Emma Maldonado

Emma Maldonado
National Autonomous University of Mexico | UNAM · Institute of Chemistry

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104
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Publications (104)
Article
Full-text available
The new labdane-type diterpenoid, physaglutinic acid (1), was isolated from the hexane extract of Physalis glutinosa. This compound is the first succinyl labdane isolated from a Physalis species. The known constituents of this plant were identified as the labdanes 12-O-acetylphysacoztomatin (3), physacoztomatin (4) and 12-epi-nicandrodiol (6). The...
Article
The investigation of the chemical constituents of Datura ceratocaula and D. discolor allowed to isolate three new withanolides, datucerolide A (1) from the first species, and datudiscolides A (8) and B (9) from the second. In addition, seven known withanolides and five ubiquitous compounds were isolated from these plants, along with 27-O-β-d-glucop...
Article
From the extracts of stems and leaves as well as of calyxes of Physalis grisea were isolated four withalactols, the new griselactols A (3) and B (6) and the known physapubescin (1) and peruvianolide E (2). Other four known compounds were also isolated, kaempferol 3-O-β-sophoroside (5) and three sterols. The structures of compounds were elucidated b...
Article
Full-text available
Recibido: 17 de octubre de 1977 ABSTRACT. Tbe chemicil study ol Eupaioríum glabratum coliected ia tv.0 differcnt places oí México is described. Tbe structure oí eopaglabric acid (4a) a new compound «-iih eudesmaoe skeletoa is discussed. INTRODUCCION En la presente comunicación se informa el estudio químico del E. glabratum H.B.K. (Com-positae) reco...
Article
Three new sucrose esters, physachenoses A-C (1–3) and the known withanolide, physachenolide D (4), were isolated from the calyxes of Physalis chenopodifolia Lam. Analysis of the MS, 1D and 2D NMR spectra of the new compounds allowed to determine their structures as 3′-O-dodecanoyl-2,3,4-tri-O-isobutyrylsucrose (1), 3′-O-dodecanoyl-2,4-di-O-isobutyr...
Article
Chemical investigation of the aerial parts (except fruits) of the medicinal, hallucinogen and toxic plant Datura innoxia Mill. [Solanaceae] led to the isolation of the new withanolide, dinnoxolide A ( 1 ), along with the known compounds 21,27-dihydroxy-1-oxowitha-2,5,24-trienolide ( 2 ), daturamalakin B ( 3 ) and withametelin ( 4 ). Their structure...
Article
Full-text available
Lippia graveolens is a plant used for a variety of medicinal purposes and as a seasoning. Chemical investigation of a methanol extract obtained by percolation of its leaves and flowers led to the isolation of two monoterpenes (1–2) and twelve flavonoids, including two flavonols (3–4), two flavones (5–6), four flavanones (7–10), two dihydroflavonols...
Article
Full-text available
Five withanolides identified as daturalactone (1) , withanicandrin (2), withanolide B (3), nicandrin B (4), and daturalactone 2 (5) were isolated from the aerial parts (flowers, leaves, and stems) of Datura quercifolia Kunth. Their structures were determined by analysis of the IR, MS, 1D and 2D NMR spectra. All the isolates were evaluated for their...
Article
A chemical study of the aerial parts of Stevia jorullensis was carried out as a contribution to the knowledge of the chemistry of the genus Stevia. In this investigation the sesquiterpene lactones 11β,13-dihydrocostunolide (1), 11,13-dihydroreynosin (4), and 1β-hydroxycolartin (5) were isolated for the first time in the genus. Additionally, chlorog...
Article
Chemical investigation of the aerial parts (except fruits and calixes) of Physalis nicandroides var. attenuata led to the isolation of a series of new labdane-type diterpenoids, including the closely related compounds 1-3, the labdane glucosides 4 and 5, a mixture of the epimeric alcohols 6 and 7, and one labdanetriol, isolated as its tri-O-acetyl...
Article
A phytochemical study from Zinnia peruviana L. resulted in the isolation of a new elemene-type sesquiterpene lactone, zinaflorin VI (1), along with the known elemenolides 2–5 and the flavone onopordin (6). The structures of these compounds were determined by analysis of their spectroscopic data. The antibacterial activity of the γ-elemenolides 1, 4...
Article
Full-text available
A chemical investigation of the leaves, flowers, and stems of Physalis gracilis led to the isolation of three withanolides identified as withanolide D (1), 24,25-dihydrowithanolide D (2), and withaphysacarpin (3). The structures of these compounds were determined by analyses of their spectroscopic data, including 1D and 2D NMR. The antibacterial, a...
Article
A series of neo-clerodane-type diterpenoids were isolated from the aerial parts of Salvia filipes, including the new compounds 4-epi-polystachyne A (1), salvifilines A (3), C (7), and D (8), and salvifiline B, which was isolated as the 15-O-methyl derivatives 4/5. In addition, the five known diterpenoids (2, 9-12), together with ursolic, oleanolic,...
Article
A new withanolide, physangulide B (1), was isolated from calyxes of Physalis angulata. This compound was also present in the aerial parts along with the known physangulide (4), which was isolated as the acetonide 3, and 24,25-epoxywithanolide D (6). Structures of these compounds were determined by analysis of their spectroscopic data, which indicat...
Article
Full-text available
Chemical study of the aerial parts of Asclepias otarioides led to the isolation of four pentacyclic triterpenes and one cardenolide glycoside. This is the first report on the occurrence of the triterpenes 1, 3, and 4 in the genus Asclepias.
Article
A mixture of the new epimeric labdenetriols 1 and 2 was isolated from the aerial parts of Physalis nicandroides. The structures of 1 and 2, including their absolute configurations, were established by analyses of their spectroscopic data, together with the X-ray diffraction analysis of acetonide 3 and chemical correlation with (-)-(13E)-labd-13-ene...
Article
Highlights ►The first chemical study of Marsdenia callosa was carried out. ► Four triterpenes and conduritol A were isolated from the title plant. ► Two of the triterpenes are esters of the unusual 5-phenyl-(2E,4E)-penta-2,4-dienoic acid.
Article
Full-text available
The sucrose esters 1 and 2 together with the flavonoid rutin (3) were isolated from the calyxes of Physalis solanaceus while 4,7-didehydrophysalin B (4) was obtained from the roots. The structural elucidation of the isolates was carried out by analysis of their spectroscopic data. Compound 4 was obtained as natural product for the first time.
Article
Full-text available
Chemical investigation of the aerial parts of Salvia herbacea led to the isolation of eight new neo-clerodane diterpenes (1-8), named tehuanins A-H, and three known compounds. The structures of these compounds were determined by analysis of their spectroscopic data. Three of the new diterpenes possess a 1,8-epoxy group (1-3). This unusual structura...
Article
Full-text available
A new withanolide, orizabolide (1), together with the known flavonoid rutin (2) were isolated from the aerial parts of Physalis orizabae. Structural elucidation of these compounds was carried out by interpretation of their spectroscopic data.
Article
Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR.
Article
Two new withanolides, philadelphicalactone C (1) and philadelphicalactone D (4), along with the known withaphysacarpin (3), ixocarpanolide (5), philadelphicalactone A (6), and ixocarpalactone A (7) were isolated from the aerial parts of Physalis philadelphica Lam. Structures of these compounds were determined by spectroscopic analyses and that of p...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Three new lupane-type triterpenes, lippiolide (1), lippiolidolic acid (2), and lippiolic acid (3), were isolated from aerial parts of Lippia mexicana. Compounds 1 and 2 exhibited a δ-lactone at ring E. The known cycloartane triterpene 5 was also isolated. The structures of these compounds were established on the basis of spectroscopic data and chem...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Eight new compounds, labdanes 2-4, homoergostane 10, and sucrose esters 12-15, were isolated from aerial parts of Physalis sordida together with several known compounds. Structures of the new compounds were elucidated using spectroscopic evidence and chemical transformations. The structure of 10 was confirmed by X-ray crystallographic analysis of i...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Virginols A-C are three new withanolides containing an epoxylactol at the side chain. They were isolated from the aerial parts of Physalis virginiana Miller. Structures of these compounds were determined by analyses of their spectroscopic data, including 1D and 2D NMR. The structure of virginol A was confirmed by X-ray diffraction analysis. The ant...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Full-text available
Chia (Salvia polystachya Ort., Lamiaceae) is frequently used in Mexican traditional medicine to treat dysentery. In this study the main neo-clerodane diterpenes (polystachynes A, B and D, as well as linearolactone) were isolated from the aerial parts of chia, and their antiprotozoal activities toward Entamoeba histolytica and Giardia lamblia tropho...
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Article
Full-text available
An efficient microwave-assisted Au(I) catalyzed cleavage of the pyran ring of brevifloralactone is described. We report one of the first combination reactions of gold and microwave irradiation. In base to this reaction, nine new ent-clerodane diterpene derivatives have been obtained by partial synthesis from brevifloralactone, a naturally occurring...
Article
A chemical study of the leaves of Casimiroa pringlei led to the isolation of six coumarins, six flavones and the sesquiterpene, cryptomeridiol. Four of these compounds are new natural products which, on the basis of spectroscopic analyses, were characterized as (Z)-trichoclin acetate, 5,3′,5′-trimethoxyflavone, 5,2′,3′,4′-tetramethoxyflavone, and 5...
Article
Three 2,3,1',3'-tetraacyl- and two 2,3,3'-triacylsucroses, nicandroses A-E (1-5), were isolated from the fruits of Physalis nicandroides var. attenuata. The acyl groups in these new compounds were identified as decanoyl, isobutyryl, 2-methylbutanoyl, and acetyl. The structures of 1-5 were determined on the basis of NMR and MS analyses.
Article
Full-text available
A new 5,10-seco-neoclerodane diterpene, polystachyne F (1), was isolated from the aerial parts of Salvia polystachya. Its structure was established on the basis of its spectroscopic properties and X-ray crystallographic analysis. Some correlations in the NOESY spectrum of 1 suggested the existence of a conformational equilibrium.
Article
Aerial parts of Physalis coztomatl afforded a new labdane diterpene, physacoztomatin (1), and five new withanolides, physacoztolides A-E (5-9). Six known compounds were also isolated. The structures of the new compounds were established after analyses of their spectroscopic data and by means of chemical transformations. X-ray diffraction analyses o...
Article
Two new withanolides, cinerolide and 24,25-dihydrowithanolide S, together with the new androstane, cinedione, and the known withanolides, visconolide, physalactone, withanolide S and 4beta-hydroxywithanolide E were isolated from the EtOAc extract of leaves, flowers and stems of Physalis cinerascens. The structures of these compounds were establishe...
Article
Five 2-phenoxychromones, the new tenuiflorin A [5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenoxy)-6-methoxychromone], tenuiflorin B [5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenoxy)-6-methoxychromone] and tenuiflorin C [5,7-dihydroxy-2-(3-hydroxy-4-methoxyphenoxy)chromone], along with the known 6-demethoxycapillarisin and 6-demethoxy-4'- O-methylcapillarisi...
Article
Five new withasteroids, physachenolides A - E were isolated from the acetone and methanol extracts of leaves, flowers and stems of Physalis chenopodifolia Lam. The structural assignments of these compounds were based on spectral evidence. The absolute configuration of physachenolide A was established by X-ray analysis.
Article
The absolute configuration of cuauhtemone, a eudesmane-type sesquiterpene isolated from Pluchea species (Asteraceae), has been revised from 1 to 2 by chemical correlation with (R)-(+)-2-methyl-1,2-butanediol 3 through the naturally occurring 2,3-epoxy-2-methylbutanoate derivative 4. The relative stereochemistry of 4 was confirmed by X-ray diffracti...
Article
Full-text available
The absolute configuration of the neoclerodane glycoside amarisolide, presented here as the monohydrate, C26H36O9·H2O, has been determined by association with the known configuration of the glucose moiety. Its structure was established as 2β-(O-β-d-gluco­pyran­osyl)­neocleroda-3,13(16),14-trien-15,16-epoxy-18,19-olide. Extensive hydrogen bonding am...
Article
Three new modified clerodanes (10, 12, 17) containing a tricyclo[5.4.0.01,3]undecane ring system were isolated from Dodonaea viscosa. These types of compounds have not been found in nature until now, but they have been proposed as hypothetical intermediates in the biogenetic pathway of diterpenes possessing bicyclo[5.4.0]undecane or bicyclo[5.3.0]d...
Data
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...
Article
From the aerial parts of Salvia polystachya five new neo-clerodane diterpenoids, polystachynes A-E, have been isolated. The structures were established by spectroscopic methods, including the X-ray analysis of polystachynes C and D. The known clerodanes salvifaricin, linearolactone and dehydrokerlin were also isolated.
Article
Two new neurolenin-type sesquiterpene lactones were found in the leaves of Neurolaena macrocephala Sch. Bip. Ex Hemsl. (Asteraceae). These compounds were identified by their NMR spectra as the 8β-isobutyryloxy- and 8β- (2-methyl)butyryloxy analogs of neurolenin B. Additionally, the known neurolenins B, C and D and the furanoheliangolide 9a-acetoxy-...
Article
De las partes aéreas de Stevia laxiflora se aislaron dos flavonas conocidas y tres nuevas guayanólidas cuyas estructuras están muy relacionadas con la de eupahakonenina B, también presente en esta planta.
Article
The structures of three phenyl propanoids isolated from the aerial parts of Coreopsis mutica var. mutica were established by spectroscopic analysis as (-)-bornyl p-coumarate (1), (-)-bornyl ferulate (2), and (-)-bornyl caffeate (3). These compounds have been previously isolated from diverse sources. Their complete and assigned 1H- and 13C-NMR data...
Article
In addition to known compounds, the aerial parts of Podachaenium eminens contained the guaianolide named eminensin A, the eudesmanolide eminensin B and podachaenin, a compound formed through esterification of an hydroxyguaianolide by costic acid. Structures of these compounds were established by analysis of their spectroscopic data and, in the case...
Article
The aerial parts of Perymenium hintonii gave, in addition to known coumarins, flavonoids and triterpenes, two new phytane-type diterpenes named tuxpanolide and isotuxpanolide. Their structures were elucidated by 1D and 2D NMR techniques.
Article
The aerial parts of Perymenium hintonii gave, in addition to known coumarins, flavonoids and triterpenes, two new phytane-type diterpenes named tuxpanolide and isotuxpanolide. Their structures were elucidated by 1D and 2D NMR techniques.
Article
NMR studies on tonalensin 1, a diterpene containing a ten membered ring, made evident the presence of three conformational isomers in solution. At room temperature compound 1 exists as a mixture of the conformers 1A and 1B in a ratio 1:1 in a CDC13 solution and 1.5:1 in a Me2CO-d6/DMSO-d6 solution. At lower temperatures a third conformer, 1C, was d...
Article
The investigation of Salvia thymoides afforded, in addition to known triterpenes and flavones, four neo-clerodane diterpenoids, 7α-hydroxy-neo-cleroda-3,13-dien-18,19: 15,16-diolide, 7-oxo-neo-cleroda-3,13-dien-18,19: 15,16-diolide, 6α,18,19-trihydroxy-neo-cleroda-3,13-dien-15,6-olide (thymonin) and 6α,7β,18,19-tetrahydroxy-neo-cleroda-3,13,-dien-1...
Article
The investigation of Salvia thymoides afforded, in addition to known triterpenes and flavones, four neo-clerodane diterpenoids, 7α-hydroxy-neo-cleroda-3,13-dien-18,19: 15,16-diolide, 7-oxo-neo-cleroda-3,13-dien-18,19: 15,16-diolide, 6α,18,19-trihydroxy-neo-cleroda-3,13-dien-15,16-olide (thymonin) and 6α,7β,18,19-tetrahydroxy-neo-cleroda-3,13,-dien-...
Article
In addition to several known compounds, the new languidulane diterpene, tonalenin (8β-hydroxy-7-epi-8,17-dihydrolanguiduline), was isolated from the aerial parts of Salvia tonalensis. The structures were elucidated by spectroscopic means. © 1997 Elsevier Science Ltd. All rights reserved
Article
From the aerial parts of Brickellia kellermanii three previously unknown labdane diterpenoids were isolated. They were named kellermanoldione (15,16-epoxy-6β-hydroxy labda-8(17),13(16),14-trien-3, 12-dione), kellermandiolone (15,16-epoxy-3β,6β-dihydroxy labda-8(17),13(16),14-trien-12-one) and kellermandioldione (15,16-epoxy-6β-19-dihydroxy labda-8(...
Article
A new neo-clerodane glycoside, amarisolide, has been isolated from the aerial parts of Salvia amarissima. Its structure was established as 2β-O-β-D-glucopyranosyl neo-cleroda-3,13(16),14-trien-15,16-epoxy-18,19-olide by chemical and spectroscopic means.
Article
We report the X-ray study on the structure of a newseco-neoclerodane diterpenoid, tonalensin, isolated from the aerial parts ofSalvia tonalensis. The compound crystallizes in the monoclinic space groupP21 witha=10.146(2),b=7.620(2),c=11.316(2) Å, ß=109.58(2)°. Thetrans,cis,cis-cyclodeca-1,3,5-triene ring adopts a boat-chair conformation in which th...
Article
The cytotoxic effect of three sesquiterpene lactones isolated from aerial parts of a Compositae plant Parthenium fruticusum var. fruticusum. Less, was studied in vitro, using two cell lines: Hep-2c cells derived from human laryngeal carcinoma, and L929 fibroblast cells from normal murine connective tissue, NCTC clone 929. The tissue cultures were p...
Article
The new elemandiolide zinnacitrin has been isolated from the aerial parts of Zinnia citrea, together with known compounds. Structure of zinnacitrin was determined as 8α-angeloyloxy-6β-epoxyangeloyloxy-2-hydroxyelema-11(13),4(15)-dien-1(3),9β(12)-diolide by spectroscopic means.
Article
The known ursolic and oleanolic acids, the abietane quinone diterpenes, sessein, and deacetylsessein, together with the also known clerodane diterpenes hardwickiic and clerodermic acids were isolated from the aerial parts of Salvia regla. The structure of a novel compound, reglin, present in this species was established by spectral means as deacety...
Article
Two germacrolides have been isolated from the aerial parts of Perymenium berlandieri. Their structures were established as 15-acetylstenophyllolide[15-acetoxy-9β-hydroxygermacra-1(10),4,11(13)-trien-6α,12-olide] and 15-acetoxy-8α-hydroxycostunolide[15-acetoxy-8α-hydroxygermacra-1(10),4,11(13)-trien-6α,12-olide] by spectroscopic means and chemical t...
Article
Glaucolide B [1] was transformed, under bentonite earth/EtOAc conditions, into compound 3 ([1R,4S,5R,6S,8S,10R]-8,10,13-triacetoxy-1(4)-epoxy-1, 5-dihydroxygermacr-7(11)-en-6(12)-olide. The structures of compound 3 and of its derivatives 4 and 5 were established by nmr spectroscopy.
Article
The cytotoxic effect of three sesquiterpene dilactones isolated from aerial part of a Compositae plant Zinnia flavicoma, were studied in vitro, using two cell lines: HEp-2c cells derived from human laringeal carcinoma, and L929 fibroblast celts from normal murine connective tissue, NCTC clone 929. The tissue cultures were performed in leighton tube...
Article
A new trihydroxy neo-clerodane diterpene, infuscatin, has been isolated from Salvia infuscata. Its structure was established as 15,16-epoxy-4beta, 8alpha, 10beta-trihydroxy neo-cleroda-1,13(16),14-trien-17,12R,18,19-diolide by spectroscopic means, including H-1H-1 COSY, C-13 NMR, DEPT 135, DEPT 90, COLOC and NOE differential experiments.
Article
Two known abietane quinones were isolated from the roots of Salvia lavanduloides. A new neo-clerodane diterpene, salvianduline D, containing a 2,6-dioxabicyclo[2.2.1]heptane structural moiety, was isolated as a minor component from the aerial parts of the plant. Thus, as a result of the chemical analysis of this plant, we have found that abietane a...
Article
A new 5,6-seco-clerodane diterpene was isolated from Salvia rhyacophila. Its structure deduced from spectral data was established as 7-epi-rhyacophiline. Several known compounds including hydroquinone and its β-glucosyl derivative (arbutin) were also isolated.
Article
From aerial parts of Gymnosperma glutinosum two new diterpenoids were isolated. Their structures were established as (+)-ent-labd-7-en-13S,14R,15-triol and (−)-17-hydroxy-neo-clerod-3-en-15-oic acid, by spectral means and chemical transformations. The structure of the labdane derivative was confirmed by X-ray diffraction analysis.
Article
(4R)-Trihydroxy-13alpha-methoxycarbonyl-30-nor-3,4-seco-7alpha, 18beta-fridela-1,20-dien-3,24-olide methylene chloride solvate, C30H44O7.0.898CH2Cl2, M(r) = 601.6, orthorhombic, P2(1)2(1)2(1), a = 9.797 (4), b = 15.039 (7), c = 20.135 (8) angstrom, V = 2966.5 (8) angstrom3, Z = 4, D(x) = 1.347 g cm-3, lambda(Cu Kalpha) = 1.54178 angstrom, mu = 23.6...
Article
The crystal and molecular structure of the gochnatolide, has been determined by X-ray crystallographic analysis. The compound, obtained from the leaves ofGochnatia hypoleuca subsp.obtusata, is a germacr-8,12-olide. The two molecules in the asymmetric unit are linked together by hydrogen bonding which results in differences in the conformation of th...
Article
One new and three previously described thymol derivatives were isolated from the aerial parts of Calea nelsonii. Transesterification products of these compounds were obtained under treatment with bentonitic earth.
Article
Two amides, two coumarins, (−)-4β,10α-aromadendranediol, nevadensin, (−)-16α-hydroxykauran-19-oic acid as well as sitosterol and stigmasterol were isolated from Simsia cronquistii. 3-Phenyl-N-(2-phenylethyl) propanamide and 5-methoxy-6,7-methylenedioxycoumarin have not previously been found in nature.
Article
The chemical investigation of Galeana pratensis afforded, in addition to known sesquiterpene lactones, the new acyl flavonoids, pratensins A (5,7-dihydroxy-3,6,4′-trimethoxy-8-tigloyloxyflavone) and B [5,4′-dihydroxy-3,6,7-trimethoxy-8-(2-methylbutyroyloxy)flavone]. Structures of pratensins A and B were elucidated by spectroscopic methods, chemical...
Article
The structure and configuration of salvianduline C, a novel 5,6-secoclerodane diterpenoid isolated fromSalvia lavanduloides, have been established by high resolution NMR spectroscopy and X-ray crystallographic analysis.
Article
Two novel 9,10-secoclerodane diterpenoids, salviandulines A and B, were isolated from aerial parts of Salvia lavanduloides. Their structures were established by high resolution NMR and X-ray diffraction analysis.
Article
From the aerial parts of Salvia tiliaefolia Vahl, the known isosalvipuberulin (1) and two new clerodane diterpenoids, salvifolin and tilifodiolide, were isolated. The structure of salvifolin (5) was deduced from spectral data. The structure of tilifodiolide (2) was established by chemical and spectral means and X-ray diffraction analysis.
Article
Investigation of Epaltes mexicana afforded several eudesmane derivatives, all of them closely related to cuauhtemone. The structures of two new compounds were elucidated by spectroscopic, methods.
Article
The aerial parts of Calea crocinervosa afforded, in addition to known compounds, the novel tris-norsesquiterpene lactone, crocinervolide, whose structure was elucidated by spectroscopic methods.
Article
Adsorption of the germacranolide 4α,5β-epoxyinunolide (1) on bentonitic earth provided the guaianolide inuviscolide (2) and 4α,5α-epoxy-10α,14H-inuviscolide (3) as well as the pseudoguaianolide 8-epiconfertin (4). This one step transformation represents the first biomimetic conversion of a germacranolide into a pseudoguaianolide, substantiating pre...
Article
Chemical analysis of Gochnatia hypoleuca subsp. obtusata afforded, in addition to several known compounds, the new sesquiterpene lactone, gochnatolide. Hydrolysis and subsequent allylic oxidation of gochnatolide gave a germacrolide which was easily isomerized into a melampolide under acid treatment. Thermal isomerization of gochnatolide was also ca...
Article
Treatment of glaucolide A with boron trifluoride etherate yielded 10-acetyl-8α-(methacryloyloxy)-2-epivernomargolide 1,4-semiacetal and 8α-(methacryloyloxy)vernomargolide 1,4-semiacetal as a result of a transannular cyclization reaction. Their structures were deduced from spectral data and X-ray diffraction analysis of 5,10-diacetyl-8α-(methacryloy...
Article
In addition to compounds which are ubiquitous in Salvia species, like ursolic and oleanolic acids, we have isolated two heterobicyclic diterpenes, brevifloralactone and brevifloralactone acetate.
Article
In addition to the known tetraneurines B-D and chiapine A, two new pseudoguaianolides, parthoxetine and isochiapine B were isolated from P. fruticosum Less var. fruticosum The structure of parthoxetine, which contains an oxetane ring was confirmed by X-ray analysis.
Article
The chemical investigation of two Perymenium species afforded, in addition to known kaurane derivatives and 14-acetoxydesacetyl laurenobiolide, a new sesquiterpene, perydiscolic acid. The structures were elucidated by spectroscopic methods and a few chemical transformations.
Article
Previous studies of Helenium scorzoneraefolium (DC.) Gray (Compositae) collected in the surroundings of Mexico City reported the isolation of one unidentified isomer of helenalin (1) as well as helenalin and linifolin A (2). In order to establish the variability in its chemical composition, we have now investigated a population of this species coll...
Article
Two novel sesquiterpene lactones were isolated from Verbesina seattonii. Their structures were elucidated as elemanolides possessing an intramolecular hemiacetal function on the basis of an extensive spectral analysis and crystal structure determination.
Article
Eleman-8β,12-olides containing a β-hydroxyl group at C-9 exist in equilibrium with 8β-hydroxyeleman-9,12-olides. Acetylation of 9β-hydroxyelemanolides gave a mixture of 8β-and 9β-acetyl derivatives in which the former predominates. The structures of zinaflorin II acetate, zinaflorin III and other 9β-hydroxyelemanolide acetates have been revised. Th...
Article
Four populations of Parthenium tomentosum var. tomentosum were examinated. In addition to the known lactones, ivalbatine, acetyl ivalbatine, parthomentine, incanine and ligulatine C, three new pseudoguaianolides: 4-O-desacetyl ligulatine C; 1-dehydroperuvinine and parthoximentine were also isolated. Chemical and spectroscopic methods were used for...
Article
The structure and stereochemistry of 8α-acetoxy and 8α-tigloyloxy dehydrocostus lactones, two guaianolides isolated from the aerial parts of Gochnatia smithii, were established by chemical and spectroscopic methods.

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