Synthesis of Novel Glucuronide Conjugates of Retinoid Carboxylic Acids

Current State of Metal-Based Drugs for the Efficient Therapy of Lung Cancers and Lung Metastases

Lung cancer is the second most common cancer in both men and women and thus a leading cause of cancer-related deaths worldwide. New efficient treatments especially for its advanced stages and metastases are desperately needed, particularly with regard to overcoming the resistance which thwarts the efficacy of most clinically established drugs such as the platinum complexes. Glimpses of hope are new metal-based drugs that have emerged over the past decade which displayed efficacy in patients with platinum-resistant tumors and metastases. This chapter provides an overview of the latest developments of such metal-based drugs against lung cancer.

Synthesis, characterization and in vitro antiproliferative activities of new 13-cis-retinoyl ferrocene derivatives

In order to improve biological behavior of the retinoyl derivatives, monoarylferrocenyl alcohols 9a and 9b were synthesized by an improved Suzuki cross-coupling method and their 13-cis-retinoic acid analogues were prepared in moderate to good yields via the Mitsunobu reaction. Their structures were confirmed by IR, (1)H NMR, (13)CNMR, MS spectra and element analysis and their antiproliferative activities were determined in vitro using human cancer cell lines. The results of bioassay showed that these organometallic analogues exhibited higher antiproliferative activities than parent 13-cis-retinoic acid and other retinoyl derivatives.

Effective Synthesis of 1β-Acyl Glucuronides by Selective Acylation

[reaction: see text] Acyl glucuronides are vital metabolites for many carboxylic acid containing drugs. We report an efficient new method for the chemical synthesis of these molecules by selective 1beta-acylation of allyl glucuronate with carboxylic acids catalyzed by HATU and then mild deprotection through treatment with Pd(PPh(3))(4) and morpholine. The method is effective for a range of aryl and alkyl carboxylic acids, including important drugs.

Properties of retinoids. Structure, handling, and preparation

Retinoids are unstable compounds being readily oxidized and/or isomerized to altered compounds, especially in the presence of oxidants including air, light, and excessive heat. They are labile toward strong acids and solvents that have dissolved oxygen or peroxides. In this review, procedures for handling and storage of retinoids and biological samples containing them have been described. The physical and chemical properties of retinoids have been reported. Simplified procedures for derivatizations and purification, and methods for quantitation of retinoids have been presented.

Reversed-phase gradient high-performance liquid chromatographic procedure for simultaneous analysis of very polar to nonpolar retinoids, carotenoids and tocopherols in animal and plant samples

A reversed-phase gradient high-performance liquid chromatographic (HPLC) procedure, which utilizes gradient elution and detection by a photodiode-array detector, has been developed to analyze simultaneously very polar retinoids, such as 4-oxo-retinoyl-beta-glucuronide, retinoyl beta-glucuronide and 4-oxo-retinoic acid; polar retinoids, such as retinoic acid and retinol; nonpolar retinoids, such as retinyl esters; along with xanthophylls, monohydroxy carotenoids, hydrocarbon carotenoids, and tocopherols. The procedure has been applied to the simultaneous analysis of retinoids, carotenoids, and tocopherols present in human serum and liver, rat serum and tissues, and for carotenoids in a number of fruits and vegetables. Bilirubin present in human serum can also be simultaneously analyzed. By this gradient HPLC procedure, 3.4-didehydroretinyl ester (vitamin A2 ester) has been identified as a minor constituent in a human liver sample. Lycopene was identified as a major carotenoid in one specimen of papaya fruit, and 5,6,5',6'-diepoxy-beta-carotene was characterized as a major carotenoid in one specimen of mango fruit.

Retinoyl beta-glucuronide: a biologically active form of vitamin A

Retinoyl beta-glucuronide is a naturally occurring, biologically active metabolite of vitamin A. Although retinoyl beta-glucuronide is regarded as a detoxification product of retinoic acid, it plays several roles in the functions of vitamin A. It can serve as a source of retinoic acid, and it may be a vehicle for transport of retinoic acid to target tissues. Topically applied retinoyl beta-glucuronide is comparable in efficacy to retinoic acid in the treatment of acne in humans, without the same side effects. Retinoyl beta-glucuronide may or may not be teratogenic, depending on the mode of administration and the species in which it is used. It may be a valuable therapeutic compound for the treatment of skin disorders and certain types of cancers.