New Cytotoxic Flavonoids from Thelypteris torresiana

Abstract

During our search for anti-tumor agents from pteridophytes, three new flavonoids, protoapigenone (1), 5′,6′-dihydro-6′-methoxyprotoapigenone (2), and protoapigenin (3), along with four known compounds, protoapigenin 4′-O-β-D-glucoside (4), apigenin 4′-O-β-D-glucoside (5), kaempferol 3-O-α-L-rhamnopyranoside (6), kaempferol 3,7-di-O-α-L-rhamnopyranoside (7), were isolated from Thelypteris torresiana using bioactivity-guided fractionation methods. The structures of the new isolates were elucidated by 1D- and 2D-NMR spectral analysis. Among the 7 compounds, protoapigenone (1) exhibited significant anti-tumor activities toward Hep G2, Hep 3B, MCF-7, A549, and MDA-MB-231 with IC₅₀ values of 1.60, 0.23, 0.78, 3.88 and 0.27 μg/mL, respectively.

Key words

Thelypteris torresiana - Thelypteridaceae - flavonoids - flavonoid glycosides - anti-tumor - cytotoxicity

References

• 1 Elliott W M, Auersperg N. Comparison of the neutral red and methylene blue assays to study cell growth in culture.  Biotech Histochem. 1993;  68 29-35
• 2 Wada W, Fujita H, Murakami T, Saiki Y, Chen C M. Chemical and chemotaxonomical studies of ferns. LXXIII. New flavonoids with modified B-ring from the genus Pseudophegopteris (Thelypteridaceae).  Chem Pharm Bull. 1987;  35 4757-62
• 3 Cuyckens F, Claeys M. Mass spectrometry in the structural analysis of flavonoids.  J Mass Spectrom. 2004;  39 1-15
• 4 Cheng M J, Lee S J, Chang Y Y, Wu S H, Tsai I L, Jayaprakasam B, Chen I S. Chemical and cytotoxic constituents from Peperomia sui .  Phytochemistry. 2003;  39 603-8
• 5 Veit M, Beckert C, Höhne C, Bauer K, Geiger H. Interspecific and intraspecific variation of phenolics in the genus Equisetum subgenus Equisetum .  Phytochemistry. 1995;  38 881-91
• 6 Teng R, Xie H, Li H Z, Liu X, Wang D, Yang C. Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.-Mazz.  Magn Reson Chem. 2002;  40 415-20
• 7 Deng J Z, Marshall R, Jones S H, Johnson R K, Hecht S M. DNA-damaging agents from Crypteronia paniculata .  J Nat Prod. 2002;  65 1930-2
• 8 Pauli G F. Higher order and substituent chemical shift effects in the proton NMR of glycosides.  J Nat Prod. 2000;  63 834-8
• 9 Peterson J, Dwyer J. Flavonoids: dietary occurrence and biochemical activity.  Nutr Res. 1998;  18 1995-2018