Enhancement of apixaban's solubility and dissolution rate by inclusion complex (ß-cyclodextrin and hydroxypropyl ß-cyclodextrin) and computational calculation of their inclusion complexes.

Background and Purpose: Apixaban (AP) is a factor X inhibitor, an orally active drug that inhibits blood coagulation for better prevention of venous thromboembolism. It has poor solubility, dissolution rate and low bioavailability. The aim of this study was to improve the aqueous solubility and dissolution rate of oral AP as a step to enhance its bioavailability by preparing it as an inclusion complex with beta- and hydroxy propyl beta-cyclodextrin. Experimental Approach: A simple, rapid method of analysis of AP was developed using ultraviolet spectrophotometry (UV) and partially validated in terms of linearity, precision and accuracy, recovery, and robustness. AP was prepared as a complex with beta cyclodextrin (ßCD) and hydroxy propyl beta cyclodextrin (HPßCD) in weight ratios 1:1, 1:2, and 1:3 by kneading, solvent evaporation and spray drying methods and characterized by Fourier transfer infra-red (FTIR), differential scanning calorimetry (DSC), and percent drug content in each of the prepared complex. Using the computer simulation, the interactions of AP with ßCD and HPßCD were investigated. Key Results: The phase solubility study showed that the solubility of AP was greatly enhanced from 54×10-3 mmol /L to 66 mmol/L using HPßCD with acceptable stability constant. Computer docking supports the formation of a stable 1:1 complex between AP and CD's. The dissolution test results showed that the complex gave a significantly higher percentage of drug release (95%) over one hour compared to the free AP (60%) (p<0.05). Conclusion: AP- HPßCD complex in the ratio of 1:2 (w/w) can significantly improve the solubility and in vitro dissolution rate of AP.

Characteristics and Mitigation Measures of Candida auris Infection: Descriptive Analysis from a Quaternary Care Hospital in Saudi Arabia, 2021-2022.

OBJECTIVE: To analyze the characteristics of C. auris cases, and to describe the interventions applied for improving the diagnosis and controlling the transmission. METHOD: Medical records of C. auris cases reported between January 2021 until June 2022 at King Saud Medical City (KSMC), Riyadh, Kingdom of Saudi Arabia have been reviewed. We analyzed the demographic and clinical characteristics of the cases to illustrate the possible contributing factors with C. auris infection. A multidisciplinary committee has been formulated to investigate the potential source of the outbreak among clusters of cases in the intensive care units (ICU). A bundle of mitigation measures has been applied which was successful to contain the outbreak. RESULTS: During the study period, a total of 129 cases of C. auris were identified, their mean age is 47 ± 22.3 SD, and 72.1% are males. 57% of cases were colonized, all of them were identified through active screening. A number of comorbidities were present including 27.9% were having hypertension, 27.1% with diabetes, 22.5% with COVID-19 and 20.2% with respiratory diseases. The average length of stay before reported positive was 36.23 days. 78.3% of those patients were in the critical care unit, 73.6% with vascular catheter, 88% with urinary catheters and 66.7% with mechanical ventilation. The vast majority of patients were using multiple antibiotics (86%). As per the univariate logistic model, risk factors significantly associated with mortality were (Age, Trauma RTA, ICU, Vascular Access, Foley Catheters, Mechanical Ventilation, Tracheostomy and Endotracheal Tubes) with p values (0.0038, 0.0159, 0.0108, 0.0122, 0.0071, <.0001, 0.0148 and 0.0107), respectively. Multivariate logistic regression showed that having a Foley Catheter was the only statistically significant factor associated with mortality. CONCLUSION: This retrospective analysis  highlights the main characteristics associated with C. auris-infected patients. In addition, it highlights the effectiveness of the bundle of mitigation strategies applied to limit the spread of C. auris in healthcare facilities.

Rhizophora mucronata Lam., a halophyte from Mauritius Island, inhibits the entry of Zika virus in human cells (A549)- an in vitro and in silico analysis.

The recent appearance of Zika virus (ZIKV) in Brazil should serve as a wake-up call to international authorities, as it poses a threat to global public health. In the present study, we investigated whether a mangrove plant, Rhizophora mucronata Lam. (R. mucronata) collected in Mauritius, possesses anti-ZIKV activity at the non-cytotoxic doses. ZIKVMC-MR766NIID (ZIKVGFP) was used for assessing anti ZIKV activity. In silico docking (Autodock 4) and molecular simulation were performed on collected data. Using a recombinant ZIKV expressing reporter green fluorescent protein(GFP) protein, we discovered that fruit and root methanolic, decocted fruit and root extracts were effective inhibitors of ZIKV infection in human epithelial A549 cells at negligible cytotoxicity. The mechanisms by which such extracts prevented ZIKV infection are linked to the inability of the virus to attach to the host cell surface. The outcomes of this study were supported by the docking calculations in which some of the dominant compounds have shown high binding affinity against ZIKV. The scientific data gathered in this study might pave the way for the future development of possible R. mucronata inhibitors to combat ZIKV.fCommunicated by Ramaswamy H. Sarma.

Impact of a national collaborative project to improve the care of mechanically ventilated patients.

This prospective quasi-experimental study from the NASAM (National Approach to Standardize and Improve Mechanical Ventilation) collaborative assessed the impact of evidence-based practices including subglottic suctioning, daily assessment for spontaneous awakening trial (SAT), spontaneous breathing trial (SBT), head of bed elevation, and avoidance of neuromuscular blockers unless otherwise indicated. The study outcomes included VAE (primary) and intensive care unit (ICU) mortality. Changes in daily care process measures and outcomes were evaluated using repeated measures mixed modeling. The results were reported as incident rate ratio (IRR) for each additional month with 95% confidence interval (CI). A comprehensive program that included education on evidence-based practices for optimal care of mechanically ventilated patients with real-time benchmarking of daily care process measures to drive improvement in forty-two ICUs from 26 hospitals in Saudi Arabia (>27,000 days of observation). Compliance with subglottic suctioning, SAT and SBT increased monthly during the project by 3.5%, 2.1% and 1.9%, respectively (IRR 1.035, 95%CI 1.007-1.064, p = 0.0148; 1.021, 95% CI 1.010-1.032, p = 0.0003; and 1.019, 95%CI 1.009-1.029, p = 0.0001, respectively). The use of neuromuscular blockers decreased monthly by 2.5% (IRR 0.975, 95%CI 0.953-0.998, p = 0.0341). The compliance with head of bed elevation was high at baseline and did not change over time. Based on data for 83153 ventilator days, VAE rate was 15.2/1000 ventilator day (95%CI 12.6-18.1) at baseline and did not change during the project (IRR 1.019, 95%CI 0.985-1.053, p = 0.2812). Based on data for 8523 patients; the mortality was 30.4% (95%CI 27.4-33.6) at baseline, and decreased monthly during the project by 1.6% (IRR 0.984, 95%CI 0.973-0.996, p = 0.0067). A national quality improvement collaborative was associated with improvements in daily care processes. These changes were associated with a reduction in mortality but not VAEs. Registration The study is registered in clinicaltrials.gov (NCT03790150).

Towards the Pharmacological Validation and Phytochemical Profiling of the Decoction and Maceration of Bruguiera gymnorhiza (L.) Lam.-A Traditionally Used Medicinal Halophyte.

Decoctions (leaves and roots) of Bruguiera gymnorhiza (L.) Lam. are traditionally used against diabetes in many countries, including Mauritius. This study endeavoured to evaluate the inhibitory potential of leaves, roots, twigs and fruits extracts (decoction and maceration) of B. gymnorhiza against key enzymes relevant to diabetes. Considering complications related to diabetes, other clinical enzymes, namely, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), tyrosinase, elastase and pancreatic lipase, were used. Identification of compounds was carried out using ultra-high-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). Antioxidant capacities were assessed using DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum, metal chelating. The relationship between mode of extraction, plant parts and biological activities was determined using multivariate analysis. Macerated fruits, rich in phytochemicals (phenolic, flavanol, tannin, and triterpenoid), exhibited substantially high antioxidant capacities related to radical scavenging (DPPH: 547.75 ± 10.99 and ABTS: 439.59 ± 19.13 mg TE/g, respectively) and reducing potential (CUPRAC: 956.04 ± 11.90 and FRAP: 577.26 ± 4.55 mg TE/g, respectively). Additionally, the same extract significantly depressed AChE and BChE (3.75 ± 0.03 and 2.19 ± 0.13 mg GALAE/g, respectively), tyrosinase (147.01 ± 0.78 mg KAE/g), elastase (3.14 ± 0.08 mg OE/g) and amylase (1.22 ± 0.01 mmol ACAE/g) enzymatic activities. Phytochemical results confirmed the presence of 119 compounds in all maceration and 163 compounds in all decoction samples. The screening also revealed important compounds in the extracts, namely, quinic acid, brugierol, bruguierol A, epigallocatechin, chlorogenic acid, to name a few. Multivariate analysis reported that the plant parts of B. gymnorhiza greatly influenced the observed biological activities in contrast to the types of extraction methods employed. Docking calculations have supported the findings of the experimental part through the high binding affinity and strong interactions of some compounds against tyrosinase, AChE, BChE and elastase enzymes. The decocted root and leaf of B. gymnorhiza showed low to moderate antidiabetic activity, thereby partially supporting its traditional uses in the management of diabetes. However, the fruit, the most active organ, can be used as a diet supplement to reduce the risk of diabetes complications after evaluating its cytotoxic effects.

SARS-CoV-2 antibody prevalence among healthcare workers: A cross-sectional study at a quaternary healthcare center in Saudi Arabia.

BACKGROUND: The objective of this study was to determine the seroprevalence of SARS-CoV-2 antibodies among Healthcare Workers (HCWs). METHODS: We carried out a cross-sectional study among 3644 HCWs at King Saud Medical City (KSMC) during the last two weeks of December 2020. A Google form survey was used to collect data on demographics, underlying health conditions, job duties, infection control competencies, COVID-19 exposure history, symptoms, and confirmed infections. FINDINGS: 26.5% demonstrated seropositivity to SARS-CoV-2 antibodies, 10-fold higher than the national seroprevalence (2.36) conducted in May 2020. Seropositivity was significantly higher among non-Saudi HCWs and participants who lived outside the hospital dormitory p < 0.0001 and 0.01, respectively). Seropositivity was significantly higher among HCWs who worked on clinical areas of high exposure level, and those who spent longer duration working with patients with COVID-19; p = 0.002 and 0.005, respectively). CONCLUSION: SARS-CoV-2 infections among HCWs can go unrecognized, which magnifies the importance of complying with universal masking and social distancing directives. Detecting SARS-CoV-2 antibodies in HCWs can help healthcare leaders in considering staff allocations and assignments accordingly.

Study of the association between a MICA gene polymorphism and cholangiocarcinoma in Egyptian patients.

Introduction: An inflammatory environment is the common pathway for the development of cholangiocarcinoma (CCA). The natural killer group 2D receptor (NKG2D), an activating receptor for NK cells, is a potent immune axis in the antitumor and antimicrobial immune response through its binding to NKG2D ligands (NKG2DLs). NKG2DLs are normally absent or poorly expressed in most cells; conversely, they are upregulated in stressed cells. We studied the rs2596542 polymorphism located upstream of the MICA gene, which encodes an NKG2DL, in patients with CCA as a marker for early disease detection and a possible therapeutic target. Material and methods: A case-control study was conducted on 40 patients with CCA and 45 healthy individuals (as controls). After routine examination, the rs2596542 polymorphism of the MICA gene was investigated using real-time PCR. Results: We found that a TT homozygous genotype was significantly predominant in patients with CCA (p = 0.039), with the T allele being dominantly distributed in CCA (p = 0.007). High levels of CA19-9 were significantly associated with the TT genotype in the patients. However, we did not detect significant differences in rs2596542C/T genotype and allele distribution between patients with CCA with cirrhosis and those without cirrhosis (p > 0.05). Conclusions: The MICA rs2596542 polymorphism may affect the susceptibility to CCA, but not its progression. The TT genotype could be used as a potential diagnostic marker for CCA and triggering the MICA pathway could be a promising therapeutic target.

Characteristics of healthcare workers with COVID-19: A retrospective descriptive study in a quaternary care center in Riyadh, Saudi Arabia.

BACKGROUND: The aim of this study was to describe the epidemiological and clinical presentation of Healthcare Workers (HCWs) affected by COVID-19. METHODS: A cross-sectional retrospective study was conducted at King Saud Medical City (KSMC), Saudi Arabia (KSA). All KSMC employees who acquired COVID-19 between March 22nd to July 15th, 2020 have been included. Their data has been anonymously analyzed. FINDINGS: During the study period, among the 12000 HCWs working at KSMC, 9.75% tested positive for COVID-19. The source of HCWs infections was mainly community acquired (85%) which included incidences of transmission in hospital dormitories. Transmission among coworkers was the main source of hospital acquired incidences. Direct patient care was reported in 99.8% of study subjects among the high-risk areas, compared to 3.4% in low-risk areas (p-value <0.001), 12-h shifts were more common in the medium and high-risk areas, and at least one symptom was reported by 93.1% of HCWs in high-risk areas compared to 81.6% in low-risk areas (p-value <0.001). CONCLUSION: In KSA, for HCWs, reducing lapses in compliance with masking in non-patient care areas should be considered. In KSA the role that hospital dormitories play in the community transmission of COVID-19 among HCWs need further studies.

Bruguiera gymnorhiza (L.) Lam. at the Forefront of Pharma to Confront Zika Virus and Microbial Infections-An In Vitro and In Silico Perspective.

The recent emergence of Zika virus (ZIKV) in Brazil and the increasing resistance developed by pathogenic bacteria to nearly all existing antibiotics should be taken as a wakeup call for the international authority as this represents a risk for global public health. The lack of antiviral drugs and effective antibiotics on the market triggers the need to search for safe therapeutics from medicinal plants to fight viral and microbial infections. In the present study, we investigated whether a mangrove plant, Bruguiera gymnorhiza (L.) Lam. (B. gymnorhiza) collected in Mauritius, possesses antimicrobial and antibiotic potentiating abilities and exerts anti-ZIKV activity at non-cytotoxic doses. Microorganisms Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Klebsiella pneumoniae ATCC 70603, methicillin-resistant Staphylococcus aureus ATCC 43300 (MRSA), Salmonella enteritidis ATCC 13076, Sarcina lutea ATCC 9341, Proteus mirabilis ATCC 25933, Bacillus cereus ATCC 11778 and Candida albicans ATCC 26555 were used to evaluate the antimicrobial properties. Ciprofloxacin, chloramphenicol and streptomycin antibiotics were used for assessing antibiotic potentiating activity. ZIKVMC-MR766NIID (ZIKVGFP) was used for assessing anti-ZIKV activity. In silico docking (Autodock 4) and ADME (SwissADME) analyses were performed on collected data. Antimicrobial results revealed that Bruguiera twig ethyl acetate (BTE) was the most potent extract inhibiting the growth of all nine microbes tested, with minimum inhibitory concentrations ranging from 0.19-0.39 mg/mL. BTE showed partial synergy effects against MRSA and Pseudomonas aeruginosa when applied in combination with streptomycin and ciprofloxacin, respectively. By using a recombinant ZIKV-expressing reporter GFP protein, we identified both Bruguiera root aqueous and Bruguiera fruit aqueous extracts as potent inhibitors of ZIKV infection in human epithelial A549 cells. The mechanisms by which such extracts prevented ZIKV infection are linked to the inability of the virus to bind to the host cell surface. In silico docking showed that ZIKV E protein, which is involved in cell receptor binding, could be a target for cryptochlorogenic acid, a chemical compound identified in B. gymnorhiza. From ADME results, cryptochlorogenic acid is predicted to be not orally bioavailable because it is too polar. Scientific data collected in this present work can open a new avenue for the development of potential inhibitors from B. gymnorhiza to fight ZIKV and microbial infections in the future.

From mathematics to medicine: A practical primer on topological data analysis (TDA) and the development of related analytic tools for the functional discovery of latent structure in fMRI data.

fMRI is the preeminent method for collecting signals from the human brain in vivo, for using these signals in the service of functional discovery, and relating these discoveries to anatomical structure. Numerous computational and mathematical techniques have been deployed to extract information from the fMRI signal. Yet, the application of Topological Data Analyses (TDA) remain limited to certain sub-areas such as connectomics (that is, with summarized versions of fMRI data). While connectomics is a natural and important area of application of TDA, applications of TDA in the service of extracting structure from the (non-summarized) fMRI data itself are heretofore nonexistent. "Structure" within fMRI data is determined by dynamic fluctuations in spatially distributed signals over time, and TDA is well positioned to help researchers better characterize mass dynamics of the signal by rigorously capturing shape within it. To accurately motivate this idea, we a) survey an established method in TDA ("persistent homology") to reveal and describe how complex structures can be extracted from data sets generally, and b) describe how persistent homology can be applied specifically to fMRI data. We provide explanations for some of the mathematical underpinnings of TDA (with expository figures), building ideas in the following sequence: a) fMRI researchers can and should use TDA to extract structure from their data; b) this extraction serves an important role in the endeavor of functional discovery, and c) TDA approaches can complement other established approaches toward fMRI analyses (for which we provide examples). We also provide detailed applications of TDA to fMRI data collected using established paradigms, and offer our software pipeline for readers interested in emulating our methods. This working overview is both an inter-disciplinary synthesis of ideas (to draw researchers in TDA and fMRI toward each other) and a detailed description of methods that can motivate collaborative research.

Herb-drug interactions and toxicity: Underscoring potential mechanisms and forecasting clinically relevant interactions induced by common phytoconstituents via data mining and computational approaches.

Herbals in the form of medicine are employed extensively around the world. Herbal and conventional medicine combination is a potentially dangerous practice mainly in comorbid, hepato insufficient and frail patients leading to perilous herb-drug interactions (HDI) and toxicity. This study features potential HDI of 15 globally famous plant species through data mining and computational methods. Several plant species were found to mimic warfarin. Phytochemicals from M. charantia induced hypoglycemica. M. chamomila and G. biloba possessed anticoagulant activities. S. hispanica reduces postprandial glycemia. R. officinalis has been reported to inhibit the efflux of anticancer substrates while A. sativum can boost the clearance of anticancer agents. P. ginseng can alter blood coagulation. A cross link of the biological and in silico data revealed that a plethora of herbal metabolites such as ursolic and rosmarinic acid among others are possible/probable inhibitors of specific CYP450 enzymes. Consequently, plant species/metabolites with a given pharmacological property/metabolizing enzyme should not be mixed with drugs having the same pharmacological property/metabolizing enzyme. Even if combined with drugs, herbal medicines must be used at low doses for a short period of time and under the supervision of a healthcare professional to avoid potential adverse and toxic effects.

A comprehensive phytochemical, biological, toxicological and molecular docking evaluation of Suaeda fruticosa (L.) Forssk.: An edible halophyte medicinal plant.

Suaeda fruticosa is an edible medicinal halophyte known for its traditional uses. In this study, methanol and dichloromethane extracts of S. fruticosa were explored for phytochemical, biological and toxicological parameters. Total phenolic and flavonoid constituents were determined by using standard aluminum chloride and Folin-Ciocalteu methods, and UHPLC-MS analysis of methanol extract was performed for tentative identification of secondary metabolites. Different standard methods like DPPH, ABTS, FRAP, CUPRAC, total antioxidant capacity (TAC), and metal chelation assays were utilized to find out the antioxidant potential of extracts. Enzyme inhibition studies of extracts against acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-amylase and, α-glucosidase enzymes were also studied. Likewise, the cytotoxicity was also assessed against MCF-7, MDA-MB-231, and DU-145 cell lines. The higher phenolic and flavonoids contents were observed in methanol extracts which can be correlated to its higher radical scavenging potential. Similarly, 11 different secondary metabolites were tentatively identified by UHPLC profiling. Both the extract showed significant inhibition against all the enzymes except for α-glucosidase. Moreover, docking studies were also performed against the tested enzymes. In the case of cytotoxicity, both the samples were found moderately toxic against the tested cell lines. This plant can be explored further for its potential therapeutic and edible uses.

Chemical Composition and Pharmacological Evaluation and of Toddalia asiatica (Rutaceae) Extracts and Essential Oil by in Vitro and in Silico Approaches.

Toddalia asiatica (L.) Lam. is extensively used in traditional medicinal systems by various cultures. Despite its frequent use in traditional medicine, there is still a paucity of scientific information on T. asiatica growing on the tropical island of Mauritius. Therefore, the present study was designed to appraise the pharmacological and phytochemical profile of extracts (methanol, ethyl acetate and water) and essential oil obtained from aerial parts of T. asiatica. Biological investigation involved the evaluation of in vitro antioxidant and enzyme inhibitory potentials. The chemical profile of the EO was determined using gas chromatography coupled to mass spectrometry (GC/MS) analysis, while for the extracts, the total phenolic (TPC) and flavonoid content were quantified as well as their individual phenolic compounds by LC/MS/MS. Quinic acid, fumaric acid, chlorogenic acid, quercitrin and isoquercitrin were the main compounds in the extracts. Highest total phenolic (82.5±0.94 mg gallic acid equivalent (GAE/g)) and flavonoid (43.8±0.31 mg rutin equivalent (RE/g)) content were observed for the methanol extract. The GC/MS analysis has shown the presence of 26 compounds with linalool (30.9 %), linalyl acetate (20.9 %) and ß-phellandrene (7.9 %) being most abundant components in the EO. The extracts and EO showed notable antioxidant properties, with the methanol extract proved to be superior source of antioxidant compounds. Noteworthy anti-acetylcholinesterase (AChE) and anti-butyrylcholinesterase (BChE) effects were recorded for the tested samples, while only the methanol and ethyl acetate extracts were active against tyrosinase. With respect to antidiabetic effects, the extracts and EO were potent inhibitors of α-glucosidase, while modest activity was recorded against α-amylase. Docking results showed that linalyl acetate has the highest affinity to interact with the active site of BChE with docking score of -6.25 kcal/mol. The findings amassed herein act as a stimulus for further investigations of this plant as a potential source of bioactive compounds which can be exploited as phyto-therapeutics.

Are vanadium complexes druggable against the main protease Mpro of SARS-CoV-2? - A computational approach.

In silico techniques helped explore the binding capacities of the SARS-CoV-2 main protease (Mpro) for a series of metalloorganic compounds. Along with small size vanadium complexes a vanadium-containing derivative of the peptide-like inhibitor N3 (N-[(5-methylisoxazol-3-yl)carbonyl]alanyl-l-valyl-N1-((1R,2Z)-4-(benzyloxy)-4-oxo-1-{[(3R)-2-oxopyrrolidin-3-yl] methyl }but-2-enyl)-l-leucinamide) was designed from the crystal structure with PDB entry code 6LU7. On theoretical grounds our consensus docking studies evaluated the binding affinities at the hitherto known binding site of Chymotrypsin-like protease (3CLpro) of SARS-CoV-2 for existing and designed vanadium complexes. This main virus protease (Mpro) has a Cys-His dyad at the catalytic site that is characteristic of metal-dependent or metal-inhibited hydrolases. Mpro was compared to the human protein-tyrosine phosphatase 1B (hPTP1B) with a comparable catalytic dyad. HPTP1B is a key regulator at an early stage in the signalling cascade of the insulin hormone for glucose uptake into cells. The vanadium-ligand binding site of hPTP1B is located in a larger groove on the surface of Mpro. Vanadium constitutes a well-known phosphate analogue. Hence, its study offers possibilities to design promising vanadium-containing binders to SARS-CoV-2. Given the favourable physicochemical properties of vanadium nuclei, such organic vanadium complexes could become drugs not only for pharmacotherapy but also diagnostic tools for early infection detection in patients. This work presents the in silico design of a potential lead vanadium compound. It was tested along with 20 other vanadium-containing complexes from the literature in a virtual screening test by docking to inhibit Mpro of SARS-CoV-2.

GC/MS Profiling, In Vitro and In Silico Pharmacological Screening and Principal Component Analysis of Essential Oils from Three Exotic and Two Endemic Plants from Mauritius.

The chemical and pharmacological profiles of essential oils (EOs) hydrodistilled in yields of 0.03-0.77 % (w/w) from three exotic (Cinnamomum camphora, Petroselinum crispum, and Syzygium samarangense) and two endemic (Pittosporum senacia subsp. senacia and Syzygium coriaceum) medicinal plants were studied. GC-MS/GC-FID analysis of the EOs identified the most dominant components to be myristicin (40.3 %), myrcene (62.2 %), 1,8-cineole (54.0 %), ß-pinene (21.3 %) and (E)-ß-ocimene (24.4 %) in P. crispum, P. senacia and C. camphora, S. samarangense and S. coriaceum EOs, respectively. All EOs were found to possess anti-amylase (0.70-1.50 mM ACAE/g EO) and anti-tyrosinase (109.35-158.23 mg KAE/g) properties, whereas no glucosidase inhibition was displayed. Only Syzygium EOs acted as dual inhibitors of both acetyl- and butyryl-cholinesterases, while P. senacia and C. camphora EOs inhibited acetylcholinesterase selectively and P. crispum EO was inactive (AChE: 4.64-4.96 mg GALAE/g; BChE: 5.96 and 7.10 mg GALAE/g). Molecular docking revealed 1,8-cineole to present the best binding affinities with butyrylcholinesterase, amylase and tyrosinase, while both myristicin and ß-pinene with acetylcholinesterase and finally ß-pinene with glucosidase. In vitro antioxidant potency was also demonstrated in different assays (DPPH: 13.52-53.91 mg TE/g, ABTS: 5.49-75.62 mg TE/g; CUPRAC: 45.38-243.21 mg TE/g, FRAP: 42.49-110.64 mg TE/g; and phosphomolybdenum assay: 82.61-160.93 mM TE/g). Principal component analysis revealed the EOs to differ greatly in their bioactivities due to their chemodiversity. This study has unveiled some interesting preliminary pharmacological profiles of the EOs that could be explored for their potential applications as phytotherapeutics.

RP-UHPLC-MS Chemical Profiling, Biological and In Silico Docking Studies to Unravel the Therapeutic Potential of Heliotropium crispum Desf. as a Novel Source of Neuroprotective Bioactive Compounds.

Heliotropium is one of the most important plant genera to have conventional folklore importance, and hence is a potential source of bioactive compounds. Thus, the present study was designed to explore the therapeutic potential of Heliotropium crispum Desf., a relatively under-explored medicinal plant species. Methanolic extracts prepared from a whole plant of H. crispum were studied for phytochemical composition and possible in vitro and in silico biological properties. Antioxidant potential was assessed via six different assays, and enzyme inhibition potential against key clinical enzymes involved in neurodegenerative diseases (acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)), diabetes (α-amylase and α-glucosidase), and skin problems (tyrosinase) was assayed. Phytochemical composition was established via determination of the total bioactive contents and reverse phase ultra-high performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Chemical profiling revealed the tentative presence of 50 secondary metabolites. The plant extract exhibited significant inhibition against AChE and BChE enzymes, with values of 3.80 and 3.44 mg GALAE/g extract, respectively. Further, the extract displayed considerable free radical scavenging activity against DPPH and ABTS radicals, with potential values of 43.19 and 41.80 mg TE/g extract, respectively. In addition, the selected compounds were then docked against the tested enzymes, which have shown high inhibition affinity. To conclude, H. crispum was found to harbor bioactive compounds and showed potent biological activities which could be further explored for potential uses in nutraceutical and pharmaceutical industries, particularly as a neuroprotective agent.

Theoretical Characterization of the Structure and Spectroscopy of HCNO2 Isomers and Applications.

We carried out a theoretical, fully ab initio, investigation of the stable forms of the [H,C,N,O,O] pentatomic molecular system, whose isomers are involved in fundamental combustion and atmospheric processes and are of potential interest for astrophysics. By adopting the MP2 and CCSD(T) electronic structure methods, combined with extrapolations to the complete basis set (CBS) limit, we characterized 20 low-energy isomers, excluding weak van der Waals complexes. For these molecules, we determined a set of geometrical parameters, relative energies, anharmonic vibrational frequencies, IR intensities, and fragmentation/formation energies from various atomic and/or molecular fragments. We discuss the relevance of the present findings for the search of new molecular species in astrophysical and atmospheric media and give suggestions for their possible detection in laboratory experiments. The set of data provided by the present work should facilitate the identification of these species from their gas-phase and low-temperature solid matrix spectra, whenever measured.

Identifying isomers of peroxy radicals in the gas phase: 1-C3H7O2vs. 2-C3H7O2.

The two isomers of the propylperoxy radical 1-C3H7O2 and 2-C3H7O2, together with their individual rotamers, are identified and assigned by threshold photoelectron spectroscopy with the aid of high-level theoretical computations, from which their accurate adiabatic ionization energies are derived. This study paves the way to probing elusive peroxy radicals and their isomers in advanced mass spectrometry analysis of combustion and atmospheric reactions.

Anti-Tubercular Properties of 4-Amino-5-(4-Fluoro-3- Phenoxyphenyl)-4H-1,2,4-Triazole-3-Thiol and Its Schiff Bases: Computational Input and Molecular Dynamics.

In the present investigation, the parent compound 4-amino-5-(4-fluoro-3-phenoxyphenyl)-4H-1,2,4-triazole-3-thiol (1) and its Schiff bases 2, 3, and 4 were subjected to whole-cell anti-TB against H37Rv and multi-drug-resistant (MDR) strains of Mycobacterium tuberculosis (MTB) by resazurin microtiter assay (REMA) plate method. Test compound 1 exhibited promising anti-TB activity against H37Rv and MDR strains of MTB at 5.5 µg/mL and 11 µg/mL, respectively. An attempt to identify the suitable molecular target for compound 1 was performed using a set of triazole thiol cellular targets, including ß-ketoacyl carrier protein synthase III (FABH), ß-ketoacyl ACP synthase I (KasA), CYP121, dihydrofolate reductase, enoyl-acyl carrier protein reductase, and N-acetylglucosamine-1-phosphate uridyltransferase. MTB ß-ketoacyl ACP synthase I (KasA) was identified as the cellular target for the promising anti-TB parent compound 1 via docking and molecular dynamics simulation. MM(GB/PB)SA binding free energy calculation revealed stronger binding of compound 1 compared with KasA standard inhibitor thiolactomycin (TLM). The inhibitory mechanism of test compound 1 involves the formation of hydrogen bonding with the catalytic histidine residues, and it also impedes access of fatty-acid substrates to the active site through interference with α5-α6 helix movement. Test compound 1-specific structural changes at the ALA274-ALA281 loop might be the contributing factor underlying the stronger anti-TB effect of compound 1 when compared with TLM, as it tends to adopt a closed conformation for the access of malonyl substrate to its binding site.