Analiza linkozamidnih antibiotikov in njihovih metabolitov z elektrokemijsko analizo sklopljeno z masno spektrometrijo

Vidmar, Špela (author), Pajk, Stane (mentor), Rozenski, Jef (co-mentor)

Antibiotiki se uporabljajo za zdravljenje ali preprečevanje bakterijskih okužb. Linkozamidna antibiotika, ki sta preučevana v sklopu te magistrske naloge, sta klindamicin in linkomicin. Namen magistrske naloge je preučiti možnost in vitro tvorbe metabolitov in oksidacijskih produktov klindamicina z uporabo elektrokemijske analize sklopljene z masno spektrometrijo, kar bi predstavljalo veliko cenejši način pridobivanja metabolitov, saj so standardi na trgu zelo dragi in hkrati postavilo izhodišče za nadaljnje raziskave aktivnosti in neželenih učinkov metabolitov. Klindamicin je kloriran, biološko aktivni, semisintetični derivat z višjo in vivo in in vitro aktivnostjo od linkomicina. Po absorpciji se klindamicin večinoma metabolizira do oksidiranega produkta klindamicin sulfoksida in v manjši meri do N-desmetil klindamicina. V člankih je prisotno protislovje, saj nekateri trdijo, da sta metabolita aktivna, drugi pa, da sta metabolita neaktivni spojini. Za pridobitev podatkov za izdelavo masnega spektra klindamicina smo uporabili masno spektrometrijo. Izvedli smo tudi tandemsko masno spektrometrijo z izbiro vrhov pridobljenih iz masnega spektra klindamicina, ki smo jih nadalje fragmentirali. Za proizvodnjo oksidacijskih produktov klindamicina in vitro smo uporabili elektrokemijsko nastavitev Roxy. Iz rezultatov je bilo razvidno, da je pri večjih hitrostih čas napetostnega gradienta krajši. Zamenjava elektrode iz steklastega ogljika z diamantno elektrodo dopirano z borom je pokazala, da daje v našem primeru elektroda iz steklastega ogljika boljše rezultate. V nadaljevanju je bil apliciran enosmerni tok v vrednosti 1 V. Z masno spektrometrijo smo analizirali tudi analizne standarde metabolitov klindamicina. Iz rezultatov je razvidno, da smo uspešno proizvedli N-desmetil klindamicin in v manjši meri klindamicin sulfoksid. Masno spektrometrijo sklopljeno z elektrokemijo smo aplicirali tudi na linkomicin. Dobili smo ustrezen masni spekter, ki je v primerjavi s klindamicinovim brez vrha izotopa klora ob osnovnem vrhu. Rezultatov linkomicina nismo primerjali z analiznimi standardi. Vsi pridobljeni podatki so bili obdelani s programskim jezikom R Studio.

• Language: Slovenian
• Keywords: linkozamidni antibiotiki, klindamicin, metaboliti, elektrokemija, masna spektrometrija
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2022
• PID: 20.500.12556/RUL-140211
• Publication date in RUL: 13.09.2022

Secondary language

• Language: English
• Title: On-line electrochemistry coupled to mass spectrometry for the analysis of lincosamide antibiotics and their metabolites

Abstract

Antibiotics are used for treatment or prevention of bacterial infections. Lincosamide antibiotics analysed in the scope of this master's thesis were lincomycin and clindamycin. The aim of this master’s thesis is to examine the possibility of the in vitro production of the metabolites and oxidation products of antibiotic drug clindamycin using electrochemistry coupled to mass spectrometry which would represent much cheaper way of acquiring metabolites as analytical standard metabolites on the market are very expensive and also the basis for further research on the activity of the metabolites or their side effects. Clindamycin is a chlorinated highly biologically active semisynthetic lincosamide derivate with higher in vivo and in vitro activity than lincomycin. When absorbed, the compound is metabolized mainly to the oxidized product clindamycin sulfoxide and to a lesser extent to N-desmethyl clindamycin. There is a contradiction in the articles as some claim the metabolites are active and others that metabolites are inactive compounds. Mass spectrometry was used to obtain mass spectrum data of clindamycin. Additionally, tandem mass spectrometry was performed by selecting the peaks obtained from mass spectrum of clindamycin and fragmenting them to further extent. The Roxy electrochemical setup was used to produce clindamycin oxidation products in vitro. Results showed that at higher scan rates the time of voltage gradient was shorter. Switch of electrode from boron doped diamond electrode to glassy carbon electrode showed that glassy carbon electrode gave better results in our case. Further, direct current of 1 V was applied. Additionally, commercially available metabolites were examined by mass spectrometry coupled to electrochemistry to compare the results. The results show that we successfully produced N-desmethyl clindamycin and to a lesser extent clindamycin sulfoxide. Mass spectrometry coupled with electrochemistry technique was performed for lincomycin as well. We obtained the mass spectrum which has, comparing to clindamycin, no chlorine isotope peak around base peak. We did not compare lincomycin results with analytical standard metabolites. All data obtained were introduced in R Scripts in R Studio program.

• Keywords: lincosamide antibiotics, clindamycin, metabolites, electrochemistry, mass spectrometry