Naturally Occurring Homoisoflavonoids and Their Pharmacological Activities

Abstract

!Homoisoflavonoids, a special subclass of flavonoids, are rarely found in nature, mainly existing in Fabaceae and Asparagaceae families and being less common in Polygonaceae, Portulacaceae, Orchidaceae, and Gentianaceae families. Until now, approximately 240 natural occurring homoisoflavonoids have been identified from roots, barks, heartwood, bulbs, leaves, and seeds of the plants from the above mentioned families, which have often been used in traditional medicine. Homoisoflavonoids have been reported with a broad range of bioactivities, including anti-microbial, anti-mutagenic, anti-oxidant, immunomodulatory, anti-diabetic, cytotoxic, anti-angiogenic, vasorelaxant, and anti-inflammatory effects. To organize this review, the homoisoflavonoids were classified into five groups based on their structures: sappanin-type (I), scillascillin-type (II), brazilin-type (III), caesalpin-type (IV), and protosappanin-type (V). The structures of natural occurring homoisoflavonoids are described, and their proposed biosynthetic pathway and recent pharmacological studies are discussed. The main purpose of this review is to provide a comprehensive and up-to-date state of knowledge from phytochemical and pharmacological studies performed on homoisoflavonoids during the past decades. Homoisoflavonoids might have a large potential for further investigations of their bioactivities in order to identify important leads.

Synthesis and Biological Evaluation of 3-Benzylidene-4-chromanone Derivatives as Free Radical Scavengers and α-Glucosidase Inhibitors

“…We synthesized a series of 3-benzylidene-4-chromanone derivatives (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and evaluated their potential for DPPH free radical scavenging and α-glucosidase inhibitory activity. As a result, compounds 5, 13, 18, which possess a catechol moiety on the B-ring, were found to exhibit potent DPPH free radical scavenging and α-glucosidase inhibitory activities.…”

“…Compound 1a was commercially available and compounds 1b and c were synthesized from resorcinol according to the procedure of Foroumadi et al 21) With 1a-c in hand, each was condensed with benzaldehyde derivatives (2a-h) in the presence of piperidine to provide the 3-benzylidene-4-chromanone derivatives (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20).…”

“…[4][5][6][7][8][9] (3E)-3-Benzylidene-2,3-dihydro-4H-1-benzopyran-4-ones (3-benzylidene-4-chromanones) constitute a small class of natural products primarily isolated from Hyacinthaceae and Caesalpinioideae. [10][11][12][13][14] Several natural and synthetic 3-benzylidene-4-chromanones are related structurally to flavonoids and were found to possess various biological properties such as antioxidant, antifungal, antiviral, anti-mutagenic, antiproliferative, anti-allergic, antihistaminic, anti-inflammatory, and monoamine oxidase inhibitory activity. [15][16][17][18][19][20][21][22][23][24] However, no systematically evaluated data are available on the inhibitory activity of α-glucosidase by 3-benzylidene-4-chromanone derivatives.…”

Cytotoxic Homoisoflavonoids from <i>Ophiopogon japonicus</i> Tubers

“…Compound 1 was probably responsible for the cytotoxic effect observed of the MeOH extract since other isolated components showed weak or null effect. The cytotoxic effect of homoisoflavonoids has been indicated elsewhere, 12) and the structureactivity relationship has been investigated. 13) Accordingly, the 2′-hydroxy and 4′-methoxy groups seem to have a contribution to the activity.…”

Quantitative Structure-cytotoxicity Relationship of 3-Benzylidenechromanones

“…(3E)-2,3-Dihydro-3-(phenylmethylene)-4H-1-benzopyran-4-one [1], (3E)-2,3-dihydro-3-[(4-hydroxyphenyl) methylene]-4H-1-benzopyran-4-one [2], (3E)-2,3-dihydro-3-[(3,4-dihydroxyphenyl)methylene]-4H-1-benzopyran-4-one [3], (3E)-2,3-dihydro-3-[(4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one [4], (3E)-2,3-dihydro-3-[(3,4-dimethoxyphenyl)methylene]-4H-1-benzopyran-4-one [5], (3E)-2,3-dihydro-3-[(4-dimethylaminophenyl)methylene]-4H-1-benzopyran-4-one [6], (3E)-2,3-dihydro-3-[(4-fluorophenyl)methylene]-4H-1-benzopyran-4-one [7], (3E)-3-[(4-chlorophenyl)methylene]-2,3-dihydro-4H-1-benzopyran-4-one [8], (3E)-2,3-dihydro-7-hydroxy-3-[(4-hydroxyphenyl)methylene]-4H-1-benzopyran-4-one [9], (3E)-2,3-dihydro-3-[(3,4-dihydroxyphenyl)methylene]-7-hydroxy-4H-1-benzopyran-4-one [10], (3E)-2,3-dihydro-7-hydroxy-3-[(4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one [11], (3E)-2,3-dihydro-3-[(4-dimethylaminophenyl)methylene]-7-hydroxy-4H-1-benzopyran-4-one [12], (3E)-2,3-dihydro-7-methoxy-3-(phenylmethylene)-4H-1-benzopyran-4-one [13], (3E)-2,3-dihydro-3-[(4-hydroxyphenyl)methylene]-7-methoxy-4H-1-benzopyran-4-one [14], (3E)-2,3-dihydro-3-[(3,4-dihydroxyphenyl)methylene]-7-methoxy-4H-1-benzopyran-4-one [15], (3E)-2,3-dihydro-7-methoxy-3-[(4-methoxyphenyl)methylene]-4H-1-benzopyran-4-one [16] and (3E)-2,3-dihydro-3-[(4-dimethylaminophenyl)methylene]-7-methoxy-4H-1-benzopyran-4-one [17] (structures shown in Figure 1) were synthesized by base-catalyzed condensation of appropriate 4-chromanone with substituted benzaldehyde derivatives according to previous methods (19,20). All compounds were dissolved in DMSO at 40 mM and stored at -20˚C before use.…”