Background: The coronavirus spike (S) glycoprotein and M protease are two key targets that have been identified for vaccines and drug development against COVID-19. Methods: Virtual screening of some compounds of plant origin that have shown antiviral activities were carried out on the two targets, the M protease (PDB ID 6LU7) and S glycoprotein (PDB ID 6VSB), by docking with PyRx software. The binding affinities were compared with other compounds and drugs already identified as potential ligands for the M protease and S glycoprotein, as well as chloroquine and hydroxychloroquine. The docked compounds with best binding affinities were also filtered for drug likeness using the SwissADME and PROTOX platforms on the basis of physicochemical properties and toxicity, respectively. Results: The docking results revealed that scopadulcic acid and dammarenolic acid had the best binding affinity for the S glycoprotein and Mpro protein targets, respectively. Silybinin, through molecular docking, also demonstrated good binding affinity for both protein targets making it a potential candidate for further evaluation as repurposed candidate for SARS-CoV-2, with likelihood of having multitarget activity as it showed activities for both targets. Conclusions: The study proposes that scopadulcic acid and dammarenolic acid be further evaluated in vivo for drug formulation against SARS-COV-2 and possible repurposing of Silybinin for the management of COVIV-19.

COV spike (S) glycoprotein and Mpro are two key targets that have been identified for vaccines and drug development against the COVID-19 disease. Virtual screening of some compounds of plants origin that have shown antiviral activities were carried out on the two targets, 6lu7 and 6vsb by docking with the PyRx software. The binding affinities were compared with other compounds and drugs already identified as potential ligands for 6lu7 and 6vsb as well as Chloroquine and hydroxychloroquine. The docked compounds with best binding affinities were also filtered for drug likeness using the SwissADME and PROTOX platforms on the basis of Physicochemical properties and toxicity respectively. The docking results revealed that scopodulcic acid and dammarenolic acid had the best binding affinity on the s-glycoprotein and Mpro protein targets respectively. Silybinin also demonstrated a good binding affinity to both protein targets making it a potential candidate for further evaluation as repurposed candidate for SARS COV2 with likelihood of having a multitarget activity.

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Candida africana is emerging as an organism of interest. It is evolutionarily divergent from Candida albicans but has reduced virulence with a restricted ecological niche. This study aimed at comparing in silico the genome level to detect variations in the two species. Raw Illumina Hiseq data were downloaded from the European Nucleotide Archive (https://www.ebi.ac.uk/ena) with the accession number SRR6669859 and assembled using shovill (v. 1.0.9) the resulting genome was mapped against the haploid reference Candida albicans SC5314_A22 strain using the D-GENIES webtool and contigs were reordered based on the reference, then gap-filled using GapFiller (v1-10), and annotated using MAKER-P. Synima and progressive Mauve were used to compare the annotated genomes of Candida africana and Candida albicans for synteny. OrthoVenn2 webserver was used for the identification and comparison of orthologous clusters. Microsynteny variations within the genomes were determined using the GEvo. The study revealed the presence of insertions, deletions, and hypervariable regions within the genome of Candidia africana, showing a high level of synteny with Candida albicans. The genome of Candida africana is 14.04Mbp with a BUSCO score of 99.66%. The two species form a total of 5146 orthologous protein clusters and shared a total of 5124 protein, C. africana has a unique cluster protein cluster while C. albicans have 18 unique Protein clusters. The genome of C. africana has lots of structural variations and the presence of gene losses and gains. These genetic variations possibly play a role in the reduced virulence potential observed in C. africana.