Search

Chromatographic fractionation of the dichloromethane extract from roots of Virolasurinamensis yielded two new natural products, 3- epi -juruenolide C and2′-hydroxy-7,4′-dimethoxyisoflavone, as well as various known steroids, lignans, isoflavones,flavonoids and diarylpropanes. Of these, a,2′-dihydroxy-4,4′-dimethoxydihydrochalcone,biochanin A and 2′-hydroxy-7,4′-dimethoxyisoflavone displayed antifungal activity against Cladosporium cladosporioides at a minimum amount of 5 mg, whereas 7-hydroxyflavanone and7-hydroxy-4′-methoxyisoflavone exhibited an antifungal activity 10-fold higher than the positivecontrol Nystatin.

Plinia edulis, an arboreous species popularly known as "cambucá", is native to the Brazilian Atlantic Rain Forest. Despite its traditional uses, no reports are available on the safety of this utilization or on the relationship between the antiulcer activity of its extract and its phytochemical compounds. This paper reports on the investigation of the acute toxicity and gastroprotective effect of the aqueous ethanol extract of leaves of Plinia edulis on HCl/ethanol-induced ulcers. In order to correlate the secondary metabolites and the efficacy of the crude drug in traditional medicine, the extract was submitted to chromatographic fractionation after solvent partition. The extract did not show acute toxicity in mice treated with 5 g/kg p.o., but exhibited significant antiulcer activity in rats at doses of 100, 200, and 400mg/kg p.o., more active than the reference drug lansoprazole.The ethyl acetate fraction yielded beta-amyrin, oleanolic acid, ursolic acid, and maslinic acid, which were identified based on spectrometric analyses. Since antiulcerogenic activity is not restricted to one class of compounds in plants, the triterpenoids isolated in the extract can be associated with the observed effect.

A comparative phytochemical study between pericarps of Iryanthera lancifolia and Virola surinamensis showed that the first one contains a new pair of epimeric 2-alkenyl- γ -lactones, besides an aryltetralinic lignan and one tocotrienol, while the second species contains the lignans, galgravin and veraguensin, seven juruenolides : juruenolides C, D, F, G and epi -juruenolides D, F, G, together with three pairs of epimeric aliphatic 2-alkenyl- γ -lactones. Juruenolide F, epi -juruenolides D, F, G and the 2-alkenyl- γ -lactones are new natural compounds.

From the seeds of Virola surinamensis , which were collected near Altamira and near Maraba, Para State, Brazil, the following substances were isolated by chromatographic techniques: two dibenzylbutanediol lignans, dihydrocubebin and the new dihydrocubebin monolaurate, two furofuran lignans, sesamin and asarinin, three dibenzylbutyrolactol lignans, cubebin, β- O -methylcubebin and α- O -methylcubebin, one dibenzylbutyrolactone lignan, hinokinin, one aryltetralin neolignan, galbulin, two tetrahydrofuran neolignans, galgravin and the new ′4-hydroxy-′3-methoxy-3,4-methylenedioxy-8.8′,7. O .′7-neolignan, one flavone, tithonine, one isoflavone, irisolidone, and two new polyketides, 3-hydroxy- 1-(15- phenylpentadecanoyl)-2,6-cyclohexanedione and 1-(5-phenylpentanoyl)-2,6-cyclohexanedione. Different chemical constitutions of the fruits from the two localities were observed. © 1997 Published by Elsevier Science Ltd

The essential oil from leaves of Virola surinamensis shows circadian variation in elemicin and in monoterpenes during the rainy season (February). The monoterpenes represents 50% of total volatile compounds during the dry season (June). Sesquiterpenes are predominant (50%) in the early rainy season (October). © 1997 Published by Elsevier Science Ltd

Leaves and inflorescences of Iryanthera sagotiana were found to contain three known dihydrochalcones, two flavonol rhamnosides, four flavanonol rhamnosides, one dihydrocoumaric acid, besides the new 3′,3‴-bis-2′,4′,6′-trihydroxy-4-methoxydihydrochalcone and 4′,6′-dihydroxy-4-methoxydihydrochalcone-2′-O-β-d-glucopyranoside.

A hexane extract of Ocotea catharinensis leaves afforded by chromatographic fractionation, 11 neolignans, eight of the benzofuran-type (including three new compounds 1–3) and three of the bicyclo[3.2. 1]octane-type (including two new compounds 4 and 5).

The trunk wood and barks from an Aniba species contain four esters of benzoic acid with cinnamyl alcohol, five benzofuran neolignans, licarin-A, burchellin, cis -burchellin, burchellin-rearranged and cis -burchellin-rearranged, one tetrahydrofuran neolignan, aristolignin, three bicyclooctane guianin-type neolignans, (7 S , 8 S , 1′ R , 5′ R )-4-hydroxy-3,3′- dimethoxy-4′,6′-dioxo-8.1′, 7.5′-neolignan-Δ: 1,3,5,2′,8′ and the new (7 S , 8 S , 1′ R , 4′ R , 5′ S )-4′-hydroxy-3,4,3′-trimethoxy-6′-oxo-8.1′, 7.5′-neolignan-Δ: 1,3,5,2′,8′ and (7 S , 8 S , 1′ R , 4′ R , 5′ S )-4,4′-dihydroxy-3,3′-dimethoxy-6′-oxo-8.1′, 7.5′-neolignan-Δ: 1,3,5,2′,8′, one new bicyclooctane canellin-type neolignan (7 S , 8 S , 1′ S , 4′ R , 5′ R , 6′ S )-4′,6′-dihydroxy-3,4-dimethoxy-3′-oxo-8.1 ′, 7.5′-neolignan-Δ: 1,3,5,8′, two styrylpyrones, 4-methoxy-6-(11,12-dimethoxy- trans -styryl)-2-pyrone and 6-(11,12- methylenedioxy- trans -styryl)-4-methoxy-2-pyrone, two styrylpyrone dimers: 4′-methoxy-8-(11,12-dimethoxyphenyl)-7-[6-(4- methoxy-2-pyronyl)-6-( E )-styryl-1′-oxabicyclo[4,2,O]octa-4′-en-2′-one and the new 11,12-dimethoxyphenyl-7, 7′-di-[6-(4-methoxy-2-pyronyl)]-cyclobutane and six flavonoids, 3,5-dihydroxy-7,4′-dimethoxyflavone,5-hydroxy-3,7,4′ -trimethoxyflavone, 3,5,4′-trihydroxy-7-methoxyflavone, 2,3-dihydro-5-hydroxy-7,4′-dimethoxyflavone, 2,3-dihydro-3,5- dihydroxy-7-methoxyflavone, 2,3-dihydro-3,5-dihydroxy-7,4′-dimethoxyflavone and a new flavan, 6,7,3′,4′,5′-pentamethoxyflavan. © 1997 Elsevier Science Ltd. All rights reserved

The leaves and seeds of Virola surinamensis contain 17 lignans; fragansins A2 and D2, galbacin, galbelgin, 5-methoxygalbelgin, grandisin, verrucosin, aristolignan, austrobailignan, calopeptin, veraguensin, 5-methoxyveraguensin, nectandrin B, galbulin and galcatin; three propiophenone derivatives; two γ-lactones; juruenolide C and juruenolide D. Three lignans, one γ-lactone and one propiophenone are new natural products.

Unripe fruits of Ocotea corymbosa contain the known monoterpenes carvacrol and cis-3-hydroxy-p-menth-1-en-6-one, besides three novel rearranged sesquiterpenes possessing the apparently rare carbon skeleton of 10-desmethyl-1-methyl-eudesmane.

Fruits of Iryanthera grandis were found to contain two new pairs of diastereoisomeric flavonolignoids of the 1,4-diaryl-2,3-dimethyl-n-butyldihydrochalcone type.

Among the 35 neolignans isolated from bark and leaves of Ocotea porosa , 20 (including eight new compounds) belong to 12 benzofuranoid types, 11 (including six new compounds) belong to eight bicyclo[3.2.1]octanoid types and four (including one new compound) belong to four 1,2-diaryl- and 1-aryl-2-cyclohexylpropanoid types. All compounds are considered to originate through oxidative coupling of isoeugenol and eugenol and, in some relatively rare cases, of two isoeugenol units.

A hexane extract of the trunk wood of Licaria brasiliensis contained ten bicyclooctanoid neolignans, including six new representatives belonging to the 4-oxy-8-oxo-, 4-oxo-8-oxy- and 4,8-dioxy-l-allyl-6-aryl-3,5- dimethoxy-7-methylbicyclo[3.2.1]oct-2-ene series.

Virola venosa contains 5-deoxyflavones in its flowers, unripe fruits (pericarps) and seedlings (leaves). Upon ripening progressively larger quantities of gradually more strongly reduced lignans, including the novel (-)-dihydro-3′,4′-dimethoxy-3′,4′-demethylenedioxycubebin, appear in all parts of the fruits. Dibenzyllactols, including, (-)-cubebin, and the furofuran, (+)-sesamin, are the major lignans, respectively, of mature seeds and seedlings (roots).

Iryanthera laevis , I. ulei and I. paraensis contain a series of novel lignoflavonoids the formation of which can be rationalized by the cinnamylation of the phloroglucinol type A-ring of a dihydrochalcone. The lignoid attachments of the flavonoid moieties consist of an arylvinylmethyl group in iryantherin-A, of 1,4-diaryl-2,3-dimethyl- n -butyl groups in iryantherins B and C and of 3-aryl-2-cinnamyl- n -propyl groups in iryantherins D and E. The construction of iryantherin-F requires oxidative addition of the vinyl unit of an iryantherin-A type compound to the A-ring of a second dihydrochalcone moiety.

Five new compounds were isolated from fruits of Iryanthera paraensis : (2 S ,3 R )-5-methoxy-3-methyl-2-(4-hydroxy-3-methoxy-phenyl)-7-propenyl- 2,3-dihydro-benzo[1,4]dioxane, (2 S ,3 S ,4 S )-2-(9′-phenyl- n -nonyl)-3-hydroxy-4-methyl-butanolide; (2 S ,3 R ,4 S )-2-(9′-phenyl- n -nonyl)-3-hydroxy-4-methyl-butanolide; (2 S ,3 R ,4 S )-2-(11′-phenyl- n -undecyl)-3-hydroxy-4-methyl-butanolide; and (2 S ,3 R ,4 S )-2-(11′-phenyl- n -undecyl)-3-hydroxy- 4-methyl-butanolide.

A new tetrahydrofuran lignan, the (+)-(7 S ,8 R ,8′ R )-3′,4′-dimethoxy-3,4-methylenedioxy-7,9′-epoxylignan-9-ol, was isolated from kernels of germinated seeds of Virola michelii , besides 10 previously described lignans: (+)-sesamin, (+)-fargesin, (+)-phillygenin, (−)-hinokinin, (−)-kusunokinin, (−)-dimethylmatairesinol, (+)-lariciresinol dimethyl ether, (−)-dihydrocubebin, (−)-2,3-desmethoxy- seco -isolintetralin and (−)-3′,4′,-dimethoxy-3′,4′-desmethylenedioxycubebin.

Bark of Ocotea pulchella contains, besides 1-( p -methoxybenzoyl)-6,7-methylenedioxyisoquinoline, 1-(hydroxy- p -methoxybenzyl)-6,7-methylenedioxyisoquinoline and their 1,2-dihydro-derivatives, 11-eudesmen-4α-ol and 4-furanoeudesmen-6-one.

The presence of benzyl benzoates as well as of bicyclo [3.2.1] octanoid and hydrobenzofuranoid neolignans in Aniba ferrea was confirmed by the isolation of additional representatives of this class of natural products. The hydrobenzofuranoids included three novel ferrearins which, considered together with four known ferrearins, led to the stereochemical clarification of the group.

Bark and wood ofOcotea porosa contained eight new bicyclo [3.2.1]octanoid neolignans belonging to therel-(1′R,4′S,5′R,7S, 8R-Δ2′, 8′-4′-acetoxy-6′-oxo-8.1′,7.5′-neolignan, therel-(1′R,4′R,5′R,7R,8S)-Δ2′,8′-4′-acetoxy-6′-oxo-8.1′,7.5′-neolignan and therel-(1′R,5′S,6′R,7S,8R)-Δ2′,8′-3′,5′-dioxy-4′-oxo-8.1′,7.5′-neolignan series.

A benzene extract of the bark of Virola calophylla yielded, besides eight neolignans of the dibenzylbutane, benzoylbenzylbutane, aryltetralin and arylnaphthalene types, two new arylnaphthalenes, (8 R )-3,4-dimethoxy-3′,4′-methylenedioxy- > 7′8′ - 6.7′,8.8′-neolignan and 4-hydroxy-3-methoxy-3′,4′-methylenedioxy- > 7,8,7′,8′ -6.7′,8.8′-neolignan.

Iryanthera ulei (Myristicaceae) gave two dihydrochalcones, including the new 2′,4′-dihydroxy-3,4,6′-trimethoxy-derivative, five diarylpropanes, including the new 1-(2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylphenyl)-3-(2″-hydroxy-4″,5″-methylenedioxyphenyl)-propane, and two neolignans.

Aniba puchury-minor contains besides common mono- and chiefly sesquiterpenes, asaraldehyde and a series of monomeric arylpropanoids including E-asarone, magnosalicin and two of its diastereomers. © 1997 Elsevier Science Ltd. All rights reserved

Unripe fruits of Ocotea vellosiana were found to contain 13 benzylisoquinoline alkaloids, four flavonol glycosides, thalictoside, p-hydroxybenzoyl-rutinoside and asparagine, besides three novel p-coumaroyl derivatives of afzelin.

Seedlings and micropropagated leaves of Virola surinamensis afforded (2 S , 3 R , 4 S )-3-hydroxy-4-methyl-2-(7′-piperonyl- n -heptyl)-butanolide, a novel representative of the juruenolide group. Correlations between enhancement of shoot proliferation and increased lactone formation were observed by adding several phytohormones to culture media of seedling explants.

In the bark of Ocotea porosa neolignans are accompanied by the sesquiterpenoid (+)-oplopanone, the flavonoid (−)-epicatechin and two novel compounds, the 4β- and 4α-forms of epicatechin-(7,8-bc)-4 (hydroxyphenyl)- dihydro-2(3H)-pyranone.

Virola pavonis was found to contain in the arils of its fruits 8.O.4′,7.O.3′-neolignans (eusiderins A, C and K) and a 8.O.4′-neolignan (of the β-propenylaryloxy-arylpropane type) and in the seed coats of its fruits 8.5′-neolignans (carinatone, carinatol) and 8.5′,7.O.4′-neolignans (dihydrocarinatin, carinatin). Some previous 13C NMR assignments for the latter four compounds are corrected.

Re-examination of wood from Licaria aurea gave, in addition to the previously isolated neolignans eusiderin A and aurein A, the novel 2-(4-allyloxy- 3,5-methoxyphenyl)-3-(3-methoxy-4,5-methylenedioxyphenyl)-propane (aurein B) and two known virolongin-type neolignans.

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.

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

The trunk wood of Clinostemon mahuba contains eight (3R)-2-alkylidene-3-hydroxy-4-methylenebutanolides, seven (3R,4S)-2-alkylidene-3-hydroxy-4-methylbutanolides and seven (3S,4S)-2-alkylidene-3-hydroxy-4-methylbutanolides distinguished by the alkylidene side chains with respect to their E- or Z-geometry, ethenyl, ethynyl or ethyl terminals and lengths (C16 or C18).

The fruits of Virola carinata contain the lignans (−)-cubebin, (−)-hinokinin and (+)-asarinin, besides four neolignans of the β-aryloxy-arylpropane type and two neolignans of the benzodioxane (eusiderin) type.

The branches of the shrub Aniba lancifolia Kubitzki et Rodrigues (Lauraceae) contain besides 2-hydroxy-4,5- dimethoxyallylbenzene and its dimer cyclohexan-2-allyl- 5-en-4,5-dimethoxy-4-O-(2′-allyl-4′,5′-dimethoxyphenyl)-1-one (lancilin, 2) 6 further novel neolignans: (4S,2′R)- and (4R,2′E)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-guaiacyl)-propyl]-1-one (lancifolins A and B, 3a and 3b), (4S,2′R)- and (4R,2′R)-cyclohexan- 2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-veratryl)-propyl]-1-one (lancifolins C and D, 3c and 3d), (4S,2′R)-and (4R,2′R)-cyclohexan-2-allyl-2,5-dien-4,5-dimethoxy-4-[2′-(1′-piperonyl)-propyl]-1-one (lancifolins E and F, 3e and 3f).

The fruits of Virola sebifera contain several tetralone neolignans, including 2,4-dihydroxy-6,7-methylenedioxy-2,3-dimethyl-4-veratryltetralin-1-one. The 3-hydroxylated derivative of this compound may undergo a biosynthetic pinacol-pinacolone rearrangement to give 2-acetyl-3-hydroxy-2-methyl-5,6-methylenedioxy-3-veratrylindan-1-one which, together with other indanone neolignans, was also isolated.

The trunk wood of an Ocotea species from the Atlantic coast of southern Brazil contains five new neolignans: rel-(1R,4S,5S,6S,7R,8R)-4-acetoxy-1-allyl-8-hydroxy-3,5-dimethoxy-7-methyl-6-(3′,4′-methylenedioxyphenyl and 3′-methoxy-4′,5′-methylenedioxyphenyl)-bicyclo(3.2.1)oct-2-enes, rel-(1R,4S,5R,6S,7R)-4-acetoxy-1-allyl-3,5-dimethoxy-7-methyl-6-(3′,4′,5′-trimethoxyphenyl)-8-oxobicyclo(3.2.1)oct-2-ene and rel-(1S,4R,5S,6S,7R,8R)-4-acetoxy-1-allyl-8-hydroxy-5-methoxy-7-methyl-6-(3′4′-methylenedioxyphenyl and 3′-methoxy-4′,5′-methylenedioxyphenyl)-3-oxobicyclo(3.2.1)octanes. The latter two compounds are considered to be acid-catalysed demethylation products of the former pair of compounds.

Trunk wood, bark and fruit calyx of Licaria chrysophylla contain eight neolignans which differ from the normal benzofuranoid types by showing 7.1′,8. 0 .2′ (rather than 8.1′,7. 0 .2′) linkages between the propenylphenol and allylphenol derived moieties. The fundamental chrysophyllon I types, with the allyl at C-1′, can rearrange to chrysophyllon II and III types, with the allyl respectively at C-5′ and O-4′.

From the fruits of Virola sebifera 2,3-dibenzylbutanes were isolated together with tetralin and naphthalene neolignans. 2,3-Dimethyl-4-piperonyl-4-veratrylbutan-1-ol, a further constituent, probably arises by a retro-Friedel-Crafts reaction from a tetralin neolignan. An additional component was identified as a dimeric neolignan.

Seven neolignans, isolated from a C 6 H 6 extract of Nectandra miranda (Lauraceae) trunk wood, included the hitherto undescribed (2 S , 3 S , 3a S )- and (2 S , 3 S , 3a R )-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 (2 R , 3 R )-7-methoxy-2-(3′, 4′, 5′-trimethoxyphenyl)-3-methyl-5 -( E )-propenyl-2, 3-dihydrobenzofuran (licarin C).

Bark and fruit calyx of Licaria chrysophylla were found to contain five new benzodioxane type neolignans (eusiderins I, J, K, L, M), three new β-aryloxy-arylpropane type neolignans (virolongins E, F, G), besides dihydroconiferyl alcohol and its oxidative dimer dihydro-dehydrodiconiferyl alcohol.

The trunk wood of Nectandra puberula was found to contain 1,6-geranylgeranodioic acid besides five neolignans, the known veraguensin and the novel 7-hydroxy- and 7-oxo-3,4,3′,4′-tetraoxy-8.8′-neolignans, all with the (8 S ,8′ R )-absolute configuration.

The trunk wood of Ocotea porosa contains, besides porosin, porosin-B and licarin-B, six additional new 7. 0 ,2′,8.1′-neolignans of the porosin, canellin and megaphone type.

The trunk wood of an Amazonian Aniba species contains three novel neolignans: (2 R , 3 R , 3a S , 5 R )-3a-allyl-5-methoxy-2-(3,4,5-trimethoxyphenyl)-3-methyl-2,3,3a,4,5,6-hexahydro-6-oxobenzofuran (canellin-D), (2 R ,3 R ,3a S ,5 R )-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 (2 S ,3 S ,3a S ,5 R )-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.

The fruits of Virola sebifera and V. elongata (Myristicaceae) contain three ω-phenylundecanoyl-substituted compounds, a 2,6-dihydroxybenzene, a 2,6-dihydroxy-4-methoxybenzene and a 3-hydroxycyclohexan-2,6-dione. Three additional 2,6-dihydroxybenzenes are substituted by hexadecanoyl, hexadec-4 Z -enoyl and 8-hydroxyoctadec-4 Z -enoyl groups.

Analysis of Rhabdodendron amazonicum gave two new compounds, 5′-methoxy-3,4,5,3′-tetra- O -methylflavellagic acid and 3,3′-didehydroxy-5- O -methylflavellagic acid, and confirmed the triterpenoid and O -methylflavellagic acid based composition of the Rhabdodendraceae. Chemically this family fits into the Rosiflorae or even better into the Myrtiflorae.

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,4 S and 4 R ,5 S ,6 R ,7 S ,8 R )-1-allyl-4,8-dihydroxy-3,5-dimethoxy-7-methyl-6-piperonyl-bicyclo(3.2.1)oct-2-enes and rel-(1 R ,5 S ,6 R ,7 S ,8 R )-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 (2 S ,3 S ,5 R )-5-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofuran and (2 R ,3 S ,3a S )-3a-allyl-5,7-dimethoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydro-6-oxobenzofuran.

The fruits of Virola sebifera contain in the seed (2R, 3S)-3-(3,4-dimethoxybenzyl)-2-(3,4-methylenedioxybenzyl)-butyrolactone, in the pericarp (2R, 3R)-3-(3,4-dimethoxybenzyl)-2-(3,4-methylenedioxybenzyl)-butyrolactone, (2R, 3R)-2,3-di-(3, 4-dimethoxybenzyl)-butyrolactone and (2R, 3R)-2,3-di-(3,4-methylenedioxybenzyl)-butyrolactone.

The proposed structures of the neolignans canellin-A, macrophyllin-B and eusiderin were confirmed by X-ray crystallographic analyses.

The structure of juruenolide, a constituent of Iryanthera juruensis and I. ulei is revised to (2S, 3R, 4S)-3-hydroxy-4-methyl-2-(19′-piperonyl-1′-n-nonadecyl)-butanolide. The compound is epimeric at C-3 of the γ-lactone unit with grandinolide [(2S, 3S, 4S)-3-hydroxy-4-methyl-2- (19′-phenyl-1′-n-nonadecyl)-butanolide] from I. grandis. An extract of I. juruensis contained additionally juruenolide-B [(4S)-4-methyl-2-(19′-piperonyl-1′-n-nonadec-7′-enyl)-but-2-enolide]. Analogous products with heptadecyl and pentadecyl side chains co-occur with the respective nonadecyl derivatives.