The Preparation Of Chiral LACTISOL And Its’ Effects On Cultivation Of Rootless Mung Bean Sprouts

Mung bean sprout has become an increasingly popular type of food owing to its nutrition value and good taste together with a tremendous market demand.However,it is reported that substances such as 2,4-D and gibberellic acid are employed for the production of rootless sprouts by illegal traders.Surely,the use of those substances has been banned since food safety issue is a major concern in modern society.On the other hand,the traditional method for the cultivation of mung bean sprout fails to meet the enormous market demand of rootless bean sprout.As a consequence,it is an urgent task to develop an alternative safe and non-toxic reagent to produce rootless bean sprout.Lactisol is a naturally occurring substance in coffee beans.With an aim to find a novel reagent to promote the production of rootless bean sprout,we investigated the effects of lactisol on the morphology and biochemical composition of mung bean sprout as well its’ feasibility for market.The main content of this dissertation is listed as follows:1.In this dissertation,R-latisol was synthesized by two methods:(1)S-2-chloropropionic acid was synthesized with L-alanine through diazotization.Subsequently,S-2-chloropropionic acid was treated with4-methoxyphenol to generate R-lactisol.(2)Alternatively,methyl S-2-chloropropionate was synthesized by chlorination of the hydroxyl group of methyl D-lactate with solid phosegene.Then,R-lactisol was obtained upon treatment of methyl S-2-chloropropionate with 4-methoxyphenol.The e.e value of lactisol obtained from the above two methods was near 90%,after further purification,it could be over 98%.2.Resolution of racemic lactisol by lipase Novozym-435 was investigated.Optimal resolution was observed when the separation was conducted at 30 oC by using ethyl ester of lactisol and 1,4-butanediamine as the substrates and tert-butanol as the solvent.The conversion of ethyl ester of lactisol reached 54%,and the e.e value ofethyl ester of lactisol was about 43% under this condition.3.The effect of lactisol on the cultivation of mung bean sprout was investigated.The results are listed as follows:(1)The mung bean sprouts were treated with 200 ppm R-lactisol,200 ppm S-lactisol as well as 200 ppm R/S-lactisol separately on the 2th day and 3th day during cultivation in an artificial climate box,and the morphology of the mung bean sprout was measured after 6 days’ cultivation.Compared with the water control group,both R-lactisol and R/S-lactisol groups can efficiently shorten the root length,reduce the number of lateral root(P<0.05).R-lactisol group proves to be the preferential one,in this regard,the root length was shortened by 60.78%,and the number of lateral root was reduced by 50.00% compared with water control group.(2)We proceeded to disclose the effects of continuous application of 1-5 ppm R-lactisol for 6 days on the morphology of mung bean sprout.Compared with the water control group,4 ppm R-lactisol treatment gave the best result,with the root length shortened by 67.50%,and the number of lateral root reduced by 60.00%.(3)Subsequently,the effects of continuous application of 3 ppm,5 ppm,7.5 ppm,10 ppm R-lactisol,and on the 3th day 5 ppm 6-BA applied for 2h during 6 day’cultivation,on the morphology of mung bean sprout were studied.Compared with the water control group,the root length was shortened and the number of lateral roots both were reduced for the tested group(P<0.05).The 3 ppm R-lactisol with 6-BA gave the best result,with the root length shortened by 67.21%,the number of lateral roots decreased by 88.89%,while the production yield elevated by 50% than the water control group.(4)The effects of different cultivators on the mung bean sprout were investigated.75 ppm R-lactisol or 75 ppm 2,4-D applied on the 2th day and the 3th day during the6 days’ cultivation,and for the combination groups,additional 5 ppm 6-BA applied for 2 h on the 3th day.The results illustrated that a combination of R-lactisol and6-BA treatment gave the best result.Compared with the water control group,this combined group could completely inhibit the formation of lateral root,efficiently shorten the main root length by 57.37%,thicken diameter by 10.82% and reduce theroot weight by 53.33% while the whole weight almost the same.The content of soluble protein and soluble sugar of each treatment group was lower than that of control group while the content of vitamin C and gama-aminobutyric of each treatment group was higher than that of the control group.Lactisol possesses potential value for the cultivation of rootless sprouts.