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JB Mc Alpine

Bio: JB Mc Alpine is an academic researcher. The author has contributed to research in topics: Nitration & Methyl group. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.

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TL;DR: The α,α?-diaryl-β, β,β-dimethyltetrahydrofurenoid lignan, calopiptin, from Piptocalyx moorei has been converted by demethylenation and methylation into veraguensin, now also isolated from Trimenia papuana (both species, family Trimeniaceae) as mentioned in this paper.
Abstract: The α,α?-diaryl-β,β-dimethyltetrahydrofurenoid lignan, calopiptin, from Piptocalyx moorei has been converted by demethylenation and methylation into veraguensin, now also isolated from Trimenia papuana (both species, family Trimeniaceae). Ozonolysis yields (-)-2,3-dimethylsuocinic acid which establishes the absolute trans configuration of the methyl groups. The benzylic proton giving a signal at low field from the other in the p.m.r, spectrum is assigned as trans to the adjacent methyl group by shielding and spin-decoupling arguments. The signal moves to even lower field on nitration of one of the aryl groups, identified as 3,4-dimethoxyphenyl by competitive nitration experiments and high-resolution mass spectrometry. Calopiptin is 2R-(3,4-dimethoxyphenyl)-3S,4S-dimethyl-5S-(3,4-methylenedioxyphenyl)tetrahydrofuran.

14 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, five new lignans, machilin A[(2S, 3R)-2,3-dimethyl-1,4-dipiperonyl-butane], Machilin B [2S 3S]-2, 3-dihydro-7methoxy-3-methyl-2-piperon threo-2-(2-methoxide-4-trans-propenylphenoxy)-1-(4-hydroxy-3methoxyphenyl)propan-

70 citations

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TL;DR: A review of lignans and neolignans currently known in the Piperaceae can be found in this paper, where the authors summarize the structures and properties of these genera.

38 citations

Journal ArticleDOI
TL;DR: Aristolochia chilensis has yielded the new 2,5-diaryl-3,4-dimethyltetrahydrofuranoid lignans (+)-aristolignin and (−)-zuonin-A, which are classified into six stereochemical groups.

37 citations

Journal ArticleDOI
TL;DR: In this paper, 2,6-Diaryl and 3,7-dioxabicyclo[3,3,0] octan-8-one structures are assigned to two lignans isolated from Aegilops ovata L., by comparing their spectroscopic data to a synthetically prepared novel 2,4-and 2, 6-diaryl monoepoxylignanolide.

31 citations

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TL;DR: All compounds exhibited growth inhibition activity against larvae of the insect Spodoptera litura and a possible synergistic action of these compounds with other M. japonica components is discussed.

30 citations