Submitted to: Journal of Chromatographic Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/1/2014
Publication Date: 5/27/2013
Citation: Park, J.B. 2013. Synthesis, HPLC measurement and bioavailability of the phenolic amide amkamide. Journal of Chromatographic Science. DOI: 10.1093/chromsci/bmt055. Epub 2013 May 27.. Interpretive Summary: Amkamide, oretamide, becatamide, enferamide and veskamide are N-phenylethylbenzoylamide-type phenolic amides, whose analogues are found in plants that are eaten for food such as Houttuynia cordata or other plants used as medicinal plants such as Aniba riparia, Begonia nantoensis and Haplophyllum tuberculatum. Although the potential effects of these amides related to human health are of great interest, research on them is limited by their lack of availability. A recent study indicates that becatamide and analogues are able to inhibit H2O2 -induced apoptosis of PC-12 cells via protecting mitochondria. However, no specific information was available about their bioavailability. Without this information, it is practically impossible to accurately propose and/or assess their purported effects in vivo. Therefore, in this study, amkamide, oretamide, becatamide, enferamide and veskamide were chemically synthesized, and a high performance liquid chromatography (HPLC) method was developed in order to quantify becatamide and analogues in standards and plasma samples with high sensitivity and reproducibility. The appearance of becatamide in plasma after 2 oral doses was determined using this method. These studies will provide researchers in nutrition, molecular biology, and medicinal fields with new information about the syntheses, HPLC measurement and bioavailability of the amides with mitochondria protective activity.
Technical Abstract: Amkamide, oretamide, becatamide, enferamide and veskamide are phenolic amides whose analogues are found in plants. Recently, becatamide was reported to have very potent mitochondria protective activity. In this study, becatamide and analogues (amkamide, oretamide, enferamide and veskamide) were chemically synthesized and a high performance liquid chromatography (HPLC) method was developed for quantifying the amides in biological samples. Using the synthesized amides as standards, HPLC separation was performed on a Nova-Pak C18 column using a gradient condition. The HPLC method was able to produce excellent and reproducible separations of the amides which were detected using a coulometric electrochemical detector. Particularly, three amides (becatamide, enferamide and veskamide) yielded outstanding peak resolutions with detection limits as low as 100 fmol. Plasma concentrations of the becatamide were determined in mouse blood following two oral administrations (2 and 4 mg/30 g body weight) using this HPLC method. As expected, relatively high amounts of becatamide (27 and 58 'M) were detected with Tmax (20 min), at the respective doses. This HPLC method is the first reported method able to quantify becatamide in standard and plasma samples with excellent detection limit and consistent reproducibility