Search of antitubercular activities in tetrahydroacridines: synthesis and biological evaluation

A series of 9-substituted tetrahydroacridines were synthesized by nucleophilic substitution of chloro group with different nucleophiles in 9-chlorotetrahydroacridine (2). The latter could be obtained by POCl(3) mediated cyclization of the intermediate enamine, which in turn, was prepared by acid catalyzed condensation of anthranilic acid and cyclohexanone. Most of the compounds on antitubercular evaluation against M. tuberculosis H37 Rv and H37 Ra strains exhibited potent activities with MIC 6.125-0.78 microg/mL comparable to the standard drugs.     

Assignment of the 13C-nmr spectrum of Hippurin, a novel furospirostane: observation of both ends of the axis of anisotropic reorientation through the measurement of spin-lattice relaxation times

Anisotropic reorientation of 3 alpha-substituted steroids has been well documented. Assignment of the 13C-nmr spectrum of Hippurin, a novel furospirostane and the measurement of the spin-lattice (T1) relaxation times has established both points in the molecule through which the axis of anisotropic reorientation passes, specifically the 3- and 24-positions.     

Utilization of microbial community potential for removal of chlorpyrifos: a review

Chlorpyrifos (CP) is the most commonly used pesticide in agricultural fields worldwide. Exposure to CP and its metabolites creates severe neuron-disorders in human beings. Improper handling and uncontrolled application of CP by farmers have lead to the contamination of surface and ground water bodies. Biodegradation offers an efficient and cost effective method for the removal of CP and other toxic organophosphorus pesticides from the contaminated environment. The degradation of CP by various microorganisms has been investigated by several researchers over the past few years. This review presents a critical summary of the recent published results on the biodegradation of CP. A diverse range of bacterial species such as Agrobacterium sp., Alcaligenes faecalis, Enterobacter sp. Arthrobacter sp. Bacillus pumilus, Pseudomonas sp. etc., fungal species like Trichoderma viridae, Aspergillus niger, Verticillium sp., Acremonium sp. Cladosporium cladosporiodes, etc. and certain algal species viz. Chlorella vulgaris, Spirulina platensis, Synechocystis sp., etc., have been shown to degrade CP. The efficacy of these communities for CP degradation in batch and continuous modes has also been discussed but more studies are required on continuous reactors. Also, the available published information on kinetics of biodegradation of CP along with the available results on molecular biological approaches are discussed in this work.     

Diversification of indigenous gene- pool by using exotic germplasm in lentil (Lens culinaris Medikus subsp. culinaris)

Genetic diversity was studied among 21 accessions of lentil using SSR markers and morphological traits in order to assess the diversification of Indian gene-pool of lentil through introgression of exotic genes and introduction of germplasm. Among these , 16 genotypes either had ‘Precoz’ gene, an Argentine line in their pedigree or genes from introduced lines from ICARDA. Sixty five SSR markers and eight phenotypic traits were used to analyse the level of genetic diversity in these genotypes. Forty three SSR markers (66 %) were polymorphic and generated a total of 177 alleles with an average of 4.1 alleles per SSR marker. Alleles per marker ranged from 2 to 6. The polymorphic information content ranged 0.33 to 0.80 with an average of 0.57, suggesting that SSR markers are highly polymorphic among the studied genotypes. Genetic dissimilarity based a dendrogram grouped these accessions into two main clusters (cluster I and cluster II) and it ranged 33 % to 71 %, suggesting high level of genetic diversity among the genotypes. First three components of PCA based morphological traits explained higher variance (95.6 %) compared to PCA components based on SSR markers (42.7 %) of total genetic variance. Thus, more diversity was observed for morphological traits and genotypes in each cluster and sub-cluster showed a range of variability for seed size, earliness, pods/plant and plant height. Molecular and phenotypic diversity analysis thus suggested that use of germplasm of exotic lines have diversified the genetic base of lentil germplasm in India. This diversified gene-pool will be very useful in the development of improved varieties of lentil in order to address the effect of climate change, to adapt in new cropping systems niches such as mixed cropping, relay cropping, etc. and to meet consumers’ preference.     

Biotechnological potential for degradation of isoprene: a review

Isoprene, the ubiquitous, highly emitted non-methane volatile hydrocarbon, affects atmospheric chemistry and human health, and this makes its removal from the contaminated environment imperative. Physicochemical degradation of isoprene is inefficient and generates secondary pollutants. Therefore, biodegradation can be considered as the safer approach for its efficient abatement. This review summarizes efforts in this regard that led to tracking the diverse groups of isoprene degrading bacteria such as Methanotrophs, Xanthobacter, Nocardia, Alcaligenes, Rhodococcus, Actinobacteria, Alphaproteobacteria, Bacteriodetes, Pseudomonas, and Alcanivorax. Biodegradation of isoprene by such bacteria in batch and continuous modes has been elaborated. The products, pathways and the key enzymes associated with isoprene biodegradation have also been presented.     

Assessment of genetic diversity and morpho-physiological traits related to drought tolerance in Stylosanthes scabra

Among the many Stylosanthes species, Stylosanthes scabra, a range fodder legume, performs better under limited water condition. In the present investigation, thirty-four accessions of S. scabra were assessed under limited water condition, for various morpho-physiological characters associated with drought. In general, S. scabra exhibited better tolerance to drought, as evidenced by high leaf thickness and greater accumulation of proline, and malondialdehyde (MDA) in water stress condition. Transpiration efficiency (TE) was high, in both control and water stress conditions and positively correlated with root, shoot, and total dry matters, in both control and stress conditions (r ² = ranged from 0.589 to 0.961 in control and from 0.351 to 0.985 in stress). Of these, 25 accessions were assessed for estimation of genetic diversity, employing random amplified polymorphic DNA (RAPD) markers. A total of 210 RAPD bands, obtained with 32 primers, revealed high polymorphic information content (0.49) and marker index (4.41). Dendrogram analysis indicated close proximity among the accessions of S. scabra. These accessions were clustered in high similarity range (84.01–98.36 %). Accession IG-366A separated from other clusters at 85.62 % similarity level. RAPD marker system revealed 13 accessions exhibiting >90 % genetic similarity while the other accessions exhibited similarity ranging from 68 to 90 %. A higher level of genetic similarity which was also evident from the similar levels of TE, biomass production, root/shoot ratio, MDA, proline contents and drought tolerance index, indicated a cause–effect relationship among them. Results also indicated that among the accessions, S. scabra rate-reducing resistance allo-tetraploid lines were better suited for hard and cracking soils, under complete rain-fed condition.     

Effect of Trichoderma harzianum on microelement concentrations and increased growth of cucumber plants

The potential of the biocontrol agent Trichoderma harzianum strain T-203 to induce a growth response in cucumber plants was studied in soil and under axenic hydroponic growth conditions. When soil was amended with T. harzianum propagules, a 30% increase in seedling emergence was observed up to 8 days after sowing. On day 28, these plants exhibited a 95 and 75% increase in root area and cumulative root length, respectively, and a significant increase in dry weight (80%), shoot length (45%) and leaf area (80%). Similarly, an increase of 90 and 30% in P and Fe concentration respectively, was observed in T. harzianum inoculated plants. To better characterize the effect of T. harzianum during the early stages of root colonization, experiments were carried out in a gnotobiotic hydroponic system. An increased growth response was apparent as early as 5 days post-inoculation with T. harzianum, resulting in an increase of 25 and 40% in the dry weight of roots and shoots, respectively. Similarly a significant increase in the concentration of Cu, P, Fe, Zn, Mn and Na was observed in inoculated roots. In the shoots of these plants, the concentration of Zn, P and Mn increased by 25, 30 and 70%, respectively. Using the axenic hydroponic system, we showed that the improvement of plant nutritional level may be directly related to a general beneficial growth effect of the root system following T. harzianum inoculation. This phenomenon was evident from 5 days post-inoculation throughout the rest of the growth period, resulting in biomass accumulation in both roots and shoots.     

Long term fertilization effects on soil organic carbon pools in a sandy loam soil of the Indian sub-Himalayas

An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and mitigating global warming. Results of a long-term (32 years) experiment in the Indian Himalayas under rainfed soybean (Glycine max L.)- wheat (Triticum aestivum L.) rotation was analyzed to determine the effects of mineral fertilizer and farmyard manure (FYM) application at 10 Mg?ha^-1 on SOC stocks and depth distribution of the labile and recalcitrant pools of SOC. Results indicate all treatments increased SOC contents over the control. The annual application of NPK significantly (P?<?0.05) enhanced total SOC, oxidizable soil organic C and its fractions over the control plots. The increase in these SOC fractions was greater with the NPK + FYM treatment. Nearly 16% (mean of all treatments) of the estimated added C was stabilized into SOC both in the labile and recalcitrant pools, preferentially in the 0?C30 cm soil layer. However, the labile:recalcitrant SOC ratios of applied C stabilized was largest in the 15?C30 cm soil layer. About 62% of total SOC was present in the labile pool. Plots under the N + FYM and NPK + FYM treatments contained a larger proportion of total SOC in the recalcitrant pool than the plots with mineral or no fertilizer, indicating that FYM application promoted SOC stabilization.     

Synthesis and antitubercular activity of substituted phenylmethyl- and pyridylmethyl amines

A total of 42 benzyl- and pyridylmethyl amines were synthesized either by reductive amination of aromatic/heteroaromatic aldehydes with amines or by conjugate addition of amines to the cinnamates followed by reduction of the ester group with lithium aluminium hydride to the respective propanolamines. All the synthesized compounds were evaluated against both avirulent and virulent strains of Mycobacterium tuberculosis. Many of the compounds exhibited MIC as low as 1.56 μg/mL. Few of potent compounds were also evaluated against clinical isolates of MDR TB and found to be active at one or other concentrations with MIC as low as 3.12 μg/mL.