Fig 1.
Total phenolic content in the five fractions of C. nitidissima Chi flowers.
Each value is expressed as mean ± SD (n = 3). Different letters showed significant differences from each other.
Fig 2.
Chemical structures of compounds 1–12.
Table 1.
13C-NMR data of compounds 1–12 isolated from C. nitidissima Chi flowers (δ in ppm and all in CD3OD at 125 MHz).
Fig 3.
Total ion chromatogram of the C. nitidissima Chi flowers ethanolic extract (A); HPLC chromatogram of Camellia nitidissima Chi flower ethanolic extract by 360 nm detection (B).
Table 2.
Mass spectrometric data of phenolic compounds identified in the ethanolic extract from C. nitidissima Chi flowers using HPLC Triple TOF MS/MS.
Fig 4.
ABTS radical cation scavenging activity of Vc and C. nitidissima Chi flower fractions (A), compounds 1–2 (B), compounds 3–4 (C), and compounds 5–12 (D). Each value is expressed as mean ± SD (n = 3).
Table 3.
50% effective concentrations (EC50) of DPPH and ABTS radical scavenging activities for the 5 fractions and 12 flavonoids isolated from C. nitidissima Chi flowers.
Fig 5.
DPPH radical scavenging activity of Vc and C. nitidissima Chi flower fractions (A), compounds 1–2 (B), compounds 3–4 (C), and compounds 5–12 (D). Each value is expressed as mean ± SD (n = 3).
Fig 6.
Ferric reducing antioxidant power (FRAP) of Vc and C. nitidissima Chi flower fractions (A), compounds 1–2 (B), compounds 3–4 (C), and compounds 5–12 (D). Each value is expressed as mean ± SD (n = 3).
Table 4.
Pearson’s correlation coefficients for total phenolic content (TPC) of the five fractions of C. nitidissima Chi flowers and antioxidant activity.
Fig 7.
Principal component analysis (PCA) loading plot of total phenolic content (TPC) and antioxidant activity of the ethanolic extract (A) dichloromethane fraction (B), ethyl acetate fraction (C), n-butanol fraction (D), and water fraction (E) of C. nitidissima Chi flowers.
Table 5.
Component matrix of the five fractions from C. nitidissima Chi flowers.