10061-38-8Relevant articles and documents
Sesquiterpenoids, phenolic and lignan glycosides from the roots and rhizomes of Clematis hexapetala Pall. and their bioactivities
Cai, Lu,Han, Shao-Wei,Li, Shuai,Shao, Si-Yuan
, (2020)
Approximately 17 compounds were isolated from a 60% EtOH aqueous extract of the roots and rhizomes of Clematis hexapetala Pall., including three new guaianolide sesquiterpenoids with 5/7/5-fused rings and 3S-configuration (1–3), five new prenylated tetra-substituted phenolic glycosides (4–8) with 6/6-fused 9H-benzopyran skeleton (5) and 6/7-fused 7,10-dihydro-benzoxepin skeleton (6–8), one new isoferulyl glucoside (9), two new furofuran lignan diglucosides (10–11), and six known compounds. The chemical structures of the new compounds were elucidated via spectroscopic data and electronic circular dichroism (ECD) analyses in combination with a modified Mosher's method. The possible biosynthetic relationships of prenylated tetra-substituted phenols were postulated. In the in vitro assays, compound 16 exhibited moderate TNF-α secretion inhibitory activity with IC50 value of 3.419 μM. Compounds 14–16 displayed potent PTP1B enzymatic inhibitory activities with inhibition ratios of 48.30–86.00%. And compound 16 showed significant PTP1B enzymatic inhibition with IC50 value of 4.623 μM.
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)
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
Hitherto unrecognized fluorescence properties of coniferyl alcohol
Achyuthan, Komandoor Elayavalli,Adams, Paul David,Datta, Supratim,Simmons, Blake Alexander,Singh, Anup Kumar
, p. 1645 - 1667 (2010)
We instituted a quasi-quality assurance program for demonstrating coniferyl alcohol's fluorescence and fluorescence diminishment following enzymatic oxidation. The magnitude of diminishment was a measure of catalysis. High throughput screening was performed in pseudo-kinetic and endpoint modes by measuring the fluorescence at 416 nm following excitation at 290, 310 or 340 nm. Dose-response tracings were linear between two and three orders of magnitude with average limits of detection and quantitation of 1.8 and 6.9 μM coniferyl alcohol, respectively. Oxidation was evident with 0.025 μg/mL laccase or 0.003 μg/mL peroxidase or inside 5 min using 0.5 μg/mL laccase or 5 μM substrate. Sodium chloride inhibited (IC50, 25 mM) laccase oxidation of coniferyl alcohol. Fluorescence from 10 concentrations (1 to 1000 μM) of coniferyl alcohol was stable for 24 hours over 14 excitation/emission cycles at 3 different combinations of excitation and emission wavelengths. In conclusion, coniferyl alcohol absorption and fluorescence assays should facilitate biomass lignin analyses and improve delignification.
An Efficient Method for Determining the Relative Configuration of Furofuran Lignans by 1H NMR Spectroscopy
Shao, Si-Yuan,Yang, Ya-Nan,Feng, Zi-Ming,Jiang, Jian-Shuang,Zhang, Pei-Cheng
, p. 1023 - 1028 (2018)
An efficient 1H NMR spectroscopic approach for determining the relative configurations of lignans with a 7,9′:7′,9-diepoxy moiety has been established. Using the chemical shift differences of H2-9 and H2-9′ (ΔδH-9 and ΔδH-9′), the configurations of 8-H and 8-OH furofuran lignans can be rapidly and conveniently determined. The rule is applicable for data acquired in DMSO-d6, methanol-d4, or CDCl3. Notably, the rule should be applied carefully when the C-2 or C-6 substituent of the aromatic rings may alter the dominant conformers of the furofuran moiety.
NOVEL BENZYLIC ETHER REDUCTIONS IN LIGNAN BIOGENESIS IN FORSYTHIA INTERMEDIA
Katayama, Takeshi,Davin, Laurence B.,Chu, Alex,Lewis, Norman G.
, p. 581 - 592 (1993)
Forsythia intermedia cell-free preparations catalyse the stepwise conversion of pinoresinol into secoisolariciresinol via lariciresinol; to our knowledge, this represents the first documented example of the reduction of benzylic ethers (or their quinone methide analogues) in plants.In this study, the specifity of the reductive steps was established: with (+)- and (-)-pinoresinols as substrates, it was found that their overall conversion into lariciresinol was highly enantioselective (i.e > 99:1 in favour of the (+)-antipode), whereas (-)-secoisolariciresinol formation was more strictly enantioselective with only reduction of (+)-lariciresinol being observed.Under the conditions examined to date, it was not possible to demonstrate the NADP-dependent back reaction using (+/-)-lariciresinols as substrates.Interestingly, neither (+)- nor (-)-epipinoresinols underwent similar reduction to afford lariciresinol, epilariciresinol or secoisolariciresinol. Key Word Index - Forsythia; Oleaceae; biosynthesi; oxidoreductase; stereoselectivity; enantiospectifity; coniferyl alchols; lignans; lariciresinol; pinoresinol; secoisolaricireinol; epipinoresinol; quinone methide.
Dirigent Proteins Guide Asymmetric Heterocoupling for the Synthesis of Complex Natural Product Analogues
Kim, Stacie S.,Sattely, Elizabeth S.
supporting information, 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.
