Anna Stochmal has completed her PhD in 1997 and in 2012 she was nominated for a professor of agricultural sciences. She has thirty-year experience in the isolation and structure elucidation of plant secondary metabolites. She is the head of Department of Biochemistry in the Institute of Soil Science and Plant Cultivaton. She has published nearly 160 papers with impact factor.
Sea buckthorn (Hippophae rhamnoides L.) is a thorny shrub or a small tree belonging to the family Elaeagnaceae, with lanceolate leaves and orange fruit. Its fruit and other organs have been used in traditional medicine, especially in China, Tibet, and Mongolia. Preparations made from this plant are also applied in conventional medicine and the cosmetic industry. The sea buckthorn fruit is broadly known for its diverse biological activities, attributed to the presence of different secondary metabolites, including phenolic compounds. The flavonoid composition of the sea buckthorn fruit has been well characterized. Despite this fact, some literature data and our preliminary results indicated that the available descriptions of its flavonoid profile lacked some important details. The aim of our study was to investigate the composition of butanol extract from sea buckthorn fruit. The extract was subjected to UHPLC-MS analyses, performed in negative and positive ionization mode, using an ACQUITY UPLC® chromatographic system (Waters) coupled with a triple quadrupol mass specrometer. The experiments revealed the presence of a number of isorhamnetin glycosides, showing characteristic neutral losses of 230 or 246 Da in their fragmentation patterns. These observations suggested the loss of deoxyhexose and hexose, respectively, bound to a 84 Da acyl group, most probably a untypical short-chained aliphatic acid. This hypothesis confirmed after subsequent purification and NMR analyses of these compounds, and the acyl group was identified as isovaleric acid. Sea buckthorn is, according to our knowledge, the only plant known to contain flavonoids acylated with this acid.
Jiaxi Peng received his BS in applied chemistry from Zhejiang University of Technology in 2013. He is now a PhD candidate majoring in analytical chemistry under the supervision of Professor Ren’an Wu at Dalian Institute of Chemical Physics. His current research focuses on the novel affinity materials for speciﬁc interaction with polypeptides and exploring their applications in fast and sensitive trace detection in biomarker profiling.
The highly specific affinity between probes and phosphopeptides is the fundamental interaction for selective identification of phosphoproteome that uncover the mechanisms of signal transduction, cell cycle, enzymatic regulation and gene expression in biological systems. A dual-metal centered zirconium-organic framework (DZMOF) holding not only the inherent Zr-O cluster but also the immobilized Zr (IV) center was facilely prepared by immobilizing Zr (IV) on a zirconium-organic framework of UiO-66-NH2. This DZMOF possessing both interactions of metal oxide affinity chromatography (MOAC) and immobilized metal ion affinity chromatography (IMAC) demonstrates as a highly specific metal-affinity probe toward the extraction of both mono-phosphorylated and multi-phosphorylated peptides. The binding energies of zirconium 3d5/2 and 3d3/2 in DZMOF are higher than that of the intact UiO-66-NH2, confirming the stronger metal-affinity interaction between the DZMOF and phosphopeptides. This highly metal-affinity probe presents an unprecedented strong performance in anti-nonspecific interference during the capturing of phosphopeptides of β-casein with the molar ratio of β-casein vs. bovine serum albumin (BSA) up to ca. 1:5000. The enrichment of phosphopeptides from human saliva sample by DZMOF further confirms the great potential of DZMOF in the extraction of low-abundance phosphopeptides for real complex biological samples.