Cladosporin Derivatives Obtained by Biotransformation Provide Guidance for the Focused Derivatization of this Antimalarial Lead Compound

Abstract

Cladosporin, a natural product known for decades, has recently been discovered to display potent and selective antiplasmodial activity by inhibition of lysyl‐tRNA synthetase. It was subjected to a panel of oxidative biotransformations with one fungal and two actinomycetes strains, as well as a triple mutant bacterial CYP102A1, yielding eight, mostly hydroxylated, derivatives. These new compounds covered a wide chemical space and contained two pairs of epimers in the tetrahydropyran ring. Although less potent than the parent compound, all analogues showed activity in a cell‐based synthetase assay, thus demonstrating uptake and on‐target activity in living cells with varying degrees of selectivity for the enzyme lysyl‐tRNA synthetase from Plasmodium falciparum and highlighting sites suitable for synthesis of future cladosporin analogues. Compounds with adjacent hydroxy functions showed different MS/MS fragmentation that can be explained in terms of an, in some cases, regioselective loss of water followed by a retro‐Diels–Alder reaction.

Design and Synthesis of Metabolically Stable tRNA Synthetase Inhibitors Derived from Cladosporin

“…In fact, the presence of the isocoumarin ring was known to be vital, but some structural modifications were allowed by the “π cage” formed with the aromatic residues. Inspired by previous findings from a set of compounds generated by biotransformation, we proposed to introduce a strategic unsaturation within the isocoumarin core, as illustrated by compound 28 …”

“…Gratifyingly, our screening campaign has led to the identification of two additional fungal active drugs that are selective inhibitors of threonyl‐ and phenylalanyl‐tRNA synthetase, and thus, expanding the biological space modulated by this isocoumarin‐derived scaffold. Additionally, as reported in the previous publication, an additional biotransformation‐based approach resulted in the discovery of a set of active hydroxylated cladosporin analogues, which targeted specifically the lysyl‐tRNA synthetase. This discovery represents a real breakthrough because it suggests that such a natural product derived structure could provide a privileged scaffold to inhibit synthetases beyond lysyl‐tRNA synthetase.…”

Identification and Expression of New Unspecific Peroxygenases – Recent Advances, Challenges and Opportunities

“…These are mainly, amongst others, the non-homogeneous growth in liquid media due to mycelium or pellet formation, low protein production, dependence of protein production on growth condition and medium compounds ( Hofrichter et al, 2020 ; Rothschild-Mancinelli et al, 2020 ). Nevertheless, screening approaches for fungi were performed for microbial strain libraries containing bacteria and fungi, which were screened on monooxygenase activity using pharmaceutical compounds analyzed with LC-MS ( Fredenhagen et al, 2019 ; Schmitz et al, 2019b ). This screening approach is thus available to be transferred to peroxygenase activity screenings in the future, which would be a first step toward medium- to high-throughput screening of natural UPO producing strains.…”

A Promiscuous Bacterial P450: The Unparalleled Diversity of BM3 in Pharmaceutical Metabolism

“…LVQ [39] R47L/F87V/L188Q clozapine [39], diclofenac [39], acetaminophen [39], omeprazole [45], reservatrol * [46], polydatin [47,48], phloretin * [49,50], cladosporin [51] M01 [39] LVQ/E267V/G415S/G1049E clozapine [39], diclofenac [39], acetaminophen [39], testosterone * [52], noresthisterone * [53], methoxyresorufin [44], ethoxyresorufin [44] M02 [39] LVQ/L86I/N319T/A964V clozapine [39], diclofenac [39], acetaminophen [39], norandrostenedione [54], methoxyresorufin [44], ethoxyresorufin [44], buspirone [44], amitriptyline [44], aripiprazole [44] M05 [39] LVQ/F81I/E267V/G415S clozapine [39], diclofenac [39], acetaminophen [39], methoxyresorufin [44], ethoxyresorufin [44] M11 [39] LVQ/E64G/F81I/E143G/E267V/G415S clozapine [39], diclofenac [39], acetaminophen [39], Testosterone * [52,55], norethisterone * [53,55], dextromethorphan [40], nifedipine…”