Beta-D-(-)-Arabinoseyog ib qho tseem ceeb chiral qab zib molecule nrog dav daim ntawv thov nqi. Nws muaj cov ntawv thov tseem ceeb hauv kev tsim tshuaj, khoom noj khoom haus additives, dehydrating agents, tshuaj pleev ib ce thiab lwm yam. Yog li, muaj ntau txoj hauv kev los ua ke Beta-D-(-)-Arabinose. Kab lus no yuav qhia txog qee yam ntawm cov txheej txheem hluavtaws tseem ceeb.
Extraction ntawm Beta-D-(-)-Arabinose los ntawm cov khoom ntuj:
Cov txheej txheem ntawm kev rho tawm Beta-D-(-)-Arabinose los ntawm cov khoom ntuj yog qhov ncaj ncees tshaj plaws thiab tuaj yeem tau txais cov khoom zoo. Qhov feem ntau natural source ntawm Beta-D-(-)-Arabinose yog xylan, uas yog ib tug disaccharide muaj li D-xylose thiab D-glucose. Beta-D-(-)-Arabinose yog ib qho ntawm cov qauv ntawm xylan. Xylan tuaj yeem pom hauv cov phab ntsa ntawm cov nroj tsuag xws li lignin, ntoo thuv uas loj hlob hauv thaj chaw txias, thiab lwm yam.
Txoj kev rho tawm ntawm Beta-D-(-)-Arabinose yog tib yam li xylan. Feem ntau, cov kua qaub yog txoj kev siv xylan extraction ntau tshaj plaws. Ib qho piv txwv xylan yog thawj zaug ntxiv rau cov kua qaub, rhuab kom txog thaum cov piam thaj monomers raug tshem tawm los ntawm cov aggregates, ces lim thiab ntxuav. Tom qab xylan kev kho mob, Beta-D-(-)-Arabinose muaj nyob rau hauv cov kua qaub yuav raug muab cais thiab huv si los ntawm neutralization thiab crystallization.
Tshuaj synthesis:
Tam sim no, muaj ntau txoj kev siv tshuaj muaj txiaj ntsig zoo rau kev sib txuas ntawm Beta-D-(-)-Arabinose. Nov yog ob peb txoj hauv kev:
1. Glycogen txoj kev:
Qhov no yog ib qho ntawm feem ntau siv hluavtaws txoj kev
Kauj Ruam 1: Tau Xylose los ntawm Xylan:
Txoj kev glycogen synthesis ntawm Beta-D-(-)-Arabinose pib los ntawm xylose. Xylose yog 6-carbon qab zib ubiquitously tam sim no nyob rau hauv cov nroj tsuag cell phab ntsa thiab yuav tau los ntawm hydrolyzing xylan (feem ntau muab rho tawm los ntawm cov nroj tsuag).
Xylan plus H2O → Xylose ntxiv rau lwm cov suab thaj
Xylan yog polysaccharide uas muaj ntau yam xylose molecules thiab feem ntau yog xim tsis muaj xim lossis xim av hmoov. Cov tshuaj tiv thaiv hydrolysis yuav tsum tau catalyzed los ntawm cov kua qaub los yog ib qho enzyme, thiab cov kua qaub catalyst feem ntau yog siv rau cov tshuaj tiv thaiv hydrolysis. Tom qab hydrolysis, xylose tuaj yeem siv los ua ke Beta-D-(-)-Arabinose.
Kauj ruam 2: Hloov xylose rau L-arabinose:
Kev hloov pauv ntawm xylose rau L-arabinose yog ib kauj ruam tseem ceeb hauv kev sib txuas ntawm Beta-D-(-)-Arabinose ntawm txoj kev glycogen. Cov txheej txheem no yuav tsum tau siv cov txheej txheem enzymes los ua kom muaj cov tshuaj tiv thaiv uas hloov xylose rau arabinose.
Ua ntej, xylose hloov mus rau hauv D-xylose ketose los ntawm cov tshuaj tiv thaiv catalytic.
Xylose plus ATP → D-xylose ketose plus ADP
Qhov thib ob, D-xylose ketose yuav hloov mus rau L-xylose ketose los ntawm isomerization cov tshuaj tiv thaiv.
D-xylose ketulose → L-xylose ketulose
Tom qab ntawd, cov tshuaj tiv thaiv catalyzed los ntawm L-xylose glusidase tau raug Cooper cyclization kom tau L-arabino-deoxy-hex-2-ulonate.
L-xylose ketose → L-arabinuronic acid
Thaum kawg, nyob rau hauv qhov kev txiav txim ntawm arabinuronic acid, siv NADPH thiab glucosidase los txo arabinuronic acid rau L-arabinose.
L-arabinuronic acid ntxiv rau NADPH ntxiv rau H ntxiv → L-arabinose ntxiv NADP ntxiv
Kauj ruam 3: Hloov L-arabinose rau Beta-D-(-)-Arabinose:
Kev hloov pauv ntawm L-arabinose rau Beta-D-(-)-Arabinose yuav tsum muaj cov enzymes los ua kom cov tshuaj tiv thaiv.
Ua ntej, L-arabinose yog phosphorylated los ua arabinose-6-phosphate.
L-arabinose plus ATP → arabinose-6-phosphate plus ADP
Tom qab ntawd, cov tshuaj tiv thaiv hydrolysis hloov arabinose-6-phosphate rau Beta-D-(-)-Arabinose-5-phosphate (Beta-D-(-)-arabinose-5-phosphate).
Arabinose-6-phosphate plus H2O → Beta-D-(-)-arabinose-5-phosphate
Thaum kawg, Beta-D-(-)-arabinose-5-phosphate undergoes dephosphorylation los ua Beta-D-(-)-Arabinose.
Beta-D-(-)-arabinose-5-phosphate → Beta-D-(-)-arabinose ntxiv Pi
Txoj kev glycogen synthesis ntawm Beta-D-(-)-Arabinose pib los ntawm xylose. Ua ntej, xylose tau los ntawm xylan, ces xylose hloov mus rau L-arabinose, thiab thaum kawg L-arabinose hloov mus rau Beta-D-(-)-Arabinose. Cov txheej txheem no yuav tsum tau siv ntau yam enzyme-catalyzed cov tshuaj tiv thaiv, txhua qhov tseem ceeb. Los ntawm txoj kev sib xyaw no, muaj txiaj ntsig zoo, kev lag luam thiab ntshiab Beta-D-(-)-Arabinose tuaj yeem tau txais, uas muab lub hauv paus ruaj khov rau nws daim ntawv thov nyob rau hauv biology, tshuaj thiab tshuaj synthesis.
2. Knight cov tshuaj tiv thaiv:
Txoj kev, tsim nyob rau hauv 1940s, yuav tsum tau polychlorinated aromatic hydrocarbons ua cov khoom pib. Nyob rau hauv Knight cov tshuaj tiv thaiv, polychlorinated aromatic hydrocarbons yog reacted nrog ib tug sib tov ntawm acid thiab detergent, thiab ces Obenzyl-D-arabinose yog ntxiv ua ke nrog sib tov. Tom qab ib tug series ntawm cov kauj ruam, Beta-D-(-)-Arabinose yog synthesized.
Cov kauj ruam tshwj xeeb yog raws li hauv qab no:
Kauj Ruam 1: Txhawm rau npaj Beta-D-(-)-Arabinose, peb yuav tsum npaj Beta-D-(-)-Arabinose qab zib thiab pre-ntxiv reagents ua ntej, thiab oxygenation yog ib qho ntawm feem ntau txoj kev tsim khoom. Nws muaj ob theem: thawj, methyl-D-glucofuranoside tau txais cov tshuaj aromatization nyob rau hauv lub xub ntiag ntawm iodine ntsev kom tau 4,6-O-methyl anisol derivatives; ces aromatizes ntawm 5-O-angle txoj hauj lwm Structured cov tshuaj tiv thaiv, thiab ces txo kom tau Beta-D-(-)-Arabinose.
Kauj Ruam 2: Npaj cov reagents thiab cov kuab tshuaj uas xav tau rau Knight cov tshuaj tiv thaiv. Nws yog ib qho tsim nyog los npaj ib lub raj mis uas muaj 30ml ntawm 50 feem pua acetic acid thiab 10g ntawm Beta-D-(-)-Arabinose qab zib, thiab mus rau cov kauj ruam tom ntej ntawm lub hauv paus no.
Kauj Ruam 3: Ntxiv sulfuric acid ua cov kua qaub catalyst. Ua ntej ntxiv cov acidic catalyst, 100 ml ntawm ethanol yuav tsum tau muab ntxiv rau hauv lub raj kuaj, ua raws li 0.1 ml ntawm concentrated sulfuric acid.
Kauj Ruam 4: Ntxiv boric acid nyob rau hauv txias txias. Tom qab cov kuab tshuaj tau txias rau hauv chav sov, 15 0 ml ntawm isopropanol tau ntxiv, thiab tom qab ntawd 0.1 ml ntawm boric acid tau ntxiv, thiab nplawm maj mam.
Kauj Ruam 5: Cov tshuaj tiv thaiv cua sov. Tshav kub nyob rau hauv qhov kub thiab txias ntawm cov roj da dej li 40 mus rau 50 feeb kom ua tiav cov tshuaj aldose hauv cov tshuaj los tsim cov khoom qab zib enol ester.
Kauj Ruam 6: Catalytic hydrogenation. Tom qab cov tshuaj tiv thaiv tiav lawm, lub raj tshuaj tau muab tshem tawm los ntawm cov roj da dej thiab tso cai rau kom txias mus rau chav sov. Tom qab ntawd ntxiv 1 milliliter ntawm n-heptane thiab 0.05 milliliter ntawm sodium tungstate tov los ua cov tshuaj tiv thaiv catalytic hydrogenation, feem ntau yuav tsum tau tos ob peb hnub.
Kauj Ruam 7: Extract cov khoom. Cov khoom tau muab rho tawm los ntawm cov tshuaj los ntawm txoj kev immersion, thiab cov khoom raug txheeb xyuas thiab cov yam ntxwv ntawm txoj kev xws li ultraviolet spectroscopy, infrared spectroscopy thiab nuclear magnetic resonance, thiab cov qauv ntawm cov tshuaj tiv thaiv cov khoom raug txiav tawm.
3. Glycosidation cov tshuaj tiv thaiv:
Txoj kev no kuj nrov heev, thiab nws cov khoom siv raw yog D-xyloside. Ua ntej, react D-xyloside thiab methanol nyob rau hauv qhov kev txiav txim ntawm ib tug catalyst kom tau Obenzyl-D-arabinose. Tom ntej no, Obenzyl-D-arabinose yog reacted nrog oxidized NaIO4 nyob rau hauv lub xub ntiag ntawm lub substrate, ua raws li los ntawm ntxiv ntawm qhuav quaternary ammonium ntsev, yog li tau txais Beta-D-(-)-Arabinose.
Hauv ib lo lus, Beta-D-(-)-Arabinose tuaj yeem ua ke los ntawm ntau txoj hauv kev tau hais los saum no, txhua txoj kev muaj nws qhov zoo thiab qhov tsis zoo, thiab ntau txoj hauv kev tuaj yeem xaiv raws li qhov xav tau sib txawv.