title: Enzymatic Formation of Novel Ginsenoside Rg1-α-Glucosides by Rat Intestinal Homogenates.
abstract: The variation of linkage positions in ginsenosides leads to diverse pharmacological efficiencies. The hydrolysis and transglycosylation properties of glycosyl hydrolase family enzymes have a great impact on the synthesis of novel and structurally diversified compounds. In this study, six ginsenoside Rg1-α-glucosides were found to be synthesized from the reaction mixture of maltose as a donor and ginsenoside Rg1 as a sugar acceptor in the presence of rat small intestinal homogenates, which exhibit high α-glucosidase activities. The individual compounds were purified and were identified by spectroscopy (HPLC-MS, (1)H-NMR, and (13)C-NMR) as 6-O-[α-D-glcp-(1→4)-β-D-glcp]-20-O-(β-D-glcp)-20(S)-protopanaxatriol, 6-O-β-D-glcp-20-O-[α-D-glcp-(1→6)-(β-D-glcp)]-20(S)-protopanaxatriol, 6-O-β-D-glcp-20-O-[α-D-glcp-(1→4)-(β-D-glcp)]-20(S)-protopanaxatriol, 6-O-[α-D-glcp-(1→6)-β-D-glcp]-20-O-(β-glcp)-20(S)-protopanaxatriol, 6-O-[α-D-glcp-(1→3)-β-D-glcp]-20-O-(β-D-glcp)-20(S)-protopanaxatriol, and 6-O-β-D-glcp-20-O-[α-D-glcp-(1→3)-(β-D-glcp)]-20(S)-protopanaxatriol. Among these six, 6-O-β-D-glcp-20-O-α-D-glcp-(1→6)-(β-D-glcp)-20(S)-protopanaxatriol and 6-O-α-D-glcp-(1→6)-β-D-glcp-20-O-(β-D-glcp)-20(S)-protopanaxatriol are considered to be novel compounds of alpha-ginsenosidal saponins which pharmacological activities should be further characterized. This is the first report on the enzymatic elaboration of ginsenoside Rg1 derivatives using rat intestinal homogenates. To the best of our knowledge, it is also the first to reveal the sixth and 20th positions of an unusual α-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl sugar chain with 20(S)-protopanaxatriol saponins in Panax ginseng Mayer.
authors.affiliation: Graduate School of Biotechnology and Ginseng Bank, College of Life Science, Kyung Hee University, Yongin, 446-701, Republic of Korea.
authors.forename: Ramya
authors.initials: R
authors.lastname: Mathiyalagan
authors.affiliation: Department of Food Science and Biotechnology, Chonbuk National University, Iksan, 570-752, Republic of Korea.
authors.forename: Young-Hoi
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Oriental Medicinal Biotechnology, College of Life Science, Kyung Hee University, Yongin, 449-701, Republic of Korea. yeonjukim@khu.ac.kr.
authors.forename: Yeon Ju
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Food Science and Biotechnology, Chonbuk National University, Iksan, 570-752, Republic of Korea.
authors.forename: Myung-Kon
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Food Science and Biotechnology, Chonbuk National University, Iksan, 570-752, Republic of Korea.
authors.forename: Min-Ji
authors.initials: MJ
authors.lastname: Kim
authors.affiliation: Graduate School of Biotechnology and Ginseng Bank, College of Life Science, Kyung Hee University, Yongin, 446-701, Republic of Korea. dcyang@khu.ac.kr.
authors.forename: Deok Chun
authors.initials: DC
authors.lastname: Yang
mesh_terms: D000818:Animals; D036145:Ginsenosides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D005960:Glucosides / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification*; D006026:Glycoside Hydrolases; D006031:Glycosylation; D007420:Intestine, Large / Q000378:metabolism; D007421:Intestine, Small / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009097:Multienzyme Complexes; D005894:Panax / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D013379:Substrate Specificity; D014166:Transferases
chemical_list: D036145:Ginsenosides; D005960:Glucosides; D009097:Multienzyme Complexes; C023176:transglycosidase enzyme system; D014166:Transferases; D006026:Glycoside Hydrolases
keywords: Alpha glucosidase; Alpha glucosylginsenoside; Ginsenoside Rg1; Rat intestinal homogenates; Rg1 derivatives; Transglycosylation