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고체상추출과 LC-MS/MS 이용에 의한 제초제 잔류분석 특성
황재복(Hwang Jae Bok),Takashi Iwafune,Yasuhiro Yogo,이용환(Yong Hwan Lee),박창영(Chang Young Park),박성태(Sung Tae Park) 韓國雜草學會 2009 Weed&Turfgrass Science Vol.29 No.2
HLB 컬럼에서의 첨가회수율은 benfuresate, bentazone, bromobutide, cafenstrole, imazosulfuron, pyrazoxyfen, quinoclamine, 그리고 thiobencrab 제초제가 70% 이상이었으나, cyhalofop-bytyl, molinate, 그리고 pentoxazone 제초제는 32~64%로 낮게 회수되었다. PS-2 컬럼에서의 회수율은 bentazone, imazosulfuron는 거의 회수되지 않았고, benfuresate, bromobutide, cafenstrol, pentoxazone, quinoclamine, thiobencarb, cyhalofop-buthyl, 그리고 molinate 제초제는 57~87% 정도로 회수되었다. 변이계수는 HLB 컬럼에서 1~6% 정도이었고, PS-2 컬럼에서는 1~13%이었다. A comparative study was undertaken to find out the optimum solid-phase extraction (SPE) of water samples for 10 herbicide residues. Two polymer-based sorbents, balanced copolymer of lipophilic divinylbenzene monomer and hydrophilic N-vinylpyrrolidone monomer (HLB) and polystyrene-divinylbenzene copolymer (PS-2) cartridges, were investigated for extraction efficiency of neutral and weak ionic herbicide residues from water sample. Each SPE cartridges was activated by water-miscible solvents, washed with water, and then loaded with 400 to 1,000 mL of water samples containing herbicides. The trapped residue was eluted with acetonitrile and dichloromethane for HLB and PS-2 cartridges, respectively, and followed by determination using triple quadrupole LC/MS in the selective-reaction monitoring mode. Electrospray ionization was successfully applied to form positive or negative molecular ions of target analytes, and product ions derived from the precursor ions were selectively detected. Mean recoveries of HLB extraction were more than 70% except molinate cyhalofop-butyl and pentoxazone showing poor recovery of 32~64%. In PS-2 extraction, bentazone and imazosulfuron were not trapped, while recoveries of other herbicides ranged 57~87%. Relative standard deviations of two methods were in the range of 1~6% and 1~13% HLB and PS-2 cartridge, respectively. According to herbicides properties, each sorbents could be selectively employed for extraction of herbicide residues from water samples. The proposed method was simple to operate and highly specific being coupled with tandem mass spectrometric quantitation.
Chalcone suppresses lignin biosynthesis in illuminated soybean cells
Chen, Wei-Jun,Yun, Min-Soo,Deng, Fan,Yogo, Yasuhiro The Korean Society of Weed Science and The Turfgra 2011 Weed Biology and Management Vol.11 No.1
Lignin and its related metabolites play critical roles in plant growth and development. Thus, lignin biosynthesis has attracted interest as a novel target site of plant growth inhibitors. Chalcone has been shown to not only inhibit lignin biosynthesis in plants, but also to suppress the growth of many annual plant species. In order to know the direct effect of chalcone on plant metabolism, the effects of chalcone on the activities of key enzymes in lignin biosynthesis and on the related metabolites were clarified with a time-course study by using light-induced suspension cultures of soybean cells.The fresh weight and packed cell volume of the soybean cells were inhibited after 8 h of chalcone treatment. The activities of phenylalanine ammonia lyase (EC 4.3.1.24) and 4-coumarate: coenzyme A ligase (4CL; EC 6.2.1.12) were largely inhibited 4 h after the treatment with 0.15 $mmol\;L^{-1}$ chalcone. Unlike these two enzymes, the activity of cinnamyl alcohol dehydrogenase (EC 1.1.1.195) was not inhibited until 16 h after the chalcone treatment. The content of the 4CL substrates and lignin in the soybean cells became relatively lower than the control under the light condition within 4 h and 8 h after the chalcone treatment, respectively. These results suggest that the growth suppression of soybean cells is positively associated with the inhibition of lignin biosynthesis by exogenous chalcone.