A Benzofuranoid Neolignan from Magnolia biondii Pamp

Aim Isolation and structural elucidation of the constituents from the dried flower buds of Magnolia biondii Pamp. Methods Column chromatography and TLC were used to isolate chemical constituents. Spectroscopic methods were employed for structural elucidation. Results One benzo furanoid neolignan （licarin B） and two bisepoxy lignans （magnolin, fargesin） were isolated and identified. Conclusion Licarin B is the first reported benzofuranoid lignan from the family Magnoliaceae.

A new 8-O-4′-type neolignan from Ligularia narynensis

A new 8-O-4′-type neolignan named narynenol （1） was isolated from the roots of Ligularia narynensis. Its structure and the relative configurations were confirmed by spectroscopic data interpretation. 2007 Zhong Jian Jia. Published by Elsevier B.V. on behalf of Chinese Chemical Society, All rights reserved.

Symplocosionosides A-C, Three Megastigmane Glycosides, a Neolignan Glucoside, and Symplocosins A and B, Two Triterpene Glycosyl Esters from the Leaves of <i>Symplocos cochinchinensis</i>var. <i>Philippinensis</i>

From the 1-BuOH-soluble fraction of a MeOH extract of the leaves of Symplocos cochinchinensis var. philippinensis, 12 compounds were isolated. Spectroscopic analyses of compounds 1 - 3 established their structures to be megastig-mane glycosides, named symplocosionosides A-C. The absolute structure of 1 was determined by the modified Mosher’s method. Compound 4 was found to be a neolignan glucoside and named symplocosneolignan. The structures of com-pounds 5 and 6, named symplocosins A and B, were elucidated to be the saponins of hederagenin sugar esters. The structures of the remaining known compounds (7 - 12) were identified by comparison of spectroscopic data with those reported in the literature.

A New Neolignan Glycoside from Pedicularis armata

A new neolignan glycoside named armaoside (1) was isolated from the whole plant of Pedicularis armata Maxim. Its structure was elucidated by spectroscopic and chemical methods. Antibacterial assay showed that it has moderately antibacterial activities against Eschecichia coli, Bacillus subtilis and Staphylococcus aureus.

Two New Neolignan Glucosides from Pedicularis Verticillata

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A NOVEL NEOLIGNAN, BIONDININ A, FROM MAGNOLIA BIONDII PAMP

A novel neolignan, biondinin A, was isolated from the flower buds of Magnolia biondii Pamp. The structure was established as 3,3',4'- trimethoxy-4,9'-dihydroxy-6.8',9-O-7'-neolignan. It is the first reported neolignan possessing the skeleton of benzo-oxa-cyclooctane.

Neolignan glycoside from Angelica dahurica

A new neolignan glycoside, 4-O-β-d-glucopyranosyl-9-O-β-d-glucopyranosyl-(7R,8S)-dehydrodiconiferyl alcohol was isolated from the fresh roots of Angelica dahurica. The structure of the new compound was elucidated on the basis of spectral analysis.

TWO NEW NEOLIGNANS FROM MESSERSCHMIDIA SIBIRICA L.SSP.

From the aerial parts of Messerschmidia sibirica L.ssp.,two new neolignans were isolated and elucidated as messerschmidin and its acetate.

First Total Synthesis of Four Benzodioxane Neolignans

Four 1,4-benzodioxane neolignans were first synthesized from pyrogallol, in which the Claisen rearrangement was used to afford three important C-6-C-3 units.

A Novel Stereoselective Synthesis of 8-O-4' Neolignans

1-(4-hydroxy-3-methoxyphenyl)-2-(4-formyl-2-methoxyphenoxy)-propane-1,3-diol. A 8-O-4' neolignan, has been stereoselectively synthesized in eight steps from ferulic acid, and the directly cis opening of epoxide in eposidation and Mitsunobu reaction were used ingeniously as two key steps with high stereoselectively.

BICYCLOOCTANOID NEOLIGNANS FROM PIPER KADSURA

Three new bicyclooctanoid neolignans, kadsurenin A, kadsurenin B and kadsurenin C were isolated from Piper kadsura (Choisy) Ohwi. Based on the spectroscopic analysis (UV, JR, MS, NMR, and X-ray), their structures were established as 7R, 8R, 3'S, 4'R, 5'R-△^(s')-3,4-methyienedioxy-5'-methoxy-4'-acetyloxy-2',3',4',5'-tetrahydro-2'-oxo-7.3',8.5'-neolignan; 7R, 8R, 3'S, 4'R, 5'R-△^(s')-3, 4-methylenedioxy-5'-methoxy-4'-hydroxy-2',3',4',5'-tetrahydro-2'-oxo-7. 3', 8. 5'-neolignan and 7R, 8R. 3'S, 4'R, 5'R-△^(s')-3, 4, 5'-trimethoxy-4'-hydroxy- 2', 3', 4', 5'-tetrahydro-2'-oxo-7. 3', 8. 5'-neolignan respectively.

Two new neolignans from Manglietia insignis

Two new neolignans,manneoinsigins A(1)and B(2),together with four known lignans,were isolated from the leaves and stems of Manglietia insignis.The new compounds were established on the basis of extensive spectroscopic analyses.All compounds except 2 were tested for their cytotoxic activity.Compound 3 showed weak cytotoxic activity against the HL-60 human tumor cell line with the IC50 value of 23.5μM.

NEOLIGNANS FROM PIPER KADSURA

Two new neolignans, Kadsuranin G and Kadsuranin H, were isolated from Piper Kadsura (Choisy) Ohwi. Baaed on the spectroscopic analysis (UV, IR, MS, NNR, and X-ray) and chemical reactions, their structures were established as 7R,BR,1'S,2'R,3'5-△^(8')-3,4,5'-trimethoxy-2'-hydroxy-1',2',3',4'-tetrahydro-4'-oxo-7,3',8,1'-neolignan and 7R,8R,1'S,2'R,3'S-△^(8')-3,4,5'-trimethoxy-2'-acetyloxy-1',2',3',4'-tetrahydro-4'-oxo-7,3',8,1'-neolignan.

NEOLIGNANS FROM PIPER KADSURA(Ⅱ)

Two new bicyclo[3,2,1]octanoid neolignans,named as kadsurenin I and kadsurenin J were isolated from Piper kadsura(Choiey)Ohwi.Based on the spectros- copic analysis(UV,IR,MS and NMR)and chemical derivatization,their structures were established as 7R,8R,1'R,2'S,3'R-Δ~s'-3,4,5'-trimethoxy-2'-hydroxy-1',2',3',4'- tetrahydro-4'-oxo-7.3',8.1'-neolignan and 7R,8R,1'R,2'S,3'R-Δ~s'-3,4,5'-trimethoxy -2'-acetoxy-1',2',3',4'-tetrabydro-4'-oxo-7.3',8.1'-neolignan respectively.

Synthesis of (±)-Demethylnitidanin, Herpetol and Salvinal as well as Their Glycosyl Derivatives

Three neolignans, （±）-demethylnitidanin（1）, herpetol（2） and salvinal（3） were synthesized from methyl 4,5-dihydroxy-3-methoxy cinnamate or methyl 4-hydroxy-3-methoxy cinnamate with Ag2O-catalyzed biomimetic oxidative coupling as the key step of the synthetic route. Five novel benzofuran neolignan-4＇-O-β-D-glycosides（4―8） were achieved by the glycosylation reactions of benzofuran neolignans 2, 3 and 15. The structures of all the compounds synthesized were determined by MS, 1H NMR and IR spectra. （±）-Demethylnitidanin（1） and herpetol（2） were the first synthesized and the synthesis of salvinal（3） was efficiently improved by the new synthetic routes.

First Enantioselective Synthesis of Isoamericanol A and Isoamericanin A

The first enantioselective synthesis approach to two chiral 1,4-benzodioxane neolignans isoamericanol A and isoamericanin A was reported.

Synthesis of 2-aryl-5-alkyl-7-methoxylbenzo[b]furan derivatives

A series of 2-aryl-5-alkyl-7-methoxylbenzo[b]furan derivatives have been synthesized by utilizing the coupling of methyl 3- methoxy-4hydroxy-5-bromocinnamate with cuprous phenylacetylide as the key step. The structures of the new compounds were confirmed by 1H NMR, IR and MS. The structure of compound 14 was further confirmed by single crystal X-ray. Compound 17 showed cytotoxic activity against human lung carcinoma A549.

Novel Neolignan from Penthorum chinense

A new neolignan （7＇E）-2＇,4,8-trihydroxy-3-methoxy-2,4＇-epoxy-8,5＇-neolign-7＇-en-7-one （1） was isolated from the whole plants of Penthorum chinense Pursh, along with Iupeol （2）, betulinic acid （3）, glyceryl monopalmitate （4）, β-sitosterol （5）, palmitic acid （5）, ursolic acid （7）, 2β,3β,23-trihydroxy-urs-12-ene-28-oic acid （8）, glyceryl monolaurate （9）, scopoletin （10）, （-）syringaresinol （11）, 9,9＇-O-diferuIoyl-（-）-secoisolariciresionl （12）, pinocembrin （13）, apigenin （14）, kaempferol （15）, Iuteolin （16）, β-daucosterol （17）, quercetin （18）, 1-O-（β-D-glucopyranosyl）-（2S, 2＇R, 3R,4E,8E）-2-（2＇-hydroxyhexadecanoy- lamino）-4,8-octdecadiene-1,3-diol （19）, gallic acid （20）, pinocembrin-7-O-β-D-glucoside （21）, and quercetin-3-O-β-D- glucoside （22）. The structures of these compounds were elucidated on the basis of chemical and spectral evidence.

Codonopiloneolignanin A, a polycyclic neolignan with a new carbon skeleton from the roots of Codonopsis pilosula

A neolignan codonopiloneolignanin A（1） with a novel 2,9：20,9：7,70-tricyclo-8,90-neolignane skeleton was isolated from an aqueous extract of the Codonopsis pilosula roots. Its structure including the absolute configuration was elucidated by extensive spectroscopic analysis, including 2D NMR and electronic circular dichroism calculation. The proposed biosynthetic pathway of compound 1 is also discussed.

(+)-/(-)-Angelignanine,a pair of neolignan enantiomers with an unprecedented carbon skeleton from an aqueous extract of the Angelica sinensis root head

A pair of neolig nan enan tiomers with an unprecedented carb on skelet on,(+)-/(-)-angeligna nine[(+)-/(-)-1].was isolated as minor components of an aqueous extract of the Angelica sinensis root heads(guitou).Their structures were determined by spectroscopic data analysis and the absolute configurations were assigned by the circular dichroism(CD)exciton chirality method as well as electronic CD quantum calculations.The enantiomers represent the first 2,7/-cyclo-8,9z-neolignans,of which biosynthetic pathways originating from precursors ferulic acid and coniferyl alcohol is proposed.In an in vivo test,both the enantiomers showed significant hypnotic effects at a dose of 10 mg/kg(i.g.).