{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T23:30:42Z","timestamp":1774049442514,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2020,10,13]],"date-time":"2020-10-13T00:00:00Z","timestamp":1602547200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["31672599"],"award-info":[{"award-number":["31672599"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Lekethromycin, a new macrolide lactone, exhibits significant antibacterial activity. In this study, a reliable analytical ultrahigh-performance liquid chromatography electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UPLC-ESI-Orbitrap-MS) method was established and validated for the detection of lekethromycin in rat plasma. After a simple acetonitrile (ACN)-mediated plasma protein precipitation, chromatographic separation was performed on a Phenomenex Luna Omega PS C18 column (30 \u00d7 2.1 mm i.d. particle size = 3 \u03bcm) conducted in a gradient elution procedure using 0.5% formic acid (FA) in ACN and 0.5% FA in water as the mobile phase pumped at a flow rate of 0.3 mL\/min. Detection was carried out under positive electrospray ionization (ESI+) conditions in parallel reaction monitoring (PRM) mode with observation of m\/z 804.5580 &gt; 577.4056 for lekethromycin and 777.5471 &gt; 619.4522 for gamithromycin (internal standard, IS). The linear range was 5\u20131000 ng\/mL (r2 &gt; 0.99), and the lower limit of quantification (LLOQ) was 5 ng\/mL. The intra- and inter-day precision (expressed as relative standard deviation, RSD) values were \u22647.3% and \u22646.3%, respectively, and the accuracy was \u226590% \u00b1 5.3%. The mean extraction recovery RSD valWeue was &lt;5.1%. Matrix effects and dilution integrity RSD values were &lt;5.6% and &lt;3.2%, respectively. Lekethromycin was deemed stable under certain storage conditions. This fully validated method was effectively applied to study the pharmacokinetics of lekethromycin after a single intravenous administration of 5 mg\/kg in rats. The main pharmacokinetic parameters were T1\/2\u03bbz, CL_obs and VZ_obs were 32.33 \u00b1 14.63 h, 0.58 \u00b1 0.17 L\/h\/kg and 25.56 \u00b1 7.93 L\/kg, respectively.<\/jats:p>","DOI":"10.3390\/molecules25204676","type":"journal-article","created":{"date-parts":[[2020,10,17]],"date-time":"2020-10-17T08:14:50Z","timestamp":1602922490000},"page":"4676","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Determination of Lekethromycin, a Novel Macrolide Lactone, in Rat Plasma by UPLC-MS\/MS and Its Application to a Pharmacokinetic Study"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9393-8820","authenticated-orcid":false,"given":"Hongzhi","family":"Xiao","sequence":"first","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pan","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jicheng","family":"Qiu","sequence":"additional","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3349-2318","authenticated-orcid":false,"given":"Jianzhong","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lei","family":"Yan","sequence":"additional","affiliation":[{"name":"Henan Pulike Biological Engineering Co., Ltd., Luo Yang, Henan 471000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Suxia","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2063-6260","authenticated-orcid":false,"given":"Xingyuan","family":"Cao","sequence":"additional","affiliation":[{"name":"Department of Veterinary Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China"},{"name":"Laboratory of Quality &amp; Safety Risk Assessment for Animal Products on Chemical Hazards (Beijing), Ministry of Agriculture, Beijing 100193, China"},{"name":"Key Laboratory of Detection for Veterinary Drug Residue and Illegal Additives, Ministry of Agricultural, Beijing 100193, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1517\/13543781003636480","article-title":"Macrolide antibiotics and the airway: Antibiotic or non-antibiotic effects","volume":"19","author":"Murphy","year":"2010","journal-title":"Expert Opin. 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