Eremophilane Derivatives Research Articles

Antimicrobial properties of unusual eremophilanes from the endophytic Diaporthe sp. BCC69512

Six undescribed infrequent eremophilane derivatives including diaportheremopholins A – F and its previously undescribed side chain (E)-2-methyloct-2-enoic acid, together with three known compounds (testacein, xestodecalactones B and C), were isolated from the endophytic fungus Diaporthe sp. BCC69512. The chemical structures were determined based on NMR spectroscopic information in conjunction with the evidence from NOESY spectrum, Mosher's application, and chemical reactions for corroborating the absolute configurations. The isolated compounds were evaluated for biological properties such as antimalarial, anti-TB, anti-phytopathogenic fungal, antibacterial activities and for cytotoxicity against malignant (MCF-7 and NCI–H187) and non-malignant (Vero) cells. Diaportheremopholins B (2) and E (5) possessed broad antimicrobial activity against Mycobacterium tuberculosis, Bacillus cereus, Alternaria brassicicola and Colletotrichum acutatum with MICs in a range of 25.0–50.0 μg/mL. Testacein (7) exhibited strong anti-A. brassicicola and anti-C. acutatum activities with equal MIC values of 3.13 μg/mL. Moreover, diaportheremopholin F (6) and compound 8 displayed antitubercular activity with equal MIC values of 50.0 μg/mL. All tested compounds were non-cytotoxic against MCF-7, NCI–H187, and Vero cells, except those compounds 2 and 5–7 exhibited weak cytotoxicity against both malignant and non-malignant cells with IC50 values in a range of 15.5–115.5 μM.

Secondary Metabolites from Mexican Species of the Tribe Senecioneae (Asteraceae)

Abstract. A revision of the Mexican species belonging to the tribe Senecioneae chemically studied so far, shows that the genera Senecio and Packera (subtribe Senecioninae), and the genera Barkleyanthus, Pittocaulon, Psacalium, and Telanthophora (subtribe Tussilagininae) contain pyrrolizidine alkaloids (PAs) and eremophilane derivatives as their main secondary metabolites. However, from Roldana and Robinsonecio (subtribe Tussilagininae) no PAs have been isolated. A special case is the genus Pseudogynoxys in which neither PAs nor eremophilanes are reported.
 
 Resumen. Una revisión de las especies mexicanas de la tribu Senecioneae estudiadas químicamente hasta el momento, muestra que los géneros Senecio y Packera (subtribu Senecioninae), y los géneros Barkleyanthus, Pittocaulon, Psacalium y Telanthophora (subtribu Tussilagininae) contienen alcaloides pirrolizidínicos (APs) y derivados de eremofilano como sus metabolitos secundarios principales. Sin embargo, de Roldana y Robinsonecio (subtribu Tussilagininae) no se han aislado APs. Un caso especial es el género Pseudogynoxys para el cual no se han reportado ni APs ni eremofilanos.

Four new metabolites from the endophytic fungus Diaporthe lithocarpus A740

One new benzophenone derivative, named tenllone I (1), two new eremophilane derivatives lithocarins B (2) and C (3), and a new monoterpentoid lithocarin D (4), together with two know compounds (5 and 6) were isolated from the endophytic fungus Diaporthe lithocarpus A740. All of the structures for these new compounds were fully characterized and established on the basis of extensive spectroscopic interpretation. In addition, all the isolated compounds were evaluated in vitro for their cytotoxic activity. Compounds 2, 3, and 5 showed weak inhibitory activities against tumor cell lines.

Total synthesis and determination of the absolute configuration of paralemnolin C and biological studies of eremophilane derivatives

The first asymmetric total synthesis of paralemnolin C was achieved. The absolute configuration at C11 of this natural product was determined from the X-ray crystallographic analysis of the epoxide derivative. In addition, biological studies of eremophilane derivatives including paralemnolin C and sagittacin E were carried out.

Highly Substituted Benzophenone Aldehydes and Eremophilane Derivatives from the Deep-Sea Derived Fungus Phomopsis lithocarpus FS508.

Five new benzophenone derivatives named tenellones D–H (1–5), sharing a rare naturally occurring aldehyde functionality in this family, and a new eremophilane derivative named lithocarin A (7), together with two known compounds (6 and 8), were isolated from the deep marine sediment-derived fungus Phomopsis lithocarpus FS508. All of the structures for these new compounds were fully characterized and established on the basis of extensive spectroscopic interpretation and X-ray crystallographic analysis. Compound 5 exhibited cytotoxic activity against HepG-2 and A549 cell lines with IC50 values of 16.0 and 17.6 μM, respectively.

Nitric Oxide Inhibitory Sesquiterpenoids and Its Dimers from Artemisia freyniana.

Two new disesquiterpenoids (1 and 2) and 11 new (3-13) and 10 known (14-23) sesquiterpenoids were isolated from the whole plants of Artemisia freyniana. Their structures were elucidated by spectroscopic data analysis and comparison with published NMR data. The absolute configurations of the new isolates (1-13) were assigned based on single-crystal X-ray diffraction data and comparison of the experimental and calculated ECD data. The eremophilane derivatives 8 and 9 possess an unprecedented 2-isopropyl-3,7,7a-trimethyl-2,4,5,6,7,7a-hexahydro-1 H-indene scaffold, and a putative biosynthetic pathway for these compounds is proposed. Compounds 4, 5, and 9 exhibited inhibitory effects against LPS-stimulated nitric oxide (NO) production in RAW 264.7 macrophage cells with IC50 values of 10.8, 12.6, and 11.7 μM, respectively.

A new eremophilane derivative from Ligularia intermedia

A new eremophilane derivative, (3aR,4R,5S,7S,7aS)-2-acetyl-7,7a-dihydroxy-3a,4-dimethyl-3a,4,5,6,7,7a-hexahydro-3H-inden-5-yl acetate (1) and three known compounds, 10beta-hydroxy-eremophil-7 (11)-en-12,8alpha-olide(2), beta-sitosterol (3) and beta-daucosterol(4) have been isolated from Ligularia intermedia. The compounds were isolated by column chromatography on silica gel and Sephadex LH-20,and identified on the basis of spectral analyses (MS, 1H-NMR, 13C-NMR).

A new eremophilane derivative from Senecio dianthus

A new eremophilane derivative, 4,5,11-trimethyl-9( 10), 7 ( 11) -eremophiladien-8-keto-12-carboxylic acid-beta-D-glucopyranoside( which named dianthuside A) 1 and four known compounds, 5,7,4'-trihydroxy-flavonone-3-0-beta-D-glucoside (2), quercetin-3-0-beta-D-glucoside(3) ,hyperin(4) and rutin(5) have been isolated from the aerial part of Senecio dianthus. Their structures were elucidated by physicochemical properties and spectroscopic data analysis. Compounds 2, 4 and 5 were isolated from this plant for the first time.

Eremophilane derivatives from Senecio dianthus

From the aerial parts of Senecio dianthus, five eremophilane glucosides (1, 2, 4-6) and one new eremophilenolide (7) were isolated, together with sixteen known compounds (3, 8-22). Their structures and relative configurations were elucidated on the basis of extensive spectroscopic analysis, including HR-ESI-MS, X-ray, CD, 1D- and 2D-NMR experiments.

ChemInform Abstract: Furanoeremophilane Derivatives from Senecio flavus.

The aerial parts of Senecio flavus contain besides known eremophilane derivatives, four new furanoeremophilanes oxidized at C-3 and a new eremophilenone lactam. The rhizomes of the plant also contain the same ketoeremophilenes found in the aerial parts and a new epoxyeremophilanolide. The structure of these compounds has been established by spectroscopic methods.

Four New Eremophilane Derivatives from Ligularia sagitta

Abstract Four new compounds (1a and 2–4), a series of uncommon eremophilane derivatives with C19-carbon skeleton, were isolated from the roots of Ligularia sagitta Maxim. Their structures were respectively determined by extensive spectroscopic analysis (IR, MS, NMR, and X-ray).

High Diversity of Ligularia dictyoneura in Chemical Composition and DNA Sequence

The chemical composition of root extracts of the title species collected at 20 different places in the Hengduan Mountains of China was examined. From these samples, a total of 17 eremophilane derivatives were isolated, three of which were new franoeremophilane derivatives: 3beta-acetoxy-6beta-(angeloyloxy)furanoeremophilan-10beta-ol, 1alpha-acetoxyfuranoeremophilan-15,6alpha-olide, and 6beta-[2-(hydroxymethyl)prop-2-enoyloxy]furanoeremophil-1(10)-ene. Based on the chemical composition, the samples could be classified into as many as seven types: one type containing non-furanoeremophilane derivatives and the other six containing furanoeremophilane derivatives with different oxidation levels. Results of DNA sequencing of the atpB-rbcL region and the internal transcribed spacers of the ribosomal RNA gene also indicated a high diversity in the species.

Five new eremophilane derivatives from Ligularia sagitta

Ligulasagitins A–E ( 1– 5), five new eremophilane-derived metabolites possibly formed via a Diels–Alder reaction in the biosynthetic process, were isolated from Ligularia sagitta Maxim. Among them 1 and 2 possess a novel C19 skeleton, 4 and 5 are two novel dimeric eremophilane type derivatives. Their structures were determined by extensive spectroscopic analysis and the structure of 2 was also confirmed by a single-crystal X-ray diffraction analysis. Furthermore, 4 and 5 showed weak cytotoxic activity against HL-60 (human promyelocytic leukemia) cells.

Chemical constituents of Roldana lineolata

The new eremophilanolide 1, the known eremophilane derivatives 2 and 3, already described as part of mixtures, the known compounds hyperin, 2″-acetylhyperin and two calenduladiol esters were isolated from Roldana lineolata. Their structures were determined by spectroscopic methods. Compounds 1 and 2 as well as their acetylated and oxidized derivatives were tested against several fungi strains. Eremophilanolide 1 showed a mild activity against Trichophyton mentagrophytes.

New oplopane and eremophilane derivatives from Robinsonecio gerberifolius.

A phytochemical study of Robinsonecio gerberifolius afforded six new sesquiterpenoids, two oplopane (1and 2) and four eremophilane derivatives (3-6). The structures of these compounds were elucidated on spectroscopic grounds, and the absolute configurations of compounds 3 and 4 were established from CD analysis. The known 3beta-angeloyloxy-1,10-epoxyfuranoeremophilane (7) was also isolated, and its stereochemistry was revised. The cytotoxic activities of compounds 1-7 were determined against five human cancer cell lines.

Sesquiterpenes from Ligularia Hodgsonii

AbstractA new nor‐sesquiterpenoid eremophilane derivative and a new eudesmane derivative were isolated from the whole plants of Ligularia hodgsonii. Their structures were elucidated by spectroscopic methods and 2D NMR techniques.

Furanoeremophilane derivatives from Senecio flavus

The aerial parts of Senecio flavus contain besides known eremophilane derivatives, four new furanoeremophilanes oxidized at C-3 and a new eremophilenone lactam. The rhizomes of the plant also contain the same ketoeremophilenes found in the aerial parts and a new epoxyeremophilanolide. The structure of these compounds has been established by spectroscopic methods.

Furanoeremophilanes and a bakkenolide from Senecio auricula var. major

The roots of Senecio auricula var. major yielded, in addition to known compounds, four new eremophilane derivatives: the furanoeremophilanes 6 β-(2-methylbutyryloxy)-10 αH-furanoeremophilan-1-one, 6β-isobutyryloxysenberginone, 6β-(2-methylbutyryloxy)-senberginone and the bakkenolide 11 β,12 β-epoxy-6β-(2-methylbutyryloxy)- Δ 1(10)-7-epidihydrobakkenolide A (senauricolide). Alkaline hydrolysis of senberginone esters gave, apart from the expected alcohols, the isomeric new 1 β-hydroxy-10 βH-furanoremophilan-6-one. The aerial parts contained α-tocopherol, fatty esters of β-amyrin, fatty esters of 20(29)-lupene-3β,16β-diol and sitosterol.

Eremophilane Derivatives with a Novel Carbon Skeleton from Ligularia veitchiana

Abstract Ligulaverin A 1, an eremophilane derivative with a novel carbon skeleton, was isolated from the medicinal plant Ligularia veitchiana, along with four analogues (ligulaverin B 2, ligulaverin C 3, ligulaverin D 4 and ligulaverin E 5). Their structures were elucidated by NMR techniques and X-ray diffraction. The biosynthetic route to this nineteen-carbon skeleton is discussed. © 1997 Elsevier Science Ltd.

Bipolal: Anti-Microalgal Compound Isolated as a Candidate for Marine Antifouling Produced by Bipolaris sp. F5206

Bipolal [1], a new compound with marine antifouling potential, was isolated from the culture broth of Bipolaris sp. The structure was determined to be an eremophilane derivative on the basis of 2D nmr spectroscopy and chemical transformations.