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Abad, L.*; Saiki, Seiichi; Nagasawa, Naotsugu; Kudo, Hisaaki*; Katsumura, Yosuke*; Dela Rosa, A. M.*
Radiation Physics and Chemistry, 80(9), p.977 - 982, 2011/09
Times Cited Count:14 Percentile:74.1(Chemistry, Physical)The optimum molecular weight of irradiated -carrageenan for the plant growth promoting effect is known to be around 10 kDa, which is obtained by irradiation at doses of 100 kGy in solid and of 2 kGy in 1% aqueous solution. In this study, isolated fraction by membrane filter of irradiated -carrageenan was analyzed by NMR. The chemical shifts of C and H spectra at the range of 3-10 kDa indicated that the basic functional structure of -carrageenan (alternating D-galactose-4-sulfate and 3,6-anhydro-D-galactose dimer) remains intact. No radiolytic product having carbonyl groups was detected at the range of 3-10 kDa, and moved to less than 3 kDa probably. From these results, it is assumed that the plant growth promoting effect of irradiated -carrageenan depends on the molecular weight, its intact structure, and not on the radiolytic products.
Abad, L.*; Kudo, Hisaaki*; Saiki, Seiichi; Nagasawa, Naotsugu; Tamada, Masao; Fu, H.*; Muroya, Yusa*; Lin, M.; Katsumura, Yosuke*; Dela Rosa, A. M.*
no journal, ,
The radiation degradation yield of -carrageenan irradiated at atmospheric conditions, in vacuum and at 1% aqueous solutions was determined by GPC. UV-Vis characterization of irradiated -carrageenan for all irradiation conditions indicated a UV-Vis peak at 260nm. The rate constant of reaction of OH radicals with sonicated and irradiated -carrageenan with decreasing molecular weights were determined using e-beam pulse radiolysis.