Ligand fishing from Dioscorea nipponica extract using human serum albumin functionalized magnetic nanoparticles.
Dioscorea nipponica and the preparations made from it have been used for long to prevent and treat coronary heart disease in traditional Chinese medicine. A group of steroidal saponins present in the plant are believed to be the active ingredients. It has been a challenge to study the individual saponins separately due to the similarities in their chemical and physical properties. In this work, human serum albumin (HSA) functionalized magnetic nanoparticles (MNPs) were used to isolate and identify saponin ligands that bind to HSA from D. nipponica extract. Electrospray ionization mass spectrometry (ESI-MS) was used for compound identification and semi-quantification. Three saponins, i.e. dioscin, gracillin, and pseudo-protodioscin showed affinity to HSA-MNPs and thus isolated effectively from the extract. The other two saponins detected in the extract (i.e. protodioscin and 26-O-β-D-glucopyranosyl-3β,20α,26-triol-25(R)-Δ(5,22)-dienofurostan-3-O-α-L-rhamnopyranosyl (1→2)-[α-L-rhamnopyranosyl (1→4)]-β-D-glucopyranoside) exhibited no affinity at all. Among the three saponins fished out, dioscin bound to HSA much stronger than gracillin and pseudo-protodioscin did. The results indicated that affinity interaction between HSA immobilized on MNPs and small molecule compounds were highly dependent on chemical structures and, potentially, medicinal usefulness. The present work demonstrates a facile and effective way to isolate and identify ligands of receptors from medicinal plants.
Qinga
Lin-Sen
LS
Chengdu Institute of Biology, Chinese Academy of Sciences, China.
Xue
Ying
Y
Zheng
Yi
Y
Xiong
Jing
J
Liao
Xun
X
Ding
Li-Sheng
LS
Li
Bo-Gang
BG
Liu
Yi-Ming
YM
D015374:Biosensing Techniques / Q000379:methods*; D027742:Dioscorea / Q000737:chemistry*; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry*; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism
D055767:Immobilized Proteins; D008024:Ligands; D058185:Magnetite Nanoparticles; D010936:Plant Extracts; D012503:Saponins; D012709:Serum Albumin