Feliciano Rodrigo P, Meudt Jennifer J, Shanmuganayagam Dhanansayan, Metzger Brandon T, Krueger Christian G, Reed Jess D
Department of Food Science, University of Wisconsin-Madison , 1605 Linden Drive, Madison, Wisconsin 53706, United States.
J Agric Food Chem. 2014 Aug 6;62(31):7730-7. doi: 10.1021/jf502296b. Epub 2014 Jul 24.
Supercritical fluid extraction (SFE) removed lipophilic compounds and low molecular weight flavonoids from cranberries. However, SFE did not extract proanthocyanidins (PAC). The SFE PAC-enriched residue was submitted to fractionation on Sephadex LH-20 using ethanol, ethanol/methanol, and 80% acetone. PAC degree of polymerization (DP) and ratios of "A-type" to "B-type" interflavan bonds were compared with those of PAC fractions without SFE. Mass spectrometry showed that when SFE was used, PAC distribution was shifted toward higher DP and contained higher amounts of two and three "A-type" bonds compared to PAC fractions without SFE. The 80% acetone fraction with SFE had significantly greater extraintestinal pathogenic Escherichia coli (ExPEC) agglutination and significantly lower ExPEC invasion of enterocytes than the fraction without SFE. Cranberry PAC with higher numbers of "A-type" interflavan bonds are more bioactive in agglutinating ExPEC and inhibiting ExPEC enterocyte invasion.
超临界流体萃取（SFE）去除了蔓越莓中的亲脂性化合物和低分子量黄酮类化合物。然而，SFE并未萃取出原花青素（PAC）。将经SFE富集PAC的残留物用乙醇、乙醇/甲醇和80%丙酮在Sephadex LH - 20上进行分级分离。将PAC的聚合度（DP）以及“A型”与“B型”黄烷间键的比例与未经SFE处理的PAC级分进行比较。质谱分析表明，使用SFE时，与未经SFE处理的PAC级分相比，PAC分布向更高的DP偏移，并且含有更高含量的两个和三个“A型”键。与未经SFE处理的级分相比，经SFE处理的80%丙酮级分对肠道外致病性大肠杆菌（ExPEC）的凝集作用明显更强，而ExPEC对肠上皮细胞的侵袭作用明显更低。具有更多“A型”黄烷间键的蔓越莓PAC在凝集ExPEC和抑制ExPEC对肠上皮细胞的侵袭方面具有更高的生物活性。
