Aspirin prodrugs: synthesis and hydrolysis of 2-benzyloxy-2-methyl-4H-1,3-benzodioxin-4-ones

Rational design of a dual-mode optical and chemical prodrug

PURPOSE

The purpose of this study is to demonstrate the rational design and behaviour of the first dual-mode optical and chemical prodrug, exemplified by an acetyl salicylic acid-based system.

METHODS

A cyclic 1,4-benzodioxinone prodrug was synthesised by reaction of 3,5-dimethoxybenzoin and acetyl salicoyl chloride with pyridine. After purification by column chromatography and recrystallization, characterization was achieved using infrared and NMR spectroscopies, mass spectrometry, elemental analysis and single crystal X-ray diffraction. Light-triggered drug liberation was characterised via UV-visible spectroscopy following low-power 365 nm irradiation for controlled times. Chemical drug liberation was characterised via UV-visible spectroscopy in pH 5.5 solution.

RESULTS

The synthetic method yielded pure prodrug, with full supporting characterisation. Light-triggered drug liberation proceeded at a rate of 8.30x10(-2) s-1, while chemical, hydrolytic liberation proceeded independently at 1.89x10(-3) s-1. The photochemical and hydrolytic reactions were both quantitative.

CONCLUSIONS

This study demonstrates the first rational dual-mode optical and chemical prodrug, using acetyl salicylic acid as a model, acting as a paradigm for future dual-mode systems. Photochemical drug liberation proceeds 44 times faster than chemical liberation, suggesting potential use in drug-eluting medical devices where an additional burst of drug is required at the onset of infection.

Glycosyl derivatives of 2-bromosugar of selected non-steroidal anti-inflammatory drugs. Synthesis and QSAR data

On the basis of molecular modeling and calculation of physicochemical SAR data we obtained new derivatives of 2-bromosugars 5a-d and 6 for widely used non-steroidal anti-inflammatory drugs (NSAIDs). Compounds 5a-d and 6 were synthesized as stable, crystalline compounds from the reaction of phosphoroates 1-3 with salicylic acid (4a), aspirin (4b), diclofenac (4c) and indomethacin (4d) in an aprotic solvent. The reaction took place in the presence of silver carbonate as the activator of leaving groups with high stereoselectivity and good yields. The structures of the new derivatives of 5a-d and 6 for NSAIDs were established by spectroscopic methods 1H and 13C NMR, and elemental analyses.

The potential of aspirin in prodrug synthesis: a new potential delivery system of AZT and FLT

Aspirin (O-acetylsalicylic acid) has been used to synthesize prodrugs of 3'-azido-3'-deoxythymidine (AZT) and 3'-deoxy-3'-fluorothymidine (FLT). The mixed anhydride between aspirin and trifluoroacetic acid was synthesized and reacted with AZT and FLT to give the blocked nucleosides attached through the 5'-O position to the 2-position of 2-methyl-4H-1,3-benzodioxin-4-one. The prodrugs showed the same activities against HIV-1 in MT-4 cells as the original drugs. Hydrolysis of the synthesized prodrugs in the growth medium, used for anti-HIV investigations, resulted in formation of 5-O acetylated drugs which were subsequently hydrolyzed into the original drugs.

Enzymatic and nonenzymatic in vitro hydrolysis of 2-methyl-2-[2-(methoxy)phenoxy]-4H-1,3-benzodioxin-4-one and 2-methoxyphenyl O-acetylsalicylate

This paper is concerned with the synthesis and physical properties as well as the enzymatic and nonenzymatic in vitro hydrolysis of the potential aspirin prodrug MR 693 (5) and the salicylic acid prodrug guacetisalum (6). The half-lives of both prodrugs and the amount of aspirin regenerated in each hydrolytic run for 5 have been estimated over a wide range of pH values.