Mode of encapsulation of Linezolid by β-Cyclodextrin and its role in bovine serum albumin binding

•The amide chain substituted in the oxazolidinone moiety of Linezolid gets encapsulated in the cavity of β-CD.•The part of the molecule of LZ involved in BSA binding is unaffected by inclusion complexation with β-CD.•The KSV value is smaller in the presence of β-CD than for free LZ on binding with BSA.•The values of R0 and r are smaller in the presence of β-CD than for free LZ binding with BSA.•β-CD modulates the binding of LZ with BSA. We describe, in this article, the associative interaction between Linezolid and β-Cyclodextrin, and the influence of β-Cyclodextrin on Linezolid's binding to Bovine serum albumin. β-Cyclodextrin forms a 1:1 inclusion complex with Linezolid, with a binding constant value of 3.51×102M−1. The binding is studied using ultraviolet–visible absorption, fluorescence, nuclear magnetic resonance, and rotating-frame overhauser effect spectroscopic techniques. The amide substituent on the oxazolidinone ring of Linezolid is involved in its binding to β-Cyclodextrin. The binding of the Linezolid to bovine serum albumin, in the absence and the presence of β-Cyclodextrin, is studied by analyzing the fluorescence quenching and Förster resonance energy transfer. The Stern–Volmer quenching constant, the binding constant, and energy transfer occurring on the interaction of the Linezolid with BSA are found to be smaller in the presence of β-Cyclodextrin than in water.