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Background: The chemistry of organoselenium reagents provides an asset for organic synthesis. The versatility of these reagents as electrophiles and nucleophiles makes them one of the key components of organic synthesis. Various synthetic transformations such as oxyselenenylations, selenocyclization and selenoxide elimination have been successfully achieved using organoselenium reagents under mild reaction conditions. The presence of selenocysteine in a few mammalian enzymes was the key information for selenium chemists to explore the biochemistry of selenium compounds. Glutathione peroxidase (GPx), a mammalian selenoenzyme, is well known for maintaining redox equilibrium by detoxifying reactive oxygen species. Objective: The aim is to critically analyze the recent development and prospects of synthesis and antioxidant properties of organoselenium compounds. Method: In this review, we summarised research and review papers from the PubMed and Scopus databases. The primary themes were linked to the synthesis of organoselenium compounds and their capacity to maintain cellular redox equilibrium when exposed to oxidative stress. Result: The study reveals that diselenide compounds synthesised by various methods showed a better antioxidant activity profile compared to selenides. In a few cases, the activity was found better than the standard compound ebselen. Moreover, the synthesis and antioxidant activity of Selenium-based nanoparticles have been also included. Conclusion: In the past two decades, various biological properties of organoselenium compounds have been extensively studied, including the antioxidant properties. This review article will give insight into the synthesis of different types of recently synthesised organoselenium compounds. The review would be helpful to the researchers working in the field of medicinal chemistry in directing the synthesis of new organoselenium compounds as antioxidants.

The Vilsmeier–Haack reaction has historically been a topic of significant interest to organic chemists, and it continues to attract considerable attention. The reaction itself provides a facile route towards a large number of aromatic and heteroaromatic systems. The Vilsmeier–Haack reagent, generated from amides and halides, is found to be very important in organic synthesis. This account highlights recent developments in the synthetic utility of the Vilsmeier–Haack reagent.1 Introduction2 Formylation3 Formylation and Chlorination4 Formylation and Acetylation5 Chlorination6 ortho-Formylation7 Miscellaneous8 Conclusions

Since the start of COVID-19 pandemic, the definition of normal life has changed drastically. The number of cases of this pandemic is rising everyday across the globe. In this study, we propose a compartmental model, which considers the isolation factor of Coronavirus infected individuals. The model consists of five compartments: susceptible (S), exposed (E), Infected (I), Isolated (L) and recovered (R). We have estimated the parameters of the model system and the expression of the basic reproduction number \begin{document}$ R_0 $\end{document} using real data set. The exact value of the basic reproduction number is computed for India, Brazil and Peru. The local and global stability analysis of disease-free equilibrium and endemic equilibrium points is carried out. The forecasting of the pandemic is done using real data. It has been observed that to understand the pandemic the time frame has to be divided into small intervals as the parameters of the pandemic are changing with time. Within a time frame of approximately four months (i.e. from July to October 2020), the transmission rate of India has been reduced by approximately 84%. Whereas the transmission rate in Brazil and Peru has increased by 79% and 45% respectively. The sensitivity of various parameters involved in the model has been analyzed. We have presented a complete analysis to check the existence of backward bifurcation.

A number of organic transformations have been achieved using hypervalent iodine reagents under mild reaction conditions. The use of these reagents as chiral organocatalyst exhibited highly selective asymmetric reactions.

Abstract: The chemistry of hypervalent iodine reagents is now developed as an important tool of synthetic organic chemistry. These reagents play a key role in replacing the toxic heavy metal reagent because of their mild reaction condition and environmentally friendly nature. Mainly, these reagents were known for oxidative properties, but the scope of these reagents is not limited to oxidation reactions. In the past two decades, they have been used as versatile electrophiles in various key organic transformations. Recently, the demand for these reagents has increased drastically for green chemistry, mainly due to their application in catalysis. Hypervalent iodine reagents have been successfully used to develop various oxidative transformations such as the oxidation of different organic species, α-functionalization of carbonyl compounds, cyclization reactions, C-H activation reactions, lactonization and oxidative rearrangements. Moreover, the use of these reagents is not limited to general organic reactions but is successfully used to develop several stereoselective transformations by using chiral hypervalent iodine reagents. This review article highlights various acyclic and cyclic reactions where the hypervalent iodine reagents have been used as electrophiles.

The function of styryl acetate as a carbanion nucleophile source has been explored in the ring transformation reaction of 2H-pyranones. The ultrasound-assisted carbanion-induced ring transformation of 4-amino-6-aryl-3-cyano-2H-pyran-2-ones using (E)-styryl acetate in the presence of KOH and DMF at room temperature is presented as an alternative strategy for the synthesis of functionalized 1,2-teraryls in high yields. This metal-free methodology provides easy access to a series of 1,2-teraryls and features broad functional group tolerance and mild reaction condition. Single crystal X-ray diffraction analysis of 4-(piperidin-1-yl)-6-(thiophen-2-yl)-[1,1′-biphenyl]-3-carbonitrile indicated that the crystal belongs to monoclinic system with a P21 space group having twisted aryl rings.

Abstract: : Organoselenium chemistry has developed as an important tool in the field of synthetic and medicinal chemistry. Various organoselenium reagents have been developed and used successfully to achieve different organic transformations such as the selenocyclizations, oxyselenenylations and selenoxide eliminations etc. Additionally, the potential of organoselenium reagents is not limited their use as stoichiometric reagents but they have successfully used as organocatalyst in number of synthetic transformations. Various organic and inorganic oxidants have been identified as terminal oxidants to regenerate the active catalytic specie. In this review article, the recent progress of organoselenium reagents in catalysis is being highlighted along with their asymmetric variants.

Hypervalent iodine compounds as environmentally friendly and relatively inexpensive reagents have properties similar to transition metals. They are employed as alternatives to transition metal catalysts in organic synthesis as mild, nontoxic, selective and recyclable catalytic reagents. Formation of C-N, C-O, C-S, C-F and C-C bonds can be seamlessly accomplished by hypervalent iodine catalysed oxidative functionalisations. The aim of this review is to highlight recent developments in the utilisation of iodine(III) and iodine(V) catalysts in the synthesis of a wide range of organic compounds including chiral catalysts for stereoselective synthesis. Polymer-, magnetic nanoparticle- and metal organic framework-supported hypervalent iodine catalysts are also described.

The chemistry of hypervalent iodine reagents has emerged as an astonishing field in synthetic organic chemistry owing to its easy availability and benign environmental features. Hypervalent iodine reagents are mostly employed as alternatives in various metal-catalyzed reactions since they show similar reactivity to the transition metals, are less toxic, and less expensive. These reagents are often used as oxidants as well as electrophilic reagents in a number of organic transformations, such as oxidative functionalization, alpha C-H bond functionalization of carbonyl compounds, rearrangements, and cyclization reactions. Furthermore, the application of iodine(III) and iodine(V) reagents in various oxidative rearrangement processes generating a diverse array of molecules have been well explored. In this mini-review, the recent developments in the area of oxidative rearrangements, using hypervalent iodine reagents, have been covered.

African swine fever (ASF) is the most dreaded disease of pigs, which can cause mortality of up to 100%. Following disease outbreaks with high mortality in pigs in two states of north-east India, namely Arunachal Pradesh and Assam in early 2020, we confirmed the first occurrence of African swine fever (ASF) in domestic pigs in India by real-time PCR, virus isolation and nucleotide sequencing. Genetic analyses in three independent genomic regions (B646L gene encoding the p72 protein, E183L gene encoding the p54 protein and the central variable region (CVR) of B602L gene) showed that the Indian ASF viruses are similar to the post-2007-p72-genotype II viruses reported from Asia and Europe, suggesting the transboundary expansion of ongoing ASF outbreaks in the region.

Multiwall carbon nanotubes (MWNTs) decorated CdS nanocrystals have been synthesized by chemical method. Methylene blue dye as a probe has been used for determination of photo catalytic activity of CdS/MWNTs composites. Degradation of Methylene blue dye on CdS/MWNTs composites reveals that MWNTs could effectively increase the photocatalytic activity as well as rate of electron induced redox reaction of CdS nanocrystals. Structural, Optical and photocatalytic activity of MWNT-CdS composites have been characterized by X-ray Diffraction (XRD), UV–Vis Spectroscopy, Photoluminescence Spectroscopy (PL), and Scanning Electron Microscopy (SEM)

A simple yet innovative approach for the construction of multi-substituted allylbenzenes 14, 16 and 18 with ‘donor-acceptor’ functionalities has been delineated through base-mediated ring transformation of 6-aryl-2H-pyran-2-ones 13, 15 and 17 respectively with commercially available 5-hexen-2-one 11 as carbanion source. The reactions were carried out at room temperature without using any catalyst or organometallic reagents with excellent functional group tolerance. Moreover, the present method is possible alternate route to access allylbenzenes apart from usual metal-catalyzed cross-coupling reactions.

Present work describes the UV–Visible and FT-IR spectral behavior of highly functionalized diarylmethanes via theoretical investigations. Analyses of both theoretical and experimental UV data were in good agreement with the assigned bands. In addition, calculations pertaining to natural bond orbitals (NBOs) and mapped molecular electrostatic potential surface (MEPS) were also performed, revealing that the strongest hyperconjugative intramolecular interactions involves the π ⟶ π∗, LP ⟶ σ∗ and n→π* transitions in the D and A rings. Further, the theoretical vibrational analysis revealed several characteristic vibrations that may be used as a diagnostic tool for other diarylmethanes and also indicated that the experimental bands related to the nitrile group occur in regions lower than usual, which confirms high conjugation of the triple bond with the aromatic system. Molecular dynamics (MD) and molecular docking calculations were performed in order to evaluate the behavior of such molecules in aqueous medium and the pharmacological potential. Another interesting observation in this study is the HOMO–LUMO analysis, which showed that the global reactivity values changed according to the type of substituent groups.

A remarkable growth in hypervalent iodine-mediated oxidative transformations as stoichiometric reagents as well as catalysts have been well-documented due to their excellent properties, such as, mildness, easy handling, high selectivity, environmentally friendly nature, and high stability. This review aims at highlighting the asymmetric oxidative dearomatization reactions involving hypervalent iodine compounds. The present article summarizes asymmetric intra- and intermolecular dearomatization reactions using chiral hypervalent iodine reagents/catalysts as well as hypervalent iodine-mediated dearomatization reactions followed by desymmetrization.

The present study was planned to isolate Escherichia coli from pneumonic and septicemic sheep and goats and to determine antimicrobial resistance (AMR) patterns of the isolates and evaluate them for the presence of extended-spectrum s-lactamase (ESBL) using the phenotypic and molecular methods. Pneumonic lung tissues and heart blood samples were collected by performing necropsy on sheep (n = 96) and goats (n = 08). The samples were processed and used for bacterial isolation. E. coli isolates (n = 58) including 53 from 34 sheep and 5 from 3 goats were recovered and identified by the cultural and biochemical characteristics and 16S rRNA sequencing. The isolates were tested to ascertain AMR pattern, plasmid features, and ESBL production. The highest rate of resistance (65.5%) was recorded against amoxicillin, enrofloxacin, norfloxacin, and ofloxacin. Eighteen (31%) out of 58 isolates showed the ESBL phenotype by combination disk assay. There was a variability in the number (1-5) and size (2 to >20 kb) of plasmids among isolates. Polymerase chain reaction (PCR) amplification revealed the presence of blaH$_{TEM}$ (70.6%) and blaH$_{SHM}$(1.7%) genes. PCR specificity was confirmed by nucleotide sequencing. The present study indicates that the extraintestinal and multidrug-resistant (MDR) E. coli strains were associated with pneumonia and/or septicemia in sheep and goats. Therefore, thorough surveillance and monitoring of MDR bacteria are urgently needed to implement the infection control strategies and to restore the efficacy of available antibiotics.

A convenient approach for the synthesis of β-cyanoepoxides is illustrated by iodine(III)-catalyzed epoxidation of electron-deficient β-cyanostyrenes, wherein the active catalytic iodine(III) species was generated in situ. The epoxidation of β-cyanostyrenes was performed using 10 mol% PhI as precatalyst in the presence of 2.0 equivalents Oxone as an oxidant and 2.4 equivalents of TFA as an additive at room temperature under ultrasonic radiations. The β-cyanoepoxides were isolated in good to excellent yields in a short reaction time.

Pneumonia, a major sheep disease, causes high mortality among affected animals predominantly the lambs. It is caused by a number of microbes including Mannheimia haemolytica/Pasteurella multocida. It was aimed to explore the pathology in the lungs due to pneumonia, and to isolate and characterise the virulent M. haemolytica/P. multocida strains. The lung tissues and heart blood specimens were collected by necropsy of sheep (n = 96). These samples were used for isolation and characterisation of M. haemolytica/P. multocida. Moreover, the fresh and square-shaped lung pieces were also taken to perform the histopathological analysis. Grossly, the petechial and ecchymotic haemorrhages, congestion and consolidation in lung lobes were observed at necropsy. Pneumonia was diagnosed as acute fibrinous-bronchopneumonia (36), suppurative chronic bronchopneumonia (10), acute interstitial pneumonia (32) and acute pulmonary congestion (18) based on histological lesions. Bacterial isolation recovered M. haemolytica alone or along with P. multocida and/or Bibersteinia trehalosi identified by phenotypic characters and sequencing of 16S rRNA. Haemolytic colonies were documented to carry the PHSSA, plpE and Rpt2 genes. P. multocida identification at species level was carried out by KMT1 gene detection. These isolates were noted to carry the capsule types A (hyaD-hyaC gene) and D (dcbF gene) and outer membrane protein genes ompH and omp87. Sequencing revealed nucleotide variability in Rpt2, ompH and omp87 genes.We highlighted the occurrence of fatal ovine pneumonic pasteurellosis/mannheimiosis caused and/or complicated by virulent M. haemolytica/P. multocida strains.

Introduction Over half of patients that present with non-ST elevation acute coronary syndrome (NSTEACS) are older than 70 years, with these adults having a higher incidence of frailty. There is little data describing the angiographic features of the very oldest, frailest adults. We aimed to investigate angiographic and procedural characteristics in older adults with NSTEACS referred for PCI. Methods Patients aged ≥75 years presenting with NSTEACS to two tertiary centres (n=271) were recruited. Frailty was assessed using Fried Frailty Index and defined as frail (≥3 criteria met), pre-frail (1-2) and robust (0). Angiograms underwent quantitative and qualitative angiographic analysis, including SYNTAX score and residual SYNTAX score. The primary powered outcome was difference in incidence of complete revascularisation (defined as residual SYNTAX score = 0) between frailty phenotypes. Patients were followed up at one-year for incidence of composite major adverse cardiovascular events (MACE), defined as death, myocardial infarction, stroke or TIA, urgent revascularisation, or major bleeding. A secondary exploratory analysis was association between baseline SYNTAX and residual SYNTAX scores and one-year incidence of MACE. Multivariate logistic regression was performed for associations between frailty and SYNTAX scores. Cox proportional hazards modelling was performed for association between SYNTAX scores and one year MACE. Results Mean age was 80.5 ± 4.9 years, 60.5% were male. 53 patients (19.6%) were robust, 145 patients (53.5%) pre-frail and 73 patients (26.9%) frail. Baseline SYNTAX scores were split into tertiles: low (a score of 0–7), medium (7.5–15.5), and high (≥16) (table 1). Frail patients had an adjusted 2.67 increased odds (95% confidence interval CI 1.17–6.10, P=0.02) of being in the high tertile. Frail patients were more likely to have severe culprit lesion calcification (adjusted OR 5.13, 95% CI 1.59–16.5, P=0.006). Frailty phenotype did not impact the likelihood of culprit lesion PCI being performed (P=0.58). Frail patients had a lower mean improvement in culprit lesion diameter stenosis post-PCI compared to robust patients (-50.6%, 95% CI -45.7 – -55.6 vs. -58.6%, 95% CI -53.5 – -63.7, P=0.042). There were no differences in rate of procedural complications between frailty phenotypes (P>0.05). There was no relationship between frailty and incidence of complete revascularisation (adjusted OR 0.96, 95% CI 0.36–2.56, P=0.94). There was no exploratory adjusted relationship between one-year MACE and either baseline SYNTAX score (HR 1.10, 95% CI 0.59–2.04, P=0.77) or residual SYNTAX score (HR 1.36, 95% CI 0.68–2.71, P=0.38). Conclusions Frail adults presenting with NSTEACS have more adverse baseline angiographic characteristics, independent of age. Despite this, frail adults were just as likely to achieve complete revascularisation. In an exploratory analysis, baseline or residual SYNTAX score did not predict MACE at one year. Conflict of Interest No conflicts

Pyranones are important scaffolds in synthetic and natural product chemistry, with the 2H-pyran-2-one and 4H-pyran-4-one structural motifs commonly found in naturally occurring compounds. A variety of metal-free and metal-catalyzed approaches have been used to construct pyranone architectures. Furthermore, 2H-pyran-2-one ring systems can undergo a range of transformations such as electrophilic reactions, nucleophilic reactions, ring contractions, photochemical reactions, and cycloaddition reactions. This is an update to Section 14.3, and covers the major developments in the synthesis and reactions of pyranones and pyranthiones achieved since 2003.

Pasteurella multocida is one of the bacterial species involved in cases of ovine respiratory complex that has been implicated to cause significant economic losses in sheep production system worldwide. The present study was undertaken with the aim of evaluating a SYBR Green dye based real time PCR assay targeting KMT1 gene for the detection of P. multocida. The analytical specificity and sensitivity of the PCR primers were evaluated. The test showed ten-fold more sensitivity than conventional PCR and detected down to 275.5 fg/ µl of genomic DNA concentration, equivalent to 100 copies of KMT1 gene of P. multocida. The real-time PCR was found to be specific for KMT1 gene of P. multocida, as no cross reactivity was detected with a variety of known bacterial isolates. A total of 52 ovine lung tissue samples were screened for P. multocida, which showed improved level of detection as compared to conventional PCR. It is concluded that, this assay may be used as a valuable diagnostic tool for the rapid and specific detection of P. multocida. By virtue of its high throughput format and its ability to accurately identify as well as quantify the bacterial DNA, the method may be useful in large scale epidemiological studies and clarification of pathogenesis.

The present study was planned to detect the genes encoding carbapenemases, ESBLs and class 1 integron-integrase among bacteria obtained from retail goat meat. Fermenting and non-fermenting bacterial isolates (n = 57), recovered from 61 goat meat samples, were identified by 16S rRNA gene sequencing. Antimicrobial susceptibility of isolates was tested by the broth dilution method using ceftazidime, cefotaxime, meropenem and imipenem. Plasmids were isolated and tested for their physical characters. Plasmids were subjected to screening of carbapenemase, ESBL and intI1 gene. Conjugation assay was performed using blaNDM -positive isolates as the donor, and Escherichia coli HB101 as the recipient. Isolates showed the high rates of resistance to ceftazidime (77·2%), cefotaxime (70·2%), meropenem (22·8%) and imipenem (17·5%). They showed variability in number and size (~1 to >20 kb) of plasmids. Among all, 1, 4, 13 and 31 isolates showed the blaKPC , blaNDM , blaSHV and blaTEM genes, respectively. The blaKPC-2 gene was observed in one E. coli isolate. The blaNDM-1 gene was detected in Stenotrophomonas maltophilia (n = 2), Acinetobacter baumannii (n = 1) and Ochrobactrum anthropi (n = 1) isolates. These isolates co-harboured the blaTEM and blaSHV genes. The intI1 gene was detected in 22 (38·6%) isolates, and 16 of these isolates showed the carbapenemase and/or ESBL genes. The conjugative movement of blaNDM gene could not be proved after three repetitive mating experiments. The presence of genes encoding carbapenemases and ESBLs in bacteria from goat meat poses public health risks.

A simple yet convenient nucleophile-induced synthetic route for the construction of thermally stable fluorescent functionalized stilbenes from α-pyranones and aryl ketones has been delineated. The nucleophile-induced base encourage synthetic protocol was performed under mild conditions without harming the environment and products were achieved in good yields. The synthesized stilbenes showed amazing emission properties and good thermal stability. Synthesized products displayed interesting positive solvatochromism in different solvents based on variation in polarity.

An efficient metal-free approach for the synthesis of functionalized biaryl-cored diarylmethanes is described by the ring transformation of 2H-pyran-2-ones using 4-phenylbutan-2-one as carbanion source. Moreover, 2H-pyran-2-ones were reacted with 1,3-diphenylacetone in the presence of base to achieve functionalized teraryl-cored diarylmethanes. All the ring transformation reactions were performed under mild reaction conditions to afford the biaryl- and teraryl-cored reaction products in high yields.

An alternative route for the synthesis of 2-arylbenzofurans is described by iodine(III)-catalyzed oxidative cyclization of 2-hydroxystilbenes using 10 mol% (diacetoxyiodo)benzene [PhI(OAc)2] as catalyst in the presence of m-chloroperbenzoic acid. The 2-arylbenzofurans were isolated in good to excellent yields.

Hypervalent iodine reagents have been developed as highly valuable reagents in synthetic organic chemistry during the past few decades. These reagents have been identified as key replacements of various toxic heavy metals in organic synthesis. Various synthetically and biologically important scaffolds have been developed using hypervalent iodine reagents either in stoichiometric or catalytic amounts. In addition, hypervalent iodine reagents have been employed for the synthesis of spirocyclic scaffolds via dearomatization processes. In this review, various approaches for the synthesis of spirocyclic scaffolds using hypervalent iodine reagents are covered including their stereoselective synthesis. Additionally, the applications of these reagents in natural product synthesis are also covered.

An elegant approach for the rapid synthesis of β-cyanoepoxides 3 by the epoxidation of β-cyanostyrenes 1 with PIDA 2a is described. The epoxidation of β-cyanostyrenes 1 was performed with 1.2 equiv. of PIDA 2a in MeCN-H2O (1:1) at room temperature in ultrasonic bath. The epoxidation reactions were completed in short reaction time and β-cyanoepoxides 3 were isolated in 69–94% yields.

A metal-free, ultrasound-assisted approach for the synthesis of highly functionalized 2-tetralones in high yields is described. The process involves ring transformation of 2H-pyran-2-ones with the spirocyclic ketone 1,4-cyclohexandione monoethylene ketal to yield spiro­cyclic ketals and subsequent acid-mediated hydrolysis. This protocol is free from any organometallic reagents, is economical and tolerates a wide range of functional groups.