scholarly journals A multifunctional oxidosqualene cyclase from Tripterygium regelii that produces both α- and β-amyrin

RSC Advances ◽  
2018 ◽  
Vol 8 (42) ◽  
pp. 23516-23521 ◽  
Author(s):  
Yun Lu ◽  
Jiawei Zhou ◽  
Tianyuan Hu ◽  
Yifeng Zhang ◽  
Ping Su ◽  
...  
Keyword(s):  
Oxidosqualene Cyclase ◽  
Tripterygium Regelii

A multifunctional oxidosqualene cyclase was cloned from Tripterygium regelii and identified as a mixed-amyrin synthase, which can produce both α- and β-amyrin.

scholarly journals Squalene-Hopene Cyclases

2011 ◽  
Vol 77 (12) ◽  
pp. 3905-3915 ◽  
Author(s):  
Gabriele Siedenburg ◽  
Dieter Jendrossek
Keyword(s):  
Common Ancestor ◽  
Amino Acid Sequences ◽  
Enzymatic Reactions ◽  
Covalent Bonds ◽  
Content Type ◽  
Oxidosqualene Cyclase ◽  
Ring Structures ◽  
One Step ◽  
Alicyclobacillus Acidocaldarius ◽  
Eukaryotic Organisms

ABSTRACTHopanoids and sterols are members of a large group of cyclic triterpenoic compounds that have important functions in many prokaryotic and eukaryotic organisms. They are biochemically synthesized from linear precursors (squalene, 2,3-oxidosqualene) in only one enzymatic step that is catalyzed by squalene-hopene cyclase (SHC) or oxidosqualene cyclase (OSC). SHCs and OSCs are related in amino acid sequences and probably are derived from a common ancestor. The SHC reaction requires the formation of five ring structures, 13 covalent bonds, and nine stereo centers and therefore is one of the most complex one-step enzymatic reactions. We summarize the knowledge of the properties of triterpene cyclases and details of the reaction mechanism ofAlicyclobacillus acidocaldariusSHC. Properties of other SHCs are included.

scholarly journals The absolute configuration of regelidine, a novel 6-nicotinoyl dihydroagarofuran sesquiterpene alkaloid from Tripterygium regelii.

1987 ◽  
Vol 35 (11) ◽  
pp. 4683-4686 ◽  
Author(s):  
Hitoshi Hori ◽  
Guo-Mao Pang ◽  
Kenzo Harimaya ◽  
Yoichi Iitaka ◽  
Seiichi Inayama
Keyword(s):  
Absolute Configuration ◽  
Tripterygium Regelii ◽  
The Absolute

Macrolide sesquiterpene pyridine alkaloids from the stems of Tripterygium regelii

2018 ◽  
Vol 73 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Dongsheng Fan ◽  
Ting Li ◽  
Zhiyuan Zheng ◽  
Guo-Yuan Zhu ◽  
Xiaojun Yao ◽  
...  
Keyword(s):  
Tripterygium Regelii ◽  
Sesquiterpene Pyridine Alkaloids

scholarly journals Identification of Key Amino Acid Residues Determining Product Specificity of 2,3-Oxidosqualene Cyclase in Siraitia grosvenorii

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 577 ◽  
Author(s):  
Jing Qiao ◽  
Jiushi Liu ◽  
Jingjing Liao ◽  
Zuliang Luo ◽  
Xiaojun Ma ◽  
...  
Keyword(s):  
Amino Acid ◽  
Site Directed Mutagenesis ◽  
Bioactive Molecules ◽  
Amino Acid Residues ◽  
Product Specificity ◽  
Oxidosqualene Cyclase ◽  
Siraitia Grosvenorii ◽  
Initial Substrate ◽  
New Strategy ◽  
Key Residues

Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during the initial substrate preorganization step, oxidosqualene cyclases (OSCs) are roughly segregated into a dammarenyl cation group that predominantly catalyzes triterpenoid precursor products and a protosteryl cation group which mostly generates sterol precursor products. The mechanism of conversion between two scaffolds is not well understood. Previously, we have characterized a promiscuous OSC from Siraitia grosvenorii (SgCS) that synthesizes a novel cucurbitane-type triterpene cucurbitadienol as its main product. By integration of homology modeling, molecular docking and site-directed mutagenesis, we discover that five key amino acid residues (Asp486, Cys487, Cys565, Tyr535, and His260) may be responsible for interconversions between chair–boat–chair and chair–chair–chair conformations. The discovery of euphol, dihydrolanosterol, dihydroxyeuphol and tirucallenol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into cucurbitane-type and lanostane-type skeletons, and provide a new strategy to identify key residues determining OSC specificity.

scholarly journals Differential Expression of Three Oxidosqualene Cyclase mRNAs in Glycyrrhiza glabra

2004 ◽  
Vol 27 (7) ◽  
pp. 1086-1092 ◽  
Author(s):  
Hiroaki Hayashi ◽  
Pengyu Huang ◽  
Satoko Takada ◽  
Megumi Obinata ◽  
Kenichiro Inoue ◽  
...  
Keyword(s):  
Differential Expression ◽  
Glycyrrhiza Glabra ◽  
Oxidosqualene Cyclase
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