Investigation of the antioxidant activity of African potato (Hypoxis hemerocallidea)

African potato (AP) is widely used as an immune booster for the treatment of various ailments. The norlignan glycoside hypoxoside, a major phytoconstituent of AP, its aglycon rooperol, and an aqueous preparation of lyophilized AP corms were screened for in vitro antioxidant activity using the DPPH (1,1-diphenyl-2-picryl hydrazine) and FRAP (ferric reducing ability of plasma) tests. Inhibition of quinolinic acid (QA) induced lipid peroxidation in rat liver tissue was studied in vitro using the thiobarbituric assay (TBA). Superoxide free radical scavenging activity was determined by the nitroblue tetrazolium assay. An isocratic HPLC method was developed to quantitatively determine both hypoxoside and rooperol concurrently. While rooperol and AP extracts reduced QA-induced lipid peroxidation in rat liver homogenates and significantly scavenged the superoxide anion at pharmacological doses, in comparison, hypoxoside was virtually devoid of activity. Since hypoxoside is converted to rooperol in vivo following administration of AP, the results indicate that the hypoxoside component in AP could have value as an antioxidant prodrug.     

Screening of dialkoxybenzenes and disubstituted cyclopentene derivatives against the cabbage looper, Trichoplusia ni, for the discovery of new feeding and oviposition deterrents

The antifeedant, oviposition deterrent, and toxic effects of dialkoxybenzene minilibraries and of disubstituted cyclopentene minilibraries (i.e., consisting of four to five compounds) along with their pure constituent compounds were assessed against third instar larvae and adults of the cabbage looper, Trichoplusia ni, in laboratory bioassays in a search for new insect control agents. These compounds mimic naturally occurring bioactive odorants and tastants and are relatively easily prepared from commodity chemicals. Most of these libraries strongly deterred larval feeding, with some exhibiting strong toxic and oviposition deterrent effects as well. Our results suggest some structure-function relationships within these libraries. Replacement of a methyl group with larger alkyl substituents increased the feeding deterrent effects in most cases. The presence of a free hydroxyl group, irrespective of the carbon framework or alkyl substituent, served to reduce feeding deterrent effects in all series of compounds. Further, exceeding a certain group size also generally had a detrimental effect. This information will be useful in designing new insect control agents for agriculture. Some of these libraries and compounds may have potential for development as commercial insecticides.     

An Enzyme‐Linked Immunosorbent Assay (ELISA) for Detection of Marek's Disease Virus‐Specific Antibodies and its Application in an Experimental Vaccine Trial

An enzyme‐linked immunosorbent assay (ELISA) for the detection of Marek's disease virus (MDV)‐specific antibodies was developed. Chicken embryo cells (CEC) or chicken kidney cells (CKC) were infected with MDV vaccine strain CVI988/Rispens, and infected‐cell lysates were prepared at day 5 post‐infection by freeze‐thawing. Uninfected‐cell lysates served as negative controls. Sera were used at a 1 : 100 dilution and were added in parallel to wells containing the infected and uninfected cell lysates. The optical densities at 492 nm (OD_{492 nm}) were measured after detection of bound chicken antibodies with anti‐chicken IgG peroxidase conjugate and colour reactions using o‐phenylenediamine (OPD) as a substrate. The best results concerning the signal‐to‐noise ratio were obtained by using CKC cells rather than CEC for antigen preparation. The OD_{492 nm} of plasma or serum samples with infected CKC was <0.02 when samples of unvaccinated and unchallenged maternal antibody‐negative white leghorn chickens were tested. Sera and plasma samples of positive control birds exhibited OD_{492 nm} of <0.01 when tested with uninfected CKC. The assay was used to monitor a trial that compared experimental BAC DNA vaccines and a commercial vaccine. Sustained seroconversion and antibody titers that were constantly rising until day 84 after vaccination (71 days after challenge) was observed only when chickens did not develop Marek's disease. In contrast, chickens developing the disease mounted marginal and short‐lived antibody titers only. We conclude that the developed ELISA may be a valuable tool for the evaluation of the efficacy of MDV vaccination under experimental but possibly also under field conditions.     

Agro-biodiversity and ethnobotany of Lakshadweep Islands of India

The Lakshadweep is a tiny landmass of 32 km² area (8^o–12^oN, 71^o–74^oE) constituted by a group of 27 small atolls located in the Indian territory of Arabian Sea of Indian Ocean. Studies on crop genetic diversity including wild relatives of crop plants of the region are little known except for coconut palm. This report deals with 106 collections assembled in two exploration and collection missions comprising 46 plant species under 35 genera belonging to 24 families. The plant germplasm collected during the trips are mostly useful as vegetable, fibre, medicinal plant, dye, edible tuber, timber and ecosystem service provider. The crop wild relatives collected during the study include that of sunnhemp, melon, yam, jute, pigeon pea, sugarcane, etc. A set of germplasm accessions was sent to national research institutes for regeneration. Out of the total collection, 64 accessions were assigned with national identity (Indigenous Collection or IC numbers: IC 0572014 to IC 0572077), and conserved in long term storage at National Gene Bank or in the field gene bank of ICAR-NBPGR, New Delhi. The important germplasm assembled from the islands include highly pungent betel leaf and a large fruited noni. Plants of Cajanus scarabaeoides (L.) Thouars, bitter less Cucumis melo L. var. agrestis Naudin saline tolerant Canavalia cathartica Thouars, Vigna marina (Burm.) Merr. and Corchorus trilocularis L. were the unique wild relatives collected. The current report is the first of its kind on the exploration and collection of plant genetic resources (other than coconut) from Lakshadweep Islands. Wild melon accessions collected are currently employed in distant hybridization programs. During the survey, ethnobotanic information of 23 plants for medicinal and other uses was also documented. Novel uses of the native plant species in the islands indicate their potential for exploitation in other coastal ecosystems. This report aims to highlight the potential plant resources of the region for direct human use and in future breeding programs.     

Unimpeded permeation of water through helium-leak-tight graphene-based membranes

Permeation through nanometer pores is important in the design of materials for filtration and separation techniques and because of unusual fundamental behavior arising at the molecular scale. We found that submicrometer-thick membranes made from graphene oxide can be completely impermeable to liquids, vapors, and gases, including helium, but these membranes allow unimpeded permeation of water (H(2)O permeates through the membranes at least 10(10) times faster than He). We attribute these seemingly incompatible observations to a low-friction flow of a monolayer of water through two-dimensional capillaries formed by closely spaced graphene sheets. Diffusion of other molecules is blocked by reversible narrowing of the capillaries in low humidity and/or by their clogging with water.     

Enrobed Snack Product from Devis’s Anchovy (Stolephorus commersonnii) and its Quality Evaluation during Frozen Storage

Enrobing of fish improves physical as well as consumer acceptance of low value fish. The present work was undertaken to utilize a low value fish with its bones by enrobing with cereal flour based coating. Three combinations of batters were prepared, and the fish was coated and fried; based on the sensory quality, 1:2 batter to water ratio was selected for product preparation. To determine the storage life, frozen par-fried samples were prepared and stored at ?18°C. Quality parameters such as pH, total volatile basic nitrogen, free fatty acids, peroxide value, thiobarbituric acid reactive substances, color, and sensory attributes were evaluated on a monthly basis. It was observed from chemical parameters and sensory scores of the product that the par-fried form can be stored for up to 5 months. This technology will provide a better opportunity for employment of coastal women.     

An enzyme-linked immunosorbent assay (ELISA) for detection of Marek's disease virus-specific antibodies and its application in an experimental vaccine trial

An enzyme-linked immunosorbent assay (ELISA) for the detection of Marek's disease virus (MDV)-specific antibodies was developed. Chicken embryo cells (CEC) or chicken kidney cells (CKC) were infected with MDV vaccine strain CVI988/Rispens, and infected-cell lysates were prepared at day 5 post-infection by freeze-thawing. Uninfected-cell lysates served as negative controls. Sera were used at a 1 : 100 dilution and were added in parallel to wells containing the infected and uninfected cell lysates. The optical densities at 492 nm (OD(492 nm)) were measured after detection of bound chicken antibodies with anti-chicken IgG peroxidase conjugate and colour reactions using o-phenylenediamine (OPD) as a substrate. The best results concerning the signal-to-noise ratio were obtained by using CKC cells rather than CEC for antigen preparation. The OD(492 nm) of plasma or serum samples with infected CKC was <0.02 when samples of unvaccinated and unchallenged maternal antibody-negative white leghorn chickens were tested. Sera and plasma samples of positive control birds exhibited OD(492 nm) of <0.01 when tested with uninfected CKC. The assay was used to monitor a trial that compared experimental BAC DNA vaccines and a commercial vaccine. Sustained seroconversion and antibody titers that were constantly rising until day 84 after vaccination (71 days after challenge) was observed only when chickens did not develop Marek's disease. In contrast, chickens developing the disease mounted marginal and short-lived antibody titers only. We conclude that the developed ELISA may be a valuable tool for the evaluation of the efficacy of MDV vaccination under experimental but possibly also under field conditions.     

Extended summaries pesticides group symposium natural products as a source for new agricultural chemicals

The following are extended abstracts of six of the papers presented at the above meeting and, as so presented, they are entirely the responsibility of the authors and do not reflect the views of the Editorial Board of Pesticide Science.