Fig 1.
General structure of proanthocyanidins with A- and B-type linkage.
(R1, R2 = H, propelargonidin; R1 = OH, R2 = H, procyanidin; R1, R2 = OH, prodelphinidin).
Table 1.
Contents of total phenolics, total flavonoids, total proanthocyanidins, and antioxidant activities of pulp extracts of 32 litchi cultivars.
Fig 2.
Direct infusion ESI-MS spectrum of Hemaoli pulp crude extracts (HPCE) in the negative mode.
Fig 3.
Samples were dissolved in CD3OD.
Table 2.
13C (150 MHz) NMR data of (–)-epicatechin, procyanidin A1, A2, B1, B2, and C1 in CD3OD.
Fig 4.
HPLC (280 nm) analysis of HPCE and its different fractions.
A: HPCE; B: The fraction eluted with 40% methanol, F5; C: The fraction eluted with 50% methanol, F6; D: The fraction eluted with 60% methanol, F7; E: The fraction eluted with 100% methanol, F8.
Table 3.
Tentative identification and quantification of procyanidins in HPCE by using LC-ESI-MS.
Fig 5.
Antioxidant activity of HPCE, fractions, and procyanidins standards by DPPH (A, B) and ABTS (C, D) assays.
EP stands for (–)-epicatechin, and PA1, PA2, PB1, PB2, PC1 stand for the standards of procyanidin A1, A2, B1, B2, and C1, respectively.