Abstract
Two rare flavonoid-sulfonic acids complexed with calcium ions, Ca (II)-6‑methoxy-8- sulfonic acid-naringenin complexes and Ca (II)-8-sulfonic acid-isoprunetin complexes, were isolated from the fruits of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their planar structures were unambiguously established by extensive interpretation of the HRESIMS, 1D and 2D NMR data, and comparison to the literature data. The single crystal X-ray diffraction analysis revealed the location of sulfonic acid group on flavonoid C-8 position and the existence of metal atom in molecules, which was confirmed further to be calcium by elemental analysis. The two molecules represent the first examples of sulfonic flavonoids coordinated with calcium ions from the natural products. This example enriched the variety of natural product structures. All the isolates were evaluated for their antioxidant and anti-inflammatory activity.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
