Related Experiment Video
Updated: May 29, 2026

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Design, synthesis, and structure-activity relationship studies of highly potent novel benzoxazinyl-oxazolidinone
Qisheng Xin1, Houxing Fan, Bin Guo
1Shanghai Institute for Biological Sciences , Chinese Academy of Sciences, Shanghai, China.
Abstract:
A series of novel benzoxazinyl-oxazolidinones bearing nonaromatic heterocycle or aryl groups were designed and synthesized. Their in vitro and in vivo antibacterial activities were investigated. Most of the (3S, 3aS) biaryl benzoxazinyl-oxazolidinones exhibited potent activity against Gram-positive pathogens. SAR trends were observed; a pyridyl C ring was preferable to other 5- or 6-member aryl C rings, while fluorine substitution on the B ring generated derivatives with reduced activity. Various substituent group positions on the pyridyl ring were also evaluated. The resulting compounds displayed excellent activity against linezolid-resistant strains. Compound 45 exhibited excellent in vitro activity, with a MIC value of 0.25-0.5 μg/mL against MRSA and an activity against linezolid-resistant strains of 8-16-fold higher potency than linezolid. In a MRSA systemic infection model, compound 45 displayed an ED(50) < 5.0 mg/kg, a potency that is nearly 3-fold better than that of linezolid. This compound also showed excellent pharmacokinetic profiles, with a half-life of more than 5 h as well as an oral bioavailability of 81% in rats.
Related Concept Videos
Structure-Activity Relationships and Drug Design
SAR studies the intricate relationship between a drug's chemical structure and biological activity. It focuses on understanding how modifications to a drug's structure can influence its...
Inhibitors of Bacterial DNA Synthesis
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Inhibitors of Gram-positive Cell Wall Synthesis
Production of Antibiotics

