Structural optimization of a previously reported agonist of µOR, PZM21 is described resulting in the discovery of a novel series of amides with at least 4-folds enhanced CNS penetration in rat. Furthermore, these efforts yielded compounds with varying levels of efficacy on the receptor ranging from high efficacy agonists such as compound 20 to antagonists, such as 24. The correlation between in vitro activation of µOR and relative activity in models of analgesia for these compounds is discussed.
View Article and Find Full Text PDFReduction sensitive linkers (RSLs) have the potential to transform the field of drug delivery due to their ease of use and selective cleavage in intracellular environments. However, despite their compelling attributes, developing reduction sensitive self-immolative linkers for aliphatic amines has been challenging due to their poor leaving group ability and high p values. Here a traceless self-immolative linker composed of a dithiol-ethyl carbonate connected to a benzyl carbamate (DEC) is presented, which can modify aliphatic amines and release them rapidly and quantitatively after disulfide reduction.
View Article and Find Full Text PDFImprovements in ADME tools and pharmacokinetic prediction models have helped to shift attrition rates in early clinical trials from poor exposure to drug safety concerns, such as drug-induced liver injury (DILI). Assessing a new chemical entity's potential for liver toxicity is an important consideration for the likely success of new drug candidates. Reactive intermediates produced during drug metabolism have been implicated as a cause of DILI, and their formation has been correlated to the addition of a black box warning on a drug label.
View Article and Find Full Text PDFThe development of antibiotics against Gram-negative bacteria is a central problem in drug discovery. In this report, we demonstrate that aromatic sulfonyl fluorides with a nitro group in their ortho position have remarkable antibacterial activity and are active against drug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA), multidrug resistant Acinetobacter baumannii, and Pseudomonas aeruginosa.
View Article and Find Full Text PDFStudies of heterochronic parabiosis, where two animals of different ages are joined surgically, provided proof-of-principle results that systemic proteins have broad age-specific effects on tissue health and repair. In an effort to identify these systemic proteins, we previously developed a method to selectively label the proteome of only one animal joined in parabiosis utilizing bio-orthogonal non-canonical amino acid tagging (BONCAT), which can metabolically label proteins during their de novo synthesis by incorporating a methionine substitute, azido-nor-leucine (ANL), in cells expressing a mutant methionyl-tRNA synthetase (MetRSL274G). Once labeled, we can selectively identify the proteins produced by the MetRSL274G transgenic mouse in the setting of heterochronic parabiosis.
View Article and Find Full Text PDFBiochemical assays that can identify β-lactamase activity directly from patient samples have the potential to significantly improve the treatment of bacterial infections. However, current β-lactamase probes do not have the sensitivity needed to measure β-lactam resistance directly from patient samples. Here, we report the development of an instrument-free signal amplification technology, DETECT, that connects the activity of two enzymes in series to effectively amplify the activity of β-lactamase 40 000-fold, compared to the standard β-lactamase probe nitrocefin.
View Article and Find Full Text PDFAldehyde dehydrogenases (ALDHs) catalyze the oxidation of an aldehyde to a carboxylic acid and are implicated in the etiology of numerous diseases. However, despite their importance, imaging ALDH activity in cells is challenging due to a lack of fluorescent imaging probes. In this report, we present a new family of fluorescent probes composed of an oligothiophene flanked by an aldehyde and an electron donor, termed thiophene-bridged aldehydes (TBAs), which can image ALDH activity in cells.
View Article and Find Full Text PDFHydrocyanines are a class of commonly used reactive oxygen species (ROS) fluorescent imaging probes, which can image ROS in cell culture, organ culture, and in vivo. However, despite their widespread use, hydrocyanines have several drawbacks that limit their effectiveness, such as a high rate of auto-oxidation, a small Stokes shift, and poor water solubility. In addition, the hydrocyanines oxidize into cyanine dyes, which themselves decompose in the presence of ROS, and this further lowers their sensitivity towards detecting ROS.
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