Arterolane maleate

In 2012, arterolane (ART) in combination with piperaquine received approval in India for the treatment of plasmodium‐induced malaria; however, to date, a detailed metabolite identification study of ART has not been reported. Being polar in nature, ART shows early elution on reversed‐phase columns which might be the rate‐limiting factor of its systematic analytical studies. We have utilized hydrophilic interaction liquid chromatography (HILIC) to separate in vitro and in vivo metabolites of ART.

The possible sites of metabolism were predicted by XenoSite software to obtain an initial assessment. In vitro studies were conducted by incubating the drug with liver microsomes such as human, rat and human S9 fractions. Later, in vivo studies were performed to check the metabolites in urine, faeces and plasma. The samples were pooled and subjected to the protein precipitation method before analysis by liquid chromatography/quadrupole‐time‐of‐flight mass spectrometry (LC/QTOFMS).

We have observed 15 metabolites in this study which were phase I metabolites formed due to hydroxylation, dihydroxylation, peroxide bond scission and oxidation. Here, we report 11 metabolites of ART for the first time. The metabolic pathways and plausible structures were proposed according to accurate mass measurements and its MS/MS data.

The present study comprehensively reports the in vitro and in vivo metabolism of ART mentioning 11 novel metabolites. Here, extensive use of HILIC has helped to efficiently separate various metabolites. These findings would help prospects of ART disposition and its congeners.

A search for alternative Mycobacterium abscessus treatments led to our interest in the two-component regulator DosRS, which, in Mycobacterium tuberculosis , is required for the bacterium to establish a state of nonreplicating, drug-tolerant persistence in response to a variety of host stresses. We show here that the genetic disruption of dosRS impairs the adaptation of M. abscessus to hypoxia, resulting in decreased bacterial survival after oxygen depletion, reduced tolerance to a number of antibiotics in vitro and in vivo, and the inhibition of biofilm formation. We determined that three antimalarial drugs or drug candidates, artemisinin, OZ277, and OZ439, can target DosS-mediated hypoxic signaling in M. abscessus and recapitulate the phenotypic effects of genetically disrupting dosS . OZ439 displayed bactericidal activity comparable to standard-of-care antibiotics in chronically infected mice, in addition to potentiating the activity of antibiotics used in combination. The identification of antimalarial drugs as potent inhibitors and adjunct inhibitors of M. abscessus in vivo offers repurposing opportunities that could have an immediate impact in the clinic.