The F1FO‐ATP synthase is required for growth and viability of Mycobacterium tuberculosis and is a validated clinical target. A mycobacterium‐specific loop of the enzyme's rotary γ subunit plays a role in the coupling of ATP synthesis within the enzyme complex. We report the discovery of a novel antimycobacterial, termed GaMF1, that targets this γ subunit loop. Biochemical and NMR studies show that GaMF1 inhibits ATP synthase activity by binding to the loop. GaMF1 is bactericidal and is active against multidrug‐ as well as bedaquiline‐resistant strains. Chemistry efforts on the scaffold revealed a dynamic structure activity relationship and delivered analogues with nanomolar potencies. Combining GaMF1 with bedaquiline or novel diarylquinoline analogues showed potentiation without inducing genotoxicity or phenotypic changes in a human embryonic stem cell reporter assay. These results suggest that GaMF1 presents an attractive lead for the discovery of a novel class of anti‐tuberculosis F‐ATP synthase inhibitors.
Scandium triflate is an effective pre-catalyst for the deoxygenative allylation of benzylic alcohols with a narrow substrate window. The reaction is shown to proceed through a "hidden Brønsted acid" mechanism. The reaction is efficient provided that the aryl group is neither too electron rich nor too electron poor. It is shown that this allows useful selectivity. The reaction also works for benzyhydryl alcohols with broader scope. The reaction may also be catalysed by Nafion.
The F1FO‐ATP synthase is required for growth and viability of Mycobacterium tuberculosis and is a validated clinical target. A mycobacterium‐specific loop of the enzyme's rotary γ subunit plays a role in the coupling of ATP synthesis within the enzyme complex. We report the discovery of a novel antimycobacterial, termed GaMF1, that targets this γ subunit loop. Biochemical and NMR studies show that GaMF1 inhibits ATP synthase activity by binding to the loop. GaMF1 is bactericidal and is active against multidrug‐ as well as bedaquiline‐resistant strains. Chemistry efforts on the scaffold revealed a dynamic structure activity relationship and delivered analogues with nanomolar potencies. Combining GaMF1 with bedaquiline or novel diarylquinoline analogues showed potentiation without inducing genotoxicity or phenotypic changes in a human embryonic stem cell reporter assay. These results suggest that GaMF1 presents an attractive lead for the discovery of a novel class of anti‐tuberculosis F‐ATP synthase inhibitors.
Ozonolysis is an oxidative cleavage reaction of alkenes with ozone that is indispensable and has found many applications in organic synthesis. However, dedicated laboratory ozone generators are quite expensive equipment and may not be affordable by many laboratories. Recently, lowcost ozone disinfectors have become more common as a household appliance. Herein, we demonstrate the applicability of a household ozone disinfector, which can produce ozone in the order of 10 mmol/h, as alternative equipment for the laboratory scale ozonolysis of alkenes. The ozonolysis of 14 styrene derivatives bearing electron-donating and electron-withdrawing groups on aromatic rings including those with αand β-substituents, as well as 8 natural products containing olefinic moieties were investigated. Ozonolysis of these alkenes at millimole scales proceeded to completion within 30-40 minutes and the carbonyl products were obtained in 68% to quantitative yields. Preparative-scale ozonolysis of 4-methoxystyrene (6.17 g, 46 mmol) was also demonstrated. The reaction proceeded smoothly to yield 4anisaldehyde in 92% yield, which was subsequently converted to p-anisaldehyde dimethyl acetal in 66% yield. This work presents household ozone disinfector as an affordable, compact size, and practical synthetic equipment that does not require extra modification. Thus, the household ozone disinfector offers convenient access to ozonolysis or other reactions involving ozone for low-budget laboratories.
Fmoc‐protected (2S,3S)‐epi‐oxetin was synthesized from (E)‐4‐(benzyloxy)but‐2‐enal via enantioselective organocatalytic epoxidation, epoxide ring opening with azide, alcohol activation and ring closure, followed by functional‐group manipulation in eight steps with 12 % overall yield and 94 % ee. The amino acid was used as a building block for a new conformationally constrained pyrrolidinyl PNA with an oxetane‐containing backbone. The unexpected sensitivity of the oxetane backbone posed considerable synthetic challenges under standard Fmoc‐solid‐phase peptide synthesis conditions, and a mechanism for acid‐catalyzed degradation was proposed. In addition, the DNA‐ and RNA‐binding properties of the oxetane PNA were investigated. The presence of an oxetane ring decreased the stability of the PNA⋅DNA and PNA⋅RNA duplexes when compared to PNA with a cyclobutane‐containing backbone, which could be explained by the flattening of the oxetane ring, leading to a suboptimal torsional angle.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.