D-mannose thiab L-mannose yog enantiomers uas tsom ib leeg, thiab lawv qhov sib txawv tseem ceeb nyob hauv lawv qhov sib txawv spatial stereoconfigurations, uas ua rau muaj ntau yam kev ua ub no thiab kev ua haujlwm. Cov hauv qab no yog cov ntsiab lus tseem ceeb sib txawv:

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1. Qhov sib txawv hauv cov qauv tshuaj

Cov ntsiab lus tseem ceeb:

Cov mis mos molecular yog C ? H ?? O ?, uas yog C-2 isomer ntawm qabzib (piv txwv li hydroxyl (- OH) kev taw qhia ntawm qhov thib ob carbon yog opposite rau qabzib).

Core sib txawv:

Txoj kev D/L labeling yog raws li glyceraldehyde reference system:

D-Mannose: Lub hydroxyl (- OH) kev taw qhia ntawm lub siab tshaj plaws naj npawb chiral carbon (C5) nyob rau hauv lub molecule yog ua raws li D-glyceraldehyde (nyob rau sab xis nyob rau hauv lub Fischer projection).

L-mannose: Cov kev taw qhia hydroxyl ntawm C5 zoo ib yam li L-glyceraldehyde (nyob rau sab laug hauv Fischer projection).

Ob leeg yog daim iav duab ntawm ib leeg thiab tsis tuaj yeem sib tshooj. cov

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Fischer projection equation: kev sib piv ntawm cov qauv ntawm D-mannose (sab laug) thiab L-mannose (txoj cai)

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2. Kev ua haujlwm lom neeg thiab cov metabolism sib txawv

Yam ntxwv D-mannose L-mannose

Natural Existence ? Dav dav nyob rau hauv qhov (hauv txiv hmab txiv ntoo, nroj tsuag, glycoproteins) ? Tsis muaj ntuj tsim (laboratory synthesis)

Kev ua lom neeg lom neeg ? Muaj kev ua lom lom lom zem heev ?? Tsis paub txog kev ua lom lom (tsis tuaj yeem metabolized thiab siv los ntawm tib neeg lub cev)

Txoj kev metabolic tuaj yeem ua tau phosphorylated los ntawm mannose kinase (MK) thiab tsis tuaj yeem lees paub los ntawm tib neeg cov enzymes metabolic (enzymes muaj chiral tshwj xeeb)

Kev ua haujlwm ntawm lub cev muaj xws li glycoprotein synthesis, UTI tiv thaiv, CDG kho, thiab lwm yam

Yuav luag tsis muaj kev cuam tshuam rau cov ntshav qab zib (vim tsis tau nqus / metabolized)

Vim li cas D-hom tsuas yog ib daim ntawv ua haujlwm lom neeg? cov

Enzymes thiab transporters nyob rau hauv cov kab mob muaj sia muaj nruj chiral tshwj xeeb (stereoselectivity):

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Metabolic enzyme paub:

Mannose kinase (MK) hauv tib neeg lub siab tsuas paub thiab phosphorylates D-mannose thiab tsis tuaj yeem ua rau L-isomer.

Transporter specification:

Cov kab mob hauv plab hnyuv (xws li GLUT5) nyiam thauj D-mannose (txawm tias muaj kev ua haujlwm tsawg), thaum L-mannose tsis tuaj yeem nqus tau zoo.

Receptor khi:

Cov hom phiaj xws li mannose receptor (MRC1) thiab cov kab mob FimH adhesins tshwj xeeb khi rau D-mannose lossis nws cov derivatives (xws li D-mannoside).

4. Muaj peev xwm siv L-mannose

Txawm hais tias tsis muaj kev ua haujlwm lom neeg, L-mannose muaj txiaj ntsig tshwj xeeb hauv kev tshawb fawb thiab kev lag luam

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Kev tshawb fawb biochemical:

Raws li cov ntaub ntawv siv rau D-mannose, nws yog siv los kawm txog chiral kev paub txog cov enzymes.

Chemical synthesis intermediates:

Siv rau synthesizing tsawg suab thaj los yog chiral tshuaj molecules.

Inhibition tsim:

Tej zaum yuav yog ib qho kev sib tw inhibitor rau cov enzymes tshwj xeeb (yuav tsum tau ua kom pom tseeb).

Cov ntaub ntawv tshwj xeeb:

Siv los npaj chiral polymers lossis nanomaterials (xws li chiral sensors).

Cov ntsiab lus tseem ceeb

Sib piv qhov ntev D-mannose L-mannose

Cov ntsiab lus tshuaj ntawm sab tes xis isomers uas muaj nyob rau hauv cov xwm txheej, ua kom muaj kev sib txuas ntawm sab laug tes isomers

Biological metabolism ? tuaj yeem metabolized los ntawm tib neeg enzymes ? Tsis tuaj yeem lees paub los ntawm tib neeg cov enzymes

Physiological muaj nuj nqi glycosylation, tiv thaiv kab mob, kev kho mob tsis tshua muaj kab mob tsis muaj

Siv cov tshuaj muaj txiaj ntsig (UTI kev tiv thaiv, kev kho CDG), kev tshawb fawb txog kev noj zaub mov ntxiv, cov tshuaj synthesis intermediates

Cov koob tshuaj ntau yuav ua rau raws plab (tab sis tag nrho muaj kev nyab xeeb), tsis muaj tshuaj lom tab sis tsis muaj bioavailable

Yooj yim nco:

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D-type = "biologically active type": nws muaj nyob rau hauv qhov xwm txheej, tuaj yeem metabolized, thiab muaj kev siv tau.

L-type = "daim iav tswj hom": cov khoom siv hluavtaws, tsis muaj kev ua haujlwm lom neeg, tsuas yog siv rau kev tshawb fawb txog kev tshawb fawb lossis tshuaj engineering.

Lo lus 'mannose' tau hais hauv cov tshuaj thiab khoom noj khoom haus yog hais txog D-mannose. L-mannose tsis muaj nqi kho mob, tab sis raws li cov cuab yeej tshuaj, nws muaj qee yam kev tshawb fawb tshawb fawb.