Antifeedant activity of a novel 6-(4,7-hydroxy-heptyl) quinone? from the leaves of the milkweed Pergularia daemia on the cotton bollworm Helicoverpa armigera (Hub.) and the tobacco armyworm Spodoptera litura (Fab.)

The effects of crude extracts and an isolated compound from the leaves of milkweed, Pergularia daemia (Forssk) Choiv., on the antifeedant activity against two important lepidopteran pests, Helicoverpa armigera (Hub.) and Spodoptera litura (F.), were studied. Maximum antifeedant activity was recorded in ethyl acetate crude extract against H. armigera (70.3%) and S. litura (71.82%) at 1% concentration. Ethyl acetate crude extract was further subjected to column chromatography, which was performed using hexane as initial solvent and then by increasing the polar strength using ethyl acetate. Fractions collected at hexane and ethyl acetate (80:20) yielded 6-(4,7-hydroxy-heptyl) quinone, a novel compound which showed significant antifeedant activity against H. armigera (80.22% at 2000 ppm) and S. litura (68.31% at 2000 ppm).     

A study of 1,2-dibromoethane residues in wheat and milled products

A method is described for determining residues of 1,2-dibromoethane (EDB) in milled wheat products. The residues are first extracted with benzene, then recovered azeotropically for reaction with alkali and subsequent determination of liberated bromide ion by a Volhard titration. Freshly milled flours from wheat fumigated with 65.0 and 325 mg EDB/litre at 37°C were found to contain 10.6 to 39.4 mg EDB/kg and the bran contained from 51.4 to 153 mg EDB/kg.     

A mixed indicator strip for phosphine detection

A rapid, sensitive and reliable mixed indicator paper strip impregnated with dimethyl yellow (0.05%), cresol red (0.1%) and mercuric chloride (1.0%) in methanol has been developed for the detection of phosphine (PH₃) in air at the permissible level (TLV). The paper strip turns red in the presence of phosphine. It is highly sensitive and has better shelf-life than indicator strips impregnated with dimethyl yellow plus mercuric chloride or cresol red plus mercuric chloride.     

Effect of pectolinaringenin,a flavonoid from Clerodendrum phlomidis,on total protein,glutathione S-transferase and esterase activities of Earias vittella and Helicoverpa armigera

Pectolinaringenin was isolated from chloroform extract of Clerodendrum phlomidis L. and was evaluated at 12.5 to 100 ppm concentrations for its effects on total protein, esterase and glutathione S-transferase (GST) activities of Earias vittella and Helicoverpa armigera. At 100 ppm, the compound reduced total protein content by 55.75% and 53.01% over control with IC₅₀ values of 74.37 and 212.31 ppm in E. vittella and H. armigera, respectively. At 100 ppm it also reduced GST and esterase enzyme activities in E. vittella by 37.53% and 43.09% over control, with IC₅₀ values of 133.00 and 111.76 ppm, respectively. It also reduced GST and esterase activities in H. armigera by 43.14% and 47.421% over control with IC₅₀ values of 114.38 and 98.78 ppm, respectively. Data were analyzed for their normality using the Shapiro-Wilk test and Levene’s statistics to determine the significant deviation. Pectolinaringenin could be used for the management of agricultural pests.     

An evaluation of impregnated respirator canister carbons for phosphine removal from air

The following gas mask canister carbon fillings were evaluated in laboratory and man tests against phosphine which is finding favour as a fumigant for food stuffs: activated carbons impregnated with (1) copper sulphate, (2) potassium dichromate and silver chromate, (3) copper carbonate, potassium chromate and silver chromate and (4) potassium permanganate. Impregnation with copper sulphate (12% w/w) proved to be effective and economical. A cumulative service time of 5.2 mg h/litre was obtained in the laboratory tests at 1.7 mg/litre phosphine in air and 3.1 mg h/litre at 0.2-1.5 mg/litre phosphine in the man tests.     

Spectrophotometric determination of phosphine residues in rice

Phosphine residues were determined in 2 types of rice samples, raw polished and parboiled. The yellow chromophore due to phosphine from raw polished rice had 2 absorption maxima, a strong one at 370-380 nm and a weaker one at 400-410 nm. The chromophore from parboiled rice also had 2, one at 390-400 nm and the other at 410-420 nm. A closed system containing rice and a phosphine tablet or powder yielded 93-99% recovery of fortified phosphine. At any given dose of phosphine, parboiled rice retained a higher amount of residue after aeration than did raw polished rice.     

Enhancement of the productivity of tea (Camellia sinensis) secondary metabolites in cell suspension cultures using pathway inducers

Tea cell suspension culture is an alternative method for the synthesis of secondary metabolites. For the separation of cells, different concentrations of pectinase were used and a concentration of 0.5% was found to be the optimum concentration for the separation of cells (41.7%) in the culture medium than the other two concentrations (33.3 and 25.0%). The separated cells were cultured in liquid MS medium using different PGR combinations. The time taken for the cells to reach stationary phase, under different PGRs, ranged from 17 to 21 d. The maximum cell density was found in IAA and 2, 4-D medium at 21 d followed by 2, 4-D. Results revealed that the amount of secondary metabolites such as catechins were high with stationary phase when compared to other growth phases (lag and log phases). Different concentrations of shikimic acid (10, 20, and 30 mM) were added to the stationary phase of cell culture in the bioreactor and the secondary metabolite content was analyzed. Synthesis of polyphenols, catechins, caffeine, and other secondary components were high (33.87, 22.85, and 4.66%) with 20 mM shikimic acid treatment than the other two concentrations.     

Carbon footprint reduction in the textile process chain: Recycling of textile materials

It is an important task of people connected with the textiles and clothing sector to work on the feasible ways to trim down the carbon footprint in each phase of a textile product??s life cycle. One of the possible ways to decipher the reduction of carbon footprint of textiles and clothing sector is to recycle the textile process waste and also to recycle at the end-of-life of textile products and these aspects are exemplified in this paper in detail. Detailed investigation of the possibilities, barriers, challenges to recycle textile waste materials are discussed in this paper with relevant case studies. For recycling of process waste, an example was modelled by recycling the process waste and the carbon footprint results were demonstrated with the aid of 7.3 version of SIMAPRO LCA (Life cycle assessment) software. From the results of this case study, it was understood that recycling of process waste would contribute to the direct reduction of carbon footprint. For the second case of recycling at the end-of-life, there are many barriers and challenges to the textile products to be recycled, which are discussed in detail. For this case, two hypothetical situations were defined and the carbon footprint results of them were modeled and demonstrated with the aid of 7.3 version of SIMAPRO software to illustrate the benefits of recycling to reduce the carbon footprint. Designers need to conisder, ??Ecological Design?? in design phase to address most of the difficulties faced by recycling of textile products at the end-of-life, which will of certain help to reduce the carbon footprint of the textile products.