Methanolic extract fractionation HPLC chromatograms

Our previous screening work showed that the methanol extract of Alpinia officinarum exhibited potent activity in the apoptosis assay. Then the column cWmatography indicated that 30 1 chloroform/methanol fraction was the most active one in the bioassay. This fraction was then analyzed by reverse phase HPLC and its corresponding HPLC chromatogram at 205 nm is presented in Figure 1. The 30 1 fraction was further subfractionated into three fractions and subjected to the bioassay again. It was shown that all three were active and the second fraction was the most potent. 

Fig. 4.2 HPLC-DAD chromatograms of anthocyanins from soluble and insoluble extracts of black, red-brown, and brown soybean seed coats at 520 nm. (a, d) Black (Clark), (b, e) red-brown (Mil), and (c, f) brown (MlOO) seed coats, (a and b) Pulverized fresh seed coats extracted with 80% methanol in water, (d-f) Insoluble pulverized seed coat fraction extracted with 1-butanol/HCl (19 1) 1% SDS. Compound identifications were based on comparison of retention times and absorption spectra to authentic standards. Peak 1, unknown peak 2, delphinidin-3-O-galactoside peak 3, delphinidin-3-O-glucoside peak 4, cyanidin-3-O-galactoside peak 5, cyanidin-3-O-glucoside peak 6, petunidin-3-O-glucoside peak 7, pelargonidin-3-O-glucoside peak 8, peonidin-3-O-glucoside and peak 9, malvidin-3-O-glucoside...

The 60% methanol sep-pak fractions from the mimosa foliage and sericea extracts were analyzed by LC/MS. The mimosa foliage fractionhad nearly the same profiles by both LC/MS (Fig. 4B) and HPLC (Fig. 4A), as indicated by the three major peaks. The LC/MS profile showed that the mimosa foliage fraction had major peaks at 42.5 (significant ions at m/z 303 and 633), 49.0 (m/z 303 and 487), and 53.5 (m/z 303 and 471), min. The molecular weights of compounds were inferred from the positive-ion mass spectra (results not shown). On the other hand, the chromatograms for the sericea extracts (Fig. 5A, 5B) are quite different. The LC/MS profile for sericea in Fig. 5B shows major peaks at 47.0 (major ions at m/z 433 and 545) and 48.5 (m/z 517 only) min. 

An HPLC-DAD method was developed for the separation and the determination of flavonoid and phenolic antioxidants in commercial and freshly prepared cranberry juice.Two sample preparation procedures were used with and without hydrolysis of the glycoside forms of flavonoids carried out by the addition of HCl in the step prior to solid-phase extraction (SPE). The flavonoid and phenolic compounds were then fractionated into neutral and acidic groups via a solid-phase extraction method (Sep-Pak Cig), followed by a RP HPLC separation with gradient elution with water-methanol-acetic acid and a detection at 280 and 360 nm. A comparison of the chromatograms obtained for extracts prepared with and without hydrolysis showed that flavonoids and phenolic acids exist predominantly in combined forms such as glycosides and esters. In a freshly squeezed cranberry juice, for instance, 400 mg of total flavonoids and phenolics per liter of sample was found, 56% of which were flavonoids. Quercetin was the main flavonoid in the hydrolyzed products, where it accounted for about 75% of the total flavonoids, while it was absent in the unhydrolyzed products. 

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