D-mannose ndi L-mannose ndi ma enantiomers omwe amafanana, ndipo kusiyana kwawo kofunikira kuli m'malo osiyanasiyana, zomwe zimapangitsa kuti pakhale zochitika ndi ntchito zosiyanasiyana. Nawa mfundo zazikulu zosiyanitsa:

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1. Kusiyana kwakukulu pamapangidwe amankhwala

Mfundo zofanana:

Maselo a molekyulu ndi C ? H ?? O ?, yomwe ndi C-2 isomer ya shuga (ie hydroxyl (- OH) yolowera pa kaboni yachiwiri yotsutsana ndi glucose).

Kusiyana Kwakukulu:

Njira yolembera ya D/L imachokera ku glyceraldehyde reference system:

D-Mannose: Njira ya hydroxyl (- OH) ya chiral carbon (C5) yochuluka kwambiri mu molekyulu imagwirizana ndi D-glyceraldehyde (yomwe ili kumanja kwa Fischer projection).

L-mannose: Njira ya hydroxyl ya C5 imagwirizana ndi L-glyceraldehyde (yomwe ili kumanzere kwa Fischer projection).

Awiriwa ndi zithunzi zamagalasi a wina ndi mzake ndipo sizingafanane. pa

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Fischer projection equation: kuyerekeza kwapangidwe pakati pa D-mannose (kumanzere) ndi L-mannose (kumanja)

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2. Biological ntchito ndi kusiyana kwa metabolic

Makhalidwe a D-mannose L-mannose

Kukhalapo Kwachilengedwe ? Kupezeka m'chilengedwe (mu zipatso, zomera, glycoproteins) ? Kusakhalako kwachilengedwe (kaphatikizidwe ka labotale)

Tizilombo toyambitsa matenda ? Imakhala ndi zochitika zazikulu zamoyo ?? Palibe zodziwika bwino zachilengedwe (sizingapangidwe ndi kugwiritsidwa ntchito ndi thupi la munthu)

Njira ya kagayidwe kachakudya imatha kukhala phosphorylated ndi mannose kinase (MK) ndipo sichingadziwike ndi michere ya anthu (ma enzymes ali ndi chiral specificity)

Ntchito zakuthupi zimaphatikizapo kaphatikizidwe ka glycoprotein, kupewa UTI, CDG therapy, etc

Pafupifupi palibe chiwopsezo cha shuga wamagazi (chifukwa chosayamwa / kusungunuka)

Chifukwa chiyani mtundu wa D ndiwokhawo womwe umagwira ntchito mwachilengedwe? pa

Ma enzyme ndi zonyamula mu zamoyo zimakhala ndi chiral chokhazikika (stereoselectivity):

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Kuzindikira kwa metabolic enzyme:

Mannose kinase (MK) mu chiwindi cha munthu amangozindikira ndi phosphorylates D-mannose ndipo sangathe kuchitapo kanthu pa L-isomer.

Mchitidwe wa Transporter:

Onyamula shuga m'matumbo (monga GLUT5) amakonda kunyamula D-mannose (ngakhale ndi mphamvu yochepa), pomwe L-mannose sangathe kuyamwa bwino.

Kumanga kwa receptor:

Zolinga monga mannose receptor (MRC1) ndi zomatira za bakiteriya za FimH zimamangiriza ku D-mannose kapena zotumphukira zake (monga D-mannoside).

4. Kugwiritsa ntchito L-mannose

Ngakhale kusowa kwachilengedwe, L-mannose ili ndi phindu lenileni mu kafukufuku wa sayansi ndi mafakitale

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Kafukufuku wa Biochemical:

Monga chinthu chofotokozera cha D-mannose, chimagwiritsidwa ntchito pophunzira njira yozindikiritsa chiral ya ma enzyme.

Chemical synthesis intermediates:

Amagwiritsidwa ntchito popanga shuga wosowa kapena mamolekyu a mankhwala a chiral.

Mapangidwe oletsa:

Itha kukhala ngati choletsa champikisano cha michere inayake (yofuna kutsimikizika kolunjika).

Zida zapadera:

Amagwiritsidwa ntchito pokonzekera ma polima a chiral kapena nanomaterials (monga masensa a chiral).

Chidule Chachidule

Kuyerekeza kwa D-mannose L-mannose

Zomwe zimapangidwira za ma isomers akumanja omwe amapezeka m'chilengedwe, opangidwa mochita kupanga ma isomers akumanzere

Biological metabolism ? Itha kupangidwa ndi michere yamunthu ? Sizingazindikirike ndi michere yamunthu.

Physiological ntchito glycosylation, anti matenda, mankhwala osowa matenda palibe

Mankhwala ogwiritsidwa ntchito (kupewa kwa UTI, chithandizo cha CDG), zowunikira zowonjezera zakudya, zopangira mankhwala.

Mlingo waukulu ungayambitse kutsekula m'mimba (koma kotetezeka kwathunthu), wopanda poizoni koma osapezeka ndi bioavailable

Kukumbukira kosavuta:

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D-mtundu = "biologically active type": ilipo m'chilengedwe, imatha kusinthidwa, ndipo imakhala ndi ntchito zothandiza.

L-mtundu = "galasi lowongolera": opangidwa mwaluso, opanda ntchito yachilengedwe, amangogwiritsidwa ntchito pofufuza zasayansi kapena uinjiniya wamankhwala.

Mawu akuti 'mannose' otchulidwa muzamankhwala ndi zakudya amatanthauza D-mannose. L-mannose ilibe phindu lachipatala, koma ngati chida chamankhwala, ili ndi kuthekera kofufuza zasayansi.