Objective:
This study aimed to discover chemiluminescent analogues of luminol, predict their molecular
binding to hemoglobin of bloodstains in household crime, and expound the mechanism of chemiluminescence of luminol.
Methods:
Similarity and clustering analyses of luminol analogues were conducted, and molecular dockingwas
carried out using hemoglobin from Homo sapiens and four domestic organisms namely Gallus gallus, Drosophila
melanogaster, Rattus norvegicus, and Canis familiaris.
Results:
The results show the order of overall binding score as D. melanogaster > H. sapiens > C. familiaris > R.
norvegicus > G. gallus. Seven compounds namely ZINC16958228, ZINC17023010, ZINC19915427, ZINC34928954,
ZINC19915369, ZINC19915444, and ZINC82294978, were found to be consistently stable in binding to diverse
hemoglobin and possibly have chemiluminescence than luminol in this in silico study. The amino acid residues involve in
the interaction of human hemoglobin with 30 chemical compounds which include luminol, showed that His45, Lys61,
Asn68, Val73, Met76, Pro77, Ala79, Ala82, Leu83, Pro95, Phe98, Lys99, Ser102, Ser133, Ala134, and Thr134 were
possibly significant in the mechanism of action of presumptive test compounds. It was hypothesized that the improved
mechanism of chemiluminescent for identification of blood was based on peroxidase-like reaction, that produce nitric
oxide which bind to hemoglobin (Hb) and inhibits Hb degradation without yield of fluorescent products. The compound
2,3-benzodioxine-1,4,5(6H)-trione was formed which possibly emit light.
Conclusion:
This study provides novel insight on the luminol and its expanded mechanism for broader possible
applications of luminol with careful development of new methodologies.