Non-Enzymatic Electrochemistry in Characterization and Analysis of Steroid Compounds

Abstract

This review summarizes achievements in electrochemistry-related research of steroid-based compounds in clinical, pharmaceutical, and environmental analysis. Special attention is paid to compounds possessing none or only isolated double bonds at the steroid core. Their direct redox activity is limited to far positive/negative potentials under variety of conditions and electrode materials and relies on the functional groups attached to the steroid skeleton, or as the case may be its double bond or moieties present at the side chain. The possibilities of electroanalytical methods in sterol characterization and analysis are demonstrated in a table with 31 references devoted to direct voltammetric and amperometric methods of oxidation of cholesterol, phytosterols, oxysterols, and related compounds at carbon-based and metal-based nanoparticles modified electrodes, and the reduction of bile acids and their conjugates at mercury-based electrodes, and modified glassy carbon electrodes. Furthermore, methods based on the indirect oxidation of cholesterol using bromine species as a mediator at platinum electrode and non-enzymatic cholesterol biosensors are reviewed. Their drawbacks and benefits are discussed with respect to the challenging task of identification and quantitation of these compounds in biological matrices, otherwise mostly performed using expensive mass spectrometric techniques preceded by a chromatographic separation step.

Implantable Nanosensors for Human Steroid Hormone Sensing In Vivo Using a Self‐Templating Corona Phase Molecular Recognition

“…[13] For similar reasons, new point-of-care technologies based on molecular imprinting, aptamers, and antibodies, while valuable, do not address this specific problem of dynamic profiling. [28][29][30][31][32] Conversely, in the literature, there exist only a few examples in vivo steroid sensors, which have direct access to biological fluids. Takase et al coupled cholesterol oxidase and an implantable electrode to monitor the cholesterol level in eye interstitial fluid in fish for 48 h. [33] Cook measured cortisol in sheep and cattle using an electrochemical immunosensor implanted into the jugular veins.…”

“…[ 13 ] For similar reasons, new point‐of‐care technologies based on molecular imprinting, aptamers, and antibodies, while valuable, do not address this specific problem of dynamic profiling. [ 28–32 ] Conversely, in the literature, there exist only a few examples in vivo steroid sensors, which have direct access to biological fluids. Takase et al.…”

Electrochemical Oxidation of Primary Bile Acids: A Tool for Simulating Their Oxidative Metabolism?

“…Another study dealt only with a determination of sterols, but did not consider the generation of oxidation products [ 29 ]. Steroid compounds and bile acids are electrochemically active only under specific conditions and the use of specific electrode material (e.g., mercury-based electrodes, or modified glassy carbon electrodes) [ 30 ]. A current study presented an approach of an anodic electrochemical oxidation of bile acids by activating the saturated steroid core by introducing double bonds via dehydration [ 31 ].…”

Desenvolvimento de métodos eletroanalíticos para a determinação de tibolona e metabólitos em saliva e 1-(3-clorofenil)piperazina (mCPP) em amostras apreendidas

“…A presença de diversos grupos funcionais e sua configuração ligados a esse grupo de quatro anéis, estado de oxidação, presença de cadeia lateral e insaturações presentes na estrutura básica dos esteroides determinam sua função biológica em animais, plantas e microrganismos. Entre os esteroides que normalmente são encontrados em humanos e animais estão o colesterol, estradiol, progesterona, testosterona e epitestosterona (KLOUDA et al, 2017;YADAV et al, 2013).…”

“…As amostras biológicas recolhidas para a análise e detecção de possíveis substâncias proibidas pela WADA são normalmente analisadas por cromatografia gasosa acoplada a espectrometria de massas (GC-MS) ou cromatografia líquida acoplada a espectrometria de massa (LC-MS) ou ainda técnicas semelhantes hifenizadas (KLOUDA et al, 2017;WOLTHERS;KRAAN, 1999). As análises por meio dessas técnicas normalmente consomem muito tempo, necessitam de laboratórios com infraestrutura adequada, analistas treinados e em diversos casos requerem pré-tratamento da amostra como derivatização, hidrólise, etc.…”