Department of Analytical Chemistry and Pharmaceutical Technology, Centre for Pharmaceutical Research, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, B-1090, Brussels, Belgium.
Medicinal and Aromatic Plants Research Department, Horticulture Institute, Agriculture Research Centre, Dokki, Giza, Egypt.
Phytochem Anal. 2018 Jan;29(1):5-15. doi: 10.1002/pca.2709. Epub 2017 Aug 4.
The plant species Ipomoea aquatica contains various bioactive constituents, e.g. phenols and flavonoids, which have several medical uses. All previous studies were executed in Asia; however, no reports are available from Africa, and the secondary metabolites of this plant species from Africa are still unknown.
The present study aims finding suitable conditions to identify the bioactive compounds from different fractions.
Chromatographic fingerprint profiles of different fractions were developed using high-performance liquid chromatography (HPLC) and then these conditions were transferred to thin-layer chromatography (TLC). Subsequently, the chemical structure of some bioactive compounds was elucidated using ultra-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry (UPLC-QTOF-MS) and liquid chromatography-solid phase extraction-nuclear magnetic resonance (LC-SPE-NMR) spectroscopy.
The HPLC fingerprints, developed on two coupled Chromolith RP-18e columns, using a gradient mobile phase (methanol/water/trifluoroacetic acid, 5:95:0.05, v/v/v), showed more peaks than the TLC profile. The TLC fingerprint allows the identification of the types of chemical constituents, e.g. flavonoids. Two flavonoids (nicotiflorin and ramnazin-3-O-rutinoside) and two phenolic compounds (dihydroxybenzoic acid pentoside and di-pentoside) were tentatively identified by QTOF-MS, while NMR confirmed the structure of rutin and nicotiflorin.
The HPLC and TLC results showed that HPLC fingerprints give more and better separated peaks, but TLC helped in determining the class of the active compounds in some fractions. Bioactive constituents were identified as well using MS and NMR analyses. Two flavonoids and two phenolic compounds were tentatively identified in this species for the first time, to the best of our knowledge. Copyright © 2017 John Wiley & Sons, Ltd.
植物物种Ipomoea aquatica 含有多种生物活性成分，例如酚类和类黄酮，具有多种医疗用途。以前的所有研究都是在亚洲进行的；然而，非洲没有报道，这种植物物种的次生代谢产物仍不清楚。
本研究旨在寻找合适的条件来鉴定不同馏分中的生物活性化合物。
使用高效液相色谱法（HPLC）开发不同馏分的色谱指纹图谱，然后将这些条件转移到薄层色谱法（TLC）。随后，使用超高效液相色谱-四极杆飞行时间串联质谱（UPLC-QTOF-MS）和液相色谱-固相萃取-核磁共振（LC-SPE-NMR）光谱法阐明一些生物活性化合物的化学结构。
使用甲醇/水/三氟乙酸（5:95:0.05，v/v/v）作为梯度流动相在两个偶联的 Chromolith RP-18e 柱上开发的 HPLC 指纹图谱显示出比 TLC 图谱更多的峰。TLC 指纹图谱可识别化学成分的类型，例如类黄酮。通过 QTOF-MS 初步鉴定了两种类黄酮（野靛苷和鼠李糖苷-3-O-芸香糖苷）和两种酚类化合物（二羟基苯甲酸五糖苷和二戊糖苷），而 NMR 则证实了芦丁和野靛苷的结构。
HPLC 和 TLC 结果表明，HPLC 指纹图谱提供了更多和更好分离的峰，但 TLC 有助于确定某些馏分中活性化合物的类别。通过 MS 和 NMR 分析也鉴定了生物活性成分。据我们所知，这是首次在该物种中暂定鉴定出两种类黄酮和两种酚类化合物。
