Mechanistic Study on Artificial Stabilization of Lithium Metal Anode via Thermal Pyrolysis of Ammonium Fluoride in Lithium Metal Batteries.

The use of the "Holy Grail" lithium metal anode is pivotal to achieve superior energy density. However, the practice of a lithium metal anode faces practical challenges due to the thermodynamic instability of lithium metal and dendrite growth. Herein, an artificial stabilization of lithium metal was carried out via the thermal pyrolysis of the NH4F salt, which generates HF(g) and NH3(g). An exposure of lithium metal to the generated gas induces a spontaneous reaction that forms multiple solid electrolyte interface (SEI) components, such as LiF, Li3N, Li2NH, LiNH2, and LiH, from a single salt. The artificially multilayered protection on lithium metal (AF-Li) sustains stable lithium stripping/plating. It suppresses the Li dendrite under the Li||Li symmetric cell. The half-cell Li||Cu and Li||MCMB systems depicted the attributions of the protective layer. We demonstrate that the desirable protective layer in AF-Li exhibited remarkable capacity retention (CR) results. LiFePO4 (LFP) showed a CR of 90.6% at 0.5 mA cm-2 after 280 cycles, and LiNi0.5Mn0.3Co0.2O2 (NCM523) showed 58.7% at 3 mA cm-2 after 410 cycles. Formulating the multilayered protection, with the simultaneous formation of multiple SEI components in a facile and cost-effective approach from NH4F as a single salt, made the system competent.

Inhibition of Trehalose Synthesis in Lepidoptera Reduces Larval Fitness.

Trehalose is synthesized in insects through the trehalose 6-phosphate synthase and phosphatase (TPS/TPP) pathway. TPP dephosphorylates trehalose 6-phosphate to release trehalose. Trehalose is involved in metamorphosis, but its relation with body weight, size, and developmental timing is unexplored. The expression and activity of TPS/TPP fluctuate depending on trehalose demand. Thus, TPS/TPP inhibition can highlight the significance of trehalose in insect physiology. TPS/TPP transcript levels are elevated in the pre-pupal and pupal stages in Helicoverpa armigera. The inhibition of recombinantly expressed TPP by N-(phenylthio)phthalimide (NPP), is validated by in vitro assays. In vivo inhibition of trehalose synthesis reduces larval weight and size, hampers metamorphosis, and reduces its overall fitness. Insufficient trehalose leads to a shift in glucose flux, reduced energy, and dysregulated fatty acid oxidation. Metabolomics reaffirms the depletion of trehalose, glucose, glucose 6-phosphate, and suppressed tricarboxylic acid cycle. Reduced trehalose hampers the energy level affecting larval vitality. Through trehalose synthesis inhibition, the importance of trehalose in insect physiology and development is investigated. Also, in two other lepidopterans, TPP inhibition impedes physiology and survival. NPP is also found to be effective as an insecticidal formulation. Overall, trehalose levels affect the larval size, weight, and metabolic homeostasis for larval-pupal transition in lepidoptera.

Comparative Evaluation of Solubility of Gutta-Percha in Three Different Solvents: A Cone-Beam Computed Tomography (CBCT) Study.

Background Gutta-percha is the most frequently used filling material for root canal obturation. This thermoplastic material fulfills the primary requisites for root canal filling, one of which is easily removable material in cases of endodontic retreatment. The most commonly used solvents were chloroform, xylene, and orange oil due to their effectiveness in dissolving and removing maximum gutta-percha in a minimum time. Aims The aim is to evaluate and compare the solubility of gutta-percha in three different organic solvents, i.e., orange oil, xylene, and chloroform. Methods and material Forty extracted mandibular second premolars with a single canal were selected. The sample was categorized into control, orange oil, xylene, and chloroform. Access cavity preparations with cleaning and shaping were performed by k files and rotary files, followed by obturation. Two drops of assigned solvent were placed on the orifices of the obturated canal, and corona-gutta-percha ha was removed by gates glidden drills. Cone-beam computed tomography (CBCT) images were taken before and after the gutta-percha removal, and the solvents' efficacy was assessed. Statistical analysis The statistical test applied for the analysis was one-way analysis of variance (ANOVA). The confidence interval and p-value were set for this test at 95% and < 0.05, respectively. Results Gutta-percha Removal was found to be maximum with orange oil (Group II) followed by xylene (Group III) >Chloroform (Group IV) >Control Group. The Statistical Analysis by ANOVA revealed a significant difference between the four groups with a p-value of less than 0.05. Furthermore, the pair-wise comparison revealed that the amount of gutta-percha removal with orange oil significantly differs from xylene and chloroform, with a significance level of less than 0.021,001. However, there was no difference observed between control and chloroform. Conclusions Within the limitations of this in vitro study, it can be concluded that the maximum amount of gutta-percha removal was found in the orange oil group. The amount of gutta-percha removal with orange oil significantly differs from xylene and chloroform, with a significance level of less than 0.02,001. Hence there was no difference observed between Control and Chloroform groups.

A Rare Insidious Case of Skin and Soft Tissue Infection Due to Mycobacterium abscessus: A Case Report.

Mycobacterium abscessus complex (MABc) is part of the rapid-growing non-tuberculous mycobacteria group that usually resides in natural water sources. When it affects humans, it can be highly resistant and difficult to manage. The most common presentation is localized, mainly in the lungs and soft tissue, but can be generalized in immunocompromised patients. Here we present a case report of a 40-year-old female with a chronic infection of the abdominal wall after abdominoplasty.

Assessment of empagliflozin add-on therapy to metformin and glimepiride in patients with inadequately controlled type-2 diabetes mellitus.

Diabetes mellitus is a multifaceted metabolic disorder, which often required frequent blood glucose monitoring, poly-pharmacy and timely adjustments for its management. The present study focuses to check the effectiveness of empagliflozin add-on therapy in diabetic patients already taking metformin and glimepiride. This was observational, comparative and follow-up cohort study, conducted in a tertiary care hospital of Pakistan. Ninety subjects were enrolled and evenly distributed in Group A (patients on oral therapy of Metformin & Glimepiride) and Group B (patients on oral therapy of metformin, glimepiride and empagliflozin) randomly. The results showed that the addition of empagliflozin to metformin and glimepiride standard therapy provided better control over blood sugar with a significant decrease in HbA1c (16.1% decrease in HbA1c for Group B patients against 8.2% in Group A patients), FBS (23.8% decrease as compared to 14.6% decrease) and BMI (1.5% decrease in Group B patients against 0.06% increase in Group A). The addition of empagliflozin did not exacerbate the toxicity of the existing regimen and is safe to be included in multiple drug regimens. Empagliflozin addition to standard antidiabetic therapy might possess beneficial impacts in managing poorly controlled Type-2 Diabetes Mellitus in the Pakistani population.

Comparative Evaluation of Antimicrobial Efficacy of Herbal Formulations of Septilin and Triphala with Conventional 2% Chlorhexidine on Root Canal and Oral Commensal Bacteria using Kirby Bauer Method: An in-vitro Study.

Background: Endodontic flareups are always very difficult to treat because of reasons like drug resistance previously sodium hypochlorite and chlorhexidine have been used in the literature but with advancements newer materials like herbal products have been tried for this purpose. Thus, present vitro study was conducted to comparatively evaluate the efficacy of herbal formulations on commensals of oral cavity and root canal. Materials and Methods: In this in vitro study antimicrobial efficacy of chlorhexidine 2%, Septilin and Triphala wer evaluated with the help of Kirby Bauer test. The microorganisms used were Staphylococcus aureus and Escherichia coli. The samples were placed in standardized wells and were subjected to incubation. Subsequently zones of inhibition were measured with the help of a caliper. One-factor analysis of variance, Tukey's least significant difference post hoc test and Student's independent t-test were performed to find a significant difference (P < 0.05) in the two groups. Results: For chlorhexidine in S. aureus mean antibacterial efficacy was 11.10 ± 1.25 and in E. coli 10.0 ± 1.33. The value for S. aureus was lesser in Triphala with a value of 10.35 ± 1.63 and in E. coli mean value was 9.05 ± 1.27. For Septilin the mean for S. aureus was 10.40 ± 1.04, and the mean antibacterial efficacy in E. coli was 9.65 ± 1.38. Conclusion: Septilin and Triphala showed remarkable efficacy concerning zones of inhibition. These herbal formulations have tremendous potential to be used as adjuncts to traditional disinfection modalities though it has scope of further research.

A comparative assessment of pomegranate extract, sodium hypochlorite, chlorhexidine, Myrrh (Commiphora molmol), tulsi extract against Enterococcus faecalis, Fusobacterium nucleatum and Staphylococci epidermidis.

BACKGROUND: The presence of pathogenic bacteria, toxins and byproducts in the root canal system show a decisive part in success of endodontic therapy. Thus, the complete removal of this bacterium is highly desirable. Several intracanal medicaments were tried to disinfect the root canal before obturation. AIM: The present study was conducted to compare Pomegranate, sodium hypochlorite, Chlorhexidine, Myrrh (Commiphora molmol), tulsi extract against Enterococcus faecalis, Fusobacterium nucleatum and Staphylococci epidermidis. SETTINGS AND DESIGN: Cross-sectional observational prospective study. MATERIALS AND METHODOLOGY: Aqueous extract of 20% pomegranate peel, 20% pomegranate peel, 0.2% CHX, 2.5% sodium hypochlorite, Tulsi extract and Myrrh (Commiphora molmol) was used as agent against E. faecalis, F. nucleatum and Staphylococci Epidermidis. Zone of inhibition and minimum inhibitory concentration (MIC) was calculated and compared using analysis of variance and Mann-Whitney test. The information was statistically evaluated with SPSS software version 20 with P < 0.05. RESULTS AND CONCLUSION: The mean zone of inhibition against E. faecalis, F. nucleatum and S. Epidermidis was highest in chlorhexidine and sodium hypochlorite groups compared to herbal groups. MIC was least with group III followed by group II against all bacterial species (P < 0.05). Sodium hypochlorite found comparatively better followed by chlorhexidine and other agents against E. faecalis, F nucleatum and S. epidermidis.

Preclinical assessment of analgesic, anti-inflammatory and antipyretic potential of Fragaria ananassa and Actinidia deliciosa fruit extract.

Fragaria ananassa (garden strawberry) and Actinidia deliciosa (kiwi) fruits are widely consumed due to their taste and nutritive value however several studies also supports their medicinal uses. Current study was designed to assess the In-Vivo analgesic, anti-inflammatory and antipyretic activity of ethanol extract of Fragaria ananassa (EEFA), Actinidia deliciosa (EEDA) and their 1:1 combination. Albino Wistar rats were divided into five groups (n=5) for each study comprising of vehicle control, reference standards *(aspirin and paracetamol 100 mg/kg/day), EEFA (800 mg/kg/day), EEAD (800 mg/kg/day) and 1:1 combination of EEFA and EEAD (400 + 400mg/kg/day). The results revealed significant anti-inflammatory potential of EEAD and their combination with 79.35% and 82.03% inhibition in carrageenan induced paw edema whereas 52.54% inhibition was produced by EEFA against control. However most powerful analgesic effect was produced by EEFA with 52.23% at 60 min followed by EEAD (48.38%) and EEFA+ EEAD combination (44.09%). Similarly, EEFA, EEAD and their combination also lowered the rectal temperature in highly significant manner (p< 0.01) against control. These results suggested the possible role of garden strawberry and kiwi in treating the ailments related to pain, inflammation and fever however further studies are required to elucidate the constituents responsible for it and their exact mechanism.

Characterization of a Bowman-Birk type trypsin inhibitor purified from seeds of Solanum surattense.

A Bowman-Birk type trypsin inhibitor protein (SSTI) from seeds of the medicinal plant Solanum surattense was isolated, purified and characterized. SSTI showed a single band on SDS-PAGE corresponding to 11.4 kDa molecular weight. It is a glycoprotein (2.8% glycosylation) that differentially interacted with trypsin and chymotrypsin in a concentration-dependent manner. Its peptide sequence is similar to other Bowman-Birk type protease inhibitors found in Glycine max and Phaseolus acutifolius. The inhibitory activity was stable over a wide range of pH (1-10) and temperatures (10-100° C). Far-UV Circular Dichroism (CD) studies showed that SSTI contains ß sheets (~ 23%) and α helix (~ 6%) and demonstrated structural stability at wide pH and high temperature. The kinetic analysis revealed a noncompetitive (mixed) type nature of SSTI and low inhibitor constant (Ki) values (16.6 × 10-8 M) suggested strong inhibitory activity. Isothermal titration calorimetric analysis revealed its high affinity towards trypsin with dissociation constant (Kd) 2.28 µM.

Diagnostic Accuracy of Multidetector CT in Detection of Early Interstitial Lung Disease With Its Role in Characterization.

Background Multidetector CT (MDCT) has emerged as a useful option for early diagnosis of interstitial lung disease (ILD) with adequate accuracy. Methods A total of 80 patients with restricted pulmonary functions and clinical suspicion of ILD were enrolled in the study. MDCT evaluation was done using Siemens Somatom Force 384 slice multidetector computer tomography machine. Pattern analysis for reticular opacities, nodules and lung opacities was done to reach at a diagnosis. Final diagnosis was based on correlation of radiological and clinicopathological findings. Diagnostic efficacy of MDCT was evaluated in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for detection of ILD. Results Mean age of patients was 58 ± 8.75 years. Majority were females (51.3%). History of chronic obstructive pulmonary disease (COPD), tuberculosis and bronchial asthma was revealed in 31 (38.8%), 26 (32.5%) and 16 (20%) patients, respectively. There were 30 (37.5%) patients having no history of respiratory diseases. MDCT diagnosed ILD in 45 (56.3%) cases. On final diagnosis, ILD was diagnosed in 35 (43.8%) cases (15 usual interstitial pneumonia [UIP], 9 cryptogenic organizing pneumonia [COP], 8 nonspecific interstitial pneumonia [NSIP] and 3 respiratory bronchiolitis associated interstitial lung disease [RBILD]). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of MDCT in detection of ILD was 91.4%, 71.1%, 71.1%, 91.4% and 80%, respectively. Conclusion MDCT as a single modality had a high sensitivity for detection of ILD and could be recommended as first line diagnostic imaging technique.

Screening of water distilled Rosa damascena Mill. flowers as hematopoietic agent in an animal model.

Pancytopenia is classified as low blood cell count. Low levels of hemoglobin, red blood cells, white blood cells and platelets are indicative of pancytopenic state. This pancytopenic state can be treatment (drug) or disease induced. Conventional approaches available to treat pancytopenia are usually associated with many undesirable adverse effects, are costly and parenterally administered. Interest in natural products has significantly increased due to their ability to stimulate cellular components of immune system. This study is designed to investigate the hematopoietic i.e. erythropoeitic, leucopoietic and thrombopoeitic potential of water distilled flowers of Rosa damascena Mill.

In-vitro bioassays of aqueous and ethanol extracts of Aseel dates.

Aseel is amongst the most vital date variety of Pakistan. Beside its nutritional value, it also got remedial uses therefore for the first time different in-vitro bioassays were performed to assess its medicinal value. Aqueous (DFAE) and ethanol (DFEE) extracts of fresh Aseel dates were used for the purpose. Microplate alamar blue assay was done for antibacterial activity, Brine shrimp lethality test for cytotoxicity and MTT assays with different cancer cell lines were used for anti-cancer activity. Antioxidant and anti-inflammatory activity were also evaluated by free radical scavenging bioassay and chemiluminescence technique. Alamar blue assay of both extracts exhibited weak antibacterial activity against E.coli, S, flexenari and S. aureus. Brine shrimp lethality revealed absence of cytotoxicity at 1000µ/mL concentration. DFEE 50 µ/mL was effective against MCF-7,MDA-MB-231, PC3, 3T3 and Hela cancer cell lines showing 17.59%, 20.90%, 37.60%, 22.35% and 36.70% inhibition whereas DFAE exhibits 20.46%, 30.86%, 15.21%, 29.70% and 16.40 % inhibition respectively. Similarly both extracts also showed varying degree of anti-oxidant and anti-inflammatory activity against standard drug. The results are suggestive of weak bioactivity of Aseel date extracts might because of reduced potency however further studies are required for better understanding of observed results and separation of active ingredients from Aseel dates.

The Fennel, Foeniculum vulgare incorporated diet shows anxiolytic potential: A pre-clinical study.

This novel study was conducted with objective to evaluate the anxiolytic potential of whole-crushed seeds of Foeniculum vulgare (FV) which were incorporated in diet. Albino mice were divided in three groups: Control-group, Study-group 2% FV and Study-group 4% FV, each having 10 mice. Special dietary pellets containing whole-crushed Foeniculum vulgare seeds were prepared in 2% and 4% ratio, respectively and were fed to respective Study groups whereas Control-group was given regular rodent diet for 2 months. Animal behaviour was assessed using Home Cage Activity test, Head Dip test, Light and Dark Box test and Open Field test at intervals of 15 days for a period of 2 months. The results of this study showed, decrease in Cage Crossing activity, more number of Head Dips, increased time spent in Light box and increase in number of transitions between Light and Dark Box, increased number of Central Squares Crossed and increased time spent in Central Squares of Open Field arena for both study groups in comparison with control group. Foeniculum vulgare whole-crushed seeds diet of 2% and 4% was found to have anxiolytic effect.

In vivo assessment of anticoagulant and antiplatelet effects of Syzygium cumini leaves extract in rabbits.

BACKGROUND: Syzygium cumini (L.) Skeels. is one of the very popular traditionally used medicinal plants with numerous pharmacological activities including antioxidant, hypoglycemic and anti-inflammatory. However, actions of S. cumini on blood coagulation and other parameters of blood were poorly pharmacologically studied. Therefore, aim of this present investigation is to examine the effects of methanolic extract of S. cumini on blood coagulation and anticoagulation factors in healthy white albino rabbits at different doses. METHODS: Blood samples were drawn twice during this study and biochemical assays were performed to determine the effect on different parameters such as coagulation, anticoagulation, hematological, Protein C (PC) and thrombin antithrombin (TAT) complex and platelet aggregation. RESULTS: The results showed significant increase in RBCs, hemoglobin, hematocrit and platelets counts up to 1.4 × 103/cm, 2.2 g/dl, 6%, 248.2 × 103/cm respectively. While, thrombin and bleeding time were also prolonged in dose dependent manner which is highly significant (p ≤ 0.005) as compared to control. Similarly, highly significantly increased (p ≤ 0.005) in levels of protein C, thrombin antithrombin complex at dose of 500 mg/kg were observed. Whereas, levels of platelets aggregation and fibrinogen were decreased at high doses. CONCLUSION: The obtained findings of hematological and coagulation tests concludes possibly S. cumini possess anticoagulant and antiplatelet effects.

Evaluation of pharmacological and toxic effects of ethanolic extract of radish pods in albino rabbits: A biochemical and histopathological study.

Radish pods are known as vegetable eaten as a part of diet. Though the pharmacologic potential of radish has been well known but there are fewer reports regarding pharmacological and toxic effects of radish pods. On account of this reason, the current study was aimed to evaluate the pharmacological and toxic effects of ethanol extract of Raphanus caudatus (radish pods) in rabbits after 60 days of administration. The plant extract was administered in 250, 500 and 1000mg/kg doses and effect was observed on hepatic, renal, cardiac and lipid profile. The extract was found to be hepatoprotective, nephroprotective and cardioprotective. Also it showed hypocholestrolemic potential at 1000 mg/kg. However at higher doses the extract presented chronic gastritis. Conversely, no indication of histological alterations was seen in other vital organs such as liver, kidneys, heart. Thus there is critical requirement to identify toxic constituent/s inducing gastritis so that safety profile of the plant can be established for effective therapeutic use.

Community acquired Klebsiella pneumoniae meningitis: a case report.

INTRODUCTION: Klebsiella pneumoniae meningitis is most commonly seen as a nosocomial infection and in post-neurosurgical patients. Reports of community acquired Klebsiella pneumoniae meningitis cases are rare in the United States. The objective of this case report is to discuss an uncommon pathogen causing meningitis, Klebsiella pneumoniae, its risk and prognostic factors and to emphasize the importance of early recognition and appropriate antibiotic treatment. CASE REPORT: We report a clinical case of adult community acquired Klebsiella pneumoniae meningitis with recovery. A 54-year-old diabetic male presented with two-week history of intermittent fevers, acute bilateral ear pain, headache and unsteady gait. Broad spectrum antibiotics were initiated. Klebsiella pneumoniae was isolated in the cerebrospinal fluid cultures. The patient recovered with only mild hearing loss in his left ear. CONCLUSION: Our case highlights the importance of suspecting Klebsiella pneumoniae in community acquired meningitis.

In vivo evaluation of antihyperlipidemic, antihyperglycemic and hepatoprotective effects of Vernonia anthelmintica seeds in diet model.

Anti-hyperglycemic, anti-hyperlipidemic and hepatoprotective effects of Vernonia anthelmintica seeds were evaluated in diet rat model. The study included forty eight Sprague Dawley rats of either sex with eight animals in each group. Except for control the disease control, standard and treatment groups were treated with high-fat high-sugar diet for 8 weeks. After confirmation of hyperlipidemia and hyperglycemia, the standard group received atorvastatin (2.1 mg.kg-1), treatment groups received hexane extract, ethanol extract and water decoction of Vernonia anthelmintica seeds (300mg.kg-1) for next 30 days. Disease control and control were given normal saline in volume equivalent to other groups. High-fat high-sugar diet was continued in all groups except control for 30 day period. Lipid profile, liver function tests and fasting blood sugar were analyzed in fasting blood samples. Cardiac risk parameters were calculated and results were analyzed by one way ANOVA using SPSS. All three tested extracts showed significant decrease in fasting blood glucose, LDL-C, triglycerides, VLDL-C and cardiac risk parameters as compared to disease control. However, HDL-C and cholesterol levels in treatment groups were found to be significantly increased compared to disease control. Furthermore, treatment groups showed significantly decreased AST and ALP levels compared to disease control. Hexane extract, ethanol extracts and water decoction of Vernonia anthelmintica seeds exhibited potential anti-hyperglycemic, anti-hyperlipidemic effects with favorable hepatic profile. However, further studies should be designed to strengthen these findings on mechanistic ground.

Report - Antidiabetic effects of native date fruit Aseel (Phoenix dactylifera L.) in normal and hyperglycemic rats.

Change in dietary pattern, sedentary life style and increasing stresses are contributing factors for high prevalence of diabetes mellitus. Diabetic complications often lead to cardiovascular diseases, hypertension and hyperlipidemia that are the leading cause death and disability all over the world. Apart from pharmacotherapy, use of antihyperglycemic medicinal food is a new aspect in diabetes management and prevention of its complications. Phoenix dactylifera (date palm) has been traditionally used for different diseases because of the presence of bioactive agents like anthocyanin, phenols, sterols, carotenoids, procyanidins and flavonoids however its potential as a medicinal food is still unclear. Native date fruit variety Aseel oral suspension was evaluated using 32 normoglycemic and hyperglycemic Sprague dawley rats with two doses (300 and 600mg/kg) against control, disease control and standard drug (Glibenclamide 2.5mg/kg). Outcomes of normoglycemic studies reveals insignificant glucose lowering effects however hyperglycemic studies (glucose challenge and Alloxan inducted hyperglycemia) demonstrates significant glucose lowering effect of Aseel date especially with 300mg/kg dose. Data obtained during this study reveal significant anti-hyperglycemic effects of Aseel dates in diabetes management however further preclinical and clinical studies are required to verify the same.

Evaluation of anti-inflammatory and anti-oxidant potential of seed extracts of Vernonia anthelmintica.

Seeds of Vernonia anthelmintica in the form of Ethanol seed extract of Vernonia anthelmintica (EEVA), Hexane extract of Vernonia anthelmintica (HEVA) and water decoction of Vernonia anthelmintica (WDVA) were evaluated for their in-vivo anti-Inflammatory potential in carrageenan induced rat paw model. The results were compared to anti-inflammatory activity of standard drug (ibuprofen) and untreated groups. In-vitro evaluation of antioxidant potential of EEVA and HEVA were also conducted by "DPPH scavenging assay". The results of present study depicts that HEVA and EEVA in higher dose possess a strong anti-inflammatory potential as compared to standard anti-inflammatory drugs, whereas WDVA showed milder anti-inflammatory potential. DPPH assay has revealed strong anti-oxidant potential of EEVC with the percentage Radical Scavenging activity (%RSA) of 89.709 at concentrations of 500 ul as compared to standard drugs gallic acid (23.436±0.43) and acetyl salicylic acid (111.44±0.7) at concentrations of 95.95 µM. The other extract HEVC has shown to have insignificant %RSA at the concentration of 500µl. Hence the present study revealed that selected extracts of Vernonia anthelmintica exhibited significant in-vitro antioxidant and in-vivo anti-inflammatory potential.

Molecular determinants of substrate specificity revealed by the structure of Clostridium thermocellum arabinofuranosidase 43A from glycosyl hydrolase family 43 subfamily 16.

The recent division of the large glycoside hydrolase family 43 (GH43) into subfamilies offers a renewed opportunity to develop structure-function studies aimed at clarifying the molecular determinants of substrate specificity in carbohydrate-degrading enzymes. α-L-Arabinofuranosidases (EC 3.2.1.55) remove arabinose side chains from heteropolysaccharides such as xylan and arabinan. However, there is some evidence suggesting that arabinofuranosidases are substrate-specific, being unable to display a debranching activity on different polysaccharides. Here, the structure of Clostridium thermocellum arabinofuranosidase 43A (CtAbf43A), which has been shown to act in the removal of arabinose side chains from arabinoxylan but not from pectic arabinan, is reported. CtAbf43A belongs to GH43 subfamily 16, the members of which have a restricted capacity to attack xylans. The crystal structure of CtAbf43A comprises a five-bladed ß-propeller fold typical of GH43 enzymes. CtAbf43A displays a highly compact architecture compatible with its high thermostability. Analysis of CtAbf43A along with the other member of GH43 subfamily 16 with known structure, the Bacillus subtilis arabinofuranosidase BsAXH-m2,3, suggests that the specificity of subfamily 16 for arabinoxylan is conferred by a long surface substrate-binding cleft that is complementary to the xylan backbone. The lack of a curved-shaped carbohydrate-interacting platform precludes GH43 subfamily 16 enzymes from interacting with the nonlinear arabinan scaffold and therefore from deconstructing this polysaccharide.