Impact of COVID-19 lockdown in Tamil Nadu: Benefits and challenges on environment perspective

Prior to COVID-19 lockdown in our country, the air around us was highly polluted due to emission of greenhouse gases for over centuries. Melting of glaciers and rising of the sea levels were evidenced as the alarming signs of Global warming. Environmental degradation was observed rapidly due to depletion and exploitation of natural resources like soil, water and air. But there are few changes observed in the environment after the country’s lockdown due to coronavirus pandemic. The effects of lockdown are also entwined with human and political effects such as uncontrollable public mobility, poor access to health care due to lack of sufficient medical facilities, unemployment, migrants’ crisis, starvation and prevailing poverty. However, apart from sufferings of entire country especially the people by social, economic and psychologic effects in day-to-day life, this lockdown has given to the nature the most optimistic scenarios in environment especially with enhanced air quality, cleaner water and undisturbed pristine forest. The present review brings out the actual picture of the eco-processes that reduced man-made pollution in air and water as well as disposal of domestic or biological waste along with societal implications after imposing lockdown in the state of Tamil Nadu

9-(2,4-Dichloro­phen­yl)-3,3,6,6-tetra­methyl-3,4,5,6-tetra­hydro-9H-xanthene-1,8(2H,7H)-dione

The title compound, C23H24Cl2O3, was synthesized by reaction of 2,4-dichloro­benzaldehyde and 5,5-dimethyl­cyclo­hexane-1,3-dione in ethyl­ene glycol. The central ring of the xanthene moiety is almost planar (with an r.m.s. deviation of 0.0268 Å from the least-squares plane) while the two outer rings, in a cis arrangement, display envelope conformations. The ring of the 2,4-dichloro­phenyl substituent is nearly perpendicular [85.89 (4)°] to the xanthene ring system

Post-acute sequelae of SARS-CoV-2 Delta variant infection: A report of three cases in a single family

Coronavirus disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that has resulted in global pandemic and crisis in health care system. Several studies have focused only on hospitalized patients with 30 to 90 days after one cycle of illness but post-acute sequelae of COVID-19 existing even after a year remains unclear. Moreover, long-term sequelae in outpatients have not been documented and henceforth myriad clinical sequelae in long haulers continue to evolve. In this study, we report three cases represents a single family presenting several post-acute sequelae one after the other extending beyond one year of recovery. To our knowledge such a case series has not been reported in earlier studies. Herein, we present the sequelae in various organs namely neuropsychiatric (tinnitus, anxiety, depression, insomnia, and posttraumatic stress disorder, cognitive decline), cardiovascular (tachycardia, bradycardia), gastrointestinal (appendicitis) and Dermatologic (erythematous rash and acne) besides ophthalmic manifestations (conjunctivitis and dry eyes) in Long-COVID-19 and recommend management strategies

1-(2-Naphth­yl)-3-phenyl-3-(4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C25H22N2OSe, the fused six-membered cyclo­hexene ring of the 4,5,6,7-tetra­hydro-1,2,3-benzoselenadiazole group adopts a near half-chair conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.004 Å). There are weak inter­molecular C—H⋯O and C—H⋯π inter­actions in the crystal structure. Inter­molecular π–π stacking is also observed between the naphthyl units, with a centroid–centroid distance of 3.529 (15) Å

3-(3-Chloro-2-hy­droxy­phen­yl)-1-phenyl-1H-pyrazole-4-carbaldehyde

In the title compound, C16H11ClN2O2, the pyrazole ring makes dihedral angles of 11.88 (13) and 22.33 (13)° with the 3-chloro-2-hy­droxy­benzene group and phenyl rings, respectively. The phenolic hy­droxy group forms an intra­molecular O—H⋯N hydrogen bond with the imine N atom of the pyrazole unit. The formyl group is virtually coplanar with the pyrazole ring [dihedral angle = 4.5 (19)°] and acts as an acceptor in an intra­molecular C—H⋯O hydrogen bond closing seven-membered ring. In the crystal, adjacent mol­ecules are linked through C—H⋯O hydrogen bonds into infinite chains along the b axis

Structure of Mycobacterium smegmatis single-stranded DNA-binding protein and a comparative study involving homologus SSBs: biological implications of structural plasticity and variability in quaternary association

The structure of Mycobacterium smegmatis single-stranded DNA-binding protein (SSB) has been determined using three data sets collected from related crystals. The structure is similar to that of its homologue from Mycobacterium tuberculosis, indicating that the clamp arrangement that stabilizes the dimer and the ellipsoidal shape of the tetramer are characteristic features of mycobacterial SSBs. The central OB fold is conserved in mycobacterial SSBs as well as those from Escherichia coli, Deinococcus radiodurans and human mitochondria. However, the quaternary structure exhibits considerable variability. The observed plasticity of the subunit is related to this variability. The crystal structures and modelling provide a rationale for the variability. The strand involved in the clamp mechanism, which leads to higher stability of the tetramer, appears to occur in all high-G+C Gram-positive bacteria. The higher stability is perhaps required by these organisms. The mode of DNA binding of mycobacterial SSBs is different from that of E. coli SSB partly on account of the difference in the shape of the tetramers. Another difference between the two modes is that the former contains additional ionic interactions and is more susceptible to salt concentration

Impact of COVID-19 lockdown in Tamil Nadu: Benefits and challenges on environment perspective

370-381Prior to COVID-19 lockdown in our country, the air around us was highly polluted due to emission of greenhouse gases for over centuries. Melting of glaciers and rising of the sea levels were evidenced as the alarming signs of Global warming. Environmental degradation was observed rapidly due to depletion and exploitation of natural resources like soil, water and air. But there are few changes observed in the environment after the country’s lockdown due to coronavirus pandemic. The effects of lockdown are also entwined with human and political effects such as uncontrollable public mobility, poor access to health care due to lack of sufficient medical facilities, unemployment, migrants’ crisis, starvation and prevailing poverty. However, apart from sufferings of entire country especially the people by social, economic and psychologic effects in day-to-day life, this lockdown has given to the nature the most optimistic scenarios in environment especially with enhanced air quality, cleaner water and undisturbed pristine forest. The present review brings out the actual picture of the eco-processes that reduced man-made pollution in air and water as well as disposal of domestic or biological waste along with societal implications after imposing lockdown in the state of Tamil Nadu

Multi-level scoring approach to discover multi-targeting potency of medicinal plant phytochemicals against protein targets in SARS-CoV-2 and human ACE-2 receptor

SARS-CoV-2 pandemic has become a major threat to human healthcare and world economy. Due to the rapid spreading and deadly nature of infection, we are in a situation to develop quick therapeutics to combat SARS-CoV-2. In this study, we have adopted a multi-level scoring approach to identify multi-targeting potency of bioactive compounds in selected medicinal plants and compared its efficacy with two reference drugs, Nafamostat and Acalabrutinib which are under clinical trials to treat SARS-CoV-2. In particular, we employ molecular docking and implicit solvent free energy calculations (as implemented in the Molecular Mechanics -Generalized Born Surface Area approach) and QM fragmentation approach for validating the potency of bioactive compounds from the selected medicinal plants against four different viral targets and one human receptor (Angiotensin-converting enzyme 2 -ACE-2) which facilitates the SARS-CoV-2entry into the cell. The protein targets considered for the study are viral 3CL main protease (3CLpro), papain-like protease (PLpro), RNA dependent RNA polymerase (RdRp), and viral spike protein-human hACE-2 complex (Spike:hACE2)including human protein target (hACE-2). Herein, thereliable multi-level scoring approach was used to validate the mechanism behind the multi-targeting potency of selected phytochemicals from medicinal plants. The present study evidenced that the phytochemicals Chebulagic acid, Stigmosterol, Repandusinic acid and Geranin exhibited efficient inhibitory activity against PLpro while Chebulagic acid was highly active against 3CLpro. Chebulagic acid andGeranin also showed excellent target specific activity against RdRp.Luteolin, Quercetin, Chrysoeriol and Repandusinic acid inhibited the interaction of viral spike protein with human ACE-2 receptor. Moreover Piperlonguminine and Piperine displayed significant inhibitory activity against human ACE-2 receptor. Therefore, the identified compounds namely Chebulagic acid, Geranin and Repandusinic acid can serve as potent multi-targeting phytomedicine for treating COVID-1

Structural Determination of Functional Units of the Nucleotide Binding Domain (NBD94) of the Reticulocyte Binding Protein Py235 of Plasmodium yoelii

Invasion of the red blood cells (RBC) by the merozoite of malaria parasites involves a large number of receptor ligand interactions. The reticulocyte binding protein homologue family (RH) plays an important role in erythrocyte recognition as well as virulence. Recently, it has been shown that members of RH in addition to receptor binding may also have a role as ATP/ADP sensor. A 94 kDa region named Nucleotide-Binding Domain 94 (NBD94) of Plasmodium yoelii YM, representative of the putative nucleotide binding region of RH, has been demonstrated to bind ATP and ADP selectively. Binding of ATP or ADP induced nucleotide-dependent structural changes in the C-terminal hinge-region of NBD94, and directly impacted on the RBC binding ability of RH.In order to find the smallest structural unit, able to bind nucleotides, and its coupling module, the hinge region, three truncated domains of NBD94 have been generated, termed NBD94(444-547), NBD94(566-663) and NBD94(674-793), respectively. Using fluorescence correlation spectroscopy NBD94(444-547) has been identified to form the smallest nucleotide binding segment, sensitive for ATP and ADP, which became inhibited by 4-Chloro-7-nitrobenzofurazan. The shape of NBD94(444-547) in solution was calculated from small-angle X-ray scattering data, revealing an elongated molecule, comprised of two globular domains, connected by a spiral segment of about 73.1 A in length. The high quality of the constructs, forming the hinge-region, NBD94(566-663) and NBD94(674-793) enabled to determine the first crystallographic and solution structure, respectively. The crystal structure of NBD94(566-663) consists of two helices with 97.8 A and 48.6 A in length, linked by a loop. By comparison, the low resolution structure of NBD94(674-793) in solution represents a chair-like shape with three architectural segments.These structures give the first insight into how nucleotide binding impacts on the overall structure of RH and demonstrates the potential use of this region as a novel drug target