New coumarins from the umbels of Seseli sibiricum

Three new coumarins, seselinal, sesibiricol and sibirinol, and 12 known coumarins have been isolated from the umbels of Seseli sibiricum. The new coumarins have been characterized as 5, 7-dimethoxy-8-(2-methyl-2-formylpropyl)-2H-1-benzopyran-2-one, 5-(3-methylbut-2-enyloxy)-7-methoxy-8-(2-hydroxy-3-methylbut-3-enyl)-2H-1-benzopyran-2-one and 5,7-dimethoxy-8-(2-hydroxy-3-methylbut-3-enyl)-2H-1-benzopyran-2-one,respectively. The known ones were identified as sesibiricin, isosibiricin, osthol, coumurrayin, sesebrin, sesebrinol, sibiricin, imperatorin, bergapten, xanthotoxin, isopimpinellin and mexoticin.     

Coumarins and chromones from Lomatium macrocarpum

Roots of Lomatium macrocarpum (Hook. & Arn.) C. & R. yielded osthol (7-methoxy-8-[3-methyl-2-butenyl]-coumarin) and a chromone, 2-methyl-5-hydroxy-6-[3-methyl-2-butenyl]-7-methoxychromone, identified spectroscopically and by synthesis. The aerial parts of the plant also contained this chromone along with sibiricin (5,7-dimethoxy-8-[3-methyl-2,3-epoxybutyl]-coumarin) and a new coumarin named macrocarpin. By spectroscopy and chemical degradation macrocarpin was shown to be 7-methoxy-8-(3-methyl-4-[2-methyl-cis-2-butenoyloxy]-cis-2-butenyl)coumarin. These products were not found in four other Lomatium species examined.     

Furanocoumarins from Dorsteniafoetida

The linear furanocoumarins 5-(2,3-epoxy-3-methyl-butoxy)-chalepensin, 5-methoxy-3-(3-methyl-2,3-dihydroxybutyl)-psoralen-diacetate (7), 5-methoxy-3-[3-(β-d-glucopyranosyloxy)-2-acetyloxy-3-methyl-butyl]-psoralen and 5-(3-methyl-2,3-dihydroxybutyloxy)-3-[3-(β-d-glucopyranosyloxy)-2-hydroxy-3-methyl-butyl]-psoralen, and the coumarin derivative 7-hydroxy-5-methoxy-6-carboxymethyl-3-[3-(β-d-glucopyranosyloxy)-2-hydroxy-3-methyl-butyl]-coumarin were isolated from the leaves of Dorstenia foetida (Moraceae) along with the known compounds psoralen, bergapten, isopimpinellin, phellopterin, 5-methoxychalepensin and turbinatocoumarin. Further furanocoumarins were characterized by ESI-MS/MS investigations. The nonpolar extracts of D. foetida exhibit antifungal, antibacterial and cytotoxic activity, however, no anthelminthic activity.     

Antifungal constituents isolated from the seeds of Aegle marmelos

Antifungal constituents, 2-isopropenyl-4-methyl-1-oxa-cyclopenta[b]anthracene-5,10-dione and (+)-4-(2′-hydroxy-3′-methylbut-3′-enyloxy)-8H-[1,3]dioxolo[4,5-h]chromen-8-one in addition to known compounds imperatorin, β-sitosterol, plumbagin, 1-methyl-2-(3′-methyl-but-2′-enyloxy)-anthraquinone, β-sitosterol glucoside, stigmasterol, vanillin and salicin were isolated during phytochemical investigation on seeds of Aegle marmelos Correa.     

Coumarins from unripe fruits of Poncirus trifoliata

Petrol extracts of unripe fruits of Poncirus trifoliata L. were found to contain 7-geranyloxycoumarin, bergapten, imperatorin, 6-methoxy-7-geranyloxycoumarin and two new coumarins which were shown by chemical and spectroscopic means to be 7-(3′-methyl-2′,3′-epoxybutyloxy)-8-(3″-methyl-2″,3″-epoxybutyl)coumarin and 7-(3′-methyl-2′,3′-epoxybutyloxy)-8-(3″-methyl-2″-oxobutyl)coumarin respectively.     

Chromones from the tubers of Eranthis cilicica and their antioxidant activity

Chemical studies on the constituents of Eranthis cilicica led to isolation of ten chromone derivatives, two of which were previously known. Comprehensive spectroscopic analysis, including extensive 1D and 2D NMR data, and the results of enzymatic hydrolysis allowed the chemical structures of the compounds to be assigned as 8,11-dihydro-5-hydroxy-2,9-dihydroxymethyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, 5,7-dihydroxy-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-2-methyl-4H-1-benzopyran-4-one, 5,7-dihydroxy-2-hydroxymethyl-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-4H-1-benzopyran-4-one, 7-[(β-d-glucopyranosyl)oxy]-5-hydroxy-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-2-methyl-4H-1-benzopyran-4-one, 7-[(β-d-glucopyranosyl)oxy]-5-hydroxy-2-hydroxymethyl-8-[(2E)-4-hydroxy-3-methylbut-2-enyl]-4H-1-benzopyran-4-one, 9-[(O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]methyl-8,11-dihydro-5,9-dihydroxy-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, 8,11-dihydro-5,9-dihydroxy-9-hydroxymethyl-2-methyl-4H-pyrano[2,3-g][1]benzoxepin-4-one, and 7-[(O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]methyl-4-hydroxy-5H-furo[3,2-g][1]benzopyran-5-one, respectively. The isolated compounds were evaluated for their antioxidant activity.     

Neolignans from an Aniba species

A benzene extract of the trunk of an Aniba species (Lauraceae) contained benzyl benzoate, benzyl salicylate, sitosterol and the neolignans (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran (burchellin); (2S,3S,3aR)-3a-allyl-5-methoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,3aR)-3a-allyl-5,7-dimethoxy-3-methyl-2-veratryl-2,3,3a,6-tetrahydro-6-oxobenzofuran; (2S,3S,5S)-5-allyl-5-methoxy-3-methyl-2-veratryl-2,3,5,6-tetrahydro-6-oxo-benzofuran; (2R,3R)-7-methoxy-3-methyl-5-propenyl-2-veratryl-2,3-dihydrobenzofuran; rel-(1R,5R,6R,7R,8S)-1-allyl-8-hydroxy-3-methoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene (guianin); rel-(1S,5S,6S,7R,8R)-1-allyl-8-hydroxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1S,5S,6S,7R,8R)-8-acetoxy-1-allyl-3-hydroxy-5-methoxy-7-methyl-4-oxo-6-piperonyl-bicyclo[3,2,1]oct-2-ene; rel-1S,5S,6S,7R,8R)-8-acetoxy-3,5-dimethoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene; rel-(1R,5S,6R,7R)-1-allyl-3-methoxy-7-methyl-4,8-dioxo-6-piperonylbicyclo[3,2,1]oct-2-ene.     

Neolignans from an Aniba species

A benzene extract of the trunk wood of an Aniba species contained 3a-allyl-2-aryl-5-methoxy-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofurans which may be responsible, through sequential Cope, retro-Claisen and Claisen rearrangements respectively for the formation of the co-occurring 5-allyl-2-aryl-5-methoxy-3-methyl-2,3,5,6-tetrahydro-6-oxobenzofurans; the 6-O-allyl-2-aryl-5-methoxy-3-methyl-2,3-dihydrobenzofurans and the 7-allyl-2-aryl-6-hydroxy-5-methoxy-3-methyl-2,3-dihydrobenzofurans. The examination of the stereochemistry of these products led to the formulation of burchellin, previously isolated from Aniba burchellii Kostermans, as (2S,3S,3aR)-3a-allyl-5-methoxy-2-piperonyl-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran. The structure 1-allyl-4,8-dihydroxy-7-(3-methoxy-4,5-methylenedioxyphenyl)-6-methyl-3-oxobicyclo[3,2,1]octane is tentatively proposed for an additional neolignan.     

New coumarins from Pterocaulon virgatum (L.) DC

Three new coumarins, 5-hydroxy-6,7-methylenedioxycoumarin, 5-(2-hydroxy-3-methoxy-3-methylbutoxy)-6,7-methylenedioxycoumarin and 5-(2-hydroxy-3-methyl-3-butenyloxy)coumarin, were isolated from the petrol ether extract of the aerial parts of Pterocaulon virgatum. Their structures were elucidated based on spectroscopic evidence.     

Bicyclo[3,2,1]octanoid,neolignans from Aniba simulans

Six bicyclo[3,2,1]octanoid neolignans, isolated from the benzene extract of Aniba simulans Allen (Lauraceae) trunk wood, are shown to derive from two basic structures: 1-allyl-8-hydroxy-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-7-methyl-3-oxobicyclo[3,2,1]octane, substituted by 4-hydroxy, 4-hydroxy-5-methoxy, 4-methoxy or 4,5-dimethoxy groups; and 1-allyl-8-hydroxy-6-(3′-methoxy-4′,5′-methylenedioxyphenyl)-7-methyl-4-oxobicyclo[3,2,1]oct-2-ene, substituted by 3-hydroxy or 3-hydroxy-5-methoxy groups. The structural proposals are based on spectral data, interconversions synthesis of a derivative from the known (2R,3S,3aS)-3a-allyl-5-methoxy-2-(3′-methoxy,4′,5′-methylenedioxyphenyl)-3-methyl-2,3,3a,6-tetrahydro-6-oxobenzofuran.     

New bisabolane sesquiterpenes and coumarin from Leontopodium longifolium

From the roots of Leontopotium longifolium, three new bisabolane sesquiterpenes, rel-(1S,4R,5S,6R)-4,5-diacetoxy-6-[(R)-1,5-dimethylhexa-3,5-dienyl]-3-methylcyclohex-2-enyl (Z)-2-methylbut-2-enoate (1), rel-(1S,4R,5S,6R)-4,5-diacetoxy-6-[(R)-5-hydroxy-1,5-dimethylhex-3-enyl]-3-methylcyclohex-2-enyl (Z)-2-methylbut-2-enoate (2), rel-(1R,2S,4R,5S)-4-acetoxy-2-[(R)-5-hydroxy-1,5-dimethylhex-3-enyl]-5-methylcyclohexyl (Z)-2-methylbut-2-enoate (3), and a new coumarin, 2,3-dihydro-5-hydroxy-2-(1-methylethenyl)-7H-pyrano[2,3-g][1,4]benzodioxin-7-one (4) together with nine known compounds have been isolated. The structures of these compounds were established by spectroscopic methods. Compounds 1 and 2 exhibited moderate cytotoxic activities against human promyelocytic leukemia (HL-60) cells.     

Coumarins from the Malagasy Cedrelopsis rakotozafyi Cheek and Lescot (Rutaceae)

A phytochemical analysis of the bark of the Malagasy Cedrelopsis rakotozafyi Cheek and Lescot (Rutaceae) yielded the novel 8-hydroxy-7-methoxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, and 7-hydroxy-6-(2R-hydroxy-3-methylbut-3-enoxy)-2H-1-benzopyran-2-one, 5,6,7-trimethoxy-2H-1-benzopyran-2-one, scoparone, scopoletin, lupeol and β-amyrin. The placement of Cedrelopsis within the Rutaceae is supported phytochemically by the typically Rutaceous coumarins isolated.     

Phenolic derivatives from Wigandia urens with weak activity against the chemokine receptor CCR5

Three compounds, 2,3-dihydroxy-4-methoxy-6,6,9-trimethyl-6H-dibenzo[b,d]pyran (1), 8-methoxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-6-ol (2) and 4-methoxy-3-(3-methyl-2-butenyl)-benzoic acid (3), have been isolated from Wigandia urens. The structures of compounds 1, 2 and 3 were determined from spectroscopic data and showed activity in a CCR5 assay with IC(50) values of 33, 46 and 26 muM respectively.     

Natural occurrence of Erdtman's dehydrodiisoeugenol

The wood of Licaria aritu Ducke (Lauraceae) contains the neolignans licarin-A, (2S,3S)-2,3-dihydro-2-(4′-hydroxy-3′-methoxyphenyl)-7-methoxy-3-methyl-5-trans-propenylbenzofuran and licarin-B, (2S, 3S)-2,3-dihydro-7-methoxy-3-methyl-2-piperonyl-5-trans-propenylbenzofuran.     

Benzofuranoid neolignans from Aniba simulans

Forteen neolignans, isolated from the benzene extract of Aniba simulans (Lauraceae) trunk wood, included the hitherto undescribed (2S, 3S, 5R)-5-allyl-5,7-dimethoxy-2-(3′,4′,5′-trimethoxyphenyl)-3-methyl-2,3,5,6-tetra-hydro-6-oxobenzofuran, (2R,3S,5R) -5-allyl-5-methoxy-2-(3′-methoxy-4′,5′-methylenedioxyphenyl)-3-methy1-2,3,5, 6-tetrahydro-6-oxobenzofuran, (2S,3S)-6-O-allyl -5-methoxy-2-(3′-methoxy-4′-5′-methylenedioxyphenyl)-3-methyl-2,3-dihydrobenzofuran, (2R,3S)-6-O-allyl-5-methoxy-2- (3′-methoxy-4′,5′-methylenedioxyphenyl)-3-methyl-2,3-dihydrobenzofuran and 7-allyl-6-hydroxy-5-methoxy-2-(3′-methoxy-4,5′ -methylenedioxyphenyl)-3-methylbenzofuran.     

Anthraquinones from the fruits of Vismia laurentii

Phytochemical study of the fruits of Vismia laurentii resulted in the isolation of five structurally related compounds. Three of them are constituents, namely, laurentiquinone A (1) (methyl 1,6,8-trihydroxy-3-methyl-7-(3-methylbut-2-enyl)-9,10-dioxo-9,10-dihydroanthracene-2-carboxylate), laurentiquinone B (2) (methyl 5,7-dihydroxy-2,2,9-trimethyl-6,11-dioxo-6,11-dihydro-2H-anthra[2,3-b]pyran-8-carboxylate) and laurentiquinone C (3) (methyl 9-(ethanoyloxymethyl)-5,7-dihydroxy-2,2-dimethyl-6,11-dioxo-6,11-dihydro-2H-anthra[2,3-b]pyran-8-carboxylate) and two are known compounds, emodin (4) and isoxanthorin (5). Their structures were elucidated by spectroscopic means. Crude extracts of hexane and EtOAc showed anti-plasmodial activity against the W2 strain of Plasmodium falciparum.     

Three further naphthoquinones produced by Fusarium solani

Three naphthoquinone pigments are described which were produced by Fusarium solani. They are 2,3-dihydro-5,8-dihydroxy-6-methoxy-2-hydroxymethyl-3-(2-hydroxypropyl)-1,4-naphthalenedione, 2,3-dihydro-5-hydroxy-4-hydroxymethyl-8-methoxy-naphtho[1,2-b]furan-6,9-dione and 5,8-dihydroxy-2-methoxy-6-hydroxymethyl-7-(2-hydroxypropyl)-1,4-naphthalenedione. One of these pigments was shown to be the precursor of the other two.     

Dihydrostilbene derivatives plus kinsenoside from the roots of the rare species Bipinnula fimbriata (Poepp.) I.M.Johnst.

The phytochemical study of the alcoholic extract obtained from Bipinnula fimbriata (Poepp.) I.M.Johnst., allowed to isolate three metabolites, corresponding to the butanolide kinsenoside (1) and to two dihydrostilbene derivatives, which have been assigned as 3-methoxy-5-{2-[3-methoxy-2-(3-methylbut-2-en-1-yl)-phenyl]ethyl}phenol (2) and 4-[2-(3-hydroxy-5-methoxyphenyl)ethyl]-2-(3-methylbut-2-en-1-yl)phenol, also named cannabistilbene I (3). The occurrence of these compounds is consistent with the current classification of the genus and allowed to point out some chemotaxonomic considerations.     

Obtusastyrene and obtustyrene,cinnamylphenols from Dalbergia retusa

The heartwood of Dalbergia retusa contains, in addition to 8-O-methylretusin, (R)-4-methoxydalbergione, (R)-obtusaquinol and (+)-obtusafuran [(2R,3R)-2-phenyl-3-methyl-2,3-dihydro-5-hydroxy-6-methoxybenzofuran], the cinnamylphenols obtusastyrene [E-1-(4-hydroxybenzyl)-2-phenylethylenel, obtustyrene [E-1-(4-hydroxy-2-methoxybenzyl)-2-phenylethylene] and obtusaquinone [styryl-5-hydroxy-2-methoxy-4-quinonemethide]. The structural determination of compounds relied on spectra, degradations and syntheses.     

Neolignans from Aniba terminalis

A benzene extract of the trunk wood of Aniba terminalis (Lauraceae) contained besides benzyl benzoate, benzyl salicylate, d,1-camphor and sitosterol, (2S,3S,3aR)- and (2R,3S,3aS)-3a-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofurans, which may be responsible, through sequential rearrangements of the Cope, retro-Claisen and Claisen types, and finally dehydrogenation, for the formation of the co-occurring (2S,3S,5S)- and (2R,3S,5R)-5-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofurans, the (2S,3S)-6-O-allyl-5-methoxy-3-methyl-2-piperonyl-2,3-dihydrobenzofuran, the (2S,3S)- and (2R,3S)-7-allyl-6-hydroxy-5-methoxy-3-methyl-2-piperonyl-2,3-dihydrobenzofuran and the 7-allyl-6-hydroxy-5-methoxy-3-methyl-2-piperonylbenzofuran.