In this study, five derivatives of sanguinarine (1) and chelerythrine (2) were prepared, with 1 and 2 as starting materials, by reduction, oxidation and nucleophilic addition to the iminium bond C=N+. The structures of all compounds were elucidated on account of their MS, ¹H-NMR and ¹³C-NMR data. The antibacterial activities of all compounds were screened, using Staphylococcus aureus, Escherichia coli, Aeromonas hydrophila and Pasteurella multocida as test bacteria. The minimum bacteriostatic concentration and minimum bactericidal concentration of the active compounds were determined by the turbidity method. The structure-activity relationships of 1 and 2 were discussed. The results showed that 1, 2 and their pseudoalcoholates were found to be potent inhibitors to S. aureus, E. coli and A. hydrophila, while the other derivatives were found to be inactive. The pseudoalcoholates might be the prodrugs of 1 and 2. The iminium bond in the molecules of 1 or 2 was the determinant for antibacterial activity, and the substituents at the 7 and 8 positions influenced the antibacterial activities of 1 and 2 against different bacteria.

Purpose: Exemestane (EXE) and letrozole (LET) are third-generation aromatase inhibitors currently prescribed for postmenopausal hormone-dependent breast cancer. The impact on end organs of estrogen depletion in menopausal women is of significant clinical importance. We studied the effects of EXE, its principal metabolite, 17-hydroexemestane (17-H-EXE), and LET on bone and lipid metabolism in ovariectomized (OVX) rats.Experimental Design: OVX rats were treated by weekly intramuscular injection for 16 weeks with 20, 50, and 100 mg/kg EXE, 20 mg/kg 17-H-EXE, and daily oral gavage of 1 mg/kg LET. At the end of the treatment period, bone mineral density (BMD), the bone resorption marker serum pyridinoline, the bone formation marker serum osteocalcin, bone mechanical properties, histomorphometry, and serum lipid concentrations were determined.Results: Lumbar vertebral and femoral BMD, bending strength of the femur, compressive strength of the fifth lumbar vertebra, and trabecular bone volume were significantly higher in OVX animals given EXE and 17-H-EXE than in OVX controls. EXE and 17-H-EXE significantly reduced an ovariectomy-induced increase in serum pyridinoline and serum osteocalcin. EXE and 17-H-EXE given to OVX rats caused significant reductions of serum cholesterol and low-density lipoprotein cholesterol. In contrast, OVX rats treated with LET had BMD, bone biomarkers, mechanical failure properties, and lipid levels similar to those of OVX controls.Conclusions: EXE and 17-H-EXE significantly prevent bone loss, enhance bone mechanical strength, and lower serum cholesterol and low-density lipoprotein levels in OVX rats. These protective effects on end-organ function are not seen with the nonsteroidal inhibitor LET.

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