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.     

The neolignans of Licaria canella

The trunk wood of Licaria canella contains, besides dillapiol and elemicin, the neolignans canellin-A, -B and -C, for which the respective structures of 1-allyl-4,8-dihydroxy-3,5-dimethoxy-7-methyl-6-piperonylbicyclo-[3,2,1]octane; 3a-allyl-4,5-dimethoxy-3-methyl-2-piperonyl-2,3,3a,6,7,7a-hexahydro-6-oxobenzofuran and 1-allyl-4,8-dihydroxy-5-methoxy-7-methyl-6-piperonyl-3-oxobicyclo-[3,2,1] octane are proposed.     

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.     

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).     

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.     

Hexahydrobenzofuranoid neolignans from an Aniba species

The trunk wood of an Amazonian Aniba species contains three novel neolignans: (2R, 3R, 3aS, 5R)-3a-allyl-5-methoxy-2-(3,4,5-trimethoxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (canellin-D), (2R,3R,3aS,5R)-3a-allyl-5,7-dimethoxy-2-(3-methoxy-4,5-methylenedioxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (canellin-E) and (2S,3S,3aS,5R)-3a-allyl-5-methoxy-2-(3-methoxy-4,5-methylenedioxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (armenin-C). The absolute stereochemistries of these and of all other known hexahydro-6-oxobenzofurans were determined by CD comparisons with model compounds.     

Porosin: A neolignan from Ocotea porosa

The wood of Ocotea porosa (Nees) L. Barr. (Lauraceae) contains sitosterol, sesquiterpenes, n-octacosanoic acid, n-hexacosanoic acid and the neolignan porosin for which the structure of 3a-allyl-5-methoxy-3-methyl-2-veratryl-2,3,3a,6,7,7a-hexahydro-6-oxobenzofuran (II) is proposed.     

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.     

Neolignans from Ocotea catharinensis

The trunk bark of Ocotea catharinensis yielded, besides the known bicyclo(3.2.1)octanoid neolignans canellin-C and 5′-methoxycanellin-C, two epimers rel-(1R,4S and 4R,5S,6R,7S,8R)-1-allyl-4,8-dihydroxy-3,5-dimethoxy-7-methyl-6-piperonyl-bicyclo(3.2.1)oct-2-enes and rel-(1R,5S,6R,7S,8R)-1-allyl-3,8-dihydroxy-5-methoxy-7-methyl-6-piperonyl-4-oxobicyclo(3.2.1)oct-2-ene. The hydrobenzofuranoid neolignans are represented by the equally novel (2S,3S,5R)-5-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofuran and (2R,3S,3aS)-3a-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran.     

Neolignans from Aniba ferrea

The trunk wood of the Amazonian Aniba ferra Kubitzki contains, besides three benzyl benzoates (1a, b, c) and dillapiol (2), four hydrobenzofuranoid and two bicyclo [3.2.1] octanoid neolignans. The former comprise two representatives (3a, b) of the novel ferrearin- (3a-allyl-2- aryl-7a-hydroxy-3-methyl-3a,4,7,7a-tetrahydro-7-oxobenzofuran type, and two further representatives (4a, b) of the known porosin-(3a-allyl-2-aryl-5-methoxy-3a,4,5,6-tetrahydro-6-oxobenzofuran) type. The latter comprises a new representative (5a) of the known canellin- (1-allyl-6-aryl-7-methylbicyclo [3.2.1] octane) type, and the methyl ether (6a) of a known guianin- (1-allyl-6-aryl-7-methyl-4-oxobicyclo [3.2.1] oct-2-en) type neolignan.     

Lanthanide shift reagents in neolignan analysis: Revision of structure of canellin-B

PMR studies using lanthanide shift techniques showed that the constitution of canellin-B must be revised to rel-(2S,3S,3aS,5S)-3a-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran and that the previous assignments of H-2, H-4 and H-7 signals of some other benzofuranoid neolignans must be interchanged. The isolation of 5-methoxyguianin from Licaria canella (Meissn.) Kosterm. and the characterization of (2R,3S,5R)-5-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofuran from Aniba terminalis Ducke is also reported.     

Benzofuranoid neolignans from Licaria armeniaca

The trunkwood of Licaria armeniaca (Nees) Kosterm. (Lauraceae) contains sitosterol, 6,7-dimethoxy-coumarin and two novel benzofuranoid neolignans: (2S, 3S, 3aR, 5R)-3a-allyl-5-methoxy- and 5,7-dimethoxy-2-(3′, 4′-methylenedioxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofurans.     

Guianin: A neolignan from Aniba guianensis

The wood of Aniba guianensis Aubl. (Lauraceae) contains benzyl benzoate, benzyl salicylate, sitosterol, O-methyleugenol, O-methylisoeugenol and the neolignan guianin for which the structure of 1-allyl-8-hydroxy-3-methoxy-7-methyl-4-oxo-6-piperonylbicyclo[3,2,1]oct-2-ene (VI) is proposed.     

Arylbenzofurans from Dalbergia parviflora

The isolation of two polysubstituted arylbenzofurans from the heartwood of Dalbergia parviflora is described. Their structures were elucidated mainly by spectroscopic techniques (UV, IR, ¹H and ¹³C NMR). They were named parvifuran (5-hydroxy-6-methoxy-3-methyl-2-phenylbenzofuran) and isoparvifuran (5-hydroxy-6-methoxy-2-methyl-3-phenylbenzofuran) and are the first compounds of this class isolated from a Dalbergia species.     

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.     

Study of the protein-ubiquinone interaction in succinate-cytochrome C reductase with azido-ubiquinone derivatives

Several azido-ubiquinones have been synthesized for the study of protein-ubiquinone interaction in succinate-cytochrome $\text{c}$ reductase. In the absence of light, azido-ubiquinones are partially effective in restoring enzymatic activity to ubiquinone- and phospholipid-depleted reductase and the binding of azido-ubiquinones can be partially reversed by 5-(10-bromodecyl)-ubiquinone. When 2-azido-3-methoxy-5-geranyl-6-methyl-1,4-benzoquinone reactivated reductase is illuminated with long wavelength UV light, a complete and irreversible inhibition is observed. This specific photo-inactivation, exerted only by 2-azido-3-methoxy-5-geranyl-6-methyl-1,4-benzoquinone, and not by other azido-ubiquinone derivatives, is evidence for the existence of a specific benzoquinone ring binding site in the enzyme.     

Membrane-associated reactions in ubiquinone biosynthesis: 2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone methyltransferase

The O-methylation of 2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone, which has been previously postulated to be the final reaction in the biosynthesis of ubiquinone was demonstrated in vitro using cell extracts of Escherichia coli. $\text{S-}\text{Adenosyl}\text{-}\text{l}\text{-}\text{methionine}$ was active as the methyl donor for the reaction. The enzyme concerned, S-adenosyl-l-methionine: 2-octaprenyl-3-methyl-5-hydroxy-6-methoxy-1,4-benzoquinone-O- methyltransferase, was partially purified and shown to have a molecular weight of about 50 000 and to require a divalent metal and dithiothreitol for optimal acitivity in vitro. The methyltransferase was absent from extracts from ubiG^? mutants suggesting that the ubiG gene is the structural gene coding for the methyltransferase. The enzyme, although not firmly membrane-bound, showed some affinity for the cell membrane in broken cell preparations and could utilize the benzoquinone substrate when the latter was free or bound to the cell membrane, with about equal efficiency. It is concluded that in vivo, the methyltransferase reaction probably occurs at the internal surface of the cytoplasmic membrane.     

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.     

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.     

Neolignans from Ocotea aciphylla

The trunk wood of the central Brazilian Ocotea aciphylla contains two hydrobenzofuranoid and three bicyclo[3.2.1]octanoid neolignans. The former comprise a novel representative of the rare ferrearin (3a-allyl-2-aryl-7a-hydroxy-3-methyl-2,3,3a,4,7,7a-hexahydro-7-oxobenzofuran) type.