Isocassiaoccidentalin B, A New C‐Glycosyl Flavone Containing a 3‐Keto Sugar, and Other Constituents from Cassia nomame

Abstract

A new C‐glycosyl flavone containing a 3‐keto sugar, isocassiaoccidentalin B (1), was isolated from whole Cassia nomame (Sieber) Honda plants, along with eleven known compounds, including two flavonoids (2 and 3), five flavonoid glycosides (4 – 8), two chalcones (9 and 10), and two phenylpropanoids (11 and 12). The chemical structures of all compounds were determined via 1D‐ and 2D‐NMR, and ESI‐MS. Among these, compounds 2, 3, 7, and 8 were found to be the most potent in inhibiting nitric oxide release. Compounds 1, 2, 4, 8, 9, and 10 showed significant free‐radical scavenging activity.

Recent Advances on Natural Aryl-C-glycoside Scaffolds: Structure, Bioactivities, and Synthesis—A Comprehensive Review

“…Other aryl- C -glycosides include aryl- C -glycosides of amino sugars and other rare sugars [ 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Compounds 190 – 197 (4-aminosugar) and compound 198 – 199 (3-aminosugar), which are 2-deoxylaminoglycoside antibiotics, resemble the well-known pluramycins.…”

“…Nelumboside B ( 40 ) exhibited strong scavenging activity (SC 50 = 14.12 µM, ABTS assay), compared with the positive control L-ascorbic acid (SC 50 = 26.15 µM, ABTS assay) [ 12 ]. Isocassiaoccidentalin B ( 206 ), isolated from whole Cassia nomame (SIEBER) HONDA plants, showed significant free-radical scavenging activity [ 34 ]. Compound 42 , isolated from Gentiana piasezkii , showed significant free-radical scavenging activity (IC 20 = 5.20 ± 0.10 µM) in the DPPH assay [ 13 ].…”