Linear-dichroic infrared spectral (IR-LD) analysis of codeine and its derivatives

Thiol-Reactive Analogues of Galanthamine, Codeine, and Morphine as Potential Probes to Interrogate Allosteric Binding within Nicotinic Acetylcholine Receptors

Alkaloids including galanthamine (1) and codeine (2) are reported to be positive allosteric modulators of nicotinic acetylcholine receptors (nAChRs), but the binding sites responsible for this activity are not known with certainty. Analogues of galanthamine (1), codeine (2), and morphine (3) with reactivity towards cysteine thiols were synthesized including conjugated enone derivatives of the three alkaloids 4–6 and two chloro-alkane derivatives of codeine 7 and 8. The stability of the enones was deemed sufficient for use in buffered aqueous solutions, and their reactivity towards thiols was assessed by determining the kinetics of reaction with a cysteine derivative. All three enone derivatives were of sufficient reactivity and stability to be used in covalent trapping, an extension of the substituted cysteine accessibility method, to elucidate the allosteric binding sites of galanthamine and codeine at nAChRs.

A smart and rapid colorimetric method for the detection of codeine sulphate, using unmodified gold nanoprobe

Herein, we reported unique optical and electrochemical properties of citrate-stabilized gold nanoparticles (AuNPs) as a probe for smartphone-assisted, on-spot detection of codeine sulphate in toxicological screening with high sensitivity (0.9 μM).

N-methylcodeinium iodide--crystal structure and spectroscopic elucidation

The correlation between the structure and the spectroscopic properties of N-methylcodeinium iodide (1) has been studied, using the methods of single crystal X-ray diffraction, IR-LD spectroscopy of oriented samples as a suspension in nematic liquid crystals, UV-vis spectroscopy and 1H and 13C NMR spectroscopy. HPLC tandem mass spectrometry (HPLC ESI MS/MS) and thermal methods were also employed. Quantum chemical calculations have been performed with a view to obtaining the electronic structure and vibrational properties of the title compound. Compound (1) crystallizes in the space group P2(1)2(1)2(1) and its cations and anions are joined by moderate intermolecular OH...I- interaction of length 3.442A. The codeine molecule exhibits the classical T-shape for opiates. A dihedral angle value of 86.4(5) degrees between the A/B/C and D/E planes is obtained. Rings A and B are effectively coplanar with an interplanar angle of 3.6(3) degrees.