Chiral phthalimides against penicillin-binding protein 2a of methicillin-resistant Staphylococcus aureus: molecular docking and in vitro analysis.

Staphylococcus aureus (S. aureus) is a commensal bacterium and an opportunistic pathogen causing a wide variety of infections ranging from localized skin and soft tissue infections to life-threatening severe bacteremia, osteomyelitis, endocarditis, atopic dermatitis, prosthetic joint infection, staphylococcal food poisoning, medical device-related infections, and pneumonia. It is attributed to an acquired resistant gene, mecA, encoding penicillin-binding protein 2a (PBP2a). PBP2a is an essential protein responsible for the resistivity of methicillin-resistant S. aureus (MRSA) to various beta-lactam antibiotics. The antimicrobial treatment alternatives for MRSA are increasingly limited. Therefore, developing alternative therapeutic options for its treatment is the need of the day. Phthalimides and their N-substituted derivatives are of biological importance as they possess extensive biological and pharmaceutical properties and can serve as an excellent therapeutic option for MRSA. This study uses three chiral phthalimides (FIA, FIB, and FIC) to check their in silico and in vitro inhibitory effects. Molecular docking of these chiral phthalimides against PBP2a of MRSA was performed initially. After promising results, these novel compounds were screened through the agar-well diffusion method and micro-broth dilution assay to investigate their in vitro inhibitory activities with FIB being the strongest anti-staphylococcal agent yielding a 21 mm zone of inhibition and a minimum inhibitory concentration (MIC) of 0.022 ug, respectively. The zones of inhibition obtained through the in vitro activity showed that these chiral phthalimides possess substantial anti-MRSA activities and have the potential to be considered as alternative chemotherapeutics to treat the infections caused by MRSA after the confirmation of their cytotoxic and pharmacokinetic studies.

Thiadiazine thione derivatives as anti-leishmanial agents: synthesis, biological evaluation, structure activity relationship, ADMET, molecular docking and molecular dynamics simulation studies.

During last decades, 3,5-disubstituted-tetrahydro-2H-thiadiazine-2-thione scaffold remains the center of interest due to their ease of preparation, diverse range substituents at N-3 and N-5 positions, and profound biological activities. In the current study, a series of 3,5-disubstituted-tetrahydro-2H-thiadiazine-2-thiones were synthesized in good to excellent yield, and the structure of the compounds were confirmed by various spectroscopic techniques such as FTIR, 1H-NMR, 13C-NMR and Mass spectrometry, and finally evaluated against Leishmania major. Whereas, all the evaluated compounds (1-33), demonstrate potential leishmanicidal activities with IC50 values in the range of (1.30- 149.98 uM). Among the evaluated compounds such as 3, 4, 6, and 10 exhibited excellent leishmanicidal activities with IC50 values of (2.17 µM), (2.39 µM), (2.00 µM), and (1.39 µM), respectively even better than the standard amphotericin B (IC50 = 0.50) and pentamidine (IC50 = 7.52). In order to investigate binding interaction of the most active compounds, molecular docking study was conducted with Leishmania major. Further molecular dynamic simulation study was also carried out to assess the stability and correct binding of the most active compound 10, within active site of the Leishamania major. Likewise, the physiochemical properties, drug likeness, and ADMET of the most active compounds were investigated, it was found that none of the compounds violate Lipiniski's rule of five, which show that this class of compounds had enough potential to be used as drug candidate in near future.Communicated by Ramaswamy H. Sarma.

Novel Schiff bases of Vanillin: potent inhibitors of macrophage harbored Leishmania tropica.

Due to limited chemotherapeutic options for leishmaniasis, novel synthetic compounds are gaining attention for evaluation against leishmaniasis. This study aimed to synthesize the compound's Schiff bases of Vanillin to investigate and evaluate their anti-leishmanial potentials against intracellular protozoan parasites Leishmania tropica. In the current study, the phenomena of synergism by designing Schiff bases with Vanillin enhances their desired importance. A total of five compounds Schiff bases of Vanillin were synthesized using different aromatic amines and Vanillin. The structural analysis of all the compounds was done through FT-IR (Fourier Transformer-Infrared), thin layer chromatography, and spectroscopic techniques such as 13C-NMR, mass spectrometry, and 1H-NMR. The antimicrobial properties of all the compounds ZI-1, ZI-2, BS-1, KH-1, and FA-2 against promastigotes and amastigotes forms of L. tropica were analyzed at three different concentrations 25, 50, and 100 µg/ml. The in-vitro MTT assay was performed to calculate the percent inhibition, IC50 values, and their cytotoxicity. The highest percent inhibition values against promastigote form of L. tropica were BS-1 53.78% at 25 µg/ml, ZI-2 66.95% at 50 µg/ml, and again ZI-2 76.92% at 100 µg/ml. Similarly, the highest percent inhibition values against intracellular amastigote stage were BS-1 55.77% at 25 µg/ml, ZI-2 67.78% at 50 µg/ml and again ZI-2 84.93% 100 µg/ml. The highest potency was recorded for BS-1 in both stages, with IC50 values of 9.83 and 4.27 µg/ml against promastigotes and intracellular amastigotes, respectively. The percent hemolysis as toxicity; the lowest percent hemolysis was recorded for ZI-1 at three different concentrations of 25, 50, 100 µg/ml of 2.60, 3.50, and 6.31, respectively. These results suggested that all the compounds exhibited anti-leishmanial activity, with BS-1 as the most potent. Further studies are suggested to increase the activity of compounds with structural modifications by the addition of some other synergistic, novel, and analogue compounds.

Thiophene-Derived Schiff Base Complexes: Synthesis, Characterization, Antimicrobial Properties, and Molecular Docking.

Novel thiophene-derived Schiff base ligand DE, where DE is (E)-N1,N1-diethyl-N2-(thiophen-2-ylmethylene)ethane-1,2-diamine, and the corresponding M(II) complexes, [M(DE)X2] (M = Cu or Zn, X = Cl; M = Cd, X = Br), were prepared and structurally characterized. X-ray diffraction studies revealed that the geometry around the center of the M(II) complexes, [Zn(DE)Cl2] and [Cd(DE)Br2], could be best described as a distorted tetrahedral. In vitro antimicrobial screening of DE and its corresponding M(II) complexes, [M(DE)X2], was performed. The complexes were more potent and showed higher activities against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa, fungi Candida albicans, and protozoa Leishmania major compared to the ligand. Among the studied complexes, [Cd(DE)Br2] exhibited the most promising antimicrobial activity against all the tested microbes compared to its analogs. These results were further supported by molecular docking studies. We believe that these complexes may significantly contribute to the efficient designing of metal-derived agents to treat microbial infections.

Hypocalcaemia As A Rare Reversible Cause Of Dilated Cardiomyopathy.

Dilated cardiomyopathy is characterized by dilation and enlargement of one or both ventricles with reduced systolic function. Calcium plays a key role in myocardial contraction. Hypocalcaemia can lead to a decrease in contraction, left ventricular systolic dysfunction, and heart failure with reduced ejection fraction (EF). Hypocalcaemia is a rare reversible cause of dilated cardiomyopathy. The author presents a case who presented with complaints of shortness of breath on exertion, orthopnoea, paroxysmal nocturnal dyspnoea, numbness and crampy muscular pains. He had a high JVP, systolic murmur on auscultation, hepatomegaly, pedal oedema and crackles on chest auscultation. His ECG showed sinus rhythm with prolonged QT interval. His echocardiography showed dilated cardiomyopathy with reduced ejection fraction, moderate mitral regurgitation and mild tricuspid regurgitation. His Calcium levels and PTH levels were both low. He was treated with ionotrophes, diuretics, vitamin D and calcium supplements, including both intravenous and oral. With the correction of calcium levels, he was weaned off the ionotrophic support and his ejection fraction improved. Calcium levels if low should be corrected in patients with dilated cardiomyopathy.

Amphotericin B Tamed by Salicylic Acid.

Although Amphotericin B (AmB) is considered as the "gold standard" treatment for deep fungal infections, owing to its excellent antifungal effect, it often causes severe hemolytic toxicity and nephrotoxicity, which limits its clinical use. We designed and synthesized AmB derivatives by attaching salicylic acid (SA) to the carboxyl group and confirmed their structures using 1H NMR, 13C NMR, HR-MS, and IR. We evaluated its biological activity in vitro and measured its ultraviolet-visible (UV-vis) absorption spectrum. The AmB-SA conjugates exhibited good antifungal effects against Candida albicans, Candida glabrata, and Cryptococcus neoformans compared with AmB, and the renal cytotoxicity toward HEK 293T cells in vitro was significantly reduced, with almost no nephrotoxicity in the therapeutic window of the drug. At the same time, the hemolytic toxicity was significantly reduced. Therefore, modification of AmB by introducing SA is an effective strategy to maintain the broad antifungal activity of AmB and reduce its cytotoxicity. These AmB derivatives could be applied in clinical therapy in the future.

Synthesis of novel silica encapsulated spiropyran-based thermochromic materials.

A series of novel spiropyrans were synthesized through the condensation of substituted 3,3-dimethyl-2-methyleneindoline with different nitro-substituted o-hydroxy aromatic aldehydes. Indoles were initially substituted with a variety of alkanes and esters moieties. The substituted 3,3-dimethyl-2-methyleneindoline was then reacted with nitro-substituted o-hydroxy aromatic aldehydes to yield the respective spiropyrans. The synthesized novel spiropyrans were encapsulated in silica nano-shells to protect them from the effect of moisture and pH. The thermochromic behaviour of novel spiropyrans was studied by UV-visible spectroscopy. The thermally induced isomerization of spiropyran derivatives was carried out in a water/ethanol mixture. The thermal isomerization of spiro-heterocyclic (colourless form) to merocyanine (MC) (coloured form) was a discontinuous process and was observed in a temperature range of 5-60°C via UV-visible spectrometer. The absorption process occurs reversibly regardless of the heating/cooling sequence. The spiropyran derivatives, therefore, have a potential application for colorimetric temperature indication.

Cardioprotective potential of Thymus linearis Benth.

In developing countries, myocardial ischemia and the resulting impairments in heart function are the leading cause of illness and mortality. Thymus linearis Benth has been used as an antibiotic, antioxidant, and antihypertensive agent for centuries. The goal of this investigation was to see if Thymus linearis could protect isoproterenol and doxorubicin-induced myocardial ischemia in vivo at doses of 25 mg/kg s.c. and 15 mg/kg i.p., respectively. The level of cardiac enzymes (CK-MB, LDH, and AST) in the serum isolated from the experimental animal's blood was used to determine myocardial ischemia. The anti-ischemic potential was assessed by comparing the levels of the aforementioned cardiac biomarkers in the intoxicated and treated animal groups. The study found substantial increase (p0.0001) in the serum levels of CK-MB, LDH, AST when compared to intoxicated groups, while pretreatment of animals with crude extract of Thymus linearis significantly reduced the rise in serum cardiac indicators. The findings of the study indicated that the aqueous methanolic Thymus linearis crude extract has cardioprotective potential against Isoproterenol and Doxorubicin-induced cardiac necrosis in rats.

Global distribution, traditional and modern detection, diagnostic, and management approaches of Rhizoctonia solani associated with legume crops.

Sustainable development relies heavily on a food system that is both safe and secure. Several approaches may lead to sustainability and food safety. An increase in the cultivation of legume crops is one of the approaches for enhancing agricultural viability and ensuring adequate food supply. Legumes may increase daily intake of fiber, folate, and protein as substitutes for meat and dairy. They are also crucial in various intercropping systems worldwide. However, legume production has been hampered by Rhizoctonia solani due to its destructive lifestyle. R. solani causes blights, damping off, and rotting diseases in legume crops. Our knowledge of the global distribution of R. solani associated with legume crops (alfalfa, soybean, chickpea, pea, lentil, common bean, and peanut), detection, diagnosis, and management of legume crops diseases caused by R. solani is limited. Traditional approaches rely on the incubation of R. solani, visual examination of symptoms on host legume crops, and microscopy identification. However, these approaches are time-consuming, require technical expertise, fail to detect a minimal amount of inoculum, and are unreliable. Biochemical and molecular-based approaches have been used with great success recently because of their excellent sensitivity and specificity. Along with conventional PCR, nested PCR, multiplex PCR, real-time PCR, magnetic-capture hybridization PCR, and loop-mediated isothermal amplification have been widely used to detect and diagnose R. solani. In the future, Next-generation sequencing will likely be used to a greater extent to detect R. solani. This review outlines global distribution, survival, infection and disease cycle, traditional, biochemical, molecular, and next-generation sequencing detection and diagnostic approaches, and an overview of the resistant resources and other management strategies to cope with R. solani.

Culture conversion and six months interim outcomes in retreatment cases of pulmonary MDRTB - a six month interim analysis.

OBJECTIVE: To estimate the time to culture conversion and factors associated with failure to culture conversion, six-month interim outcomes and associated risk factors with poor interim outcomes in multi-drug resistant tuberculosis patients previously treated with second-line drugs. METHODS: The prospective clinical case series study was conducted from March 2016 to January 2017 at the Indus Hospital Tuberculosis Clinic and seven other sites that are part of the hospital's Programmatic Management of Drug Resistant Tuberculosis initiative. All bacteriologically confirmed multi-drug resistant tuberculosis retreatment patients were enrolled. Data was collected on age, gender, site of enrollment, detailed history of previous treatment with anti-tuberculosis drugs, medical history, history of first-line drugs, history of second-line drugs, treatment outcomes, baseline sputum smear microscopy and monthly follow-up sputum smear microscopy and culture results. Data was subjected to univariate and multiple logistic regression analyses, and risk factors for failure to culture conversion were assessed using Cox Proportional Hazards Model. RESULTS: Out of 266 patients, 143(53.8%) were males, the overall largest age group was 5-24 years 97(36.5%), and 250 (94%) patients had previous history of treatment with first-line drugs. Overall, 101(40.1%) patients experienced poor interim outcome. Poor interim outcomes were significantly associated with higher number of drugs on the regimen, (odds ratio: 1.27; 95% confidence interval: 1.03-1.58) and high sputum smear grading (odds ratio: 4.56; 95% confidence interval: 3.30-18.71). Besides, 186(70.3%) patients experienced culture conversion within the initial six months of treatment. CONCLUSIONS: The success rate of re-treatment of multi-drug resistant tuberculosis with conventional regimen was found to be unacceptably low.

The Antibacterial, Insecticidal and Nematocidal Activities and Toxicity Studies of Tanacetum falconeri Hook. f.

OBJECTIVES: Secondary bioactive metabolites from plants may be realistic alternatives to conventional synthetic chemicals. The aim of the present research was to test the Tanacetum falconeri Hook. f. in different bioassays to evaluate its potential as nematocidal, insecticidal, antibacterial, cytotoxic, and phytotoxic agent. The plant T. falconeri was further studied for its chemical constituents. MATERIALS AND METHODS: The methanolic extract from T. falconeri was fractionated into various solvent fractions. All solvent fractions were further subjected to different bioassays. Antibacterial activity and cytotoxicity were determined by broth micro-dilution method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, respectively. Nematocidal activity was evaluated by using second-stage juvenile of Meloidogyne incognita. Insecticidal activity and phytotoxicity were measured with the help of Rhyzopertha dominica and Tribolium castaneum and fronds of Lemna minor L., respectively. Compound-1 was isolated by using liquid chromatography and its structure was determined by spectroscopic data as cis-dehydromatricaria ester. RESULTS: The excellent nematocidal activity (reduction in 100% motility) of the compound-1 against a root-knot nematode was obtained at 1% concentration after 72 h incubation time, whereas the reductions in motilities were 95% and 75% at concentrations 0.5% (w/v) and 0.125% (w/v), respectively. Similarly, the mortalities were 90% and 82% at 1% and 0.5% concentrations, respectively, after 24 h of the treatment. Compound-1 also exhibited the excellent insecticidal activity against Sitophilus oryzae at 1% concentration (providing 100% mortality) with effective dose 50 (EC50) of 0.08 mg/L. The EC50 of phosphine, which was used as standard, was 0.07 mg/L. Two fractions of T. falconeri showed a moderate cytotoxic activity against 3T3 cells lines at the concentration of 30 mg/mL with inhibitory concentration 50 values of 22.4 and 25.8 mg/L corresponding to TfP and TfM, respectively. CONCLUSION: This study demonstrates that cis-dehydromatricaria ester-1 provides nematocidal activity (100% mortality) against the root-knot nematodes. Its insecticidal activity against S. oryzae may enable its use as marketable insecticide.

Phytochemical analysis of crude extract of Delphinium brunonianum and its effect on hypertension and metabolic perturbations in fructose fed rats.

The present study aims at phytochemical profiling and valuating the effect of crude extract of Delphinium brunonianum on fructose mediated rise in blood pressure and metabolic abnormalities in rats. Therefore, rats were fed on fructose (10%w/v) for 6 weeks. Rats in treatment groups received amlodipine 250, 500 and 1000 mg/kg of DB-Cr separately in concurrent to fructose. Various parameters of metabolic perturbations were assessed at the end of study. Further, DB-Cr was analyzed using LC-MS technique. DB-Cr exerted remarkable antihypertensive effect whereas, sympathetic hyperactivity and hyperinsulinemia in these rats was significantly blunted, further, endothelium functionality was successfully restored. LC-MS analysis of DB-Cr revealed the presence of a variety of chemical constituents (41) including quinic acid, scopolin, gingerol, Robinetin 3-rutinoside, KAPA and maleic acid. In conclusion, D. brunonianum possess the potential to combat the fructose mediated hypertension and metabolic perturbations, which may partially be due to its chemical constituents.

Treatment outcomes of the drug resistant tuberculosis cases previously exposed to second line anti Tuberculosis drugs in Pakistan: A multi-center cross-sectional study.

OBJECTIVE: To determine the treatment outcomes of the drug-resistant tuberculosis patients who were previously exposed to second line drugs. METHODS: The retrospective study was conducted at eight Programmatic Management of Drug Resistant Tuberculosis (PMDT) sites in Sindh and Balochistan. Data of patients who were previously exposed to second line drugs and re-enrolled in the drug-resistant tuberculosis register at PMDT sites in Sindh and Balochistan between 2008 and 2016 was included for analysis. Data of those still under treatment or transferred to another treatment site was excluded. Association was explored between treatment outcomes and other independent variables, while in order to identify the risk factors associated with poor treatment outcomes univariate and multivariate logistic regression was used. RESULTS: Overall, there were 3645 patients and 288(8%) were previously exposed to second line drugs. Of them, 95(33%) were excluded, and the final sample stood at 193; 99(51.3%) males and 94(48.7%) females. The median age of the sample was 29 years (inter-quartile range: 22-41 years). The mean duration of treatment was 20}11.14 months. Overall success rate of the re-treatment of previously treated patients was 105(54.4%). Observed relapse rate was 9(4.7%).. CONCLUSIONS: The success rate for re-treatment drug-resistant tuberculosis patients was found to be unacceptably low. New drugs and novel regimens should be made widely available.

Medicinal plants used by inhabitants of the Shigar Valley, Baltistan region of Karakorum range-Pakistan.

BACKGROUND: The inhabitants of mountainous terrains depend on folk therapies to treat various ailments; however lack of plant based research and geographical constraints set the traditional knowledge in jeopardy. Present study is the first documentation on traditional uses of plant species by the inhabitants of the Shigar Valley, Karakorum Range, Northern Pakistan. METHOD: Ethnobotanical data were collected over a period from July, 2013 to October, 2016 from 84 respondents, using semi structured questionnaire. Quantitative indices such as relative frequency citation (RFCs) and fidelity level (FL) were intended to evaluate the importance of medicinal plant species. RESULTS: In total 84 plant species belonging to 36 families and 72 genera were recorded. Fabaceae was dominant with 7 species, followed by Asteraceae, Lamiaceae and Rosacea (6 species each). Leaves, root, flowers, seeds and fruits were the frequently utilized plant parts, whereas among drug formulations, decoction (49%) was ranked first. Majority of the plant species were used to treat abdominal, respiratory and dermal ailments (31, 12 and 12, respectively). RFCs value ranged 0.477 to 0.11 for Tanacetum falconeri and Allium carolinianum, respectively; while Hippophe rhamnoides and Thymus linearis depicted 100% FL. Comparative assessment with previous reports revealed that traditional uses of 26% plant species counting Hedyserum falconeri, Aconitum violoceum var. weileri, Arnebia guttata, Biebersteinia odora, Clematis alpine var. sibirica, Corydalis adiantifolia and Saussurea simpsoniana were reported for the first time. CONCLUSION: The endemic medicinal plant species and traditional knowledge of Balti community living in extremely high mountains area were explored for the first time. A comprehensive survey of this region could be significant to drive the existing knowledge in market circuit with sustainable collection, and to evaluate economic potential of the plant species. Additionally, social livelihood could be reinforced through establishing collection sites, transformation and drying centres for micro and macro marketing of medicinal plant species. Plants and people interaction in the Karakorum Mountains.

Biologically active bergenin derivatives from Bergenia stracheyi.

New bergenin derivatives, bergecins A and B (1 and 2, resp.), have been isolated from the AcOEt-soluble fraction of Bergenia stracheyi, along with bergenin (3), and their structures were elucidated on the basis of (1) H- and (13) C-NMR spectra, and by COSY, HMQC, and HMBC experiments. Compound 2 showed potent inhibitory potential against the enzyme lipoxygenase, while 1 was moderately active. On the other hand, both compounds exhibited significant antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay.