Iron(III)‐Catalyzed Peroxide‐Mediated C‐3 Functionalization of Flavones

An iron(III)‐catalyzed C‐3 functionalization of flavones has been achieved using tert‐butyl peroxybenzoate (TBPB)/potassium persulphate (K₂S₂O₈) oxidant combinations with a suitable solvent. In the presence of iron(III)/tert‐butyl peroxybenzoate/potassium persulphate, the reaction of flavones in cycloalkanes afforded exclusive C‐3 cycloalkylation via C –C coupling, whereas the solvent N,N‐dialkylformamide provided C‐3 amidation via C –C coupling. Under identical reaction conditions just by switching the solvent to chlorobenzene, C‐3 methylated flavones were obtained where tert‐butyl peroxybenzoate (TBPB) served as the source of the methyl group.

     

Prevalence of intestinal helminth eggs on vegetables grown in wastewater-irrigated areas of Titagarh,West Bengal,India

A total of 46 wastewater samples (untreated: 24 and treated: 22), 35 soil samples and 172 vegetable samples were collected from the wastewater-irrigated area of Titagarh to assess its contamination level with intestinal helminth. 83.3% of raw wastewater, 68.2% of treated wastewater, 68.6% of soil and 44.2% of vegetables in the study area were found to be positive for helminth ova. Vegetables grown in this area were found positive for Ascaris lumbricoides (36%), Trichuris trichiura (1.7%) and hookworms (6.4%). A. lumbricoides was the most predominant species observed in all the samples. Of all the vegetables examined, Pudina was most commonly contaminated followed by Lettuce, Spinach, Coriander, Celery and Parsley. High percentage of viable-stage intestinal helminth egg positive vegetable samples grown in the wastewater-irrigated study area may pose serious public health hazards.     

In vitro evaluation of folic acid modified carboxymethyl chitosan nanoparticles loaded with doxorubicin for targeted delivery

The development of smart targeted nanoparticle that can deliver drugs to direct cancer cells, introduces better efficacy and lower toxicity for treatment. We report the development and characterizations of pH-sensitive carboxymethyl chitosan modified folic acid nanoparticles and manifest their feasibility as an effective targeted drug delivery vehicle. The nanoparticles have been synthesized from carboxymethyl chitosan with covalently bonded bifunctional 2,2′-(ethylenedioxy)-bis-(ethylamine) (EDBE) through the conjugation with folic acid. The conjugation has been analyzed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. The resultant nanoparticles with an average size less then 200 nm measured by dynamic light scattering and transmission electron microscopy. Confocal microscopy and flow cytometric analysis have revealed that folate-mediated targeting significantly enhances the cellular uptake of the nanoparticle and thus facilitates apoptosis of cancer cells (HeLa, B16F1). For the application of the nanoparticles as a drug carrier, Doxorubicin a potent anticancer drug has been loaded into the nanoparticles, with the drug loading amount and the drug release pattern observed.     

Control of viremia in simian immunodeficiency virus infection by CD8+ lymphocytes

Clinical evidence suggests that cellular immunity is involved in controlling human immunodeficiency virus-1 (HIV-1) replication. An animal model of acquired immune deficiency syndrome (AIDS), the simian immunodeficiency virus (SIV)-infected rhesus monkey, was used to show that virus replication is not controlled in monkeys depleted of CD8+ lymphocytes during primary SIV infection. Eliminating CD8+ lymphocytes from monkeys during chronic SIV infection resulted in a rapid and marked increase in viremia that was again suppressed coincident with the reappearance of SIV-specific CD8+ T cells. These results confirm the importance of cell-mediated immunity in controlling HIV-1 infection and support the exploration of vaccination approaches for preventing infection that will elicit these immune responses.     

Environmental and economic opportunities of applications of different types and application methods of chemical fertilizer in rice paddy

Mitigating greenhouse gas (GHG: Methane and nitrous oxide) emission from the rice cropland vis-à-vis increasing rice yield is one of the important challenges to the food security and climate change research. N-fertilizer input to the crop land is the key to rice productivity and GHG emission from soil. The sustainability of different types and application methods of N-fertilizers in rice cropland was studies based on the net annual C-equivalent GHG emission (CE) and total financial profit to the farmers’. The study was conducted in a low lying experimental rice field of eastern India during two consecutive years. The experiment was laid down with five replicates of the following treatments: (1) control (no N-fertilizer); (2) broadcasting ammonium sulphate (AS); (3) prilled urea (PU) and (4) deep placement of urea briquette (UB). Compared to other treatments, significantly higher GHG emission and grain yield (5–20% higher over other fertilizer applied plots) were recorded from the PU and UB applied plots respectively. Net CE was calculated using the GHG emission and secondary CE of different processes used in each treatment. The net CE followed the order: PU > UB > Control > AS. The ratio of total grain-C to net CE was significantly higher from the AS (15–51%) and UB (8–34%) plots compared to the PU applied plots. Net financial benefit ($ ha^?1) to the farmers’ followed the order: UB > AS > Control > PU. Study indicates that UB may be a climatically sustainable mitigation option in the tropical rice paddy.     

High pressure synthesis of terephthalic acid from p-dichlorobenzene

Terephthalic acid was obtained from p-dichlorobenzene, carbon monoxide and water when the reaction was carried out in the presence of nickel iodide supported on silica gel (Ni:SiO₂ = 50:50) the catalyst which showed the best catalytic activity among those tested. The maximum conversion of p-dichlorobenzene to terephthalic acid at the optimum conditions was 14.9%.     

Modeling runoff from an agricultural watershed of western catchment of Chilika lake through ArcSWAT

Chilika lake is the biggest lagoon in the Indian Eastern coast and is a source of livelihood for peoples of the coastal region surrounding it mainly through fisheries. However, the deposition of sediments in the lake carried through runoff water from its drainage basins may alter this wetland ecosystem in future. Implementation of appropriate soil water conservation measures may reduce the sediment load in runoff water and thus may protect this lagoon ecosystem. Keeping in view these concerns, runoff water from a selected watershed of western catchment of Chilika lagoon was modeled through ArcSWAT with a purpose to estimate future runoff potential from western catchment. Effective hydraulic conductivity of main channel, base flow alpha factor, curve number corresponding to antecedent moisture content II, and roughness coefficient of main channel were found most sensitive parameters in decreasing order. Nash–Sutcliffe coefficient of predicted monthly runoff was 0.72 and 0.88 during calibration and validation period, respectively whereas root mean squared error of predicted monthly runoff was 54.5 and 66.1 mm, respectively. Modeling results indicated that about 60% of rainfall is partitioned to runoff water, which carry significant amount of sediment load and contributes to Chilika lake.