Synthesis, Biochemistry, and Computational Studies of Brominated Thienyl Chalcones: A New Class of Reversible MAO-B Inhibitors

A series of (2E)-1-(5-bromothiophen-2-yl)-3-(para-substituted phenyl)prop-2-en-1-ones (TB1-TB11) was synthesized and tested for inhibitory activity toward human monoamine oxidase (hMAO). All compounds were found to be competitive, selective, and reversible toward hMAO-B except (2E)-1-(5-bromothiophen-2-yl)-3-(4-nitrophenyl)prop-2-en-1-one (TB7) and (2E)-1-(5-bromothiophen-2-yl)-3-(4-chlorophenyl)prop-2-en-1-one (TB8), which were selective inhibitors of hMAO-A. The most potent compound, (2E)-1-(5-bromothiophen-2-yl)-3-[4-(dimethylamino)phenyl]prop-2-en-1-one (TB5), showed the best inhibitory activity and higher selectivity toward hMAO-B, with Ki and SI values of 0.11±0.01 μm and 13.18, respectively. PAMPA assays for all compounds were carried out in order to evaluate the capacity of the compounds to cross the blood-brain barrier. Moreover, the most potent MAO-B inhibitor, TB5, was found to be nontoxic at 5 and 25 μm, with 95.75 and 84.59 % viability among cells, respectively. Molecular docking simulations were carried out to understand the crucial interactions responsible for selectivity and potency.

Pharmacophore Modeling, 3D-QSAR and Molecular Docking of Furanochalcones as Inhibitors of Monoamine Oxidase-B

Monoamine oxidase B inhibitors are of particular importance in the treatment of neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Herein described is pharmacophore generation and atom-based 3D-QSAR analysis of previously reported furan based MAO-B inhibitors in order to get insight into their structural requirements responsible for high affinity. The best pharmacophore model generated with the five-point hypotheses of ADHRR: hydrogen bond acceptor (A), hydrogen bond donor (D), hydrophobic (H) and two aromatic rings (R1 & R2). On the basis of generated model, a statistically valid 3D-QSAR with good predictability was developed. Molecular docking of lead compound showed binding energy of -8.66 kcal/mol with a predicted inhibition constant of 0.448 μM towards MAO-B.

Bovine carriers of Anaplasma marginale and Anaplasma bovis in South India

Carriers of bovine anaplasmosis in Northern Kerala, South India were detected using conventional microscopical and molecular techniques. PCR-RFLP and nested PCR techniques were used for detection of Anaplasma marginale and Anaplasma bovis respectively and the PCR products were confirmed by sequencing. Out of 150 samples tested, 25 were detected positive for A. marginale and five for A. bovis based on molecular tests. The inclusion bodies of A. marginale could be detected by microscopy in two blood smears after staining by giemsa while acridine orange staining detected three smears positive. The data clearly suggest the higher sensitivity of molecular techniques for diagnosis of these diseases.

DURABILITY TESTING OF SILICONE MATERIALS FOR PROTON EXCHANGE MEMBRANE FUEL CELL USE

Silicone resins are ideal candidates for proton exchange membrane fuel cells (PEMFC) sealing and gasketing. They have many advantages for PEMFC application, such as superior stability and longevity under harsh environments, low water absorption, and broad temperature range. However, as this work shows, silicone-based materials have one big drawback: low molecular weight siloxanes, oligomers, and/or degradation byproducts may readily migrate from the base material into the fuel cell membrane, forming glassy structures, reducing the mechanical durability, and ultimately fracturing the proton exchange membrane (PEM). A novel, in situ testing method has been developed to test the effect of siloxanes on PEMFCs. The mechanism for migration of cyclic siloxanes to the PEM interface, causing it to fail in a brittle fashion, is presented. A commercially available silicone gasket material was used as a case study to validate the mechanism. Optical microscopy, scanning electron microscopy, and inductively coupled plasma were used to perform failure analysis of the tested samples. Thermogravimetric analysis was used to measure the removal rate of low molecular weight cyclic siloxanes. Gas chromatography–mass spectrometry was used to separate the organic molecules off-gassing from the material at temperature and provide a mass spectrum of each component.

Haemoprotozoa of cattle in Northern Kerala, India

A cross-sectional study was conducted using 150 blood samples collected from apparently normal / healthy crossbred cattle of Northern Kerala, South India, for detection of haemoprotozoan infections using staining techniques (Giemsa and Acridine Orange) and specific PCR. Theileria like piroplasms and Babesia bigemina were the only protozoan organisms detected in blood smears. Polymerase chain reaction using specific primers revealed amplification of products specific for Trypanosoma evansi (34.6%), Theileria sp. other than T. annulata (16%) and B. bigemina (0.6%). The higher prevalence rate of Trypanosoma evansi indicated that the subclinical parasitism can be due to higher prevalence of tabanid flies. The study also revealed the presence of a theilerial piroplasm other than T. annulata in North Kerala, which needs further investigation.

Prevalence of Linguatula serrata in domestic ruminants in South India

Linguatula serrata Frohlich, 1789 is an aberrant endoparasite of occasional zoonotic importance in humans. We report the prevalence of encapsulated nymphal stages of L. serrata in domestic ruminants surveyed in Wayanad, located in Kerala State, South India. Large and small intestine mesentery were examined from 100 goats, cattle and buffaloes each revealing an infection prevalence of 21, 19, and 8%, respectively. The prevalence of L. serrata infection among ruminants is higher than previous reports from India and indicates a strong focus of infection in herbivorous domesticated mammals of South India. The potential importance of these findings to human health is discussed.

Visceral schistosomiasis among domestic ruminants slaughtered in Wayanad, South India

This short communication reports the prevalence of visceral schistosomiasis by worm counts from the mesentery of domestic ruminants of the hilly district of Wayanad, located in Kerala, one of the states in South India. We found 57.3, 50, and 4.7% of cattle, buffaloes and goats, respectively, had visceral schistosomiasis upon slaughter at a municipal slaughter house in Kalpetta. Our findings show that the prevalence of Schistosoma spindale infection is very high in Wayanad in comparison to previous reports from this and neighboring countries.