{"title":"An insight on the mechanism of the Hoppe-Seyler test for xanthine","authors":"Francisco Sánchez-Viesca, Reina Gómez","doi":"10.53022/oarjcp.2024.5.2.0087","DOIUrl":"https://doi.org/10.53022/oarjcp.2024.5.2.0087","url":null,"abstract":"Being xanthine an important biomolecule, it has attracted the attention of scholars from different points of view. In the analytical field some tests for identification have been developed. Hoppe-Seyler detected xanthine using calcium chlorohypochlorite and sodium hydroxide since a green ring, changing to brown, is formed. It is a challenge to the theoretical chemist disentangle what is happening at molecular level during the assay. In this communication emphasis is placed in a reactive tri-polar intermediate that arises in a reaction sequence. That is, a carboxylate and a newly formed zwitterion. Reaction with water can eliminate the last dipole (a negatively charged nitrogen and a carbonium ion). However, there is other pair of ions that are connected: the carboxylate and the carbonium ion at β-position. This situation produces immediate decarboxylation, eliminating two electrical charges in a single internal way, and forming a double bond. Neutralization of the negatively charged nitrogen atom gives an ureido. This reaction sequence produces the principal reaction product, imidazo-imidazolone. The observed colours are due to halochromism.","PeriodicalId":485613,"journal":{"name":"Open access research journal of chemistry and pharmacy","volume":"5 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141796307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Antioxidant activity and levels of lipid peroxidation in glucose -6- phosphate deficient neonates","authors":"I. Akinlua","doi":"10.53022/oarjcp.2024.5.1.0072","DOIUrl":"https://doi.org/10.53022/oarjcp.2024.5.1.0072","url":null,"abstract":"Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a genetic abnormality that results in inadequate amount of this all important protein that help regulate key physiological processes in the body. This study was carried out to evaluate plasma activity of antioxidants and level of lipid peroxidation in neonates with G6PD deficiency. A total of forty neonates delivered at Wesley Guide Hospital, Ilesa, Osun State were used for this study. They were divided into two groups; group 1 consists of 20 G6PD deficient neonates as the test while group2 consists of 20 G6PD positive neonates as control. 5mls of venous blood was taken from both test and control and prepared to obtain the plasma. The plasma was stored at room temperature prior analysis. The plasma activity of antioxidant enzyme [superoxide dismutase, catalase, glutathione, glutathione peroxidase (Gpx)], non-enzymatic antioxidant (vitamin E, vitamin C, beta-carotene) and plasma level of malonyldialdehyde (MDA) was carried out in both test and control using standard methods. The results of the study revealed no significant difference (p<0.05) in the plasma activity of most of the antioxidant enzymes with the exception of GPx which was significantly raised in the test subjects when compared with the control.. However, the plasma activity of both vitamin C and beta-carotene increased significantly (p<0.05) in the test when compared with the control. The plasma level of MDA was also significantly raised in the test when compared with the control group. This study revealed the presence of lipid peroxidation and possibly oxidative stress in G6PD deficient neonates.","PeriodicalId":485613,"journal":{"name":"Open access research journal of chemistry and pharmacy","volume":"19 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140420332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}