13C NMR spectral analysis of lignans from Araucaria angustifolia

Fonseca, S.F.; Campello, Jayr de Paiva; Barata, Lauro Euclides Soares; Rúveda, Edmundo A.

doi:10.1016/s0031-9422(00)89347-4

Cited by 135 publications

(78 citation statements)

References 8 publications

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“…However, in 6a an additional C6-C 3 unit appeared. The 13CNMR spectrum (Table 2) confirmed the relationship between 6a and la [8] and a triacetyl-guaiacylglycerol ether was established as the structure for this unit, according specifically to the signals at 874.51 (CH), 80.40 (CH) and 63.06 (CH2) [9]. The relative configuration of the glycerol part was established as being threo by comparing the 1HNMR data with the literature [9][10][11][12].…”

Section: Resultsmentioning

confidence: 59%

Two sesquilignans from the wood of Abies marocana

et al. 1996

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Abstract--From the chloroform extract of the wood of Abies rnarocana, consisting mainly of lignans, the acetoxyl derivatives of the new sesquilignans, 4,4",7",9,9"-pentahydroxy-3,3',3"-trimethoxy-4',8":7,9 were isolated; the trivial names, sesquimarocanols A and B, were subsequently assigned, respectively. Also, (9'R)-9'-hydroxylariciresinol tetraacetate, (7'R)-7'-hydroxylariciresinoi tetraacetate and sesquipinsapol B pentaacetate, which had previously only been found in A. pinsapo, were isolated, together with some well known compounds. The new structures were established by spectroscopic methods. Certain cytotoxic activity assays were performed on the new compounds.

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Section: Resultsmentioning

confidence: 59%

Two sesquilignans from the wood of Abies marocana

et al. 1996

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“…The NMR data exhibited the characteristics of (ϩ)-isolaricireinol. 21,24) The unusual downfield shift of H-2a and C-2a and the upfield shift of C-2 suggest the linkage of the -OSO 3 Ϫ group at C-2a. The CD spectrum of 2 resembled that of (ϩ)-isolaricireinol.…”

Section: ϫmentioning

confidence: 98%

Constituents from Polygonum cuspidatum.

Xiao

Liu

et al. 2002

CHEMICAL & PHARMACEUTICAL BULLETIN

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“…Ϫ34.6°, acetone) 6) and D-glucose [[a ] D 20 ϩ27.6°(H 2 O)], confirmed that 1 is a glucopyranoside of 1a. When downfield shifts of C-1 and C-4 of 1 were compared with those of 1a (Table 1), they indicated a glycosidic linkage at the C-4 hydroxyl group.…”

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confidence: 88%

“…Its positive FAB-MS spectrum exhibited an [MϩNa] ϩ ion peak at m/z 543, indicating that the degree of unsaturation of 2 is one greater than that of 1. In the 1 H-NMR spectrum of 2, in addition to the signals arising from two methoxyl groups, a b-glucopyranose moiety, 1,3,4-trisubstituted and 1,3,4,5-tetrasubstituted benzene rings which are similar to those of 1, two olefinic proton signals [d H 6.61 (1H, d, Jϭ16 Hz), 6.22 (1H, dt, Jϭ16, 6 Hz)] of a trans double-bond were observed. The presence of glucose was also confirmed by acid hydrolysis of 2, followed by cochromatography with an authentic sample of glucose on high performance liquid chromatography (HPLC).…”

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confidence: 99%

Studies on a Medicinal Parasitic Plant: Lignans from the Stems of Cynomorium songaricum.

et al. 2001

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Parasitic plants are defined as vascular plants that have developed specialized organs for the penetration of the tissues of other vascular plants (hosts) and the establishment of connections to the vascular strands of the host for the absorption of nutrients by the parasite. Parasitic plants are commonly divided into holoparasites that lack chlorophyll, do not carry out photosynthesis, and absorb organic matter from the hosts, and hemiparasites that are green, capable of photosynthesis, and absorb mainly inorganic nutrients from hosts. From ancient times, a number of parasitic plants have been widely used as traditional medicines in China. For the purpose of understanding the unusual secondary metabolism in parasitic plants and elucidating the pharmacologically active constituents of traditional Chinese medicines derived from parasitic plants, we initiated studies of the chemical constituents of Cynomorium songaricum RUPR. (Cynomoriaceae). C. songaricum belongs is an achlorophyllous holoparasite that is distributed in the northwestern part of China. Its stems are used as tonics and for the treatment of kidney disorders. 1)Among its chemical constituents, steroids, triterpenes, 2) fructosides, 3) flavanoids, and condensed tannins 4) have been reported previously. This paper deals with the structural elucidation of two new phenolic compounds (1 and 2) isolated from the stems of C. songaricum and their chemotaxonomic significance. Results and DiscussionMeOH extracts and 70% aqueous acetone extracts of the stems of C. songaricum were combined and subjected to partition between the EtOAc and H 2 O layers. The H 2 O layer and EtOAc layer were individually fractionated and purified by a combination of column chromatographies as described in the Experimental Methods section. Compounds 1 and 2, together with nicoloside, 5) gallic acid, phloridzin, 4) and rutin were isolated from the H 2 O layer. Methyl protocatechuicate, p-hydroxy benzoic acid, and (Ϫ) catechin were obtained from the EtOAc layer. The known compounds were identified by comparison with authentic samples or reported spectral and physical data.Compound , confirmed that 1 is a glucopyranoside of 1a. When downfield shifts of C-1 and C-4 of 1 were compared with those of 1a (Table 1), they indicated a glycosidic linkage at the C-4 hydroxyl group. The anomeric configuration of glucopyranose was determined to be b from the 3 J H1,H2 value (7 Hz). The absolute configuration of C-7Ј of 1 was further established to be R, since a positive Cotton effect at 291 nm 7) was observed in the CD spectrum. Thus compound 1 was determined to be (Ϫ)-isolariciresinol 4-O-b-D-glucopyranoside. Eight phenolic compounds including two new lignan glucopyranosides together with a known alkaloid were isolated from the stems of Cynomorium songaricum RUPR. (Cynomoriaceae). Their chemical structures were elucidated on the basis of spectral and chemical evidence. The chemotaxonomic significance of these metabolites is discussed.

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13C NMR spectral analysis of lignans from Araucaria angustifolia

Cited by 135 publications

References 8 publications

Two sesquilignans from the wood of Abies marocana

Two sesquilignans from the wood of Abies marocana

Constituents from Polygonum cuspidatum.

Studies on a Medicinal Parasitic Plant: Lignans from the Stems of Cynomorium songaricum.

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