Thomas Popoff

Formation of Aromatic Compounds from Carbohydrates : Part 1. Reaction of d-glucuronic Acid, d-glacturonic Acid, d-xylose, and l-arabinose in slightly acidic, aqueous solution

Abstract The reaction of d -glucuronic acid in aqueous solutions of pH 3.5 and 4.5 at 96° yielded 2-furaidehyde ( 1 ), 2-furoic acid ( 12 ), 2,3-dihydroxy-2-cyclopentcn-l -one (reductic acid) ( 2 ), 1,2-dihydroxybenzene ( 7 ), 1,2,3-trihydroxybenzene ( 8 ), 2,3-dihydroxytoluene ( 10 ), 2,3-dihydroxybenzoic acid ( 9 ), 2,3-dihydroxyacetophenone ( 11 ), 3,8-dihydroxy-2-methylchromo.le ( 3 ), 5,6,7,8-tetrahydro-3,5-dihydroxy-2-methyl-8oxobenzopyrone ( 4 ), and 3-acetyl-l-oxocyclohexane-2,3,6-trioI ( 18 ). The last two compounds were shown to be precursors of 3 and 11 , respectively. Two compounds of formula C 10 H 8 O 5 , ( 5, bd6 ) were also isolated. From the reaction of d -galacturonic acid at pH 4.5, most of the above compounds were isolated, but in lower yields, and from d -xylose, compounds 1,3,4,6, 10, 11 , and C 10 H 8 O 4 were obtained. l -Arabinose yielded the same main components as d -xylose (except for the absence of 6 ) but in lower yields.*Dedicated to Professor M. Stacey, C.B.E., F.R.S., in honour of his 65th birthday.

Reactions of D-xylose and D-glucose in alkaline, aqueous solutions☆

Abstract Treatment of D -xylose and D -glucose with 0.63 M sodium hydroxide at 96° in an atmosphere of nitrogen yielded, in addition to acidic, aliphatic degradation-products, the following cyclic enols and phenolic compounds: 2-hydroxy-3-methyl-2-cyclopenten-1-one ( 1 ), 2-hydroxy-3,4-dimethyl-2-cyclopenten-1-one ( 2 ), pyrocatechol ( 3 ), 3-methyl-1,2-benzenediol ( 4 ), 4-methyl-1,2-benzenediol ( 5 ), 3,4-di-methyl-1,2-benzenediol ( 6 ), 2-methyl-1,4-benzenediol ( 7 ), 2,5-dihydroxyacetophe-none ( 8 ), 3-hydroxy-5-methylacetophenone ( 9 ), 3,4-dihydroxyacetophenone ( 10 ), 3,4-hydroxybenzaldehyde ( 11 ), 2,3,4-trihydroxy-5-methylacetophenone ( 12 ), and 2,3-dihydroxy-6-methylacetophenone ( 13 ).

Dilignol glycosides from needles of Picea abies

Abstract (2R,3R)-2 3-Dihydro-2-(4′-hydroxy-3′-methoxyphenyl)-3-(hydroxymethyl)-7-methoxy-5-benzofuranpropanol 4′-O-β- d -glucopyranoside [dihydrodehydrodiconiferyl alcohol glucoside], (2R,3R)-2 3-dihydro-7-hydroxy-2-(4′-hydroxy-3′-methoxyphenyl)-3-(hydroxymethyl)-5-benzofuranpropanol 4′-O-β- d -glucopyranoside and 4′-O-α- l -rhamnopyranoside, 1-(4′-hydroxy-3′-methoxyphenyl)-2- [2″-hydroxy-4″-(3-hydroxypropyl)phenoxy]-1, 3-propanediol 1-O-β- d -glucopyranoside and 4′-O-β- d -xylopyranoside, 2,3-bis[(4′-hydroxy-3′-methoxyphenyl)-methyl]-1,4-butanediol 1-O-β- d -glucopyranoside [(−)-seco-isolariciresinol glucoside] and (1R,2S,3S)-1,2,3,4-tetrahydro-7-hydroxy-1-(4′-hydroxy-3′-methoxyphenyl)-6-methoxy-2 3-naphthalenedimethanol α2-O-β- d -xylopyranoside [(−)-isolariciresinol xyloside] have been isolated from needles of Picea abies and identified.

Two glycosides of a new dilignol from Pinus silvestris

Abstract The 4′- O -β- d -glucopyranoside and the 4′- O -α- l -rhamnopyranoside of 2,3-dihydro-7-hydroxy-2-(4′-hydroxy-3′- methoxyphenyl)-3-hydroxymethyl-5-benzofuranpropanol have been isolated and identified. Also isolated were two d -glucosides and an l -arabinoside of (+)-isolariciresinol and a l -rhamnoside, a d -xyloside and a d -glucoside of 1-(4-hydroxy-3-methoxyphenyl)- 2-[4-(3-hydroxypropyl)-2-hydroxyphenoxy]-1,3-propanediol.

Stimulation of litter-decomposing basidiomycetes by flavonoids.

The stimulating effect of extractives from pine needles on the growth of litter-decomposing basidiomycetes in synthetic nutrient nedia was partly due to 2-butanone soluble components. Taxifolin glucoside (dihydroquercetin-3′-β-glucoside) which constitutes 1–2% of the dry weight of the needles was separated and in pure form, significantly enhanced the growth rate of Marasmius androsaceus at a concentration of 5 p.p.m. Other flavonoids, belonging to the catechins, dihydrochalcones, flavanones, flavonols, and anthocyanidins, as well as gallic acid, had a similar effect. Collybia peronata and Micromphale perforons which like M. androsaceus are needle-decomposing fungi, were also stimulated by taxifolin glucoside.

Formation of aromatic compounds from D-glucuronic acid and D-xylose under slightly acidic conditions

1,2-Dihydroxybenzene, 2,3-dihydroxytoluene, 2,3-dihydroxybenzoic acid, 2,3-hydroxyacetophenone, 3,8-dihydroxy-2-methylchromone (I), and its precursor 6,7,8,8a-tetrahydro-3,8a-dihydroxy-2-methyl-8-oxobenzopyrone (II) were obtained by reaction of D-glucuronic acid in slightly acidic aqueous solution (the last three products also from D-xylose).