SIANOKOBALAMINA (WIKAMINA B12)
ʻAno a me nā Waiwai
He kristal ʻulaʻula a pauka kristal paha kēia huahana, ʻaʻohe ʻala, ʻaʻohe ʻono a he mau waiwai hoʻoulu wai ikaika. Hoʻoheheʻe iki ʻia i ka wai a i ʻole ka ethanol, ʻaʻole hoʻoheheʻe ʻia i ka chloroform a i ʻole ether. Kūpaʻa i ka wela, akā hiki ke lilo i mea pono ʻole ke hōʻike ʻia i nā mea oxidizing a hōʻemi paha (e like me ka huaora C a i ʻole hydrogen peroxide, a pēlā aku), nā paʻakai metala kaumaha a me nā waikawa ikaika a me nā alkalis ikaika.
ʻAno Kemika
ʻO ka Vitamin B12 kahi hui equioctaphedral e loaʻa ana nā ion cobalt. ʻO kona ʻano kikowaena he apo corrin pālahalaha i haku ʻia me ʻehā pyrroles i hoʻopili ʻia. ʻO nā molekala o ka vitamin B12 ua hana ʻia me 3 mau ʻāpana: he apo gourin i chylated ʻia e ʻehā mau ʻātoma N a me nā ion cobalt waena; 5,6-dimethylbenzimidazole (5,6-dimethylbenzimidazole, DMBI) i hoʻopili ʻia i nā ʻātoma N-7 a me nā ion cobalt e like me nā molekala vitamin B 12 o nā ligands haʻahaʻa (α). Eia kekahi, ua pili pū ʻo DMBI i ka aminopropanol ma o nā hui phosphate, a ua pili pū ʻo aminopropanol i ke kaulahao ʻaoʻao propionic acid ma ka pyrrole D; hui adenosyl a i ʻole ka hui methyl Ua pili ia me nā ion cobalt e hana i ka ligand luna (β) o nā molekala vitamin B12. Hoʻokumu ʻia nā ʻano mea vitamin B12 like ʻole i ka wā e ʻokoʻa ai ka hui o ka puke kemika mai ka puke kemika luna ma ke axis o ke apo goline. Hoʻopili ʻia ka hui hydroxyl (-OH) i ka ion cobalt i loko o ke apo gluline e hana i ka hydroxycobalamin. Pēlā nō, hoʻopili ʻia nā deoxyadenosine (5'-deoxyadenosyl), methyl (-CH3), cyanide (-CN) a me nā ion cobalt e hana i ka adenosine cobalt. ʻO Amine (deoxyadenosylcobalamin), methylcobalamin (methylcobalamin) a me cyanocobalamin (cyanocobalamin). Ma ke ʻano, ʻo ke ʻano hope loa o ka huaora B12 i biosynthesis ʻia e nā microorganisms ʻo ia ka adenosine cobalamine (coenzyme B12), methyl cobalamine a me hydroxycobalamine. Eia naʻe, no ka mea ʻaʻole paʻa loa ko lākou mau waiwai, hoʻohui ʻia ka sodium cyanide i ke kaʻina hana hoʻomaʻemaʻe ʻoihana e hoʻololi i ke ʻano kūlohelohe o ka huaora B12 i cyanocobalamin paʻa.
Hana Kino
Hoʻomaikaʻi i ka nui o ka hoʻohana ʻana i ka waikawa folic, synthesise meththionine (i synthesise ʻia mai ka cysteineine kiʻekiʻe) a me choline me ka waikawa folic, a synthesise cyanocobalamin precursors e like me methyl coballamin a me coenzyme B12 i ke kaʻina hana o ka hana ʻana i ka prine a me pyrimidine, a komo i ke kaʻina hana methylation o nā hui koʻikoʻi he nui. Ke nele ka huaora B12, ua emi ka hana o ka hoʻoili ʻana i nā hui methyl mai ka methyl tetrahydrofolic acid, e hoʻolilo ana i ka waikawa folic i ʻano hiki ʻole ke hoʻohana ʻia, e alakaʻi ana i ka nele o ka waikawa folic. Mālama i ka metabolism a me ka hana o ka nerve myelin sheath. ʻO ka nele o ka huaora B12 hiki ke hana i nā maʻi neurological, ka degeneration spinal, a me nā kemika hiki ke hana i nā hōʻailona noʻonoʻo koʻikoʻi. Hiki i ka nele o ka huaora B12 ke alakaʻi i ka neuritis peripheral. ʻO nā hōʻike mua o ka nele o ka huaora B12 i nā keiki he ʻano maʻamau ʻole, ka lohi o ka hōʻike ʻana, ka lohi o ka pane ʻana, a ma hope e alakaʻi i ka anemia. Hoʻolaha i ka ulu ʻana a me ka oʻo ʻana o nā ʻula koko ʻulaʻula. Hoʻololi ʻia ʻo Methylpropandiyl coenzyme A i succinoyl coenzyme A a komo i loko o ke kaʻina hana tricarboxylic acid, kahi e pili ai ka succinyl coenzyme A i ka hana ʻana o ka heme. Komo pū ka Vitamin B12 i ka hana ʻana o ka deoxynucleic acid (DNA), ka metabolism o ka momona, nā kalapona a me ka protein, a hoʻonui i ka hana ʻana o nā nucleic acid a me nā protein.
