Anti-inflammatory activities of selected synthetic homoisoflavanones

Abstract

Four homoisoflavanones of the 3-benzylidene-4-chromanone type, some of which were previously isolated from Caesalpinia pulcherrima, were synthesised to determine their anti-inflammatory activity and cytotoxicity. A range of four different homoisoflavanones (compounds 4a-4d) were synthesised from the corresponding substituted phenols. ¹H- and ¹³C-NMR data together with high-resolution mass spectroscopy data were employed to elucidate the structures. Anti-inflammatory activity was determined in mice with acute croton oil-induced auricular dermatitis. In vitro cytotoxicity was tested against a Chinese hamster ovarian cell line using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Compound 4a exhibited a tendency to inhibit oedema in a dose-dependent manner after 3 and 6 h of treatment. Compounds 4b-4d also inhibited oedema, although a clear dose-response relationship was not observed. Compounds 4a-4c were found to be less cytotoxic than compound 4d. Compound 4b was the least cytotoxic. Compounds 4a-4d exhibited anti-inflammatory activity and varying levels of cytotoxicity.

Asymmetric Synthesis of Sappanin‐Type Homoisoflavonoids

“…In another method, 3‐benzylidenechroman‐4‐one is obtained by the aldol condensation of a chroman‐4‐one and benzaldehyde . To obtain chroman‐4‐ones, three different routes are reported (Scheme (a)).…”

3-Benzyl-5,7-dimethoxychroman-4-ol

“…For the biological activity of naturally ocurring homoisoflavanones that possess a 3-benzyl-substituted chroman ring system, see: Zhang et al (2008). For our work on the synthesis and characterization of natural products from this family of compounds in the search for new medical agents, see: Shaikh et al (2011).…”

Synthesis and NMR elucidation of homoisoflavanone analogues

“…However, according to previous studies, natural homoisoflavanones exhibit anti-inflammatory, antibacterial, anti-mutagenic, hypocholesterolemic [9][10][11][12][13], antioxidant and anti-viral activities [14][15][16]. The synthesis of homoisoflavanones (3-benzylidine-4-chromanones) is well established [17] and although a variety of homoisoflavanones have been isolated from many different plants, it appears that more is known about the biosynthesis and chemistry of these compounds than about their biological activities and its relation to their structures. Previously, NMR study of similar type of natural homoisoflavanones was reported [18][19][20].…”

“…Based on the lead compound we synthesized compound 3 and its analogues with different substitution patterns at the 4 0 -position of the B-ring. The products showed good anti-inflammatory [17] and anti-fungal activity [21].…”