125638-34-8Relevant academic research and scientific papers
Lignans and neolignans from Sinocalamus affinis and their absolute configurations
Xiong, Liang,Zhu, Chenggeng,Li, Yanru,Tian, Ye,Lin, Sheng,Yuan, Shaopeng,Hu, Jinfeng,Hou, Qi,Chen, Naihong,Yang, Yongchun,Shi, Jiangong
, p. 1188 - 1200 (2011)
Twenty-two new lignans and neolignans (1-22), together with 14 known analogues, have been isolated from an ethanolic extract of the stem (with skin removed) of Sinocalamus affinis. Their structures were elucidated by spectroscopic and chemical methods. On the basis of systematic NMR and circular dichroism (CD) data analysis, the validity of J7,8 and ΔδC8-C7 values to distinguish threo and erythro aryl glycerol units in different neolignans and the CD data [particularly the Rh 2(OCOCF3)4-induced CD data (the E band)] to determine the absolute configurations at C-8 (C-7) of the aryl glycerol units are discussed. At a concentration of 10 μM, compounds 20 and 22 inhibited NO production in mouse peritoneal macrophages 84.2 ± 5.9% and 71.7 ± 1.0%, respectively. Compounds 19, 20, and 22 showed activity against serum deprivation induced PC12 cell damage by increasing the cell viability from 80.7 ± 2.8% to 91.6 ± 6.4%, 107.2 ± 8.0%, and 97.6 ± 8.5%, respectively. (Chemical Equation Presented).
Dirigent Proteins Guide Asymmetric Heterocoupling for the Synthesis of Complex Natural Product Analogues
Kim, Stacie S.,Sattely, Elizabeth S.
, p. 5011 - 5021 (2021/05/04)
Phenylpropanoids are a class of abundant building blocks found in plants and derived from phenylalanine and tyrosine. Phenylpropanoid polymerization leads to the second most abundant biopolymer lignin while stereo- and site-selective coupling generates an array of lignan natural products with potent biological activity, including the topoisomerase inhibitor and chemotherapeutic etoposide. A key step in etoposide biosynthesis involves a plant dirigent protein that promotes selective dimerization of coniferyl alcohol, a common phenylpropanoid, to form (+)-pinoresinol, a critical C2 symmetric pathway intermediate. Despite the power of this coupling reaction for the elegant and rapid assembly of the etoposide scaffold, dirigent proteins have not been utilized to generate other complex lignan natural products. Here, we demonstrate that dirigent proteins from Podophyllum hexandrum in combination with a laccase guide the heterocoupling of natural and synthetic coniferyl alcohol analogues for the enantioselective synthesis of pinoresinol analogues. This route for complexity generation is remarkably direct and efficient: three new bonds and four stereocenters are produced from two different achiral monomers in a single step. We anticipate our results will enable biocatalytic routes to difficult-to-access non-natural lignan analogues and etoposide derivatives. Furthermore, these dirigent protein and laccase-promoted reactions of coniferyl alcohol analogues represent new regio- and enantioselective oxidative heterocouplings for which no other chemical methods have been reported.
Pinoresinol-lariciresinol reductase: Substrate versatility, enantiospecificity, and kinetic properties
Davin, Laurence B.,Hwang, Julianne K.,Lewis, Norman G.,Moinuddin, Syed G. A.
, (2020/03/26)
Two western red cedar pinoresinol-lariciresinol reductase (PLR) homologues were studied to determine their enantioselective, substrate versatility, and kinetic properties. PLRs are downstream of dirigent protein engendered, coniferyl alcohol derived, stereoselective coupling to afford entry into the 8- and 8′-linked furofuran lignan, pinoresinol. Our investigations showed that each PLR homolog can enantiospecifically metabolize different furofuran lignans with modified aromatic ring substituents, but where phenolic groups at both C4/C4′ are essential for catalysis. These results are consistent with quinone methide intermediate formation in the PLR active site. Site-directed mutagenesis and kinetic measurements provided additional insight into factors affecting enantioselectivity and kinetic properties. From these data, PLRs can be envisaged to allow for the biotechnological potential of generation of various lignan skeleta, that could be differentially “decorated” on their aromatic ring substituents, via the action of upstream dirigent proteins.
New lignans from the aerial parts of Rudbeckia laciniata
Lee, Seung Young,Woo, Kyeong Wan,Kim, Chung Sub,Lee, Dong Ung,Lee, Kang Ro
, p. 320 - 325 (2013/03/28)
Three new furofuran lignans, (+)-4,4′-O-diangeloylpinoresinol (1), (+)-4,4′-O-diangeloylmedioresinol (2), and (+)-4,4′-O- diangeloylsyringaresinol (3), together with the known compound (+)-syringaresinol, were isolated from the MeOH extract of Rudbeckia l
The Constituents of Eucommia ulmoides OLIV. I. Isolation of (+)-Medioresinol Di-O-β-D-glucopyranoside
Deyama, Takeshi
, p. 2993 - 2997 (2007/10/02)
A new lignan diglycoside was isolated from the bark of Eucommia ulmoides OLIV. (Eucommiaceae) and its structure was established as (+)-medioresinol di-O-β-D-glucopyranoside (1) by means of chemical and spectral studies. (+)-Pinoresinol di-O-β-D-glucopyranoside (2),liriodendrin (3) and (+)-pinoresinol O-β-D-glucopyranoside (4) were also isolated.Keywords - Eucommia ulmoides; lignan; (+)-medioresinol di-O-β-D-glucoside; (+)-pinoresinol di-O-β-D-glucoside; (+)-pinoresinol O-β-D-glucoside; liriodendrin; (13)C-NMR
