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Summary The triazine antitubercular JSF-2019 was of interest due to its in vitro efficacy and the nitro group shared with the clinically relevant delamanid and pretomanid. JSF-2019 undergoes activation requiring F420H2 and one or more nitroreductases in addition to Ddn. An intrabacterial drug metabolism (IBDM) platform was leveraged to demonstrate the system kinetics, evidencing formation of NO⋅ and a des-nitro metabolite. Structure-activity relationship studies focused on improving the solubility and mouse pharmacokinetic profile of JSF-2019 and culminated in JSF-2513, relying on the key introduction of a morpholine. Mechanistic studies with JSF-2019, JSF-2513, and other triazines stressed the significance of achieving potent in vitro efficacy via release of intrabacterial NO⋅ along with inhibition of InhA and, more generally, the FAS-II pathway. This study highlights the importance of probing IBDM and its potential to clarify mechanism of action, which in this case is a combination of NO⋅ release and InhA inhibition.

The metabolic instability of an antitubercular small molecule CD117 was addressed through iterative alteration of a key sulfide substituent and interrogation of the effect on growth inhibition of cultured Mycobacterium tuberculosis. This process was informed by studies of the intramycobacterial metabolism of CD117 and its inactive carboxylic acid derivative. Isoxazole 4e and thiazole 4m demonstrated significant gains in mouse liver microsomal stability with slight losses in whole-cell activity. This work illustrates the challenges of antitubercular hit evolution, requiring a balance of chemical and biological insights.

Three diketopyrrolopyrrole (DPP) dyes ( ICD-3 , ICD-4 and ICD-5 ) with a D-π-A conjugation were designed and synthesized, where a symmetric phenyl-DPP-phenyl unit was used to connect a substituted diphenylamine and a thienyl acrylic acid, and two n -hexyl or 2-ethyl-hexyl chains were introduced on the periphery of the DPP macrocycle. The dyes were characterized by photophysical, electrochemical, and density functional theory calculations. Among the three dyes, the ICD-5 -based DSC afforded the best photovoltaic performance: a short circuit photocurrent density ( J sc ) of 16.34 mA/cm 2 , an open circuit voltage ( V oc ) of 753 mV, and a fill factor ( FF ) of 0.74, corresponding to an overall conversion efficiency ( η ) of 9.10% using I − / I 3 − redox couple-based liquid electrolyte under AM 1.5 conditions. The experimental results demonstrate that the DPP-based sensitizer is a promising option for DSCs, and rational molecular engineering is crucial for constructing highly efficient charge transfer sensitizers.

Selective saturation of the conjugated C–C double bonds in the title compounds was examined in a systematic way for the first time. Many established protocols effective for similar reduction of α,β-unsaturated ketones and esters in the literature were found to be inapplicable in the present context. The most satisfactory results were finally obtained using the DIBAL-H/MeLi/CuI/HMPA/THF conditions.