Two new C-methylated flavonoids from Myrica gale

From the leaves of Myrica gale 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone has been isolated. The fruits yielded 2′-hydroxy-4′,6′-dimethoxy-3′-methyldihydrochalcone. The constitutions were deduced from spectroscopic data and confirmed by synthesis.     

Xanthones from Tovomita pyrifolium

The wood of Tovomita pyrifolium (Guttiferae) contains the novel tovopyrifolins A [1,6-dihydroxy-7-methoxy-5-prenyl-6′,6′-dimethylpyrano (2′,3′:3,2)xanthone], B (1,5-dihydroxy-3,4-dimethoxyxanthone) and C (1,3,5-trihydroxy-2-methoxyxanthone) and also the known tovophyllins A and B [structure revised to 1,6-dihydroxy-5-prenyl-6′, 6′-dimethylpyrano(2′,3′:3,2)-6″,6″-dimethylpyrano(2″,3″:7,8)xanthone].     

Neolignans from Nectandra miranda

Seven neolignans, isolated from a C₆H₆ extract of Nectandra miranda (Lauraceae) trunk wood, included the hitherto undescribed (2S, 3S, 3aS)- and (2S, 3S, 3aR)-5-allyl-3a-methoxy-2-(3′, 4′, 5′-trimethoxyphenyl)-3-methyl-2, 3, 3a, 6-tetrahydro-6-oxobenzofurans (respectively mirandin-A and mirandin -B), 7-allyl-6-hydroxy-5-methoxy-2-(3′, 4′, 5′-trimethoxyphenyl)-3-methylbenzofuran and (2R, 3R)-7-methoxy-2-(3′, 4′, 5′-trimethoxyphenyl)-3-methyl-5 -(E)-propenyl-2, 3-dihydrobenzofuran (licarin C).     

Dihydrochalcones from lindera umbellata

Two dihydrochalcones, 2′,6′-dihydroxy-4′-methoxydihydrochalcone and 2,4′,6′-trihydroxydihydrochalcone have been isolated from leaves of Lindera umbellata.     

Flavonoids from the exudate of Acacia neovernicosa

2′,4′-Dihydroxychalcone, 4′-hydroxy-2′-methoxychalcone and 2′,4′-dihydroxy-3′-methoxychalcone were isolated and characterized from the resinous exudate produced by Acacia neovernicosa. Smaller amounts of isoliquiritigenin, pinocembrin and chrysin were also found and identified by their chromatographic properties and UV spectra. The material of one collection contained galangin, 3-methylkaempferol and 3,3′ -dimethylquercetin.     

Macrophyllin,a neolignan from Licaria macrophylla

The trunk wood of Licaria macrophylla (A. C. Smith) Kosterm. (Lauraceae) contains, in addition to sitosterol, terpene (borneol) and sesquiterpene (nerolidol, elemol) alcohols, a novel neolignan, macrophyllin, for which the structure of 3-allyl-8-hydroxy-1,5-dimethoxy-7-methyl-4(or 2)-oxo-6-(3′,4′-methylenedioxy-5′-methoxyphenyl)-bicyclo [3,2,1] oct-2(or 4)-ene is proposed.     

Flavonols and coumarins from the fruit of Murraya omphalocarpa

Separation of the ethanolic extract of the fruit of Murraya omphalocarpa afforded a new flavonol, murrayanol, which was characterized as 5,4′-dihydroxy-3,6,7,3′,5′-pentamethoxyflavone, together with the known substances coumurrayin, mexoticin, 3,5,6,7,3′,4′,5′-heptamethoxyflavone, 5,7-dimethoxy-8-(3′-methyl-2′-oxobutyl) coumarin and sitosterol.     

Chalcone glycosides of Antirrhinum majus

Three chalcones have been found in yellow flowers of A. majus, two of which have been identified as chalcononaringenin 4′-glucoside and 3,4,2′,4′,6′-pentahydroxychalcone 4′-glucoside.     

A New Bipyrrole and Some Phenolic Constituents in Prunes (Prunus domestica L.) and Their Oxygen Radical Absorbance Capacity (ORAC)

Isolation and structural elucidation of prune constituents were performed and total 10 compounds were determined by NMR and MS analyses. A novel compound was identified to be 2-(5-hydroxymethyl-2′,5′-dioxo-2′,3′,4′,5′-tetrahydro-1′H-1,3′-bipyrrole)carbaldehyde, and 7 phenolic compounds were isolated from prunes for the first time. In addition, antioxidant activity of them was evaluated on the basis of the oxygen radical absorbance capacity (ORAC).     

Tetronic acid and diarylpropanes from Iryanthera elliptica

The trunk wood of Iryanthera elliptica Ducke (Myristicaceae) contains, besides 2-(ω-piperonyltridecyl) -4-methylidenetetronic acid (iryelliptin), three biogenetically related compounds: (±)-7,4′-dihydroxy-3′-methoxyflavan, 1-(4′-hydroxy-2′-methoxyphenyl)- 3-(4″-hydroxy-3″-methoxyphenyl)-propane and spiro-[3-methoxy-2,5-cyclohexadien-1.1′-6′,7′- dihydroxy-5′-methoxy-1′,2′,3′,4′-tetrahydronaphthalen]-4-one-(spiroelliptin). Spiroelliptin rearranges upon methylation to 2,2′-trimethylene-3,4,5,4′,5′-penta-methoxybiphenyl.     

Flavans from Zephyranthes flava

A new optically active flavan aglucone, 7-hydroxy-3′,4′-methylenedioxyflavan, and its 7-glucoside have been isolated from the bulbs of Zephyranthes flava, collected at flowering. Additionally, two known flavans, 7,4′-dihydroxy-3′-methoxyflavan and 7-methoxy-2′-hydroxy-4′,5′-methylenedioxyflavan, have been isolated for the first time from this species. The structures of these flavans have been established by comprehensive analyses (UV, IR, ¹H NMR, ¹³C NMR, mass spectrometry, [α]_D) of the compounds and their acetates, and also by chemical correlation.     

Flavonoids from Artemisia ludoviciana var. ludoviciana

Nineteen flavonoids were isolated from Artemisia ludoviciana var. ludoviciana, including a new 2′- hydroxy- 6-methoxyflavone, 5,7,2′,4′-tetrahydroxy-6,5′-dimethoxyflavone. The known compounds include quercetagetin 3,6,3′,4′-tetramethyl ether, eupatilin, 5,7-dihydroxy-3,6,8,4′-tetramethoxyflavone, luteolin 3′,4′-dimethyl ether, jaceosidin, 5,7,4′-trihydroxy-3,6-dimethoxyflavone, tricin, hispidulin, chrysoeriol, kaempferol 3-methyl ether, apigenin, axillarin, eupafolin, selagin and luteolin together with three flavones which were previously isolated for the first time from Artemisia frigida: 5,7,4′-trihydroxy-6, 3′,5′-trimethoxyflavone, 5,7,3′-trihydroxy-6,4′,5′-trimethoxyflavone and 5,7,3′,4′-tetrahydroxy-6,5′- dimethoxyflavone.     

Flavonoids of the citrus cultivar calamondin and synthetic 2′β-dihydroxychalcones

Eight methoxyflavones were isolated and identified from the peel of calamondin. Citromitin and 5-O-desmethylcitromitin are actually nobiletin and 5-O-desmethylnobiletin, respectively. 5,6,7,8,3′,4′-Hexamethoxyflavanone and 5-hydroxy-6,7,8,3′,4′-pentamethoxyflavanone are not constituents of calamondin, although previously reported.     

Isoflavonoids from Myroxylon balsamum

Myroxylon balsamum (Leguminosae-Lotoideae) trunk wood contains a series of biogenetically related flavonoids, including the novel (±) -7-hydroxy-4′-methoxyisoflavanone, (±)-7,3′-dihydroxy-4′-methoxyisoflavanone and 2-(2′,4′-dihydroxyphenyl)-5,6-dimethoxybenzofuran.     

Chirality of plectaniaxanthin

The chirality of plectaniaxanthin, a carotenoid vic. glycol from Plectania coccinea, could not be determined by the modified Horeau method. Chiroptical correlation of plectaniaxanthin acetonide and (2′S)-16′, 17′-dinorplectaniaxanthin acetonide was taken as proof of 2′R chirality for natural plectaniaxanthin and its mono- and diesters. The synthesis of the chiral model carotenoid was effected from d-mannitol via 2, 3-O-isopropylidene-d-glyceraldehyde as key synthon.     

7,2′,4′-Trihydroxy-3′-methoxyisoflavone from zollernia paraensis

Three further compounds have been isolated from Zollernia paraensis: 2,7-dihydroxy-4′-methoxy-3-phenylcoumarin, (±)-5,7-dihydroxy-2′,4′-dimethoxyisoflavanone and the new 7,2′,4′-trihydroxy-3′-methoxyisoflavone.     

Octasubstituted flavones from Ageratum houstonianum

Two new highly oxygenated flavones, were isolated from aerial parts of Ageratum houstonianum. Their structures were established as 3′-hydroxy-5,6,7,8,2′,4′,5′-heptamethoxyflavone and 5,3′-dihydroxy-6,7,8,2′,4′,5′-hexamethoxyflavone on the basis of spectral data and chemical degradation. The structure of the latter compound was confirmed by X-ray analysis.     

1,11-diarylundecan-1-one and 4-aryltetralone neolignans from Virola sebifera

The seed of Virola sebifera contains besides the polyketide 1 - (2′,6′ - dihydroxyphenyl) - 11 - henylundecan - 1 - one, four neolignans: (2S, 3S, 4R) - 4 - hydroxy - 2,3 - dimethyl - 5,6 - methylenedioxy - 4 - piperonyl - 1 - tetralone and its 2-epimer, as well as (2R, 3R, 4S) - 4 - hydroxy - 6,7 - dimethoxy - 2,3 - dimethyl 4 - piperonyl - 1 - tetralone and its (2R, 3S, 4R) - dehydroxy analogue.     

Macrantaline and macrantoridine,new alkaloids from a turkish sample of Papaver pseudo-orientale

The major alkaloids of the aerial parts of a Turkish sample of Papaver pseudo-orientale are salutaridine and a new alkaloid, macrantaline, UV, IR, PMR, MS and CD have been used to establish the structure of macrantaline as 1-(2′-hydroxymethylene-3′,4′-dimethoxybenzyl)-2-methyl-6,7-methylenedioxy-8-methoxy-1,2,3,4-tetrahydroisoquinoline. The corresponding 2′-methyl substituted analogue prepared from (?)-α-narcotine and also from macrantaline proved to have identical properties, including CD spectra, thus confirming the structure and establishing the absolute configuration of macrantaline. A new minor alkaloid, macrantoridine, yielded macrantaline on lithium aluminium hydride reduction and differs from the latter in that the 2′-substituent is a carboxyl instead of hydroxymethylene. UV, IR, PMR, MS and CD data are reported for macrantoridine.     

Flavones from Eupatorium leucolepis

Chloroform extraction of Eupatorium leucolepis gave the new flavones 3′-hydroxy-5,6,7,8,4′,5′-hexamethoxyflavone, 4′-hydroxy-5,6,7,8,3′,5