Synthesis and evaluation of a glucose attached pyrene, as a fluorescent molecular probe in sugar and non-sugar based micro-heterogeneous media

Abstract

A new fluorescent pyrene-glucose conjugate (pyd-glc), 1-(4,6-O-butylidene-β-dglucopyranosyl)-4-(1-pyrene)-butan-2-one, has been synthesized by attaching pyrene molecule with acetal (butylidene) protected glucose via butane-2-one linker. Detailed photo-physical studies of pyd-glc in homogeneous media have been carried out in both protic and aprotic solvents which lead to a py scale, a solvent polarity scale specific to this molecule, like that of pyrene. The molecule aggregates in water and partitions as a monomer in micro-heterogeneous media. The photo-physical response of pyd-glc has been studied in various sugar and non-sugar based micro-heterogeneous media. Similar to pyrene, this molecule offers multiple fluorescence parameters to investigate the organization of micro-heterogeneous media. The fluorescence parameters of pyd-glc faithfully reflect the state of organization of these anisotropic media.

Introduction of an α,β-unsaturated carbonyl conjugated pyrene–lactose hybrid as a fluorescent molecular probe for micro-scale anisotropic media

“…3 In the previously introduced molecule, pyd-glc, the essential uorophore is the basic pyrene moiety and hence the intensity ratio of I I /I III could be used as a photophysical parameter for polarity sensing. 24 For the present molecule pyd-lact, however, the extension of conjugation results in signicantly different photophysical properties. Thus the emission spectrum is structure less and broad.…”

“…The extension of conjugation of pyrene chromophore through the a,b-unsaturated carbonyl group causes signicant blurring 2 of the vibrational ne structure of the parent pyrene chromophore. 24,44 In addition to this spectral broadening there could be the possibility of charge transfer interaction in polar solvents which give rise to the peak with a shoulder. Unlike pyrene-3-carboxaldehyde, absorption spectra of pyd-lact show minor perturbation towards solvent polarity.…”

“…21,22 Likewise, uorescent cyclodextrin derivatives are known for their good sensing ability. 16,23 Extending the versatility of uorescent carbohydrates, in our recent work, 24 we have introduced a conjugate involving pyrene and a protected glucose unit, 1-(4,6-O-butylidene-b-D-glucopyranosyl)-4-(1-pyrene)-butan-2-one (pyd-glc) for micro-heterogeneous media. Protection of the glucose moiety in this molecule allowed polarity modulation so as to impart better partitioning of the molecule to non-polar micro-heterogeneous media.…”

“…Protection of the glucose moiety in this molecule allowed polarity modulation so as to impart better partitioning of the molecule to non-polar micro-heterogeneous media. 24 The present work introduces a pyrene derivative conjugated to a highly hydrophilic lactose unit, (E)-1-(galactose-b-(1/4)-b-Dglucopyranosyl)-4-(1-pyrene)-but-3-en-2-one (pyd-lact) (Fig. 1).…”

Utilizing an aggregate forming microenvironment sensitive coumarin–cholesterol conjugate as a sensor of pluronic organization and micro-polarity

“…24 Conjugated probes are important for different domains of interest like biochemistry, biophysics, cell biology, drug delivery, imaging, sensing, analytical purposes etc. [23][24][25][26][27][28][29][30] As a result, conjugated probes have become a point of interest for multi-disciplinary and inter-disciplinary researchers. Fig.…”