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Search Results: 1 - 10 of 38 matches for " Lingappa Mallesha "
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Synthesis, antimicrobial and antioxidant activities of 1-(1,4-benzodioxane-2-carbonyl)piperazine derivatives
Lingappa Mallesha,Kikkeri Narasimhasetty Mohana
European Journal of Chemistry , 2011, DOI: 10.5155/eurjchem.2.2.193-199.282
Abstract: A series of novel 1-(1,4-benzodioxane-2-carbonyl)piperazine derivatives (6a-h) and (7a-e) were synthesized by nucleophilic substitution reaction of 1-(1,4-benzodioxane-2-carbonyl)piperazine (3) with various sulfonyl and acid chlorides. The newly synthesized compounds were characterized by elemental analyses, UV-visible, FT-IR, 1H NMR and LC-MS spectral studies. All compounds were evaluated for in vitro antibacterial, antifungal and antioxidant activities. Compound, 4-(2-trifluoromethyl)-benzenesulfonyl-1-(1,4-benzodioxane -2-carbonyl)piperazine (6b) exhibited significant antimicrobial activity against tested pathogenic bacterial and fungal strains. Compound, 4-(3-methoxy)-benzoyl-1-(1,4-benzodioxane-2-carbonyl)piperazine (7a) showed moderate antioxidant activity compared to standard drug by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay method.
Synthesis of Pyrazine Substituted 1,3,4-Thiadiazole Derivatives and Their Anticonvulsant Activity
Kikkeri P. Harish,Kikkeri N. Mohana,Lingappa Mallesha
Organic Chemistry International , 2013, DOI: 10.1155/2013/631723
Abstract: The synthesis of new pyrazine substituted 1,3,4-thiadiazole derivatives was carried out in good yield by the reaction of pyrazine substituted 1,3,4-thiadiazoles with various sulfonyl chlorides. A chemical structure of all the new compounds was confirmed by 1H NMR and mass spectral data. The new compounds were screened for their anticonvulsant activity against maximal electroshock (MES) seizure method. Rotarod method was employed to determine the neurotoxicity. Few compounds showed significant changes in anticonvulsant activity. The same compounds showed no neurotoxicity at the maximum dose administered (100?mg/kg). 1. Introduction Epilepsy has been recognized as a neurological disorder, affecting a large section of people across the world. The word epilepsy usually describes a group of common chronic neurological disorders characterized by recurrent unprovoked seizures due to excessive neuronal firing or synchronous neuronal activity in the brain [1, 2]. Seizures may vary from the briefest lapses of attention or muscle jerks to severe and prolonged convulsions [3]. The maximal electroshock (MES) test is a predictor of compounds that are active against seizures [4]. The anticonvulsant drug design is based on the presumption that at least one phenyl or similar aromatic group in close proximity to two electron donor atoms in the compound is required for the activity in MES [5, 6]. Newer drugs such as flupirtine [7], topiramate [8], zonisamide [9], and vigabatrin [10] have emerged as promising anticonvulsants. Pyrazines and its derivatives play an important role in the drug discovery realm. In particular the structural analogue of purines derivatives presents various pharmacological activities such as antibacterial [11], anti-inflammatory [12], antidepressant [13], and antiproliferative activities [14]. Thiadiazoles exhibit a broad spectrum of biological effectiveness such as antiparkinsonism [11], antihistaminic [15], and antiasthmatic [16]. Thiazolidin-4-one derivatives are also known to exhibit diverse bioactivities such as anticonvulsant [17], antidiarrheal [18], antihistaminic [19], antidiabetic [20], cardioprotective [21], and anticancer [22]. Similarly, 2,5-disubstituted 1,3,4-thiadiazoles also display wide spectrum of activities such as antibacterial [23] and anticonvulsant [24]. In the present study, a series of new pyrazine substituted 1,3,4-thiadiazole derivatives 7(a–o) have been synthesized and their anticonvulsant effects are determined through maximal electroshock (MES) seizure test. 2. Materials and Methods 2.1. Chemistry Melting range was
Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety
Basavapatna N. Prasanna Kumar,Kikkeri N. Mohana,Lingappa Mallesha,Kikkeri P. Harish
International Journal of Medicinal Chemistry , 2013, DOI: 10.1155/2013/725673
Abstract:
Synthesis and In Vitro Antimicrobial Evaluation of New 1,3,4-Oxadiazoles Bearing 5-Chloro-2-methoxyphenyl Moiety
Basavapatna N. Prasanna Kumar,Kikkeri N. Mohana,Lingappa Mallesha,Kikkeri P. Harish
International Journal of Medicinal Chemistry , 2013, DOI: 10.1155/2013/725673
Abstract: A series of new 1,3,4-oxadiazole derivatives, 4(a–h), containing 5-chloro-2-methoxy benzohydrazide moiety were synthesized by the reaction of 5-chloro-2-methoxybenzoate with different aromatic carboxylic acids. These newly synthesized compounds were characterized by FT-IR, 1H NMR, mass spectra, and also by elemental analysis. All the newly synthesized compounds were screened for their antibacterial and antifungal activities. Antimicrobial studies revealed that compounds 4c, 4f, and 4g showed significant activity against tested strains. 1. Introduction Resistance to number of antimicrobial agents among a variety of clinically significant bacteria is becoming increasingly important. There are various problems arising with the use of antimicrobials such as local tissue irritation, interference with wound healing process, hypersensitivity reactions, system toxicity, narrow antimicrobial spectrum, and emergency of resistance [1]. So, the increasing clinical importance of drug resistant microbial pathogens has additional urgency in microbiological and antifungal research. A wide variety of heterocyclic systems have been explored for developing pharmaceutically important molecules. Among them the derivatives of oxadiazoles have been playing an important role in the medicinal chemistry [2]. The 1,3,4-oxadiazole derivatives have been found to exhibit diverse biological activities such as antimicrobial [3, 4], anti HIV [5], antitubercular [6], antimalarial [7], anti-inflammatory [8, 9], anticonvulsant [10], and antitumor [11]. The 2,5-disubstituted-1,3,4-oxadiazole derivatives are known for various pharmacological activities such as antibacterial [12], antihypertensive [13], anticonvulsant [14], and antiproliferative [15]. The choice of 1,3,4-oxadiazole is due to its multiapplicability in the field of medicine. In the present study, some new 1,3,4-oxadiazoles 4(a–h) have been synthesized and characterized by different spectral studies. All the new compounds were screened for their antibacterial and antifungal studies. 2. Results and Discussion 2.1. Chemistry The novel 1,3,4-oxadiazoles 4(a–h) were synthesized according to Scheme 1. Formation of 1,3,4-oxadiazole derivatives, 4(a–h), was confirmed by recording their elemental analyses, FT-IR, 1H NMR, and mass spectra. The absorptions around 3050?cm?1 in synthesized compounds confirm the aromatic C–H stretching vibrations and the appearance of a medium to strong absorption bands above 1600?cm?1 due to a stretching vibration of the azomethine (C=N) bond formation in synthesized compound. The 1H NMR spectra of 4c
Virtual Screening and Biological Evaluation of Piperazine Derivatives as Human Acetylcholinesterase Inhibitors
Kavitha Raj Varadaraju,Jajur Ramanna Kumar,Lingappa Mallesha,Archana Muruli,Kikkeri Narasimha Shetty Mohana,Chethan Kumar Mukunda,Umesha Sharanaiah
International Journal of Alzheimer's Disease , 2013, DOI: 10.1155/2013/653962
Abstract: The piperazine derivatives have been shown to inhibit human acetylcholinesterase. Virtual screening by molecular docking of piperazine derivatives 1-(1,4-benzodioxane-2-carbonyl) piperazine (K), 4-(4-methyl)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S1), and 4-(4-chloro)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S3) has been shown to bind at peripheral anionic site and catalytic sites, whereas 4-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S4) and 4-(2,5-dichloro)-benzenesulfonyl-1-(1,4-benzodioxane-2-carbonyl) piperazine (S7) do not bind either to peripheral anionic site or catalytic site with hydrogen bond. All the derivatives have differed in number of H-bonds and hydrophobic interactions. The peripheral anionic site interacting molecules have proven to be potential therapeutics in inhibiting amyloid peptides aggregation in Alzheimer’s disease. All the piperazine derivatives follow Lipinski’s rule of five. Among all the derivatives 1-(1,4-benzodioxane-2-carbonyl) piperazine (K) was found to have the lowest TPSA value. 1. Introduction Acetylcholinesterase (AChE) hydrolyses acetylcholine is associated with nerves and muscles mainly found in synapses. AChE plays an important role in regulation of cholinergic function. It has been shown to be involved in dysfunction of the central cholinergic system in Alzheimer’s disease (AD). It is a progressive neurodegenerative disorder, characterized by an impairment of cognitive function leading to dementia. The main characteristic features of the disease include β-amyloid (Aβ) plaques, neurofibrillary tangles, and their by synaptic loss. AD is estimated to account for about 50–60% dementia cases, in persons over 65 years of age [1]. Symptoms of Alzheimer’s disease include memory loss, language deficit, depression, agitation, and mood disturbances [2–4]. But the exact cause for AD is still not known. Several hypotheses tried to explain the cause of the disease [5]. Among those, the oldest, on which most currently available drug therapies are based, is the cholinergic hypothesis, which proposes that AD is caused by reduced synthesis of the neurotransmitter acetylcholine [1]. Even though the hypothesis failed to get widespread support, but it can be stated that cholinergic scarcity is responsible for the symptoms of AD [5]. This led to the designing and synthesis of AChE inhibitors. The inhibition causes an increase in the concentration of acetylcholine in cholinergic synapse. This might ameliorate the disease symptoms of AD [6, 7]. Tacrine, Donepezil, Rivastigmine,
Areca nut: To chew or not to chew?
Ashok Lingappa
e-Journal of Dentistry , 2011,
Abstract:
ROLE OF RESEARCH IN ORAL HEALTH CARE
Ashok Lingappa
e-Journal of Dentistry , 2012,
Abstract:
Immobilization of Aspergillus niger in Polyurethane Foam for Citric Acid Production from Carob Pod Extract
T. Pramod,K. Lingappa
American Journal of Food Technology , 2008,
Abstract: Aspergillus niger strains MTCC 281 and KLP20 immobilized on polyurethane foam were utilized for the batch fermentation of citric acid from carob pod extract. Carob pods are the fruits of carob tree (Ceratonia siliqua). Carob pod extract with 40-50% sugars were inoculated with immobilized polyurethane foam and incubated at 30 °C. Maximum citric acid yields of 23 and 33 g L-1 with free and immobilized cells in case of A. niger MTCC 281 and 27 and 38 g L-1 in case of A. niger KLP20 were obtained after 72 h of fermentation. From the studies A. niger KLP20 seems to be a potential strain among the two strains for the maximum citric acid production.
Microwave Assisted Rapid and Green Synthesis of Silver Nanoparticles Using a Pigment Produced by Streptomyces coelicolor klmp33
Deene Manikprabhu,K. Lingappa
Bioinorganic Chemistry and Applications , 2013, DOI: 10.1155/2013/341798
Abstract: Traditional synthesis of silver nanoparticles using chemical methods produces toxic substances. In contrast biological synthesis is regarded as a safe and nontoxic process but the major drawback of biological synthesis is, this process is slow. In the present investigation, we developed a rapid and green synthesis of silver nanoparticles employing a pigment produced by Streptomyces coelicolor klmp33 in just 90?s. The silver nanoparticles were characterized by UV-visible spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The biobased synthesis developed in this method is a safe, rapid, and appropriate way for bulky synthesis of silver nanoparticles. 1. Introduction Nanotechnology is expected to be the basis of many important technological innovations in the 21st century [1]. Various physical and chemical methods were reported for the synthesis of silver nanoparticles, but most of these methods cause potential environmental and biological hazards [2]. Compared to physical and chemical methods, biological synthesis using microbes and plants was regarded as a safe and ecofriendly process [3]. Several biological synthesis methods, using microbes like Cladosporium cladosporioides [4] and Fusarium oxysporum [5], have been suggested as safe, cost-effective, possible ecofriendly ways and alternatives to chemical and physical methods, but these methods also have the drawback that these processes were rather slow [6]. Parallel to microbes mediated synthesis, several rapid plant mediated synthesis method using crude plant parts extracts like Sorbus aucuparia [7] and Chenopodium album [8] were also reported, but large scale usage of plants for industrial purpose synthesis may lead to loss of valuable species [9]. Therefore, there is a need to develop a rapid and ecofriendly process for the synthesis of silver nanoparticles. In our earlier study, we reported synthesis of silver nanoparticles using pigment produced by Streptomyces coelicolor klmp33 by photoirradiation method in 20?min, but still we think the synthesis is more time consuming [10]. So, we explored different methods using the same pigment produced by S. coelicolor klmp33 to overcome this problem. Among different methods, microwave assisted synthesis showed promising result; the advantage of microwave irradiation over conventional biological synthesis is the improvement in rate kinetics of the reaction due to rapid heating and penetration involved, which may result in a narrow distribution of the particle size [11, 12].
Gamma Ray Induced Radio Sensitivity in Three Different Mulberry (Morus) Genotypes  [PDF]
Hyadalu Lingappa Ramesh, Veerapura Narayanappa Yogananda Murthy,   Munirajappa
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.47165
Abstract:

Mulberry genotypes M5, S54 and Kosen were procured from mulberry germplasm bank, Department of Sericulture, Bangalore University. Juvenile twigs of mulberry genotypes were used for cuttings preparation. Newly prepared juvenile cuttings were irradiated with different doses of gamma rays (1 kR - 10 kR) from Co60 gamma unit. Propagation parameters like sprouting, rooting, survivability, plant height, number of branches, internodal distance and leaf area were recorded. Results revealed decline in growth parameters with the increase in gamma ray dosage (1 kR - 10 kR). Moderate dosages (4 kR - 7 kR) are the most competent range and height of the irradiated population significantly reduced with the increase in gamma rays dosage. Higher doses of gamma rays (8 kR - 10 kR) drastically reduced the number of branches. M5 and S54 showed marked improvement in plant height at 4 kR (155.14 cm) and 7 kR (147.86 cms) respectively compared to control. Morphologically, leaf mutants like enlarged (4 kR), curled (8 kR), mosaic (8kR) and biforked (9 kR) leaves were observed in gamma irradiated M5 genotype. Kosen exhibited small, crumpled, biforked and chlorophyll deficient leaves (8 kR - 10 kR). S54 exhibited boat shaped leaves with wrinkled texture (8 kR).

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