24563-03-9Relevant articles and documents
Two glycosides from the stem bark of Tetracentron sinense
Yi, Jin-Hai,Zhang, Guo-Lin,Li, Bo-Gang,Chen, Yao-Zu
, p. 1001 - 1003 (2000)
Two glycosides, tetracentronsides A and B, were isolated from the stem bark of Tetracentron sinense Oliv., along with ten known compounds, β- sitosterol, lupeol, betulinic acid, oleanolic acid, vanillic aldehyde, vanillic acid, maslinic acid, huazhongilexin, daucosterol and catechin. On the basis of spectral and chemical evidence, tetracentronside A and B were identified as 3,4,5-trimethoxyphenyl-O-6'-O-vanilloyl-β-D-glucopyranoside and (8R, 8'R) 9-β-D-glucopyranosyl dihydrocubebin, respectively. (C) 2000 Elsevier Science Ltd.
Lignans from the fruit of Schisandra glaucescens with antioxidant and neuroprotective properties
Yu, Heng-Yi,Chen, Zu-Yu,Sun, Bin,Liu, Junjun,Meng, Fan-Yu,Liu, Ye,Tian, Tian,Jin, An,Ruan, Han-Li
, p. 1311 - 1320 (2014)
Two rare 7,8-seco-lignans (1, 2), three new lignan glycosides (3, 4a, 4b), and 10 known lignans (5-14) were isolated from the fruit of Schisandra glaucescens Diels. The absolute configurations of 1 and 2 were determined by comparing their experimental and calculated electronic circular dichroism spectra. The molecular structures of the new compounds (3, 4a, and 4b), including their absolute configurations, were determined using various spectroscopic methods and hydrolysis reactions. The antioxidant activities of the isolated compounds were tested using 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. Compounds 4, 7, 8, 10, 11, and 12 exhibited antioxidant activities of varying potential in both assays. Of these compounds, 7 showed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, with IC50 values of 15.7 (150 μM DPPH) and 34.6 μM (300 μM DPPH), respectively, and 4, 12, and 7 displayed higher total antioxidant activities than Trolox in the ferric reducing antioxidant power assay. The neuroprotective effects of these compounds against Aβ25-35-induced cell death in SH-SY5Y cells were also investigated. Compounds 1, 2, 6, 7, 8, 11, and 12 exhibited statistically significant neuroprotective effects against Aβ25-35-induced SH-SY5Y cell death compared with the group treated only with Aβ25-35.
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.
REDUCTION OF C-0 BONDS BY CATALYTIC TRANSFER HYDROGENOLYSIS
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Page/Page column 15-16, (2012/09/22)
The present invention relates to a method of reducing a C-O bond to the corresponding C-H bond in a substrate which could be a benzylic alcohol, allylic alcohol, ester,or ether or an ether bond beta to a hydroxyl group or alpha to a carbonyl group.
Synthesis and bioactivity of erythro-nordihydroguaiaretic acid, threo-(-)-saururenin and their analogues
Xia, Yamu,Zhang, Yuanyuan,Wang, Wei,Ding, Yining,He, Rui
, p. 1325 - 1335 (2011/09/12)
Full details of the total syntheses of erythro-nordihydroguaiaretic acid, threo-(-)-saururenin and their analogues are presented. The syntheses were based on a unified synthetic strategy involving the Stobbe reaction, alkylation to construct the skeleton
Synthesis, anti-virus and anti-tumour activities of dibenzylbutyrolactone lignans and their analogues
Xia, Yamu,You, Jia,Zhang, Yuanyuan,Su, Zhongliang
experimental part, p. 565 - 569 (2010/03/03)
An efficient synthesis of dibenzylbutyrolactone lignans and their analogues has been developed. Based on a Stobbe condensation of piperonal or veratraldehyde with diethylsuccinate and alkylation with 3,4- methylenedioxybenzyl bromide to give the skeleton
Lipase-catalyzed esterification of a (±)-2,3-di(arylmethyl)-1,4- butanediol and its application to the synthesis of (S,S)-(+)-hinokinin
Morimoto, Toshiaki,Nagai, Hazuki,Achiwa, Kazuo
, p. 857 - 865 (2007/10/03)
Racemic trans-2,3-di[(3,4-methylenedioxy)benzyl]-1,4-butanediol (dihydrocubebin) 6 was enantioselectively esterified using lipases as catalysts with vinyl acetate. Optically active (S,S)-1,4-butanediol 6 obtained was selectively oxygenated with a Fetizon reagent, affording (S,S)-(+)-hinokinin 9 in a high yield.
Oxidative Homocoupling of Chiral 3-Arylpropanoic Acid Derivatives. Application to Asymmetric Synthesis of Lignans
Kise, Naoki,Ueda, Takako,Kumada, Kimikage,Terao, Yuichi,Ueda, Nasuo
, p. 464 - 468 (2007/10/03)
The oxidative homocouplings of lithium enolates of (4S)-3-(3-arylpropanoyl)-4-isopropyl-2-oxazolidinones and (4R,5S)-1-(3-arylpropanoyl)-3,4-dimethyl-5-phenyl-2-imidazolidinones gave the corresponding R,R-dimers stereoselectively with TiCl4, Ph
LIGNANDS FROM NECTANDRA TURBACENSIS
Carvalho, Mario G. De,Yoshida, Massayoshi,Gottlieb, Otto R.,Gottlieb Hugo E.
, p. 265 - 268 (2007/10/02)
Bark and wood of Nectanandra turbacensis (Lauraceae) contain, besides the known furofuran lignands (+)-sesamin, (+)-demethoxyexcelsin and (+)-piperitol, the novel (1R,5R,2S,6S)-2-(3'-methoxy-4',5'-methylenedioxyphenyl)-6-(4"-hydroxy-3"-methoxyphenyl)-3,7-dioxabicyclooctane and (1R,2S,5R)-2-(3'-methoxy-4',5'-methylenedioxyphenyl)-3,7-dioxa-6-oxobicyclooctane. Key Word Index--Nectandra turbacensis; Lauraceae; furofuran lignands; 2-aryl-3,7-dioxa-6-oxobicyclooctane