kuraridin and sophoflavescenol

The genus Sophora (Fabaceae) has been used in traditional medicine for years. Prenylated flavonoids are one of the constituents of Sophora species that play important roles in their biological properties. Different classes of prenylated flavonoids are produced by Sophora spp. including prenylated flavonol (e.g., sophoflavescenol), prenylated flavanone (e.g., sophoraflavanone G), prenylated flavonostilbene (e.g., alopecurones A and B), and prenylated chalcone (kuraridin). Prenylated flavonoids have a more lipophilic structure, which leads to its high affinity to the cell membranes and enhancement of the biological activity, which includes cytotoxicity, antibacterial, anti-inflammatory, and estrogenic activities. However, it is reported that prenylation decreases the plasma absorption but increases the tissue accumulation. The presence of the prenyl or lavandulyl groups on C8 position of flavonoids plays an important role in the biological activity. It seems that prenylated flavonoids have the potential to be developed as new drugs or supplements for human health.

Topics: Biological Products; Chalcones; Flavanones; Flavonoids; Humans; Medicine, Traditional; Monoterpenes; Plant Extracts; Prenylation; Sophora; Structure-Activity Relationship

During the search for naturally occurring cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) inhibitors, it was found that the extracts from Sophora flavescens exhibit potent inhibitory activity against cGMP PDE5 prepared from rat diaphragm. Therefore, the inhibitory activities of five flavonoids, kushenol H (1), kushenol K (2), kurarinol (3), sophoflavescenol (4) and kuraridine (5), isolated from S. flavescens were measured against cGMP PDE5 to identify potent cGMP PDE5 inhibitory constituents. Among tested compounds, sophoflavescenol (4), a C-8 prenylated flavonol, showed the most potent inhibitory activity (IC(50)=0.013 microM) against cGMP PDE5 with 31.5- and 196.2-fold selectivity over PDE3 and PDE4, respectively. Kinetic analysis revealed that sophoflavescenol was a mixed inhibitor of PDE5 with a K(i) value of 0.005 microM.

Topics: 3',5'-Cyclic-AMP Phosphodiesterases; 3',5'-Cyclic-GMP Phosphodiesterases; Animals; Cyclic Nucleotide Phosphodiesterases, Type 3; Cyclic Nucleotide Phosphodiesterases, Type 4; Cyclic Nucleotide Phosphodiesterases, Type 5; Dose-Response Relationship, Drug; Enzyme Inhibitors; Flavonoids; Inhibitory Concentration 50; Kinetics; Rats; Sophora; Structure-Activity Relationship

A new prenylated flavonol, sophoflavescenol (1), together with five known flavonoids, kurarinol, kushenol K, kushenol H, trifolirhizin, and kuraidin, were isolated from the roots of Sophora flavescens. The structure of 1 was determined by spectroscopic analysis. Among the five known flavonoids, kurarinol, kushenol K, and kushenol H showed weak antiviral activity against Herpes simplex virus types I and II.

Topics: Antiviral Agents; China; Flavonoids; Herpesvirus 1, Human; Herpesvirus 2, Human; Magnetic Resonance Spectroscopy; Mass Spectrometry; Plant Roots; Plants, Medicinal; Spectrophotometry, Ultraviolet