Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada.
Department of Biological Sciences, Brock University, 1812 Sir Isaac Brock Way, St. Catharines, Ontario L2S 3A1, Canada.
Food Chem. 2018 May 30;249:184-192. doi: 10.1016/j.foodchem.2018.01.006. Epub 2018 Jan 2.
Our recent research indicated that honey active macromolecules form colloidal particles that scatter the light and produce elaborate UV spectral profile dominated by double absorption peaks at 240-250 nm. The absorption at 240-250 nm signified the stable honey conformation that supported antibacterial activity and hydrogen peroxide production. Our aim was to identify the bioactive constituent relevant to this absorption. The methodology included activity-guided fractionation of honey through size-exclusion chromatography, solid-phase extraction and UPLC-UV-MS. UV spectral analysis of UPLC peaks revealed compounds with UV λ (max) typical of naphtoquinones. The MS chromatograms showed mass ions differing by [M-68] indicating a polyisoprene structure and the fragmentation patterns typical for menaquinones. The exact mass measurements of menaquinones using a quadrupole-Orbitrap mass spectrometry confirmed their identification as a series of MK-3 to MK-7 aptimers. Detection of menaquinones, previously unknown constituents of honey, suggests that they might play role in honey redox and antibacterial activities.
我们最近的研究表明，蜂蜜活性大分子形成胶体颗粒，散射光线并产生精细的紫外光谱轮廓，其特征是在 240-250nm 处存在双重吸收峰。240-250nm 的吸收表明了稳定的蜂蜜构象，支持抗菌活性和过氧化氢的产生。我们的目的是确定与这种吸收相关的生物活性成分。该方法包括通过大小排阻色谱、固相萃取和 UPLC-UV-MS 对蜂蜜进行活性导向的分段。UPLC 峰的紫外光谱分析显示出具有典型萘醌 UV λ(max)的化合物。MS 色谱图显示质量离子相差 [M-68]，表明存在聚异戊二烯结构和典型的甲萘醌片段模式。使用四极杆-Orbitrap 质谱对甲萘醌进行精确质量测量证实了它们是一系列 MK-3 到 MK-7 适体的鉴定。先前未知的蜂蜜中甲萘醌的检测表明，它们可能在蜂蜜的氧化还原和抗菌活性中发挥作用。
