Sesquiterpene lactones from Stevia alpina var. glutinosa

Hernández, Zaida N.J.de; Catalán, César A.N.; Hernández, Lucina; Guerra-Ramı́rez, Diana; Joseph‐Nathan, Pedro

doi:10.1016/s0031-9422(98)00542-1

Cited by 14 publications

(9 citation statements)

References 14 publications

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“…Previous investigations of Acanthospermum species − have led to the isolation of cis , cis -germacranolides and melampolides, in agreement with the fact that many species of the genera Acanthospermum , Melampodium, and Lecocarpus, belonging to the tribe Heliantheae, subtribe Melampodiinae, contain melampolides . In view of the fact that these compounds show cytotoxic and in vivo anticancer activity, and as a continuation of our work on sesquiterpene lactones of the Argentinian species of Asteraceae, − we have carried out an exhaustive examination of the minor constituents of A. hispidum (Asteraceae), a shrub indigenous to northern Argentina. The aerial parts afforded the new guaianolides hispidunolides A ( 1 ) and B ( 2 ) with an unprecedented oxygen bridge between C-4 and C-14; the new cis,cis -germacranolides 4 , 7 , and 8 ; the new melampolides 25 and 26 ; and the known sesquiterpene lactones 3 , 5 , 6 , 9 − 18 , previously isolated from American 1,2 and African 3,4 collections of A. hispidum ; compounds 19 − 23 , previously found in species of Lecocarpus from Ecuador; , compound 24 , previously isolated from an Australian collection of Siegesbeckia orientalis ; and loliolide …”

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confidence: 81%

Germacranolides and a New Type of Guaianolide from Acanthospermum hispidum

et al. 2000

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The aerial parts of an Argentinian collection of Acanthospermum hispidum afforded 26 sesquiterpene lactones, including the two guaianolides (1 and 2) having a novel oxygen bridge between C-4 and C-14, three new cis,cis-germacranolides (4, 7, and 8), and two new melampolides (25 and 26). Guaianolides 1 and 2 seem to derive biosynthetically from the germacranolide 27 having the (1)D(14, 15)D(5) conformation. The structures were elucidated using extensive spectroscopic analysis.

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confidence: 81%

Germacranolides and a New Type of Guaianolide from Acanthospermum hispidum

et al. 2000

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“…es2 7 Centaurea babylonica 44 CAR CAR.es1 6 Centaurea acaulis 45 CAR CAR.es2 6 SteVia alpina var. glutinosa 46 EUP EUP.es1 9 Viguiera eriophora 47 HLT HLT.es1 11 Carpesium abrotanoides 48 INU INU.es1 8 Leontodon palisae 49 LAC LAC.es1 5 Vernonanthura lipeoensis 50 VER VER.es1 17 total 72 tion of compounds which show certain features at specific positions of their skeletons, e.g. R-or -oriented hydroxyl groups and their corresponding esters, reduction of double bonds, epoxy groups, etc.…”

Section: Atom Countsmentioning

confidence: 99%

Sesquiterpene Lactones-Based Classification of the Family Asteraceae Using Neural Networks and k-Nearest Neighbors

Hristozov

Costa

Gasteiger

2006

J. Chem. Inf. Model.

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In a recent publication we described the application of an unsupervised learning method using self-organizing maps to the separation of three tribes and seven subtribes of the plant family Asteraceae based on a set of sesquiterpene lactones (STLs) isolated from individual species. In the present work, two different structure representations--atom counts (2D) and radial distribution function (RDF) (3D)--and two supervised classification methods--counterpropagation neural networks and k-nearest neighbors (k-NN)--were used to predict the tribe in which a given STL occurs. The data set was extended from 144 to 921 STLs, and the Asteraceae tribes were augmented from three to seven. The k-NN classifier with k = 1 showed the best performance, while the RDF code outperformed the atom counts. The quality of the obtained model was assessed with two test sets, which exemplified two possible applications: (1) finding a plant source for a desired compound and (2) based on a plant species chemical profile (STLs): (a) study the relationship between the current taxonomic classification and plant's chemistry and (b) assign a species to a tribe by majority vote. In addition, the problem of defining the applicability domain of the models was assessed by means of two different approaches-principal component analysis combined with Hotelling T2 statistic and an a posteriori probability-based rule.

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“…230 species, is distributed from southwestern United States to central Argentina. Although its chemistry is not very uniform, the main secondary metabolites of the genus are sesquiterpene lactones, diterpenes, and longipinenes, as recently reviewed . Continuing the search for new substances from North American representatives of this genus, − we studied the hexane extracts of the roots of Stevia connata Lag.…”

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Longipinane Derivatives from Stevia connata

et al. 1999

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The hexane extracts of the roots of Stevia connata afforded three new longipinene derivatives, longipinane-7beta,8alpha, 9alpha-triol-1-one 7-angelate-8-methylbutyrate (1), longipin-2-ene-7beta,8alpha,9alpha-triol-1-one 8,9-diangelate (6), and longipin-2-ene-7beta,8alpha,9alpha-triol-1-one 8-angelate-9-methylbutyrate (8), together with the known longipinane-7beta,8alpha,9alpha-triol-1-one 8,9-diangelate (2), longipinane-7beta,8alpha,9alpha-triol-1-one 7,9-diangelate (3), longipinane-7beta,8alpha,9alpha-triol-1-one 7,8-diangelate (4), longipin-2-ene-7beta,8alpha,9alpha-triol-1-one 7,8-diangelate (5), longipin-2-ene-7beta,8alpha,9alpha-triol-1-one 7-angelate-8-methylbutyrate (12), and stigmasterol. The structures of the new compounds were determined by chemical transformations and spectral methods including 2D NMR measurements. Spontaneous intramolecular transesterifications starting from the 8-angelate-9-methylbutyrate 8 provided an equilibrated mixture of the 7-angelate-9-methylbutyrate 10, the 7-angelate-8-methylbutyrate 12 and the starting material when stored in MeOH-H(2)O solution, while the 8,9-diangelate 6 only provided a binary mixture of the 7, 9-diangelate 7 and the starting material under the same conditions. The structures of 6-8, 10, and 12 and those of the nonisolable reaction intermediates 9, 11, and 14 were further evaluated by AM1 semiempirical calculations.

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Sesquiterpene lactones from Stevia alpina var. glutinosa

Cited by 14 publications

References 14 publications

Germacranolides and a New Type of Guaianolide from Acanthospermum hispidum

Germacranolides and a New Type of Guaianolide from Acanthospermum hispidum

Sesquiterpene Lactones-Based Classification of the Family Asteraceae Using Neural Networks and k-Nearest Neighbors

Longipinane Derivatives from Stevia connata

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