Phospholipase A2 (PLA2) promotes inflammation via lipid mediators and releases arachidonic acid (AA), and these enzymes have been found to be elevated in a variety of diseases, including rheumatoid arthritis, sepsis, and atherosclerosis. The mobilization of AA by PLA2 and subsequent synthesis of prostaglandins are regarded as critical events in inflammation. Inflammatory processes may be treated with drugs that inhibit PLA2, thereby blocking the COX and LOX pathways in the AA cascade. To address this issue, we report herein an efficient method for the synthesis of a series of octahydroquinazolinone compounds (4a-h) in the presence of the catalyst Pd-HPW/SiO(2) and their phospholipase A2, as well as protease inhibitory activities. Among eight compounds, two of them exhibited overwhelming results against PLA2 and protease. By using FT-IR, Raman, NMR, and mass spectroscopy, two novel compounds were thoroughly studied. After carefully examining the SAR of the investigated compounds against these enzymes, it was found that compounds (4a, 4b) containing both electron-donating and electron-withdrawing groups on the phenyl ring exhibited higher activity than compounds with only one of these groups. DFT studies were employed to study the electronic nature and reactivity properties of the molecules by optimizing at the BLYP/cc-pVDZ. Natural bond orbitals helped to study the various electron delocalizations in the molecules, and the frontier molecular orbitals helped with the reactivity and stability parameters. The nature and extent of the expressed biological activity of the molecule were studied using molecular docking with human non-pancreatic secretory phospholipase A2 (hnps-PLA2) (PDB ID: 1DB4) and protease K (PDB ID: 2PWB). The drug-ability of the molecule has been tested using ADMET, and pharmacodynamics data have been extracted. Both the compounds qualify for ADME properties and follow Lipinski's rule of five.
In tropical and sub-tropical areas of the world the most damaging pest of the livestock sector are cattle tick, Rhipicephalus microplus. The current study was aimed to generate phytochemical derived acaricides to control Rhipicephalus microplus populations, to maintain livestock herd production, minimize economic losses and to reduce uses of man-made chemicals acaricides. To achieve this goal, Adult immersion and larval package test were used to determine the feasibility of Berberium lyceum and Tamarixa aphylla against Rhipicephalus microplus ticks. Further, an In silico technique was employed to discover biologically active substances from both plants using docking method. Berberium lyceum and Tamarixa aphylla exhibited a reasonably high fatal effect at 40.0 mg/L on egg laying (index of egg laying = 0.19 and 0.19) respectively, thus inhibiting the oviposition (49.5 and 45.1, respectively) and the larval mortality (97% and 93%, respectively). Further, we also used Chem-Draw ultra-software (v. 12.0.2.1076. 2010) to illustrate different structures of38 known bioactive phytochemicals which are discovered in the PubChem database and verify the hypothesis that tick inhibition was linked to acetylcholinesterase (AChE). Barbamunine and rutin from Berberium lyceum showed remarkable interaction with RmAChE1 active site residues with docking scores of -9.11 to -8.71 while phytol and dehydrodigallic acid from Tamarix aphylla showed comparable docking scores of -7.17 and -7.14 respectively against Rhipicephalus microplus acetylcholinesterase protein. Based on obtained result, we believe that Berberium lyceum and Tamarixa aphylla bioactive components could be potential candidates in the control and management of Rhipicephalus microplus and should be studied further as a supplement or replacement for synthetic acaricides.
Ranunculus muricatus L. is a spiny fruit buttercup that is used in various traditional medicinal systems. In the current investigation of R. muricatus, the new chalcone 4-benzyloxylonchocarpin (1), the new anthraquinone muracatanes A (2), the new-to-nature anthraquinone muracatanes B (3), and the new naphthalene analog muracatanes C (4) were isolated, in addition to the three previously reported compounds, 4-methoxylonchocarpin (5), beta-sitosterol (6), and beta-sitosterol beta-D-glucopyranoside (7). Their structures were elucidated using 1D ((1)H and (13)C) and 2D (COSY, HSQC, and HMBC) NMR spectroscopy and HR-ESI-MS. Chalcone 1 showed potent acetylcholinesterase inhibitory effects with K(i) of 5.39 microM and K(i') of 3.54 microM, but none of the isolated compounds showed inhibitory activity towards butyrylcholinesterase. Anthraquinone 3 illustrated alpha-glucosidase inhibitory effects with IC(50)-values of 164.46 +/- 83.04 microM. Compound 5 displayed moderate cytotoxic activity towards ovarian carcinoma (A2780, IC(50) = 25.4 microM), colorectal adenocarcinoma (HT29, IC(50) = 20.2 microM), breast cancer (MCF7, IC(50) = 23.7 microM), and thyroid carcinoma (SW1736, IC(50) = 26.2 microM) while it was inactive towards pharynx carcinoma (FaDu: IC(50) > 30 microM).
Salinomycin with antibacterial and anticoccidial activities is a commercial polyether polyketide widely used in animal husbandry as a food additive. Malonyl-CoA (MCoA), methylmalonyl-CoA (MMCoA), and ethylmalonyl-CoA (EMCoA) are used as extension units in its biosynthesis. To understand how the salinomycin modular polyketide synthase (PKS) strictly discriminates among these extension units, the acyltransferase (AT) domains selecting MCoA, MMCoA, and EMCoA were structurally characterized. Molecular dynamics simulations of the AT structures helped to reveal the key interactions involved in enzyme-substrate recognitions, which enabled the engineering of AT mutants with switched specificity. The catalytic efficiencies ( kcat/ Km) of these AT mutants are comparable with those of the wild-type AT domains. These results set the stage for engineering the AT substrate specificity of modular PKSs.
In this study, three different extracts (soxhlet, microwave and decoction) from two species of broccoli: Brassica oleracea L. convar. Italica botrytis (L.) Alef. var. cymosa Duch. (Broccolo Fiolaro) and Brassica oleracea acephala L. convar. acephala (DC.) Alef. var. sabellica L. (Cavolo Nero), which are commonly spread in north-central Italy, were tested for their enzyme inhibitory effects. Enzyme inhibitory effects were investigated against cholinesterases, tyrosinase, alpha-amylase and alpha-glucosidase. The soxhlet extracts had the highest inhibitory AChE effects with 1.08 mgGALAE/g (in Cavolo Nero) and 0.90 mgGALAE/g (in Broccolo Fiolaro). The significant tyrosinase inhibitory effect was observed in the soxhlet extract of Cavolo Nero with 11.93 mgKAE/g. In addition, we evaluated the antioxidant activity of Broccolo Fiolaro and Cavolo Nero on lipopolysaccharide (LPS)-stimulated bladder, kidney and liver specimens, ex vivo. We observed a significant reduction of both nitrite and malondialdehyde (MDA) following treatment that indicates a significant inhibitory effect on oxidative/nitrosative stress and lipoperoxidation, respectively. Additionally, the blunting effect induced by extracts on LPS-induced lactate dehydrogenase (LDH) activity further support a protective effect by both Broccolo Fiolaro and Cavolo Nero in bladder, kidney and liver. HPLC analysis revealed that catechin, epicatechin, vanillic and 3-hydroxy benzoic acids were the major components. The phenolic components may contribute to the observed enzyme inhibitory effects. in vivo tests also demonstrated that the extracts decreased the biochemical parameters in diabetic rats. Particularly, we observed the reduction of plasma glucose levels, urea and total cholesterol following oral administration, with the higher inhibitory effects exerted by Broccolo Fiolaro compared to Cavolo Nero. Overall, our results could provide new insights on the use of these Broccoli species not only as foods but also as functional and nutraceutical supplements.
Title: Chemical composition, antioxidant and anticholinesterase potentials of essential oil of Rumex hastatus D. Don collected from the North West of Pakistan Ahmad S, Ullah F, Sadiq A, Ayaz M, Imran M, Ali I, Zeb A, Shah MR Ref: BMC Complement Altern Med, 16:29, 2016 : PubMed
BACKGROUND: Ethnomedicinally Rumex hastatus D. Don has been used since long for various ailments especially in neurological disorders. The reported data and the importance of Rumex genus demonstrate the vital medicinal value of R. hastatus. METHODS: In the current investigational study, isolation of essential oil and its antioxidant and anticholinesterase assays were performed. The essential oil of R. hastatus was analyzed by GC-MS for the first time. The essential oil was evaluated for anticholinesterase and antioxidant assays. The anticholinesterase assay was conducted at various concentrations (62.5 to 1000 mug/ml) against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Similarly, the antioxidant potential was determined using DPPH and ABTS free radicals. RESULTS: The GC-MS analysis of essential oil showed 123 components. The result recorded for the anticholinesterase assays demonstrated a marked potential against AChE and BChE with IC50 values of 32.54 and 97.38 mug/ml respectively which were comparable with the positive control i.e., galanthamine (AChE, IC50 = 4.73 mug/ml and BChE, IC50 = 11.09 mug/ml). The antioxidant assays against DPPH and ABTS free radicals also exhibited significant scavenging potential with IC50 values of 3.71 and 6.29 mug/ml respectively, while for ascorbic acid the IC50 value was <0.1 mug/ml against both free radicals. CONCLUSIONS: Based on the current investigational studies, it may be concluded that R. hastatus is an effective source of essential oil's components having anticholinesterase and antioxidant potentials, which after subjecting to drug development may lead to novel drug candidates against neurodegenerative disorders.
Title: Alterations in Brain Inflammation, Synaptic Proteins, and Adult Hippocampal Neurogenesis during Epileptogenesis in Mice Lacking Synapsin2 Chugh D, Ali I, Bakochi A, Bahonjic E, Etholm L, Ekdahl CT Ref: PLoS ONE, 10:e0132366, 2015 : PubMed
Synapsins are pre-synaptic vesicle-associated proteins linked to the pathogenesis of epilepsy through genetic association studies in humans. Deletion of synapsins causes an excitatory/inhibitory imbalance, exemplified by the epileptic phenotype of synapsin knockout mice. These mice develop handling-induced tonic-clonic seizures starting at the age of about 3 months. Hence, they provide an opportunity to study epileptogenic alterations in a temporally controlled manner. Here, we evaluated brain inflammation, synaptic protein expression, and adult hippocampal neurogenesis in the epileptogenic (1 and 2 months of age) and tonic-clonic (3.5-4 months) phase of synapsin 2 knockout mice using immunohistochemical and biochemical assays. In the epileptogenic phase, region-specific microglial activation was evident, accompanied by an increase in the chemokine receptor CX3CR1, interleukin-6, and tumor necrosis factor-alpha, and a decrease in chemokine keratinocyte chemoattractant/ growth-related oncogene. Both post-synaptic density-95 and gephyrin, scaffolding proteins at excitatory and inhibitory synapses, respectively, showed a significant up-regulation primarily in the cortex. Furthermore, we observed an increase in the inhibitory adhesion molecules neuroligin-2 and neurofascin and potassium chloride co-transporter KCC2. Decreased expression of gamma-aminobutyric acid receptor-delta subunit and cholecystokinin was also evident. Surprisingly, hippocampal neurogenesis was reduced in the epileptogenic phase. Taken together, we report molecular alterations in brain inflammation and excitatory/inhibitory balance that could serve as potential targets for therapeutics and diagnostic biomarkers. In addition, the regional differences in brain inflammation and synaptic protein expression indicate an epileptogenic zone from where the generalized seizures in synapsin 2 knockout mice may be initiated or spread.
Title: Two new cholinesterase inhibitors asiatoates A and B from Buddleja asiatica Ali F, Khan HU, Afzal M, Samad A, Khan SU, Ali I Ref: J Asian Nat Prod Res, 15:631, 2013 : PubMed
Two new benzoates, asiatoate A (1) and asiatoate B (2), have been isolated from the ethyl acetate soluble fraction of Buddleja asiatica whole plant. Their structures were elucidated with the help of spectroscopic data. Both showed significant inhibitory effect on acetylcholinesterase (AChE) and butylcholinesterase (BChE) in a dose-dependent manner. The IC50 values of compounds 1-2 were 5.54 and 8.34 muM against AChE while 30.94 and 35.94 muM against BChE, respectively.
In this review, literature data on phytochemical and biological investigations on the genus Pluchea are compiled. Pluchea is a genus of flowering plants in the Asteraceae family and comprises ca. 80 species distributed mainly in Northern and Southern America, Africa, Asia, and Australia. Sesquiterpenoids and flavonoids are the main constituents of this genus. Compounds isolated from plants of the Pluchea genus display a variety of biological properties, viz., anticancer, antileishmanial, immunosuppressive, antioxidant, anti-acetylcholinesterase, antimicrobial, trypanocidal, hepatoprotective, cytotoxic, larvicidal, anti-ulcer, anti-inflammatory, and antinociceptive activities.
Title: Studies on the effect of alcohols on the chiral discrimination mechanisms of amylose stationary phase on the enantioseparation of nebivolol by HPLC Aboul-Enein HY, Ali I Ref: Journal of Biochemical & Biophysical Methodsods, 48:175, 2001 : PubMed
The chiral recognition mechanism of amylose CSPs has been described by achieving the enantiomeric resolution of (+/-)-nebivolol on Chiralpak AD and Chiralpak AD-RH columns with methanol, ethanol, 1-propanol, 2-propanol, 1-butanol as mobile phases at different flow rates. The energies of interactions of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol with both phases were calculated. The (+)-RRRS enantiomer eluted first when using methanol, ethanol and 1-propanol, while the elution order was reversed when using 2-propanol and 1-butanol as the mobile phases. It has been concluded that the reversal elution order observed was due in part to the chiral cavities on the amylose CSP which were responsible for the bondings of different magnitude between chiral stationary phase and enantiomers, which are influenced with the type of alcohol used as mobile phase on the conformation of the 3,5-dimethyl phenyl carbamate moiety on the pyranose ring system of the amylose.
