1. Covalent immobilization of delipidated human serum albumin on poly(pyrrole-2-carboxylic) acid film for the impedimetric detection of perfluorooctanoic acid
Alessandro Angelini, Fabio Bottari, Sonia Covaceuszach, Alberto Cassetta, Giulia Moro, Ligia Maria Moretto, Karolien De Wael, Stefano Liberi Bioelectrochemistry . 2020 Aug;134:107540. doi: 10.1016/j.bioelechem.2020.107540.
The immobilization of biomolecules at screen printed electrodes for biosensing applications is still an open challenge. To enrich the toolbox of bioelectrochemists, graphite screen printed electrodes (G-SPE) were modified with an electropolymerized film of pyrrole-2-carboxilic acid (Py-2-COOH), a pyrrole derivative rich in carboxylic acid functional groups. These functionalities are suitable for the covalent immobilization of biomolecular recognition layers. The electropolymerization was first optimized to obtain stable and conductive polymeric films, comparing two different electrolytes: sodium dodecyl sulphate (SDS) and sodium perchlorate. The G-SPE modified with Py-2-COOH in 0.1 M SDS solution showed the required properties and were further tested. A proof-of-concept study for the development of an impedimetric sensor for perfluorooctanoic acid (PFOA) was carried out using the delipidated human serum albumin (hSA) as bioreceptor. The data interpretation was supported by size exclusion chromatography and small-angle X-ray scattering (SEC-SAXS) analysis of the bioreceptor-target complex and the preliminary results suggest the possibility to further develop this biosensing strategy for toxicological and analytical studies.
2. 1H-Pyrrole-2-carboxylic acid
Dong Dong Li, Xing Yan Xu, Gui Hong Tang, Gang Huang, Xiang Chao Zeng Acta Crystallogr Sect E Struct Rep Online . 2009 Apr 25;65(Pt 5):o1121. doi: 10.1107/S1600536809014044.
In the title compound, C(5)H(5)NO(2), the pyrrole ring and its carboxyl substituent are close to coplanar, with a dihedral angle of 11.7 (3)° between the planes. In the crystal structure, adjacent mol-ecules are linked by pairs of O-H⋯O hydrogen bonds to form inversion dimers. Additional N-H⋯O hydrogen bonds link these dimers into chains extending along the a axis.
3. Sulfur-containing constituents and one 1H-pyrrole-2-carboxylic acid derivative from pineapple [Ananas comosus (L.) Merr.] fruit
Zhi-Xiu Lin, Mingfu Wang, Jinyu Ma, Qin Zhu, Ka-Wing Cheng, Zong-Ping Zheng, Jianfei Chao, Raymond Chuen-Chung Chang, Ming Zhao Phytochemistry . 2010 Dec;71(17-18):2046-51. doi: 10.1016/j.phytochem.2010.08.014.
Two sulfur-containing compounds, (S)-2-amino-5-((R)-1-carboxy-2-((E)-3-(4-hydroxy-3-methoxyphenyl)allylthio)ethyl-amino)-5-oxopentanoic acid (1) and (S)-2-amino-5-((R)-1-(carboxymethylamino)-3-((E)-3-(4-hydroxyphenyl)allylthio)-1-oxopropan-2-ylamino)-5-oxopentanoic acid (2), and one 1H-pyrrole-2-carboxylic acid derivative, 6-(3-(1H-pyrrole-2-carbonyloxy)-2-hydroxypropoxy)-3,4,5-trihydroxy-tetrahydro-2H-pyran-2-carboxylic acid (3), together with eighteen known phenolic compounds, were isolated from the fruits of pineapple. Their structures were elucidated by a combination of spectroscopic analyses. Some of these compounds showed inhibitory activities against tyrosinase. The half maximal inhibitory concentration values of compounds 1, 4, 5, 6, 7 are lower than 1 mM. These compounds may contribute to the well-known anti-browning effect of pineapple juice and be potential skin whitening agents in cosmetic applications.
