoisomerase (hTopo1). The analysis was further corroborated by DNA binding studies and in silico-based molecular modeling studies that validated the intercalating binding mode between the compounds and the DNA.

Pn Ring Size Dependence on NHC-Induced Ring Contraction Reactions of [CoCp‴(η4-P4)], [Ta(CO)2Cp″(η4-P4)], and [FeCp*(η5-P5)]: A DFT Study.

The facile ring contraction of [CoCp‴(η4-P4)] and [Ta(CO)2Cp″(η4-P4)] to [CoCp‴(η3-P3)][(MeNHC)2P] and [Ta(CO)2Cp″(η3-P3)] [(MeNHC)2P] induced by MeNHC and the absence of the ring contraction of [FeCp*(η5-P5)] under the same conditions are studied by density functional theory (DFT) computations. The latter is estimated to be thermodynamically the least favorable reaction and also has a very high energy barrier. The similar strain energies of P3 and P4 rings and the lower strain energy of the P5 ring play a decisive role in the ring contraction capability of these [TM-cyclo-Pn] complexes. Theoretical approaches involving NBO and IBO analysis have been employed to provide a qualitative picture of the overall reactions. The role of substituents and the nature of transition metals in determining the energetics of these reactions has also been studied and an isolobal perspective on these systems affords a simplified picture.

Correction: Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis.

Correction for 'Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis' by Elagandhula Sathish et al., Org. Biomol. Chem., 2022, 20, 4746-4752, https://doi.org/10.1039/D2OB00467D.

Pd-Catalysed [3 + 2]-cycloaddition towards the generation of bioactive bis-heterocycles/identification of COX-2 inhibitors via in silico analysis.

In the current research, we envisaged the synthesis of bis-heterocycles containing the dihydroisoxazole ring by [3 + 2] cycloaddition of VECs (vinyl ethylene carbonates) and nitrile oxides, assisted by a Pd catalyst. Herein we explored hydroximoyl chlorides as versatile precursors for the in situ generation of nitrile oxides that were exploited to achieve the cycloaddition reaction on a vinyl group of VECs to generate bis-heterocycles. In silico-based studies of bis-heterocycles on the cyclooxygenase (COX) enzyme displayed selective COX-2 inhibition.

Design, synthesis and anticancer activity of 2-arylimidazo[1,2-a]pyridinyl-3-amines.

A series of imido-heterocycle compounds were designed, synthesized, characterized, and evaluated for the anticancer potential using breast (MCF-7 and MDA-MB-231), pancreatic (PANC-1), and colon (HCT-116 and HT-29) cancer cell lines and normal cells, while normal cells showed no toxicity. Among the screened compounds, 4h exhibited the best anticancer potential with IC50 values ranging from 1 to 5.5 µM. Compound 4h caused G2/M phase arrest and apoptosis in all the cell lines except MDA-MB-231 mammosphere formation was inhibited. In-vitro enzyme assay showed selective topoisomerase IIα inhibition by compound 4h, leading to DNA damage as observed by fluorescent staining. Cell signalling studies showed decreased expression of cell cycle promoting related proteins while apoptotic proteins were upregulated. Interestingly MDA-MB-231 cells showed only cytostatic effects upon treatment with compound 4h due to defective p53 status. Toxicity study using overexpression of dominant-negative mutant p53 in MCF-7 cells (which have wild type functional p53) showed that anticancer potential of compound 4h is positively correlated with p53 expression.

Epidemiology, clinical presentation and management of COVID-19 associated mucormycosis: A single centre experience from Pune, Western India.

BACKGROUND: The second COVID-19 wave in India has been associated with an unprecedented increase in cases of COVID-19 associated mucormycosis (CAM), mainly Rhino-orbito-cerebral mucormycosis (ROCM). METHODS: This retrospective cohort study was conducted at Noble hospital and Research Centre (NHRC), Pune, India, between 1 April, 2020, and 1 August, 2021, to identify CAM patients and assess their management outcomes. The primary endpoint was incidence of all-cause mortality due to CAM. RESULTS: 59 patients were diagnosed with CAM. Median duration from the first positive COVID-19 RT PCR test to diagnosis of CAM was 17 (IQR: 12,22) days. 90% patients were diabetic with 89% having uncontrolled sugar level (HbA1c >7%). All patients were prescribed steroids during treatment for COVID-19. 56% patients were prescribed steroids for non-hypoxemic, mild COVID-19 (irrational steroid therapy), while in 9%, steroids were prescribed in inappropriately high dose. Patients were treated with a combination of surgical debridement (94%), intravenous liposomal Amphotericin B (91%) and concomitant oral Posaconazole (95.4%). 74.6% patients were discharged after clinical and radiologic recovery while 25.4% died. On relative risk analysis, COVID-19 CT severity index ≥18 (p = .017), presence of orbital symptoms (p = .002), presence of diabetic ketoacidosis (p = .011) and cerebral involvement (p = .0004) were associated with increased risk of death. CONCLUSIONS: CAM is a rapidly progressive, angio-invasive, opportunistic fungal infection, which is fatal if left untreated. Combination of surgical debridement and antifungal therapy leads to clinical and radiologic improvement in majority of cases.

In Vivo Anticancer Evaluation of 6b, a Non-Covalent Imidazo[1,2-a]quinoxaline-Based Epidermal Growth Factor Receptor Inhibitor against Human Xenograft Tumor in Nude Mice.

Tyrosine kinase inhibitors are validated therapeutic agents against EGFR-mutated non-small cell lung cancer (NSCLC). However, the associated critical side effects of these agents are inevitable, demanding more specific and efficient targeting agents. Recently, we have developed and reported a non-covalent imidazo[1,2-a]quinoxaline-based EGFR inhibitor (6b), which showed promising inhibitory activity against the gefitinib-resistant H1975(L858R/T790M) lung cancer cell line. In the present study, we further explored the 6b compound in vivo by employing the A549-induced xenograft model in nude mice. The results indicate that the administration of the 6b compound significantly abolished the growth of the tumor in the A549 xenograft nude mice. Whereas the control mice bearing tumors displayed a declining trend in the survival curve, treatment with the 6b compound improved the survival profile of mice. Moreover, the histological examination showed the cancer cell cytotoxicity of the 6b compound was characterized by cytoplasmic destruction observed in the stained section of the tumor tissues of treated mice. The immunoblotting and qPCR results further signified that 6b inhibited EGFR in tissue samples and consequently altered the downstream pathways mediated by EGFR, leading to a reduction in cancer growth. Therefore, the in vivo findings were in corroboration with the in vitro results, suggesting that 6b possessed potential anticancer activity against EGFR-dependent lung cancer. 6b also exhibited good stability in human and mouse liver microsomes.

Hexagonal Planar [B6 H6 ] within a [B6 H12 ] Borate Complex: Structure and Bonding of [(Cp*Ti)2 (µ-ɳ6 : ɳ6 -B6 H6 )(µ-H)6 ].

Isolation of planar [B6 H6 ] is a long-awaited goal in boron chemistry. Several attempts in the past to stabilize [B6 H6 ] were unsuccessful due to the domination of polyhedral geometries. Herein, we report the synthesis of a triple-decker sandwich complex of titanium [(Cp*Ti)2 (µ-η6 : η6 -B6 H6 )(µ-H)6 ] (1), which features the first-ever experimentally achieved nearly planar six-membered [B6 H6 ] ring, albeit within a [B6 H12 ] borate. The small deviation from planarity is a direct consequence of the predicted structural pattern of the middle ring in 24 Valence Electron Count (VEC) triple-decker complexes. The large ring size of [B6 H6 ] in 1 brings the metal-metal distance into the bonding range. However, significant electron delocalization from the M-M bonding orbital to the bridging hydrogen and B-B skeleton in the middle decreases its bond strength.

Noncanonical Cell Death Induction by Reassortant Reovirus.

Triple-negative breast cancer (TNBC) constitutes 10 to 15% of all breast cancer and is associated with worse prognosis than other subtypes of breast cancer. Current therapies are limited to cytotoxic chemotherapy, radiation, and surgery, leaving a need for targeted therapeutics to improve outcomes for TNBC patients. Mammalian orthoreovirus (reovirus) is a nonenveloped, segmented, double-stranded RNA virus in the Reoviridae family. Reovirus preferentially kills transformed cells and is in clinical trials to assess its efficacy against several types of cancer. We previously engineered a reassortant reovirus, r2Reovirus, that infects TNBC cells more efficiently and induces cell death with faster kinetics than parental reoviruses. In this study, we sought to understand the mechanisms by which r2Reovirus induces cell death in TNBC cells. We show that r2Reovirus infection of TNBC cells of a mesenchymal stem-like (MSL) lineage downregulates the mitogen-activated protein kinase/extracellular signal-related kinase pathway and induces nonconventional cell death that is caspase-dependent but caspase 3-independent. Infection of different MSL lineage TNBC cells with r2Reovirus results in caspase 3-dependent cell death. We map the enhanced oncolytic properties of r2Reovirus in TNBC to epistatic interactions between the type 3 Dearing M2 gene segment and type 1 Lang genes. These findings suggest that the genetic composition of the host cell impacts the mechanism of reovirus-induced cell death in TNBC. Together, our data show that understanding host and virus determinants of cell death can identify novel properties and interactions between host and viral gene products that can be exploited for the development of improved viral oncolytics.IMPORTANCE TNBC is unresponsive to hormone therapies, leaving patients afflicted with this disease with limited treatment options. We previously engineered an oncolytic reovirus (r2Reovirus) with enhanced infective and cytotoxic properties in TNBC cells. However, how r2Reovirus promotes TNBC cell death is not known. In this study, we show that reassortant r2Reovirus can promote nonconventional caspase-dependent but caspase 3-independent cell death and that the mechanism of cell death depends on the genetic composition of the host cell. We also map the enhanced oncolytic properties of r2Reovirus in TNBC to interactions between a type 3 M2 gene segment and type 1 genes. Our data show that understanding the interplay between the host cell environment and the genetic composition of oncolytic viruses is crucial for the development of efficacious viral oncolytics.

Metal-Stabilized [B8 H8 ]2- Derivatives with Dodecahedral Structure in the Solid and Solution States: [(Cp2 MBH3 )2 B8 H6 ] (Cp=η5 -C5 H5 ; M=Zr (1-Zr) and Hf (1-Hf)).

Despite the synthesis and structural characterization of closo-hydroborate dianions, [Bn Hn ]2- (n=6-12) more than 50 years ago, some ambiguity remains about the structure of [B8 H8 ]2- . Although the solid-state structure of [B8 H8 ]2- was established by single-crystal X-ray studies in 1969, fast rearrangements in solution at accessible temperatures prevented its detailed characterization. We therefore stabilized a derivative of [B8 H8 ]2- by using Cp2 MBH3 and structurally characterized two new octaborane analogues, [(Cp2 MBH3 )2 B8 H6 ] (Cp=η5 -C5 H5 ; M=Zr (1-Zr) and Hf (1-Hf)), so that the dynamics of the B8 skeleton were arrested. The solid-state structures of both 1-Zr and 1-Hf comprise a dodecahedron core protected by {Cp2 MBH3 } moieties on both sides of the cluster. Spectroscopic characterization (11 B NMR) validates the intactness of the B8 dodecahedron core in solution as well. Theoretical calculations establish that the two exo-{Cp2 MBH3 } fragments provide structural and electronic structural stability to the B8 core and its intact dodecahedral dianionic nature. Furthermore, we propose isodesmic equations for the formation of higher analogues of the Bn core (n>8) guarded by different group 4 transition metals. Our analysis suggests that, as we move to higher polyhedra (n>10), the formation becomes unfavourable irrespective of metal.

Design, synthesis, biological evaluation of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehydes as non-purine xanthine oxidase inhibitors: Tracing the anticancer mechanism via xanthine oxidase inhibition.

Xanthine oxidase (XO) has been primarily targeted for the development of anti-hyperuriciemic /anti-gout agents as it catalyzes the conversion of xanthine and hypoxanthine into uric acid. XO overexpression in various cancer is very well correlated due to reactive oxygen species (ROS) production and metabolic activation of carcinogenic substances during the catalysis. Herein, we report the design and synthesis of a series of 3,5-diaryl-4,5-dihydro-1H-pyrazole carbaldehyde derivatives (2a-2x) as xanthine oxidase inhibitors (XOIs). A docking model was developed for the prediction of XO inhibitory activity of our novel compounds. Furthermore, our compounds anticancer activity results in low XO expression and XO-harboring cancer cells both in 2D and 3D-culture models are presented and discussed. Among the array of synthesized compounds, 2b and 2m emerged as potent XO inhibitors having IC50 values of 9.32 ± 0.45 µM and 10.03 ± 0.43 µM, respectively. Both compounds induced apoptosis, halted the cell cycle progression at the G1 phase, elevated ROS levels, altered mitochondrial membrane potential, and inhibited antioxidant enzymes. The levels of miRNA and expression of redox sensors in cells were also altered due to increase oxidative stress induced by our compounds. Compounds 2b and 2m hold a great promise for further development of XOIs for the treatment of XO-harboring tumors.

Design and Synthesis of Non-Covalent Imidazo[1,2-a]quinoxaline-Based Inhibitors of EGFR and Their Anti-Cancer Assessment.

A series of 30 non-covalent imidazo[1,2-a]quinoxaline-based inhibitors of epidermal growth factor receptor (EGFR) were designed and synthesized. EGFR inhibitory assessment (against wild type) data of compounds revealed 6b, 7h, 7j, 9a and 9c as potent EGFRWT inhibitors with IC50 values of 211.22, 222.21, 193.18, 223.32 and 221.53 nM, respectively, which were comparable to erlotinib (221.03 nM), a positive control. Furthermore, compounds exhibited excellent antiproliferative activity when tested against cancer cell lines harboring EGFRWT; A549, a non-small cell lung cancer (NSCLC), HCT-116 (colon), MDA-MB-231 (breast) and gefitinib-resistant NSCLC cell line H1975 harboring EGFRL858R/T790M. In particular, compound 6b demonstrated significant inhibitory potential against gefitinib-resistant H1975 cells (IC50 = 3.65 µM) as compared to gefitinib (IC50 > 20 µM). Moreover, molecular docking disclosed the binding mode of the 6b to the domain of EGFR (wild type and mutant type), indicating the basis of inhibition. Furthermore, its effects on redox modulation, mitochondrial membrane potential, cell cycle analysis and cell death mode in A549 lung cancer cells were also reported.

E-pharmacophore guided discovery of pyrazolo[1,5-c]quinazolines as dual inhibitors of topoisomerase-I and histone deacetylase.

In the quest to ameliorate the camptothecin (CPT) downsides, we expedite to search for stable non-CPT analogues among 11 motifs of pyrazoloquinazolines reported. E-pharmacophore drug design approach helped filtering out pyrazolo[1,5-c]quinazolines as Topoisomerase I (TopoI) 'interfacial' inhibitors. Three compounds, 3c, 3e, and 3l were shown to be potent non-intercalating inhibitors of TopoI specifically and showed cancer cell-specific cytotoxicity in lung, breast and colon cancer cell lines. The compounds induced cell cycle arrest at S-phase, mitochondrial cell death pathway and modulated oxidative stress in cancer cells. Furthermore, a preliminary study was conducted to explore the feasibility of these compounds to be developed as dual TopoI-HDAC1 (histone deacetylase 1) inhibitors (4a) to combat resistance. Compound 4a was found to possess dual inhibitory capabilities in-vitro. Cytotoxic potential of 4a was found to be significantly higher than parent compound in 2D as well as 3D cancer cell models. Probable binding modes of 4a with TopoI and HDAC1 active sites were examined by molecular modelling.

Pd-Catalyzed Four-Component Sequential Reaction Delivers a Modular Fluorophore Platform for Cell Imaging.

A Pd-catalyzed cascade reaction of four versatile privileged synthons is described. The sequential reaction involves the formation of five new chemical bonds by concatenating three distinct chemical steps. One of the derivatives exhibited absorption in the visible region, fluorescence with a high quantum yield, and excellent photostability. Its application is explored in live cell imaging, which exhibited cytoplasmic and mitochondrial specific staining with no toxicity.

Nano-Co-Delivery of Berberine and Anticancer Drug Using PLGA Nanoparticles: Exploration of Better Anticancer Activity and In Vivo Kinetics.

PURPOSE: Combinatorial approach can be beneficial for cancer treatment with better patient recovery. Co-delivery of natural and synthetic anticancer drug not only valuable to achieve better anticancer effectivity but also to ascertain toxicity. This study was aimed to co-deliver berberine (natural origin) and doxorubicin (synthetic origin) utilizing conjugation/encapsulation strategy through poly (lactic-co-glycolic acid) (PLGA) nanoparticles. METHODS: Doxorubicin was efficiently conjugated to PLGA via carbodiimide chemistry and the PLGA-doxorubicin conjugate (PDC) was used for encapsulation of berberine (PDBNP). RESULTS: Significant anti-proliferative against MDA-MB-231 and T47D breast cancer cell lines were observed with IC50 of 1.94 ± 0.22 and 1.02 ± 0.36 µM, which was significantly better than both the bio-actives (p < 0.05). The ROS study revealed that the PDBNP portrayed the slight increase in the reactive oxygen species (ROS) pattern in MDA-MB-231 cell line in a dose-dependent manner, while in T47D cells, no significant change in ROS was seen. PDBNP exhibits significant alteration (depolarization) in mitochondrial membrane permeability and arrest of cell cycle progression at sub G1 phase while the Annexin V/PI assay followed by confocal microscopy resulted into cell death mode to be because of necrosis against MDA-MB-231 cells. In vivo studies in Sprague Dawley rats revealed almost 14-fold increase in half life and a significant increase in plasma drug concentration. CONCLUSION: The overall approach of PLGA based co-delivery of doxorubicin and berberine witnessed synergetic effect and reduced toxicity as evidenced by preliminary toxicity studies.

Exploration of Pd-catalysed four-component tandem reaction for one-pot assembly of pyrazolo[1,5-c]quinazolines as potential EGFR inhibitors.

A series of pyrazolo[1,5-c]quinazolines as EGFR inhibitors was designed and synthesized by highly efficient and novel multicomponent route involving Pd-catalyzed tandem one-pot four-component reaction. The reaction proceeds with good functional group tolerance under a simple condition with excellent regioselectivity and high efficiency. Target compounds were screened against cancer cell lines MDA-MB-231, A549 and H1299. Of these, 9b and 10b exhibited superior anticancer activity (IC50 < 2.5 µM) to erlotinib and gefitinib. Synthetics were able to inhibit EGFR mediated kinase activity, induced ROS in cancer cells promoting mitochondrial mediated apoptosis via halting cell cycle progression at G1 phase.

Toward an Understanding of Structural Insights of Xanthine and Aldehyde Oxidases: An Overview of their Inhibitors and Role in Various Diseases.

Almost all drug molecules become the substrates for oxidoreductase enzymes, get metabolized into more hydrophilic products and eliminated from the body. These metabolites sometime may be more potent, active, inactive, or toxic in nature compared to parent molecule. Xanthine oxidoreductase and aldehyde oxidase belong to molybdenum containing family and are well characterized for their structures and functions, in particular to their ability to oxidize/hydroxylate the xenobiotics. Their upregulated clinical levels causing oxidative stress are associated with pathways either directly involved in the progression of diseases, gout, or indirectly with the succession of other diseases such as diabetes, cancer, etc. Herein, we have put forth a comprehensive review on the xanthine and aldehyde oxidases pertaining to their structures, functions, pathophysiological role, and a comparative analysis of structural insights of xanthine and aldehyde oxidases' binding domains with endogenous ligands or inhibitors. Though both the enzymes are molybdenum containing and are likely to share some common pathways and interact with inhibitors in a similar manner but we have focused on structural prerequisites for inhibitor specificity to both the enzymes keeping in view of the existing X-ray structures. This review also provides futuristic implications in the design of inhibitors derived from inorganic complexes or small organic molecules considering the spatial features and structural insights of both the enzymes.