Telmisartan

FDA-approved drugs Ciclesonide (HY-B0625), Losartan (HY-17512), Hesperidin (HY-15337) and Telmisartan (HY-13955) were obtained from the MedChemExpress LLC (Monmouth Junction, NJ, USA), and the Natural Products (NP1; MolPort-039-052-621, CFN97157) and (NP2; MolPort-039-141-993, CFN97918) were obtained from the MolPort database/ChemFaces Biochemical Co., Ltd. (Wuhan, China).

Adult male Wistar rats, weighing 240–260 g, were purchased from Beijing Weitong Lihua experimental animal center (Beijing, PR China). Five-week-old male diabetic db/db mice (BKS - Lepr^em2Cd479/Gpt, stock number T002407) were obtained from GemPharmatech Co., Ltd (Nanjing, China). Rats and mice were maintained in specific-pathogen-free surroundings, with a 12 h-light/dark cycles under controlled temperature (22 ± 2°C) and humidity (55–60%) conditions, and with free access to water and food. All animal care and experimental procedures conformed to the ethical guidelines for animal research at Shanxi Medical University and were approved by the Animal Care and Use Committee of Shanxi Medical University (Taiyuan, China). Telmisartan, valsartan, GW9662 were purchased from MedChemExpress (Shanghai, China), irbesartan was purchased from Aladdin (Shanghai, China).

IRB (≥98%) and telmisartan (TLN, internal standard, ≥98%) were procured from MedChem Express (USA). Glacial acetic acid and ammonium acetate (LR grade) were purchased from Sigma Aldrich (St. Louis, MO, USA). Acetonitrile and methanol (HPLC-grade) were also purchased from Sigma Aldrich (St. Louis, MO, USA). HPLC- grade water was produced in the laboratory using Milli-Q plus water purification system and used to prepare aqueous solutions (Missouri city, TX, USA).