Qhov sib txawv tseem ceeb ntawm ester thiab thioester yog cov ester tebchaw muaj carbon, hydrogen thiab oxygen atoms whereas thioester compounds muaj carbon, hydrogen, oxygen thiab sulfur atoms.
Ester thiab thioester tebchaw muaj feem cuam tshuam rau ib leeg raws li lawv lub npe cuam tshuam; thioester txawv ntawm ester vim muaj cov sulfur atom, uas hloov ib qho oxygen atom tam sim no nyob rau hauv ib qho ester compound. Cov khoom thiab lwm qhov sib txawv ntawm ester thiab thioester tau tham hauv qab no hauv kab lus no.
Ester yog dab tsi?
Esters yog cov organic compounds uas muaj cov tshuaj formula R-C(=O)-OR'. Cov tshuaj sib xyaw ua ke no tau muab los ntawm cov organic lossis inorganic acid tebchaw uas tsawg kawg ib pawg hydroxyl hloov los ntawm pawg alkoxy. Feem ntau, esters pib los ntawm kev hloov cov tshuaj tiv thaiv ntawm carboxylic acids thiab cawv.
Daim duab 01: Cov qauv dav dav ntawm tus Ester
Muaj ib lub chaw carbonyl nyob rau hauv ib qho ester, uas muab cov ester nws geometry - lub trigonal planar nyob ib ncig ntawm cov carbonyl carbon. Raws li kev tsim qauv, esters yog cov pab pawg ua haujlwm tau yooj yim (tsis zoo li amides) vim tias qhov thaiv lossis kev sib hloov ntawm pawg carbonyl no tsawg. Ntxiv mus, cov tebchaw no muaj tsawg polarity. Yog li ntawd, cov esters zoo li tsis tshua muaj zog thiab tsis yooj yim dua li cov amides sib raug.
Thaum xav txog cov kev cuam tshuam ntawm esters, cov tshuaj lom neeg no yuav ua rau muaj kev cuam tshuam nrog nucleophiles ntawm carbonyl carbon. Cov pab pawg carbonyl tsis muaj zog electrophilic, tab sis nws tuaj yeem raug kev tawm tsam los ntawm cov nucleophiles muaj zog xws li amines thiab alkoxides.
Muaj ntau yam kev siv ntawm esters; siv lawv los ua cov khoom hauv cov tshuaj tsw qab rau lawv cov ntxhiab tsw, ua cov khoom hauv cov roj yam tseem ceeb, cov khoom noj khoom haus, tshuaj pleev ib ce, thiab lwm yam. Tsis tas li ntawd, esters tseem ceeb xws li cov kuab tshuaj organic, raws li ntuj pheromones, raws li ib txwm muaj rog thiab roj (fatty acid esters ntawm glycerol), etc.
Thioester yog dab tsi?
Thioesters yog cov organic compounds uas muaj cov tshuaj formula R-C(=O)-SR'. Cov tebchaw no zoo ib yam rau carboxylate esters thiab txawv ntawm lawv vim muaj cov sulfur atom uas txuas cov pa atom tshwm sim hauv carboxylate ester. Ib qho thioester tsim thaum thiol reacts nrog carboxylic acid. Hauv thaj chaw biochemistry, coenzyme-A derivatives xws li acetyl-CoA yog cov paub zoo thioesters.
Daim duab 02: Cov Qauv Tshuaj General ntawm Thioester
Thaum xav txog kev npaj ntawm thioesters, txoj hauv kev zoo tshaj plaws yog cov tshuaj tiv thaiv ntawm cov kua qaub chloride thiab alkali hlau ntsev ntawm thiol. Lwm txoj hauv kev yog kev hloov pauv ntawm halides los ntawm alkali hlau ntsev ntawm thiocarboxylic acid.
Muaj ib lub chaw carbonyl nyob rau hauv thioester uas yog reactive ntawm nucleophiles, suav nrog dej. Yog li, cov tshuaj sib xyaw ua ke no yog cov nruab nrab ntawm kev hloov pauv ntawm alkyl halides rau hauv alkyl thiols. Ntxiv mus, tus thioester tuaj yeem ua ke nrog amine los muab ib qho amide.
Muaj ntau daim ntawv thov ntawm thioesters nrog rau kev sib txuas ntawm tag nrho cov esters, koom nrog kev sib txuas ntawm ntau lwm cov cellular Cheebtsam xws li peptides, fatty acids, sterols, terpenes, thiab lwm yam.
Qhov txawv ntawm Ester thiab Thioester yog dab tsi?
Ester thiab thioester yog ob qhov sib txuas. Qhov sib txawv tseem ceeb ntawm ester thiab thioester yog cov ester tebchaw muaj carbon, hydrogen thiab oxygen atoms whereas thioester tebchaw muaj carbon, hydrogen, oxygen thiab sulfur atoms. Ntxiv mus, esters tshwm sim ib txwm muaj thiab tuaj yeem tsim tau siv txoj hauv kev sib txawv xws li esterification ntawm carboxylic acids nrog cawv thaum txoj kev zoo tshaj plaws rau thioesters yog cov tshuaj tiv thaiv ntawm cov kua qaub chloride thiab alkali hlau ntsev ntawm thiol.
Hauv qab infographic tabulates ntau qhov sib txawv ntawm ester thiab thioester.
Summary – Ester vs Thioester
Ib tus thioester txawv ntawm ib qho ester vim muaj cov sulfur atom hloov cov pa atom hauv ester. Qhov sib txawv tseem ceeb ntawm ester thiab thioester yog cov ester tebchaw muaj carbon, hydrogen thiab oxygen atoms whereas thioester tebchaw muaj carbon, hydrogen, oxygen thiab sulfur atoms.
