Investigation of potential inhibitor properties of violacein against HIV-1 RT and CoV-2 Spike RBD:ACE-2

Abstract

A violacein-producing bacterium was isolated from a mud sample collected near a hot spring on Kümbet Plateau in Giresun Province and named the GK strain. According to the phylogenetic tree constructed using 16S rRNA gene sequence analysis, the GK strain was identified and named Janthinobacterium sp. GK. The crude violacein pigments were separated into three different bands on a TLC sheet. Then violacein and deoxyviolacein were purified by vacuum liquid column chromatography and identified by NMR spectroscopy. According to the inhibition studies, the HIV-1 RT inhibition rate of 1 mM violacein from the GK strain was 94.28% and the CoV-2 spike RBD:ACE2 inhibition rate of 2 mM violacein was 53%. In silico studies were conducted to investigate the possible interactions between violacein and deoxyviolacein and three reference molecules with the target proteins: angiotensin-converting enzyme 2 (ACE2), HIV-1 reverse transcriptase, and SARS-CoV-2 spike receptor binding domain. Ligand violacein binds strongly to the receptor ACE2, HIV-1 reverse transcriptase, and SARS-CoV-2 spike receptor binding domain with a binding energy of −9.94 kcal/mol, −9.32 kcal/mol, and −8.27 kcal/mol, respectively. Deoxyviolacein strongly binds to the ACE2, HIV-1 reverse transcriptase, and SARS-CoV-2 spike receptor binding domain with a binding energy of −10.38 kcal/mol, -9.50 kcal/mol, and −8.06 kcal/mol, respectively. According to these data, violacein and deoxyviolacein bind to all the receptors quite effectively. SARS-CoV-2 spike protein and HIV-1-RT inhibition studies with violacein and deoxyviolacein were performed for the first time in the literature. Graphical abstract

Synthesis of a new diarylhydrazone derivative and an evaluation of its in vitro biofilm inhibition and quorum sensing disruption along with a molecular docking study

“…The molecule responsible for a pigment called violacein is a derivative of an indole that results from the condensation of two molecules of tryptophan, and it has numerous biological activities. 43 C. violaceum , while growing, produces a violet coloration through a quorum sensing–mediated process, and violacein plays an antioxidant role, protecting the bacterial membrane from oxidative damage. 44 BHBANA ( 6 ) exhibits a minimal inhibitory concentration (MIC) value of 1.25 mg mL −1 against C. violaceum CV12472, as shown in Table 1.…”

The G36S, M147I, G265S, T568I, N852S new mutations in the Spike of Omicron JN.1 subvariants: New subvariants JN.1.1 to JN.1.5 nomenclature and oligonucleotides design for JN.1 subvariants detection

“…But Paxlovid (remdesivir plus nirmatrelvir) is now widely used against COVID-19 worldwide. The RBD spike-ACE-2 binding blocker (violacein) also has suggested as good candidate drug against RNA viruses (34,35).…”

Study on extraction and characterization of new antibiotics violacein from engineered Escherichia coli VioABCDE‐SD

“…Due to the Genevac EZ-2 evaporator, this extraction process can be completed within a few hours. Compared with other extraction methods, 16,19,41 the extraction method in our manuscript did not require the time-and energyconsuming process of hot air drying or lyophilization. In addition, only nontoxic absolute ethanol was used in the whole extraction process, and no surfactant such as SDS or other toxic organic solvents such as acetone was required, which greatly reduced the hazard of solvent residues.…”