Botany and Microbiology Department, Faculty of Science, Menoufia University, Shebin EL-Koum 32511, Egypt.
Biochemistry and Physiology of Plants, Faculty of Biology W5, Bielefeld University, 33501 Bielefeld, Germany.
Int J Mol Sci. 2021 Feb 21;22(4):2149. doi: 10.3390/ijms22042149.
The present study aimed to investigate the enzymatic potential of leaves to bioconvert phenolic acids produced in callus into silymarin derivatives as chemopreventive agent. Here we demonstrate that despite the fact that leaves of did not accumulate silymarin themselves, expanding leaves had the full capacity to convert di-caffeoylquinic acid to silymarin complex. This was proven by HPLC separations coupled with electrospray ionization mass spectrometry (ESI-MS) analysis. Soaking the leaf discs with callus extract for different times revealed that silymarin derivatives had been formed at high yield after 16 h. Bioconverted products displayed the same retention time and the same mass spectra (MS or MS/MS) as standard silymarin. Bioconversion was achieved only when using leaves of a specific age, as both very young and old leaves failed to produce silymarin from callus extract. Only medium leaves had the metabolic capacity to convert callus components into silymarin. The results revealed higher activities of enzymes of the phenylpropanoid pathway in medium leaves than in young and old leaves. It is concluded that cotyledon-derived callus efficiently produces compounds that can be bio-converted to flavonolignans in leaves tissue of .
本研究旨在探讨叶片的酶促潜力，以将愈伤组织中产生的酚酸生物转化为具有化学预防作用的水飞蓟宾衍生物。在这里，我们证明了一个事实，即尽管 的叶片本身并不积累水飞蓟宾，但展开的叶片完全有能力将二咖啡酰奎宁酸转化为水飞蓟宾复合物。这一点通过高效液相色谱（HPLC）分离与电喷雾电离质谱（ESI-MS）分析得到了证明。用愈伤组织提取物浸泡叶片圆盘不同时间后发现，16 小时后以高产率形成了水飞蓟宾衍生物。生物转化产物的保留时间和标准水飞蓟宾的质谱（MS 或 MS/MS）完全相同。只有在使用特定年龄的叶片时才能进行生物转化，因为非常年轻和老的叶片都无法从愈伤组织提取物中产生水飞蓟宾。只有中叶才有将愈伤组织成分转化为水飞蓟宾的代谢能力。结果表明，中叶苯丙素途径的酶活性高于幼叶和老叶。因此可以得出结论，子叶衍生的愈伤组织有效地产生了可以在 叶片组织中生物转化为类黄酮木脂素的化合物。
