Ubururu bwa metilene n'ubururu bwa leukometilene: ubwoko bubiri bufitanye isano ya redox, amabara abiri

Umunyeshuri ashyira ibitonyanga bike by'irangi ry'ubururu mu icupa rya laboratwari, akarizunguriza buhoro, akareba ibara rizimira. Aracugusa iryo cupa, ubururu bukagaruka. Hagati y'iyo mimerere yombi, nta kintu cyongeweho cyangwa cyakuweho uretse elekitironi no guhura n'umwuka. Iryo cupa ririmo ingingo yose y'iyi nyandiko: ubururu bwa metilene n'ubwoko bujyana na bwo bwakiriye elekitironi, ari bwo bururu bwa leukometilene, bihindurana muri redox ishobora kugana mu byerekezo byombi, aho ibara ari ryo ryerekana ibibaye.

Ingingo y'ingenzi mu bikorwa ibanza. Ihinduka ry'ibara si ingaruka yo ku ruhande hano. Ni ikimenyetso gikoreshwa mu isesengura. Umuntu wese utegura imvange zirimo ubururu bwa metilene, abukoresha muri titirasiyo, cyangwa abwigishirizaho, yagombye gushobora kwandika igice cy'ireaksiyo atarebye ahandi, kuvuga imimerere ituma kigana ibumoso cyangwa iburyo, no gutanga amazina y'imyanda ituma igisubizo kitagaragara neza.

Ubwoko bubiri bufitanye isano mu kigereranyo kimwe

Ubururu bwa metilene bwatanze elekitironi ni katiyoni ya metilitioniniyumu: imiterere irambuye ya fenotiyaziniyumu ifite sulufure na azote mu mpeta yo hagati, n'itsinda rya dimetilamino kuri buri mpera, itangwa nk'umunyu wa kolorure. PubChem ibwandika nka kolorure ya metilitioniniyumu, C.I. Basic Blue 9. Mu mazi, monomeri inyunyuza urumuri hafi ya 664 nm, ari na byo bituma ijisho ribona ubururu.

Ubururu bwa leukometilene (LMB) bwakiriye elekitironi bufite uwo murongo shingiro umwe, ariko azote yo mu mpeta yo hagati iba yakiriye protoni, maze imiterere itanga ibara ikabura. Nta muriro w'amashanyarazi bufite kuri pH iri hafi y'itagira aside cyangwa baze, kandi busa n'ubutagira ibara; inyunyuza ryabwo ry'urumuri rugaragara ni rito cyane, ariko bufite igice gikomeye cyo kunyunyuzamo urumuri rwa ultraviolet hafi ya 258 nm (inyandiko ya PubChem ku bururu bwa leukometilene, CAS 613-11-6). Umubare wa protoni mu gice cy'ireaksiyo uterwa na pH, kuko imiterere yakiriye elekitironi yakira protoni muri aside (agaciro ka pKa kaba hafi ya 4.5 na 5.8). Imimerere itatu ikubiyemo urugero rukunze gukoreshwa:

MB(+) + 2 e(-) + H(+) <=> LMB, ubururu <=> nta bara (kuri pH iri hafi y'itagira aside cyangwa baze, protoni 1)

MB(+) + 2 e(-) + 2 H(+) <=> LMBH(+), ubururu <=> nta bara (muri aside iri ku rugero ruringaniye, protoni 2)

MB(+) + 2 e(-) + 3 H(+) <=> ubwoko bwa leuco bwakiriye protoni ebyiri (muri aside ikomeye, protoni 3)

Ibi byanditswe uko ari bitatu bisobanura ubwoko bubiri bumwe bufitanye isano, ariko buri mu mimerere itandukanye yo kwakira protoni; inyandiko ku myitwarire ya redox y'amarangi ya tiyazine zisobanura iyi ngingo mu buryo bufite gahunda. Uko pH ibigiramo uruhare gukurikiza ikigereranyo cya Nernst kuri Ox + mH(+) + 2e(-) <=> Red, kigatanga igipimo cy'ihinduka cya hafi 29.6, 59.2, cyangwa 88.7 mV kuri buri gice cya pH iyo m = 1, 2, cyangwa 3. Ibipimo by'ihinduka byapimwe biri hafi ya 28, 58, na 87 mV kuri buri gice cya pH byemeza uko bisobanuwe; bityo potansiyeli yatangajwe idafite pH yayo nta cyo isobanura.

Icyo ikigereranyo kibwira utegura imvange

Ibintu bitatu biva mu bipimo by'ibinyabutabire byitabira ire action. Icya mbere, elekitironi ebyiri kuri buri molekile bivuze ko, mu ire action yabwo yose, ubururu bwa metilene ari ikimenyetso n'umuhuza bya elekitironi ebyiri, atari igitwara elekitironi imwe. Icya kabiri, protoni zirayigiramo uruhare, bityo potansiyeli ya redox yagenwe igahinduka uko pH ihinduka, nk'uko byasobanuwe haruguru. Icya gatatu, potansiyeli ya redox yagenwe kuri pH 7 iba hafi ya +0.011 V ugereranyije na elegitorode isanzwe ya hidurojeni (hafi +0.53 V kuri pH 0), ibyo bikaba bishyira ubu bwoko bubiri mu binyabutabire byakira elekitironi bidakomeye cyane: bifite imbaraga zihagije zo kwakira elekitironi ku bitanga neza nka NAD(P)H cyangwa asikorubate, ariko bikagira intege nke zihagije zo kuzitanga kuri ogisijeni yashongeye mu mazi cyangwa ku bice birimo feri mu mimerere ya ferric. Uwo mwanya wo hagati ni wo utuma irangi risubira muri izo mimerere yombi aho kuguma ku ruhande rumwe.

Ubwinshi bw'ikinyabutabire mu mazi bwongeraho indi ngingo. Iyo burenze hafi mikromolari ijana mu mazi, bihuye n'agaciro gahoraho katangajwe ko gutandukana kwa dimeri ikavamo monomeri kari hafi ya 170 kugeza kuri 250 uM kuri pH 7, katiyoni yatanze elekitironi iraterana ikabyara dimeri n'amatsinda manini kurushaho, igice cy'inyunyuza ry'urumuri kikimukira hafi ya 610 kugeza kuri 615 nm. Bityo igishushanyo cy'inyunyuza ry'urumuri kigaragara nk'icyavuye ku gasongero kacyo gishobora gusobanura ko molekile zateranye, atari uko harimo imyanda. Banza ugabanye ubwinshi bw'ikinyabutabire wongeramo amazi, hanyuma ubone gusuzuma.

Imimerere ituma ire action igana muri buri cyerekezo

Imbonerahamwe ikurikira ni iyo kwifashisha ku meza ya laboratwari. Kwakira elekitironi bisaba ikinyabutabire kizitanga; kongera gutanga elekitironi bisaba ikinyabutabire kizakira, kandi akenshi umwuka urahagije.

Buri murongo ukurikiza ikigereranyo kimwe. Igihinduka gusa ni imbaraga ziyobora ire action. Ni muri ubwo buryo ubu bwoko bubiri bufitanye isano bushobora guhindurana: inzira ni imwe, ikanyurwamo mu byerekezo bihabanye no mu mimerere ihabanye.

Gusobanura icupa ry'ubururu

Ubu buryo bwo kwerekana ire action bukwiye gusobanurirwa imikorere yabwo mu buryo bworoshye, kuko bugaragaza ubu bwoko bubiri ku rugero ruto. Mu gisubizo cya gilukoze gifite baze, baze yoroshya ihinduka rya gilukoze rikabyara enol, maze enediyolate ibivuyemo igatanga elekitironi ku bururu bwa metilene bukaba ubururu bwa leukometilene; bityo ibiri mu icupa bigatakaza ibara. Gucugusa bituma ogisijeni iri mu mwanya uri hejuru y'amazi ishongera muri yo, ogisijeni igatuma imiterere ya leuco yongera gutanga elekitironi, ubururu bukagaruka. Kureka icupa ridacuguswa bigabanya ogisijeni yashongeye mu mazi hafi y'ahantu ire action ibera ku buso, maze gilukoze ikongera gutsinda. Uru ruziga rusubirwamo kugeza gilukoze ishize, kandi buri gucugusa ni ikigereranyo cya Nernst kigaragara: ongera igikorwa cy'ikinyabutabire cyakira elekitironi, maze uburinganire bugane ku bururu.

Radikali iri hagati

Ire action yose yimura elekitironi ebyiri, ariko intambwe z'ibanze zimura imwe imwe. Hagati ya katiyoni y'ubururu n'imimerere ya leuco itagira ibara hari radikali ya semikinone yo hagati; aho kwirundanya, ahanini irasubirana ikavamo bwa bwoko bubiri, zimwe mu molekile zayo zitanze elekitironi izindi zikazakira. Potansiyeli yayo ya elekitironi imwe, iri hafi ya munsi ya zeru ho 0.23 V kuri pH 7, iri hasi cyane ya potansiyeli yo hagati y'ireaksiyo yose ya elekitironi ebyiri; ni yo mpamvu radikali iguma ari ubwoko buri ku rugero ruto mu mimerere ihamye. Ifite akamaro kubera impamvu ebyiri. Iyo irangi riri mu rumuri, rigera mu mimerere ifite ingufu nyinshi ifungura inzira za radikali; ni yo mpamvu ibisubizo by'ubururu bwa metilene byumva urumuri, kandi ni yo mpamvu ubutabire buterwa n'urumuri bugomba gushyirwa mu buryo bwose bwo gusuzuma ko ikinyabutabire kidahinduka. Nanone, iyo ubwinshi bw'ikinyabutabire buri hejuru, imiterere yatanze elekitironi ikora dimeri, bigahindura igishushanyo cy'inyunyuza ry'urumuri n'umuvuduko wa ire action ugaragara, ariko ntibihindure ubwoko bubiri bw'ibanze bufitanye isano. Nta na kimwe muri ibyo gitesha ire action ubushobozi bwo kugana mu byerekezo byombi. Byombi bisobanura ibigaragara byashoboraga gufatwa nk'ibimenyetso ko ire action itagishobora gusubira inyuma.

Ubwoko bifitanye isano bwakuweho metile buhindura ibipimo

Kuraho amatsinda ya metile ku maboko abiri ya dimetilamino, maze bwa bwoko bubiri bugumane isano yabwo ariko ibiranga bihinduke. Buri uko itsinda rya metile rivanyweho, agaciro k'uburebure bw'umuraba aho inyunyuza ry'urumuri riba ryinshi kurusha ahandi kagenda kimukira ku ruhande rw'ubururu: ubururu bwa metilene hafi ya 664 nm, Azure B hafi ya 654, Azure A hafi ya 630, Azure C hafi ya 615, na tiyonine hafi ya 600 nm. Azure B, itagira itsinda rimwe rya metile, ni yo bifitanye isano ya hafi cyane: ni kimwe mu binyabutabire by'ingenzi biva mu ihindurwa ry'ubururu bwa metilene mu mubiri, kandi ni umwanda wanditswe ko uboneka mu bururu bwa metilene. Azure A na Azure C bikomeza uru ruhererekane, bifite imiterere shingiro imwe ikora muri redox. Tiyonine, ifite amatsinda yombi ya amino yakuweho metile zose, iri ku mpera, ifite potansiyeli ya redox yagenwe iri hafi ya +0.06 V kuri pH 7, ugereranyije n'ubururu bwa metilene kuri +0.011 V; bityo kwakira elekitironi birayorohera ku buryo bugaragara. Potansiyeli za redox muri uru ruhererekane ziterwa n'ibidukikije by'ireaksiyo na elegitorode, bityo gereranya gusa agaciro kapimwe mu mimerere imwe. Ni yo mpamvu kumenya ubwoko n'ingano by'imyanda ari ikibazo cya redox, atari ugushyira akamenyetso gusa ku rutonde rw'isuku y'ikinyabutabire. Ijanisha rito rya Azure B risobanura ijanisha rito ry'ubundi bwoko bubiri bufitanye isano ya redox mu icupa, kandi Azure B nk'umwanda n'ikinyabutabire kiva mu ihindurwa ryo mu mubiri isobanura uko icyo gice kigenzurwa.

Aho ibinyabuzima bihurira n'iyi ire action

Mu turemangingo dutukura tw'amaraso, NADPH iha ubururu bwa metilene elekitironi bugahinduka ubururu bwa leukometilene, maze imiterere ya leuco ikazigeza kuri feri yo muri heme iri mu mimerere ya ferric, igasubiza hemoglobine mu mimerere ya ferrous. Uwo muyoboro umwe wo guhererekanya elekitironi ni ishingiro ry'ubutabire ry'imikoreshereze y'ubururu bwa metilene muri methemoglobinemia itari iy'uruhererekane. Ibikurikira byose kuri uwo muyoboro, harimo imikorere y'umubiri ijyanye n'ingufu, urujya n'uruza rwa elekitironi muri mitokondiriya, n'ingaruka zose ku binyabuzima, biri mu ngingo y'itwarwa rya elekitironi muri mitokondiriya, kandi byasizwe nkana aho.

Gura ubwoko bubiri bufitanye isano, atari ibara gusa

Ubwiza bw'irangi rya redox bugarukira ku bipimo ngenderwaho byaryo. Kuba rifite isuku yo ku rwego rwo hejuru ni ingenzi, kuko ubururu bwa metilene butujuje USP ubusanzwe buba ari ubwo gusiga imyenda, bukaba burimo Azure B, ibyuma biremereye, cyangwa ibisigazwa by'imiti ishongesha bihindura ibipimo bya redox kandi bigatuma aho ire action irangirira hatagaragara neza; ibyo nta buryo bwo gusiga ibara bugenzura. Abacuruzi benshi bavuga ko bujuje USP bapima gusa ibyuma biremereye, bakavuga ko batsinze. Kuzuza ibisabwa byose bikubiyemo kwemeza ikinyabutabire icyo ari cyo, gupima ingano yacyo, imyanda y'ibinyabutabire bya karubone, ibisigazwa by'imiti ishongesha, imyanda y'elementi, ibisigazwa nyuma yo gutwika, imipaka y'udukoko, n'uburozi bwa endotoxins bwa bagiteri; kandi uko wahitamo ubururu bwa metilene bwo ku rwego rwo gukora imiti isobanura uko wasoma izo nyandiko. Blupreme ikorana n'uruganda rukora ubururu bwa metilene bwo ku rwego rwo gukora imiti, ikapima ibisabwa byose na USP, kandi igatangaza COA yuzuye. Iyo ibara ari ryo gipimo, izo nyandiko ziba ari igice cy'igikoresho cyo gupima.