Diterpenes and diterpene xylosides from Conyza trihecatactis

Torrenegra, Rubén; Robles, Jorge; Waibel, Reiner; Löwel, Matthias; Achenbach, Hans

doi:10.1016/s0031-9422(00)90533-8

Cited by 21 publications

(19 citation statements)

References 23 publications

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“…On the other hand, several epithets of the Conyza Less. genus (Asteraceae, Asteroidae, tribe Astereae) (Torrenegra et al, 1994;Galal et al, 1998) have been transferred to the Laennecia Cass. genus (Sancho and Ariza Espinar, 1999).…”

Section: Introductionmentioning

confidence: 99%

Antiinflammatory activity from aerial parts of Baccharis Medullosa, Baccharis rufescens and Laennecia sophiifolia in mice

Cifuente¹,

Simirgiotis²,

Favier³

et al. 2001

Phytotherapy Research

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The antiinflammatory activities of ten organic extracts from the aerial parts of Baccharis medullosa DC., Baccharis rufescens S. and Laennecia sophiifolia (Kunth) G. L. Nesom were investigated in mice subjected to carrageenan induced paw oedema. Intraperitoneally administered organic extracts given at doses equivalent to 80 mg/kg of material inhibited the acute phases of inflammation in this model. Our results indicate that the most effective extracts were: n-hexane (I) from B. medullosa, acetone (V) and chloroform (VII) from L. sophiifolia, and acetone (VIII) and chloroform (X) from B. rufescens. All exerted the strongest effect at 5 h after injection of the phlogistic agent.

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Section: Introductionmentioning

confidence: 99%

Antiinflammatory activity from aerial parts of Baccharis Medullosa, Baccharis rufescens and Laennecia sophiifolia in mice

Cifuente¹,

Simirgiotis²,

Favier³

et al. 2001

Phytotherapy Research

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“…27 The literature also reports the 13 C NMR data for sclareol, 25 ent-sclareol 27 and 13-epi-sclareol 16 epi-sclareol, based mainly on the C-13 chemical shift (δ 75.2), which in the case of sclareol (or ent-sclareol) is found at δ 73.0. (Table 1).…”

Section: Resultsmentioning

confidence: 99%

“…27 The literature also reports the 13 C NMR data for sclareol, 25 ent-sclareol 27 and 13-epi-sclareol 16 (Table 1). 16,25,27 Thus, according to the latter evidences we suggest that the diterpenes here reported belong to the 13-epi-sclareol series whose stereochemistry is depicted in Figure 1. On the basis of the above spectroscopic data, in addition to all optical rotation considerations, compound 1 was identified as the novel labdane diterpenoid 8α-hydroxylabd-14(15)-ene-13(S)-O-β-D-ribopyranoside.…”

Section: Resultsmentioning

confidence: 99%

A Labdane diterpene from the aerial parts of Egletes viscosa less

Silva-Filho

Lima

Bezerra

et al. 2007

J. Braz. Chem. Soc.

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Um novo labdano glicosilado, 8α-hidroxilabd-14(15)-eno-13(S)-O-β-D-ribopiranosídeo, foi isolado das partes aéreas de Egletes viscosa Less, juntamente com o 13-epi-esclareol, barbatol, tarapacol, espinasterol, ternatina e triacontano. As estruturas dos compostos isolados foram elucidadas pelo uso de métodos espectrométricos e preparação de derivados químicos.A new labdane glycoside, 8α-hydroxylabd-14(15)-ene-13(S)-O-β-D-ribopyranoside, was isolated from the aerial parts of Egletes viscosa Less, along with 13-epi-sclareol, barbatol, tarapacol, spinasterol, ternatin and triacontane. The structures of the isolated compounds were elucidated by the use of spectrometric methods and preparation of chemical derivatives. Keywords: Asteraceae, Egletes viscosa, diterpene glycoside, 8α-hydroxylabd-14(15)-ene-13(S)-O-β-D-ribopyranoside IntroductionEgletes viscosa Less (Asteraceae) is an annual herb mostly native to intertropical Americas. It is known in the Northeast of Brazil as "macela" or "macela-da-terra" and grows throughout the margins of river and lakes as soon as the raining season ends. The flower buds are largely sold in the herbal stores and used in the folk medicine as emmenagogue, diaphoretic, 1 stomachic and antidiarrhoeal. 2 Previous studies with E. viscosa have reported the isolation of biologically active flavonoids and diterpenoids. [3][4][5][6][7][8][9][10][11][12][13][14] Recently, Lee et al reported the isolation of labdane diterpene glycosides and flavonoids from the entire plant native from Peru. 15 In continuation of the work with this species, we report now the isolation of the new labdane glycoside 8α-hydroxylabd-14(15)-ene-13(S)-O-β-D-ribopyranoside 1 in addition to 13-epi-sclareol, 16 barbatol, 17 tarapacol, 18 spinasterol, 19 ternatin, 7, 20-23 and triacontane from the aerial parts of E. viscosa. The complete proton and carbon assignments of the known compounds and of the new diterpene 1, including the unpublished 13 C and 1 H NMR data of the new derivatives 2-4 were accomplished by the use of a series of 2D NMR experiments such as 1 H-1 H COSY, HMQC and HMBC. Results and DiscussionCompound 1 was isolated as a white solid. Its molecular formula was determined as C 25 H 44 O 6 from the NMR and EImass spectroscopy measurements (m/z = 440). The absorption band in the IR spectrum at 3400 cm -1 was consistent with hydroxyl groups. Inspection of the 1 H NMR spectrum indicated the presence of three angular methyl groups at δ 0.81 (s, H-19 and H-20) and 0.88 (s, H-18), two methyls attached to oxygenated tertiary carbons at δ 1.11 (s, H-17) and 1.35 (s, H-16), and an anomeric hydrogen at δ 4.32 (d, J 6.4 Hz,. Moreover, the presence of a vinyl moiety was suggested by the signals at δ 5.92 (dd, J 17.8, 10.9, H-14); 5.22 (dd, J 17.8, 1.2, H-15a) and 5.17 (dd, J 10.9, 1.2, H-15b). The 13 C NMR spectral data of 1 confirmed 1375 Silva-Filho et al. Vol. 18, No. 7, 2007 the β-ribopyranosyl unit by the signals at δ 98.6 (C-1´), 73.1 (C-3´), 71.3 (C-2´), 68.2 (C-4´) and 65.1 (C-5´); 24 together with 20 carbon ...

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“…1 Pure thallusin strongly induced the differentiation of Monostroma oxyspermum with a minimum effective concentration between 1 fg/mL and 1 ag/mL. The structure of 1 was established by X-ray crystal structure determination of a derivative Me1H1W4 (16); the absolute stereochemistry was not assigned.…”

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confidence: 99%

“…ent-Sclareol has been isolated once from Conyza trihecatactis. 16 The related diterpene copalic acid 17 with the same absolute stereochemistry as thallusin can be isolated from copaiba oil in up to 46% enantiomeric excess. 18 The widely used natural sweetener stevioside contains a tetracyclic diterpene with the same absolute stereochemistry as thallusin.…”

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confidence: 99%