The in vivo metabolic pathway of Deg-AZM and in vitro investigations into the contribution of drug metabolizing enzymes and drug transporters in the drug interactions of Deg-AZM, a clinical-stage new transgelin agonist

IntroductionDeglycosylated azithromycin (Deg-AZM), a new transgelin agonist with positive therapeutic effects on slow transit constipation, has been approved for clinical trials in 2024. This work investigated the drug metabolism and transport of Deg-AZM to provide research data for further development of Deg-AZM.MethodsA combination of UPLC-QTOF-MS was used to obtain metabolite spectra of Deg-AZM in plasma, urine, feces and bile. Caco-2 cells was used to investigate the permeability of Deg-AZM and whether it is a potential substrate of the efflux transporter P-glycoprotein. Human liver microsome phenotyping assays with chemical inhibition and recombinant CYPs phenotyping assays were used to investigate the CYP450 enzyme phenotype involved in Deg-AZM metabolism in vitro. A HLM inhibition reaction system was established to evaluate the inhibitory effect of Deg-AZM on CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. The mRNA expression of human primary hepatocytes incubated with Deg-AZM or not was evaluate the induction of Deg-AZM on CYP1A2, CYP2B6, and CYP3A4.Results44 metabolites of Deg-AZM were identified in rat urine, feces, bile, and plasma, the metabolic pathways included demethylation, monohydroxylation, dihydroxylation, dehydroxidation, hydroreduction, hydrolysis, methylation, glucuronidation and the combination of different metabolic pathways. Deg-AZM was a low permeability drug in the intestine and a potential substrate of the efflux transporter P-glycoprotein. CYP3A4 was the major CYP isoform responsible for Deg-AZM metabolism. Deg-AZM showed moderate inhibition with CYP2B6 and CYP2D6. Data in three batches of human primary hepatocytes disclosed induction potential of Deg-AZM on CYP2B6 and CYP3A4.ConclusionThe in vivo metabolic pathway of Deg-AZM and in vitro possibility of drug interaction for Deg-AZM with CYP enzymes and drug transporter were fully investigated. It was suggested that dose adjustments may be warranted depending on the potency of the corresponding modulators in clinical

Deglycosylated azithromycin alleviates cisplatin-evoked constipation in mice by altering host metabolome and gut microbiota composition

IntroductionChemotherapy induced constipation (CIC) is a gastrointestinal side effect that occurs in patients receiving chemotherapy, which can further deteriorate the living quality of cancer patients. Deglycosylated azithromycin (Deg-AZM), a newly developed Class I drug with good therapeutic effects on chronic constipation, has been approved for clinical trials in 2024. However, it is unclear whether Deg-AZM has any impact on gut microbiota of CIC mice. The purpose of this study was to explore the role of Deg-AZM in treating CIC by modulating the gut microbiota.MethodsThe therapeutic effects of Deg-AZM on intestinal motility were assessed in a cisplatin-induced CIC mouse model. The gut microbiota composition was analyzed using 16S rRNA sequencing, and metabolic changes were evaluated through untargeted metabolomics of fecal samples.ResultsDeg-AZM significantly enhanced intestinal motility in the mice with cisplatin-evoked constipation. Gut microbiota analysis revealed that Deg-AZM altered the community composition by decreasing Deferribacterota and Pseudomonadota and increasing Bacteroidota, Lactobacillus and Muribaculaceae. The feces metabolomics revealed that alanine, aspartate and glutamate metabolism, citrate cycle (TCA cycle), purine metabolism, primary bile acid biosynthesis and taurine and hypotaurine metabolism in CIC model were modulated by Deg-AZM.ConclusionDeg-AZM could alleviate cisplatin-evoked constipation in mice by reshaping the structure of gut microbial community, which may provide a potential basis for the use and clinical development of Deg-AZM for CIC treatment

Auto-normalization algorithm for robotic precision drilling system in aircraft component assembly

AbstractA novel approach is proposed to detect the normal vector to product surface in real time for the robotic precision drilling system in aircraft component assembly, and the auto-normalization algorithm is presented based on the detection system. Firstly, the deviation between the normal vector and the spindle axis is measured by the four laser displacement sensors installed at the head of the multi-function end effector. Then, the robot target attitude is inversely solved according to the auto-normalization algorithm. Finally, adjust the robot to the target attitude via pitch and yaw rotations about the tool center point and the spindle axis is corrected in line with the normal vector simultaneously. To test and verify the auto-normalization algorithm, an experimental platform is established in which the laser tracker is introduced for accurate measurement. The results show that the deviations between the corrected spindle axis and the normal vector are all reduced to less than 0.5°, with the mean value 0.32°. It is demonstrated the detection method and the auto-normalization algorithm are feasible and reliable

Structure-guided engineering of a Thermobifida fusca cutinase for enhanced hydrolysis on natural polyester substrate

AbstractCutinases could degrade insoluble polyester, including natural cutin and synthetic plastic. However, their turnover efficiency for polyester remains too low for industrial application. Herein, we report the 1.54-Å resolution X-ray crystal structure of a cutinase from Thermobifida fusca and modeling structure in complex with a cutin mimic oligo-polyester C24H42O8. These efforts subsequently guided our design of cutinase variants with less bulky residues in the vicinity of the substrate binding site. The L90A and I213A variants exhibit increased hydrolysis activity (5- and 2.4-fold, respectively) toward cutin and also showed enhanced cotton scouring efficiency compared with the wild-type enzyme.</jats:p