Synthesis and antitumour activity of new derivatives of flavone-8-acetic acid (FAA). Part 4: Variation of the basic structure

Synthesis, selective cytotoxicities and probable mechanism of action of 7-methoxy-3-arylflavone-8-acetic acids

Thirteen new analogues of flavone-8-acetic acid, that is, compounds 10a-m bearing a methoxy group at the 7-position and diverse subsitiuents on the benzene ring at the 2- and 3-positions of flavone nucleus, were synthesized and evaluated for their direct antiproliferative effects on two human tumor cell lines and for their indirect antiproliferative activities in the transwell co-culture system. The results indicated that most of compounds 10a-m showed moderate direct cytotoxicities. Among them, compound 10i exhibited higher direct cytotoxicity and selectivity for both cell lines over BJ human foreskin fibroblast cells than 5,6-dimethylxanthenone-4-acetic acid (DMXAA). Interestingly, compared with DMXAA, compound 10e showed comparable indirect cytotoxicity and higher selectivity. In addition, compound 10e was found to be able to induce tumor necrosis factor α (TNF-α) production in human peripheral blood mononuclear cells.

Flavonoids: A versatile source of anticancer drugs

An exponential increase in the number of studies investigating how different components of the diet interact at the molecular and cellular level to determine the fate of a cell has been witnessed. In search for anticancer drugs compelling data from laboratories, epidemiologic investigations, and human clinical trials showed that flavonoids have important effects on cancer chemoprevention and chemotherapy. In many molecular mechanisms of action for prevention against cancer, flavonoids play a major role by interacting between different types of genes and enzymes. Many mechanisms of action have been identified, including carcinogen inactivation, antiproliferation, cell cycle arrest, induction of apoptosis, inhibition of angiogenesis, antioxidation, and reversal of multidrug resistance or a combination of these mechanisms. This review focuses on the anticancer activity of flavonoids as well as their molecular mechanisms, including the treatment of mammary and prostate cancer. This review also highlights some advanced derivatives of flavonoids, which play an important role against cancer.

Erigeroflavanone, a flavanone derivative from the flowers of Erigeron annuus with protein glycation and aldose reductase inhibitory activity

A novel 2,3-dioxygenated flavanone, erigeroflavanone ( 1), as well as eight known flavonoids and two known gamma-pyranone derivatives, were isolated from an ethyl acetate-soluble extract of the flowers of Erigeron annuus. The structure of compound 1 was elucidated by interpretation of spectroscopic data. All of the isolates were subjected to in vitro bioassays to evaluate their inhibitory activity against advanced glycation end products formation and rat lens aldose reductase.

Mass spectrometric analysis of 1,2,4-oxadiazoles and 4,5-dihydro-1,2,4-oxadiazoles

1,2,4-Oxadiazoles and 4,5-dihydro-1,2,4-oxadiazoles are an interesting class of compounds because of their pharmacological and other properties. Although short descriptions of these compounds under mass spectrometric conditions exist, we thought it worthwhile to write a comprehensive review of this class of compounds. Therefore, this revision deals first with 1,2,4-oxadiazoles and then 4,5-dihydro-1,2,4-oxadiazoles from 1964 until the year 2002. Much work on these compounds has been described under electron impact conditions and only a little under chemical ionization (CI).

Synthesis and biological evaluation of 3-alkoxy analogues of flavone-8-acetic acid

New analogues of flavone-8-acetic acid were synthesized, bearing an alkoxy group in position 3 and different substituents on the benzene ring in position 2 of the flavone nucleus. The compounds were tested for direct cytotoxicity against four human tumor cell lines and for indirect antitumor effects by measuring their ability to enhance lytic properties of murine macrophages and human monocytes. Though direct toxicity was very low, the compounds were able to induce significant indirect toxicity. Notably, most of them (4c, 4d, 4e, 4f, 4h, 4i, 4m,4n, and 4o) showed important activity on human monocytes and could be regarded as the first flavone derivatives endowed with such activity. Particularly interesting seem to be compounds 4m and 4n, which showed IC(50) values up to 7 times higher than DMXAA, which has now completed phase I clinical trials.