title: Enzymatic transformation of vina-ginsenoside R₇ to rare notoginsenoside ST-4 using a new recombinant glycoside hydrolase from Herpetosiphon aurantiacus.
abstract: An eco-friendly and convenient preparation method for notoginsenoside ST-4 has been established by completely transforming vina-ginsenoside R7 using a recombinant glycosidase hydrolyzing enzyme (HaGH03) from Herpetosiphon aurantiacus. This enzyme specifically hydrolyzed the glucose at the C-20 position but not the external xylose or two inner glucoses at position C-3. Protein sequence BLAST revealed that HaGH03, composed of 749 amino acids and presumptively listed as a member of the family 3 glycoside hydrolases, has highest identity (48 %) identity with a thermostable β-glucosidase B, which was not known of any functions for ginsenoside transformation. The steady state kinetic parameters for purified HaGH03 measured against p-nitrophenyl β-D-glucopyranoside and vina-ginsenoside R7 were K M = 5.67 ± 0.24 μM and 0.59 ± 0.23 mM, and k cat = 69.2 ± 0.31/s and 2.15 ± 0.46/min, respectively. HaGH03 converted 2.5 mg/mL of vina-ginsenoside R7 to ST-4 with a molar yield of 100 % and a space-time yield of 104 mg/L/h in optimized conditions. These results underscore that HaGH03 has much potential for the effective preparation of target ginsenosides possessing valuable pharmacological activities. This is the first report identifying an enzyme that has the ability to transform vina-ginsenoside R7 and provides an approach to preparing rare notoginsenoside ST-4.
authors: Department of Pharmacognosy, China Pharmaceutical University, Nanjing, 210038, People's Republic of China.
authors: Ru-Feng
authors: RF
authors: Wang
authors: Ming-Min
authors: MM
authors: Zheng
authors: Yue-De
authors: YD
authors: Cao
authors: Hao
authors: H
authors: Li
authors: Chun-Xiu
authors: CX
authors: Li
authors: Jian-He
authors: JH
authors: Xu
authors: Zheng-Tao
authors: ZT
authors: Wang
mesh_terms: D001711:Biotransformation; D041862:Chloroflexi / Q000201:enzymology* / Q000235:genetics; D019295:Computational Biology; D006026:Glycoside Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012503:Saponins / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D012503:Saponins; D014315:Triterpenes; C560686:notoginsenoside ST-4; D006026:Glycoside Hydrolases