Trypsin is inhibited by phytocompounds liquiritin and terpinen-4-ol from the herb Glycyrrhiza glabra: in vitro and in silico studies

Serine proteases are a class of hydrolytic enzymes involved in various physiological functions like digestion, coagulation, fibrinolysis and immunity. The present study evaluates the serine protease inhibitory potential of phytochemicals liquiritin and terpinen-4-ol present in the herb Glycyrrhiza glabra L. using trypsin as the model enzyme. In silico studies showed that both the compounds have a significant binding affinity towards trypsin with a binding energy of -26.66 kcal/mol and -19.79 kcal/mol for liquiritin and terpinen-4-ol, respectively. Their binding affinity was confirmed through in vitro enzyme inhibition assays. The mode of inhibition was found to be uncompetitive. In order to explain the mode of inhibition, docking of the ligands to the enzyme-substrate complex was also done and binding energy was calculated after MD simulation. The energy values showed that the binding affinities of these compounds towards the enzyme substrate complex are more than that towards the enzyme alone. This explains the uncompetitive mode of inhibition.Communicated by Ramaswamy H. Sarma.

Carboxylic acid derivatives suppress the growth of Aspergillus flavus through the inhibition of fungal alpha-amylase

Aspergillus favus (A. flavus) is a saprophytic fungus and a pathogen affecting several important foods and crops, including maize. A. flavus produces a toxic secondary metabolite called aflatoxin. Alpha-amylase (α-amylase), a hydrolytic enzyme produced by A. Flavus helps in the production of aflatoxin by hydrolysing the starch molecules in to simple sugars such as glucose and maltose. These simple sugars induce the production of aflatoxin. Inhibition of α-amylase has been proven as a potential way to reduce the production of aflatoxin. In the present study, we investigated the effect of selected carboxylic acid derivatives such as cinnamic acid (CA), 2, 4-dichlorophenoxyacetic acid (2,4-D), and 3-(4-hydroxyphenyl)-propionic acid (3,4-HPPA) on the fungal growth and for the α-amylase inhibitory activity. The binding potentials of these compounds with α-amylase have been confirmed by enzyme kinetics and isothermal titration calorimetry. Molecular docking and MD simulation studies were also performed to deduce the atomic level interaction between the protein and selected ligands. The results indicated that CA, 2,4-D and 3,4-HPPA can inhibit the fungal growth which could be partly due to the inhibition on fungal α-amylase activity.Communicated by Ramaswamy H. Sarma.

Unveiling the molecular basis of lobeline's allosteric regulation of NMDAR: insights from molecular modeling

Neurological and psychiatric disorders contribute significantly to the global disease burden, adversely affecting the quality of life for both patients and their families. Impaired glutamatergic signaling is considered to be a major cause for most of the neurological and psychiatric disorders. Glutamate receptors are over activated in excitotoxic conditions, leading to dysregulation of Ca2+ homeostasis, triggering the production of free radicals and oxidative stress, mitochondrial dysfunction and eventually cell death. Excitotoxicity primarily results from the overactivity of NMDARs, a subtype of ionotropic glutamate receptors, due to their pronounced Ca2+ permeability and conductance characteristics. NMDAR antagonists are suggested to have therapeutic use as they can prevent excitotoxicity. Our previous studies demonstrated lobeline, an alkaloid, exerts neuroprotective action in excitotoxic conditions by blocking NMDAR. However, the atomic level interactions of lobeline with NMDAR was not characterized yet. Structural comparison of lobeline with a known NMDAR antagonist ifenprodil, followed by molecular docking and dynamics simulations revealed that lobeline could bind to the ifenprodil binding site i.e., in the heterodimer interface of GluN1-GluN2B subunits and exert ifenprodil like activities. By in silico structure guided modifications on lobeline and subsequent free energy calculations, we propose putative NMDAR antagonists derived from lobeline.

An online mind-body program improves mental health and quality of life in primary biliary cholangitis: A randomized controlled trial

BACKGROUND AND AIMS

People with primary biliary cholangitis (PBC) experience high rates of mental distress and fatigue despite standard of care therapy. We aimed to assess the impact of an online mind-body intervention on these symptoms.

METHODS

This 12-week RCT used sequential mixed-methods evaluation. Alongside standard of care, participants with primary biliary cholangitis were randomized to receive weekly countdown emails, or the intervention consisting of (i) a weekly 20-30 minute-mind-body follow-along video, (ii) weekly 5-10-minute psychology-based "managing chronic disease skills videos," and (iii) 10-minute telephone check-ins. The primary outcome was a change in the Hospital Anxiety and Depression Scale (HADS). Secondary outcomes evaluated changes in fatigue, perceived stress, resilience, and health-related quality of life. ANCOVA determined between-group differences.

RESULTS

Of the 87 randomized patients (control group: n = 44, intervention group: n = 43), the between-group HADS total score improved by 20.0% (95% CI 4.7, 35.2, p = 0.011). Significant improvements were seen in depression (25.8%), perceived stress (15.2%), and 2 primary biliary cholangitis-40 domains [emotional symptoms (16.3%) and social symptoms (11.8%)] with a mean satisfaction of 82/100. This corresponded with end-of-study qualitative findings. Although no improvements were observed in fatigue in the main analysis, a significant benefit was observed in the subgroup of intervention participants (20/36;56%) who completed the mind-body video routine at least 3 times per week.

CONCLUSION

This intervention improved measures of mental wellness and quality of life with high satisfaction and reasonable adherence. Future studies could explore strategies to optimize adherence and target fatigue.

Examining Patient Engagement in Chatbot Development Approaches for Healthy Lifestyle and Mental Wellness Interventions: Scoping Review

BACKGROUND

Chatbots are growing in popularity as they offer a range of potential benefits to end users and service providers.

OBJECTIVE

Our scoping review aimed to explore studies that used 2-way chatbots to support healthy eating, physical activity, and mental wellness interventions. Our objectives were to report the nontechnical (eg, unrelated to software development) approaches for chatbot development and to examine the level of patient engagement in these reported approaches.

METHODS

Our team conducted a scoping review following the framework proposed by Arksey and O'Malley. Nine electronic databases were searched in July 2022. Studies were selected based on our inclusion and exclusion criteria. Data were then extracted and patient involvement was assessed.

RESULTS

16 studies were included in this review. We report several approaches to chatbot development, assess patient involvement where possible, and reveal the limited detail available on reporting of patient involvement in the chatbot implementation process. The reported approaches for development included: collaboration with knowledge experts, co-design workshops, patient interviews, prototype testing, the Wizard of Oz (WoZ) procedure, and literature review. Reporting of patient involvement in development was limited; only 3 of the 16 included studies contained sufficient information to evaluate patient engagement using the Guidance for Reporting Involvement of Patients and Public (GRIPP2).

CONCLUSIONS

The approaches reported in this review and the identified limitations can guide the inclusion of patient engagement and the improved documentation of engagement in the chatbot development process for future health care research. Given the importance of end user involvement in chatbot development, we hope that future research will more systematically report on chatbot development and more consistently and actively engage patients in the codevelopment process.

Binding of rosmarinic acid curcumin and capsaicin with PLA2: A comparative study

Phospholipase A2 (PLA2) is a key enzyme involved in the formation of pro-inflammatory mediators like eicosanoids. Inhibition of PLA2 is regarded as one of the effective methods of controlling inflammation. The present study investigated the binding potentials of three natural compounds, rosmarinic acid (RA), capsaicin (CAP), and curcumin (CUR) by means of in silico and in vitro methods. Our study revealed that RA has relatively better binding affinity and inhibition potentials when compared to the other two molecules. Our ITC experiments were also suggested a slightly better binding energy for the RA. The stoichiometry of the protein ligand complex obtained from one of the ITC experiments suggested the possibilities of binding of a small molecule MCW (degraded product of CUR) on PLA2. Overall study demonstrated that the anti-inflammatory activity of RA, CUR and CAP may be partly due to the inhibition of PLA2.

Neuroprotective derivatives of tacrine that target NMDA receptor and acetyl cholinesterase - Design, synthesis and biological evaluation

The complex and multifactorial nature of neuropsychiatric diseases demands multi-target drugs that can intervene with various sub-pathologies underlying disease progression. Targeting the impairments in cholinergic and glutamatergic neurotransmissions with small molecules has been suggested as one of the potential disease-modifying approaches for Alzheimer’s disease (AD). Tacrine, a potent inhibitor of acetylcholinesterase (AChE) is the first FDA approved drug for the treatment of AD. Tacrine is also a low affinity antagonist of N-methyl-D-aspartate receptor (NMDAR). However, tacrine was withdrawn from its clinical use later due to its hepatotoxicity. With an aim to develop novel high affinity multi-target directed ligands (MTDLs) against AChE and NMDAR, with reduced hepatotoxicity, we performed in silico structure-based modifications on tacrine, chemical synthesis of the derivatives and in vitro validation of their activities. Nineteen such derivatives showed inhibition with IC₅₀ values in the range of 18.53 ± 2.09 – 184.09 ± 19.23 nM against AChE and 0.27 ± 0.05 – 38.84 ± 9.64 μM against NMDAR. Some of the selected compounds also protected rat primary cortical neurons from glutamate induced excitotoxicity. Two of the tacrine derived MTDLs, 201 and 208 exhibited in vivo efficacy in rats by protecting against behavioral impairment induced by administration of the excitotoxic agent, monosodium glutamate. Additionally, several of these synthesized compounds also exhibited promising inhibitory activitiy against butyrylcholinesterase. MTDL-201 was also devoid of hepatotoxicity in vivo. Given the therapeutic potential of MTDLs in disease-modifying therapy, our studies revealed several promising MTDLs among which 201 appears to be a potential candidate for immediate preclinical evaluations.

Drug repurposing against SARS-CoV-2 using E-pharmacophore based virtual screening, molecular docking and molecular dynamics with main protease as the target

Since its first report in December 2019 from China, the COVID-19 pandemic caused by the beta-coronavirus SARS-CoV-2 has spread at an alarming pace infecting about 5.59 million, and claiming the lives of more than 0.35 million individuals across the globe. The lack of a clinically approved vaccine or drug remains the biggest bottleneck in combating the pandemic. Drug repurposing can expedite the process of drug development by identifying known drugs which are effective against SARS-CoV-2. The SARS-CoV-2 main protease is a promising drug target due to its indispensable role in viral multiplication inside the host. In the present study an E-pharmacophore hypothesis was generated using a crystal structure of the viral protease in complex with an imidazole carbaximide inhibitor. Drugs available in the superDRUG2 database were used to identify candidate drugs for repurposing. The hits obtained from the pharmacophore based screening were further screened using a structure based approach involving molecular docking at different precisions. The binding energies of the most promising compounds were estimated using MM-GBSA. The stability of the interactions between the selected drugs and the target were further explored using molecular dynamics simulation at 100 ns. The results showed that the drugs Binifibrate and Bamifylline bind strongly to the enzyme active site and hence they can be repurposed against SARS-CoV-2. However, U.S Food and Drug Administration have withdrawn Binifibrate from the market as it was having some adverse health effects on patients.Communicated by Ramaswamy H. Sarma.

Mitral valve repair in an octogenarian with symptomatic severe mitral regurgitation: First use of MitraClip in India

Percutaneous mitral valve repair is an accepted treatment of choice in Europe and North America for severe primary or secondary mitral regurgitation, in highly symptomatic patients for whom surgical repair is prohibitively high risk. We describe the first use of the MitraClip in India in a frail elderly female with symptomatic heart failure from severe primary mitral regurgitation who was considered high risk for surgical repair. She had substantial improvement in her symptoms as well as quality of life following the procedure.

Virtual screening-based identification of novel fatty acid synthase inhibitor and evaluation of its antiproliferative activity in breast cancer cells

Cancer cells activate de novo lipogenesis by overexpressing the lipogenic enzymes ACLY, ACC and FASN to support rapid cell division. FASN, previously known as oncogenic antigen-519 (OA-519) catalyzes seven sequential reactions to synthesize palmitic acid (C16) from substrates acetyl CoA, and malonyl CoA. The dependence of cancer cells on FASN-derived lipids and the differential expression of FASN in cancer cells compared to their normal counterparts make it an attractive metabolic drug target in cancer therapy. In the present study, an attempt has been made to identify potent FASN inhibitors from Asinex-Synergy compound database using structure-based virtual screening. The serial docking protocols of increasing precisions identified LEG-17649942, with glide score -10.34 kcal/mol as a promising compound which can directly interact with active site residues H293 and H331. LEG-17649942 possesses drug-like pharmacokinetic properties as predicted by Qikprop. LEG-17649942 exhibited cytotoxicity in breast cancer cell lines SK-BR-3, MCF-7 and MDA-MB-231 with maximum activity against MDA-MB-231 cells with IC50 of 50 μM. The study put forward LEG-17649942 as a novel drug-lead compound against triple negative breast cancer with an exquisite binding pattern to FASN-KS domain.

Chemical similarity assisted search for acetylcholinesterase inhibitors: Molecular modeling and evaluation of their neuroprotective properties

Alzheimer's disease (AD) is an obstinate and progressive neurodegenerative disorder, mainly characterized by cognitive decline. Increasing number of AD patients and the lack of promising treatment strategies demands novel therapeutic agents to combat various disease pathologies in AD. Recent progresses in understanding molecular mechanisms in AD helped researchers to streamline the various therapeutic approaches. Inhibiting acetylcholinesterase (AChE) activity has emerged as one of the potential treatment strategies. The present study discusses the identification of two potent AChE inhibitors (ZINC11709541 and ZINC11996936) from ZINC database through conventional in silico approaches and their in vitro validations. These inhibitors have strong preferences towards AChE than butyrylcholinesterase (BChE) and didn't evoke any significant reduction in the cell viability of HEK-293 cells and primary cortical neurons. Furthermore, promising neuroprotective properties has also been displayed against glutamate induced excitotoxicity in primary cortical neurons. The present study proposes two potential drug lead compounds for the treatment of AD, that can be used for further studies and preclinical evaluation.

Pyridine derivatives as anticancer lead compounds with Fatty Acid Synthase as the target: An in silico-guided in vitro study

For the past few decades, structure-based drug discovery (SBDD) has become an inevitable technique in the drug development process for screening hit compounds against therapeutic targets. Here, we have successfully used the SBDD approach viz. virtual high-throughput screening to identify potential inhibitors against the Ketoacyl synthase (KS) domain of Fatty acid synthase (FASN). Overexpression of FASN, and subsequent enhancement of de novo lipogenesis is a key survival strategy of cancer cells. Hence, targeting lipid metabolism using FASN inhibitors has been considered as a promising method to induce metabolic stress, thereby posing a survival disadvantage to cancer cells. In the present study, we have successfully identified eight FASN inhibitors from Asinex Elite database by implementing in silico tools. Five of the hit compounds share a common ring structure, which enables characteristic binding interactions with FASN-KS. Among them, in vitro validation showed that SFA 22637550 possesses significant FASN inhibitory activity and antiproliferative effect in human cancer cells of various origins. The maximum sensitivity was exhibited towards HepG2 hepatocellular carcinoma cells (IC50 = 28 µM). The mode of cell death was found to be apoptosis with a significant increase in SubG0 population without affecting any other phases of the cell cycle. The current study puts forward an excellent core structure for the development of potent FASN inhibitors for successfully targeting cancer cell metabolism, thereby causing selective cell death.

Indole fragments for the design of lead molecules against pancreatitis

Communicated by Ramaswamy H. Sarma.

Computational and experimental validation of morin as adenosine deaminase inhibitor

Adenosine deaminase (ADA) is one of the major enzymes involved in purin metabolism, it has a significant role in cell growth and differentiation. Over-activity of ADA has been noticed in some pathology, like malignancy and inflammation and makes it an attractive target for the development of drugs for such diseases. In the present study, ADA inhibitory activity of morin, a bioactive flavonoid, was assessed through computational and biophysical methods. The enzyme kinetics data showed that morin is a competitive inhibitor of ADA. Binding energy calculated from ITC analysis was -7.11 kcal/mol. Interaction of morin with ADA was also studied using fluorescence quenching method. Molecular docking studies revealed the structural details of the interaction. Molecular dynamics study in explicit solvent was also conducted to assess the structural stability of protein ligand complex.

Inhibitory activity of hibifolin on adenosine deaminase- experimental and molecular modeling study

Adenosine deaminase (ADA) is an enzyme involved in purine metabolism. ADA converts adenosine to inosine and liberates ammonia. Because of their critical role in the differentiation and maturation of cells, the regulation of ADA activity is considered as a potential therapeutic approach to prevent malignant and inflammatory disorders. In the present study, the inhibitory activity of a plant flavonoid, hibifolin on ADA is investigated using enzyme kinetic assay and isothermal titration calorimetry. The inhibitory constant of hibifolin was found to be 49.92μM±3.98 and the mode of binding was reversible. Isothermal titration calorimetry showed that the compound binds ADA with binding energy of -7.21Kcal/mol. The in silico modeling and docking studies showed that the bound ligand is stabilized by hydrogen bonds with active site residues of the enzyme. The study reveals that hibifolin can act as a potential inhibitor of ADA.

Trichoderma viride Laccase Plays a Crucial Role in Defense Mechanism against Antagonistic Organisms

Fungal laccases are involved in a variety of physiological functions such as delignification, morphogenesis, and parasitism. In addition to these functions, we suggest that fungal laccases are involved in defense mechanisms. When the laccase secreting Trichoderma viride was grown in the presence of a range of microorganisms including bacteria and fungi, laccase secretion was enhanced in response to antagonistic organisms alone. In addition, growth of antagonistic microbes was restricted by the secreting fungi. Besides, our study for the first time shows the inability of the secreting fungi (T. viride) to compete with antagonistic organism when laccase activity is inhibited, further emphasizing its involvement in rendering a survival advantage to the secreting organism. When laccase inhibitor was added to the media, the zone of inhibition exerted by the antagonist organism was more pronounced and consequently growth of T. viride was significantly restricted. Based on these observations we accentuate that, laccase plays an important role in defense mechanism and provides endurance to the organism when encountered with an antagonistic organism in its surrounding.

Comparative studies on the inhibitory activities of selected benzoic acid derivatives against secretory phospholipase A2, a key enzyme involved in the inflammatory pathway

Inhibitory activities of selected benzoic acid derivatives against phospholipase A₂.

TRAIL-based tumor sensitizing galactoxyloglucan, a novel entity for targeting apoptotic machinery

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for cancer therapy due to its ability to selectively induce apoptosis in cancer cells, without causing significant toxicity in normal tissues. We previously reported that galactoxyloglucan (PST001) possesses significant antitumor and immunomodulatory properties. However, the exact mechanism in mediating this anticancer effect is unknown. This study, for the first time, indicated that PST001 sensitizes non-small cell lung cancer (A549) and nasopharyngeal (KB) cells to TRAIL-mediated apoptosis. In vitro studies suggested that PST001 induced apoptosis primarily via death receptors and predominantly activated caspases belonging to the extrinsic apoptotic cascade. Microarray profiling of PST001 treated A549 and KB cells showed the suppression of survivin (BIRC5) and anti-apoptotic Bcl-2, as well as increased cytochrome C. TaqMan low density array analysis of A549 cells also confirmed that the induction of apoptosis by the polysaccharide occurred through the TRAIL-DR4/DR5 pathways. This was finally confirmed by in silico analysis, which revealed that PST001 binds to TRAIL-DR4/DR5 complexes more strongly than TNF and Fas ligand-receptor complexes. In summary, our results suggest the potential of PST001 to be developed as an anticancer agent that not only preserves innate biological activity of TRAIL, but also sensitizes cancer cells to TRAIL-mediated apoptosis.

Cuminaldehyde as a lipoxygenase inhibitor: in vitro and in silico validation

The search for lipoxygenase (LOX) inhibitors has been carried out for decades due to its importance in inflammatory diseases. In the present study, it was observed that the methanolic extract of Cuminum cyminum L. inhibited LOX activity. Activity-guided screening of the C. cyminum crude extracts helped the identification and isolation of cuminaldehyde as a 15-LOX inhibitor. The enzyme kinetics analysis suggested cuminaldehyde to be a competitive inhibitor and the IC 50 value derived from LB plots is 1,370 μM. Binding constants of cuminaldehyde on LOX was deduced by isothermal titration calorimetry. The combined thermodynamics and molecular modeling analyses suggested cuminaldehyde as a competitive LOX inhibitor. It is proposed from the present study that the coordinate bond between the Fe(2+) atom in the active site of the enzyme and the cuminaldehyde may be responsible for the enzyme inhibition. The study suggests that cuminaldehyde may be acting as an anti-inflammatory compound and may be therefore included in the category of leads for developing dual COX-LOX inhibitors as non-steroidal anti-inflammatory drugs (NSAIDs).

Flavanone glycosides as acetylcholinesterase inhibitors: computational and experimental evidence

Acetylcholinesterase hydrolyzes the neurotransmitter called acetylcholine and is crucially involved in the regulation of neurotransmission. One of the observable facts in the neurodegenerative disorders like Alzheimer's disease is the decrease in the level of acetylcholine. Available drugs that are used for the treatment of Alzheimer's disease are primarily acetylcholinesterase inhibitors with multiple activities. They maintain the level of acetylcholine in the brain by inhibiting the acetylcholinesterase function. Hence acetylcholinesterase inhibitors can be used as lead compounds for the development of drugs against AD. In the present study, the binding potential of four flavanone glycosides such as naringin, hesperidin, poncirin and sakuranin against acetylcholinesterase was analysed by using the method of molecular modeling and docking. The activity of the top scored compound, naringin was further investigated by enzyme inhibition studies and its inhibitory concentration (IC50) towards acetylcholinesterase was also determined.

Isolation of a salt tolerant laccase secreting strain of Trichoderma sp. NFCCI-2745 and optimization of culture conditions and assessing its effectiveness in treating saline phenolic effluents

Most of the hazardous pollutants are phenolic in nature and persists in the environment. The ability of laccases to oxidize phenolic compounds and reduce molecular oxygen to water has led to intensive studies of these enzymes. Therefore the fungal strains with high laccase activity and substrate affinity that can tolerate harsh environmental conditions have a potential for biotechnological applications. Salt tolerant laccase secreting fungi can be utilized in treatment of saline and phenolic rich industrial effluents such as coir effluent and textile effluent that needed to be diluted several fold before microbial treatment. This is the first study describing the isolation and optimization of a salt tolerant strain of Trichoderma sp. potential for industrial applications. The fungus was identified based on morphological characteristics and was subsequently confirmed with molecular techniques and deposited at National Fungal Culture Collections of India (NFCCI) under the Accession No. Trichoderma viride NFCCI 2745. In contrast to other laccase secreting fungi, light conditions did not exert much influence on laccase production of this strain and salinity enhanced its laccase secretion. The fungus effectively removed the phenolic content of the textile effluent, coir-ret liquor and wood processing effluent within 96 hr of incubation. The tolerance of the fungus to high salinity and phenolic compounds makes this strain ideal for treating saline and phenolic rich industrial effluents.

Interactions of selected indole derivatives with COX-2 and their in silico structure modifications towards the development of novel NSAIDs

Cyclooxygenase-2 (COX-2) is an important enzyme responsible for the formation of potent inflammatory mediators like prostaglandins, prostacyclin and thromboxane. Hence, inhibition of COX-2 is one of the best ways to control the inflammation. Non-steroidal anti-inflammatory drugs can control inflammation by inhibiting Cyclooxygenase. Selective inhibition of COX-2 is preferable over the inhibition of COX-1 because of the fewer adverse effects produced. Molecular modeling and docking of 134 selected indole compounds were done against COX-2. The pharmacophore-based in silico structural modifications of the best scored compounds were carried out in order to enhance the binding affinity and selectivity. The modification resulted in derivatives with better binding energies than that of known COX-2 inhibitors. The four best derivatives in terms of the binding energies were selected and their binding stabilities were studied by molecular dynamics simulation methods.

Potential of the salt-tolerant laccase-producing strain Trichoderma viride Pers. NFCCI-2745 from an estuary in the bioremediation of phenol-polluted environments

Industrialization causes the generation of phenolic pollutants in the environment. The ability of laccases to oxidize phenolic compounds and reduce molecular oxygen to water has led to intensive studies on these enzymes. Although salt-tolerant fungi are potential sources of enzymes for industrial applications, they have been inadequately explored for laccase production. This study describes the isolation of a salt- and phenol-tolerant strain of Trichoderma sp. with the ability to produce laccase, and thus with the potential for industrial applications. The coconut husk retting ground in the estuaries of Kerala, India, a saline environment highly polluted with phenolic compounds, was selected for isolating the fungus. Enhanced laccase production was observed at 5-10 ppt salinity. The organism could grow even at 30 ppt salinity with reduced biomass production and laccase secretion. The optimum concentration of different phenolic compounds for enhanced laccase secretion ranged between 20 and 80 mg L(-1) . As the concentration of phenolic compounds increased beyond 200 mg L(-1) , the enzyme activity decreased and was completely inhibited at 800 mg L(-1) . The tolerance of Trichoderma viride Pers. NFCCI-2745 to salinity and various phenolic compounds can be utilized in the bioremediation of highly saline and phenolic compound-rich industrial effluents.

Crystallization and preliminary X-ray studies of a galactose-specific lectin from the seeds of Spatholobus parviflorus

A galactose-specific seed lectin was purified from the legume Spatholobus parviflorus and crystallized using the hanging-drop vapour-diffusion technique. The crystals belonged to space group P1, with unit-cell parameters a = 60.998, b = 60.792, c = 78.179 Å, α = 101.32, β = 91.38, γ = 104.32°. X-ray diffraction data were collected under cryoconditions (100 K) to a resolution of 2.04 Å using a MAR image-plate detector system mounted on a rotating-anode X-ray (Cu Kα) generator. Molecular replacement using legume-lectin coordinates as a search model gave a tetrameric structure.

Identification of a novel and potent inhibitor of phospholipase A(2) in a medicinal plant: crystal structure at 1.93Å and Surface Plasmon Resonance analysis of phospholipase A(2) complexed with berberine

Crystal of Russell Viper venom phospholipase A(2) complexed with an isoquinoline alkaloid, berberine from a herbaceous plant Cardiospermum halicacabum, was prepared and its structure was solved by X-ray crystallography. The crystal diffracted up to 1.93Å and the structure solution clearly located the position of berberine in the active site of the enzyme. Two hydrogen bonds, one direct and the other water mediated, were formed between berberine and the enzyme. Gly 30 and His 48 made these two hydrogen bonds. Additionally, the hydrophobic surface of berberine made a number of hydrophobic contacts with side chains of neighboring amino acids. Surface Plasmon Resonance studies revealed strong binding affinity between berberine and phospholipase A(2). Enzyme inhibition studies proved that berberine is a competitive inhibitor of phospholipase A(2). It was inferred that the isoquinoline alkaloid, berberine, is a potent natural inhibitor of phospholipaseA(2).

Crystallization and preliminary X-ray diffraction analysis of a galactose-specific lectin from the seeds of Butea monosperma

The galactose-specific lectin from the seeds of Butea monosperma has been crystallized by the hanging-drop vapour-diffusion technique. The crystals belonged to space group P1, with unit-cell parameters a = 78.45, b = 78.91, c = 101.85 Å, α = 74.30, β = 76.65, γ = 86.88°. X-ray diffraction data were collected to a resolution of 2.44 Å under cryoconditions (100 K) using a MAR image-plate detector system mounted on a rotating-anode X-ray generator. Molecular-replacement calculations carried out using the coordinates of several structures of legume lectins as search models indicate that the galactose-specific lectin from B. monosperma forms an octamer.

Bisphenol-A can bind to human glucocorticoid receptor as an agonist: an in silico study

Bisphenol-A (BPA) is a primary monomer in polycarbonate plastics and epoxy resins. BPA may be released into the environment following its formation via hydrolysis of ester bonds of the polymers. It has been detected in human plasma, placenta, amniotic fluid, amniotic chord, urine and saliva. BPA disrupts normal cell function by acting as an estrogen agonist as well as an androgen antagonist. The present study was carried out to investigate whether BPA can bind to human glucocorticoid receptor (GR) and elucidate its mode of interaction. BPA has been successfully docked in silico into the ligand binding site of GR using the program Discovery Studio 2.0. The structure has been compared with other agonist and antagonist bound structures of GR. It is found that the mode of interactions and binding energy of BPA were similar to that of DEXA and cortisol, two known agonists of GR. This reveals that BPA can bind to GR as an agonist. Hence, BPA may produce biological effects similar to that produced by glucocorticoids.

Isolation of 1,4-naphthalenedione, an antibacterial principle from the leaves of Holoptelea integrifolia and its activity against beta-lactam resistant Staphylococcus aureus

Antimicrobials derived from plants have been receiving increasing attention in recent years. Antimicrobial activities of a number of phytochemicals have been reported. Many present day antibiotics are ineffective against several pathogenic organisms. About 90% of Staphylococcus aureus isolates from clinical specimens is reported to have resistance against beta-lactam antibiotics. In the present study, the effect of hexane, diethyl ether, acetone and water extracts of leaves of a medicinal plant Holoptelea integrifolia has been tested against beta-lactam resistant strain of S. aureus in presence of antibiotics such as ampicillin, amoxicillin, cefotaxime and ceftriaxone. The diethyl ether extract has shown the maximum antibacterial activity and the active principle is found to be 1,4-naphthalenedione which is characterized by GC-MS and FTIR spectroscopy. The minimum inhibitory concentration (MIC) of the compound is found to be 4 mg/ml. Structural similarity of this compound with a functional group of a beta-lactamase-resistant antibiotic indicates that 1,4-naphthlenedione may be acting as an inhibitor to beta-lactamase.