Sinteza in biokemijsko vrednotenje 5-(benziloksi)indolov kot selektivnih zaviralcev monoamin oksidaze B

Alič, Neža (avtor), Hrast, Martina (mentor), Knez, Damijan (komentor)

Monoamin oksidaza (MAO) je encim, ki katalizira oksidativno deaminacijo monoaminov. Nahaja se na zunanji membrani mitohondrijev in je v različnem odstotku prisoten v večini tkiv v telesu. Odkriti sta bili dve izoobliki, MAO-A in MAO-B, ki imata različno oblikovano aktivno mesto. Razliko posledično najdemo tudi v substratih, ki jih metabolizirata. MAO ima pomembno vlogo pri razgradnji monoaminov, zaužitih v hrani, in služi tudi za inaktivacijo monoaminskih nevrotransmiterjev. Zaradi slednjega je povezan z različnimi nevrodegenerativnimi boleznimi, kot sta Parkinsonova in Alzheimerjeva bolezen. Za namen zdravljenja teh bolezni je bilo razvitih že več zaviralcev MAO, ki zavirajo eno ali obe izoobliki. V sklopu magistrske naloge smo sintetizirali analoge 5-(benziloksi)indola kot potencialne zaviralce MAO-B na podlagi predhodno testirane spojine 1-(4-acetilpiperazine-1-il)-2-(5-(benziloksi)-1H-indol-1-il)etan-1-on 4, ki je imela zaviralno delovanje. Sintezo analogov smo izvedli po dveh različnih postopkih, ki sta obsegala reakcije N-alkiliranja in N-aciliranja ter v nekaterih primerih še hidrolizo estra ter odstranitev Boc zaščite. Sintetizirani analogi so se razlikovali v substituentih, pripetih na dušik v piperazinskem obroču, oziroma so imeli piperazinski obroč zamenjan z obročem brez bazičnega centra na mestu 4. Sintetiziranim končnim spojinam smo z biokemičnim testiranjem določili zaviralno aktivnost na humanih MAO-A in MAO-B. Potrdili smo, da naše spojine bolje zavirajo MAO-B izoobliko. Ugotovili smo, da je za zaviralno delovanje pomemben bazičen center, saj so primerljivi derivati s piperazinskim obročem imeli boljše delovanje. Ugoden vpliv na zaviralno delovanje je imela tudi prisotnost nenasičene vezi v alkilni verigi, pri nasičenih verigah pa je podaljševanje verige zmanjšalo delovanje. Kot najmočnejši zaviralec MAO-B se je izkazal 2-(5-(benziloksi)-1H-indol-1-il)-1-(4-benzilpiperazin-1-il)etan-1-on (spojina 12) z IC50 = 1,95 ?M, ki se je najbolj približal nanomolarnim koncentracijam, ki smo jih želeli doseči. Zaključimo lahko, da je spojina 12 dobro izhodišče za nadaljnjo raziskovalno delo na področju novih močnejših zaviralcev MAO-B kot potencialnih zdravilnih učinkovin pri nevrodegenerativnih stanjih.

• Jezik: Slovenski jezik
• Ključne besede: MAO, ireverzibilni inhibitorji, nevrodegenerativne bolezni
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2019
• PID: 20.500.12556/RUL-108711
• Datum objave v RUL: 13.07.2019

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Synthesis and biochemical evaluation of 5-(benzyloxy)indoles as selective inhibitors of monoamine oxidase B

Izvleček

Monoamine oxidases (MAOs) are a family of enzymes that catalyze the oxidative deamination of monoamines. They are found bound on the outer membrane of mitochondria and are present in almost all the body tissues with varying percentage. Two isoforms, MAO-A and MAO-B, where discovered and the important difference is in the shape of their active site, which also impacts their ability to metabolize different substrates. MAOs are important in the breakdown of monoamines ingested by food and also serve to inactivate monoamine neurotransmitters. Because of the latter, they are involved in a number of neurodegenerative diseases, such as Parkinson's and Alzheimer's disease. Several MAO inhibitors have been developed that inhibit one or both of the isoforms for the purpose of treating these diseases. As part of this master's thesis we synthesized 5-(benzyloxy) indole analogs, as potential MAO-B inhibitors, based on the previously tested compound 1-(4-acetylpiperazin-1-yl)-2- (5-(benzyloxy)-1H-indol-1-yl)ethane-1-one 4, which showed an inhibitory effect on MAO-B. We used two different protocols for the synthesis of our analogs that consisted of reactions N-alkylation, N-acylation, and in some cases ester hydrolysis and removal of Boc protection group. Synthesized analogs differed in substituents attached to the nitrogen of the piperazine ring, or alternatively, the piperazine ring was replaced with a ring without a basic center on position 4. We evaluated synthesized final compounds with biochemical testing on human MAO-A and MAO-B and determined their inhibitory potencies. We confirmed that our compounds were more potent at inhibiting MAO-B isoform. The basic center was important for inhibition, because comparable derivatives with the piperazine ring had better performance than those without it. The presence of an unsaturated bond in the alkyl chain has also been shown to have a favorable effect on the inhibitory potency; in the case of saturated chains, the prolongation of the chain decreased activity. The most potent inhibitor was 2-(5-(benzyloxy)-1H-indol-1-yl)-1-(4-benzylpiperazin-1-yl) ethane-1-one (compound 12) with IC50 = 1.95 ?M, which was the closest one to the nanomolar concentrations we wanted to achieve. To conclude, the compound 12 represents an important starting point for further development of new potent MAO-B inhibitors as potential active substances in neurodegenerative conditions.

• Ključne besede: MAO, irreversible inhibitors, neurodegenerative diseases