1. F13459, a new derivative of mycophenolic acid. I. Taxonomy, isolation, and biological properties
M Muroi, K Sano, G Okada, H Koshino, T Oku, A Takatsuki J Antibiot (Tokyo). 2001 Jun;54(6):489-93. doi: 10.7164/antibiotics.54.489.
In the course of screening for inhibitors of intracellular trafficking of glycoprotein, a new inhibitor, F13459 was isolated from the culture broth of a Penicillium sp. It was purified using solvent extraction, silica gel, Sephadex LH-20 and ODS column chromatography. From structural analysis, F13459 was a derivative of mycophenolic acid, an inhibitor of inosine 5'-monophosphate dehydrogenase. F13459 inhibited hemagglutinin synthesis of NDV at concentrations more than 25 microg/ml. However, syncytium formation as a result of cell surface expression of F-glycoprotein of NDV was inhibited at concentrations of F13459 lower than those required for appreciable inhibition of glycoprotein synthesis.
2. Molecular modelling and simulation techniques to investigate the effects of fungal metabolites on the SARS-CoV-2 RdRp protein inhibition
Uday M Muddapur, Shrikanth Badiger, Ibrahim Ahmed Shaikh, et al. J King Saud Univ Sci. 2022 Aug;34(6):102147. doi: 10.1016/j.jksus.2022.102147. Epub 2022 Jun 3.
Various protein/receptor targets have been discovered through in-silico research. They are expanding rapidly due to their extensive advantage of delivering new drug candidates more quickly, efficiently, and at a lower cost. The automation of organic synthesis and biochemical screening will lead to a revolution in the entire research arena in drug discovery. In this research article, a few fungal metabolites were examined through an in-silico approach which involves major steps such as (a) Molecular Docking Analysis, (b) Drug likeness and ADMET studies, and (c) Molecular Dynamics Simulation. Fungal metabolites were taken from Antibiotic Database which showed antiviral effects on severe viral diseases such as HIV. Docking, Lipinski's, and ADMET analyses investigated the binding affinity and toxicity of five metabolites: Chromophilone I, iso; F13459; Stachyflin, acetyl; A-108836; Integracide A (A-108835). Chromophilone I, iso was subjected to additional analysis, including a 50 ns MD simulation of the protein to assess the occurring alterations. This molecule's docking data shows that it had the highest binding affinity. ADMET research revealed that the ligand might be employed as an oral medication. MD simulation revealed that the ligand-protein interaction was stable. Finally, this ligand can be exploited to develop SARS-CoV-2 therapeutic options. Fungal metabolites that have been studied could be a potential source for future lead candidates. Further study of these molecules may result in creating an antiviral drug to battle the SARS-CoV-2 virus.
3. F13459, a new derivative of mycophenolic acid. II. Physico-chemical properties and structural elucidation
H Koshino, M Muroi, T Tajika, Y Kimura, A Takatsuki J Antibiot (Tokyo). 2001 Jun;54(6):494-500. doi: 10.7164/antibiotics.54.494.
F13459 is a new inhibitor of synthesis and trafficking of virus glycoprotein isolated from the culture broth of a Penicillium sp. The molecular formula of F13459 was determined to be C27H28O11 by HRFAB-MS and NMR spectral analyses. The structure of F13459 was elucidated to be 3,4-dihydro-3,4,6,8-tetrahydroxy-3-methyl-1H-2-benzopyran-1-one 4-O-mycophenolate, an ester derivative of mycophenolic acid. F13459 was isolated as the optically inactive form. F13459 exists in epimeric mixtures at C-3' through relatively fast hemiacetal-ketone tautomerism and at C-4' through slow keto-enol tautomerism. Those epimerizations were confirmed by NOE differential experiments for fast chemical exchange and equilibrium and by deuteration experiments in NMR for slow chemical exchange.