No abstract

Members of the Allium genus are consumed for their culinary flavor attributes, but also contain antioxidant and anticarcinogenic phytochemicals. Bunching onions (Allium fistulosum L.) are commonly used in Asian cuisine, in which both leaves and pseudostems are consumed. Carotenoids and chlorophylls are important classes of phytochemicals gaining attention for their health attributes. The goal of our study was to characterize carotenoids and chlorophylls and identify possible genetic and environmental influences on carotenoid concentrations among A. fistulosum accessions. Twelve USDA-ARS accessions were field grown in Knoxville, TN, and Geneva, NY, during the summer of 2007. After harvest, carotenoid and chlorophyll pigments were evaluated in leaf and pseudostem tissues using high-performance liquid chromatography. We were able to identify the presence of antheraxanthin, β-carotene, chlorophyll a and b, lutein, neoxanthin, and violaxanthin in leaf tissues; however, pigments were not found in pseudostem tissues. Carotenoid and chlorophyll concentrations did not differ among accessions or between locations. It is possible that accessions evaluated in this study were a narrow genetic base or were selected based on flavor attributes and not leaf tissue pigmentation.

Plants from the Allium genus are valued worldwide for culinary flavor and medicinal attributes. In this study, 16 cultigens of bunching onion (Allium fistulosum L.) were grown in a glasshouse under filtered UV radiation (control) or supplemental UV-B radiation [7.0 μmol·m−2 ·s−2 (2.68 W·m−2)] to determine impacts on growth, physiological parameters, and nutritional quality. Supplemental UV-B radiation influenced shoot tissue carotenoid concentrations in some, but not all, of the bunching onions. Xanthophyll carotenoid pigments lutein and β-carotene and chlorophylls a and b in shoot tissues differed between UV-B radiation treatments and among cultigens. Cultigen “Pesoenyj” responded to supplemental UV-B radiation with increases in the ratio of zeaxanthin + antheraxanthin to zeaxanthin + antheraxanthin + violaxanthin, which may indicate a flux in the xanthophyll carotenoids towards deepoxydation, commonly found under high irradiance stress. Increases in carotenoid concentrations would be expected to increase crop nutritional values.

Topical ocular application of demecarium causes transient suppression of systemic acetylcholinesterase levels in most dogs. Acetylcholinesterase levels generally do not fall to toxic levels, but may do so in certain individuals. Demecarium bromide eye drops generally do not cause AChE toxicity, but dogs receiving such therapy should be monitored for signs of AChE toxicity, and concomitant use of other AChE inhibitors should be avoided.