Sesquiterpenoids from Ligularia virgaurea spp. oligocephala

Four novel eremophilane-type sesquiterpene lactones, 6β,10α-dihydroxy-1-oxoeremophila-7(11),8(9)-dien-12,8-olide (1), 6β-acetyl-2-oxoeremophila-1(10),7(11), 8(9)-trien-12,8-olide (2), 6β,8β-diacetyl-2-oxoeremophila-1(10),7(11)-dien-12,8-olide (3), dimeric eremophilane ligulolide B (5), and known sesquiterpenoid, 6β,8α-diacetyleremophila-1(10),7(11)-dien-12,8-olide (4), were isolated from an extract of the whole plant of Ligularia virgaurea spp. oligocephala. The structure of 1 was confirmed by NMR spectra and single crystal X-ray crystallography investigation, as well as 2, 3, and 5 were elucidated by spectroscopic methods including 1D and 2D NMR spectra. A discussion of biogenesis of 5 was described. Cytotoxicities of compound 1 were measured in vitro against selected cancer cells human promyelocytic leukemia (HL-60), human ovarian (HO-8910) and human lung epithehial (A-549).     

Complete assignments of 1H and 13C NMR spectral data for three sesquiterpenoids from Inula helenium

The complete assignments of all the (1)H and (13)C NMR signals of three sesquiterpene lactones, 4-oxo-5(6),11-eudesmadiene-8,12-olide (1), 4-oxo-11-eudesmaene-8,12-olide (2) and (1(10)E)-5beta-Hydroxygermacra-1(10),4(15),11-trien-8, 12-olide (3), were carried out by various 2D NMR experiments. Compounds 1-3 were isolated from the roots of Inula helenium for the first time. Among them, 1 was identified as a new nor-sesquiterpene lactone, and 2 was isolated from a natural source for the first time. The (13)C-NMR data of compound 3 was also reported for the first time.     

Chemical constituents from Farfugium japonicum var. formosanum

Two new eremophilenolides, 6beta,8beta,10beta-trihydroxyeremophil-7(11)-en-12,8-olide (1) and 3beta-acetoxy-8alpha-hydroxy-6beta-methoxyeremophila-7(11),9-dien-12,8-olide (2) along with twenty-nine other compounds were obtained from the methanolic extracts of the aerial parts and rhizomes of Farfugium japonicum (L.) Kitam. var. formosanum (Hayata) Kitam. (Compositae = Asteraceae). The structures of the isolated compounds were characterized and identified by spectral techniques. Compounds 5, 6, 10, 12-24, 29, and 30, were reported for the first time from this genus. Cytotoxicity and anti-inflammatory activity of the isolated compounds were evaluated. Compounds 3 and 16 possessed moderate cytotoxicity against human breast cancer cell line (MCF 7). Compounds 3, 16, 25 and 26 exhibited moderate cytotoxicity against hepatoma cells (Hep G2 and Hep 3B). With respect to the anti-inflammatory activity, compounds 15 and 16 (each 10 microg/mL) inhibited superoxide anion generation by human neutrophils in response to fMLP/CB by 92.0% and 87.3%, respectively.     

A New Eremophilane Sesquiterpenoid from Ligularia przewalskii

Chemistry of Natural Compounds - A new eremophilane sesquiterpenoid, 3β-acetoxy-6α-angeloyloxy-eremophil-1(10),7(11),8(9)-trien-12,8-olide (1), was isolated from Ligularia przewalskii....     

Eremophilane sesquiterpenes from the endophytic fungus Xylaria sp. GDG-102

A new eremophilane sesquiterpene, xylareremophil (1), together with five known eremophilanes, 1α,10α-epoxy-3α-hydroxyeremophil-7(11)-en-12,8β-olide (2), 1,10α,13-trihydroxyeremophil-7(11)-en-12,8-olide (3), 1α,10α-epoxy-13-hydroxyeremophil-7(11)-en-12,8β-olide (4), mairetolides B (5) and G (6) were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from Sophora tonkinensis. Their structures were elucidated on the basis of spectroscopic data analysis. The absolute configurations of 1 was determined by comparing computed electronic circular dichroism (ECD) and optical rotation (OR) with experimental results. Compounds 1, 5 and 6 showed antibacterial activities against Proteus vulgaris, Micrococcus luteus, Micrococcus lysodeikticus and Bacillus subtilis with MIC values of 25–100 μg/mL.     

Tobacco Chemistry.29. (7S)-10-Oxo-4xi-methyl-7-isopropyl-5E-undecen-4-olide, a New Thunbergan-type Nor-isoprenoid isolated from Greek Nicotiana tabacum L.

The structure of a new C15-lactone, (7S)-10-oxo-4xi-methyl-7-isopropyl-5E-undecen-4-olide, isolated from Greek tobacco, has been determined mainly be 1H NMR, 13C NMR and high resolution MS, and its absolute configuration established by degradation to (2S)-5-oxo-2-isopropylhexanal. The carbon skeleton of the new compound indicated that it is derived from a thunbergane precursor and constitutes the first C15 nor-thunberganoid in tobacco.     

Two new sesquiterpene lactones from Ixeris chinensis

Phytochemical investigation of Ixeris chinensis NAKAI (Asteraceae) has resulted in the isolation of a new guaianolide-type sesquiterpene lactone, ixerochinolide (1) as well as the related glucoside, ixerochinoside (2). In addition, the known guaianolides, 8beta-hydroxy-3-oxo-guaia-4(15),10(14),11(13)-trien-1alpha,5alpha,6beta,7alphaH-12,6-olide (8beta-hydroxydehydrozaluzanin), 8beta,15-dihydroxy-2-oxo-guaia-1(10),3,11(13)-trien-5alpha,6beta,7alphaH-12,6-olide (lactucin), 3beta,8alpha,10alpha-trihydroxy-guaia-4(15),11(13)-dien-1alpha,5alpha,6beta,7alphaH-12,6-olide (10alpha-hydroxy-10,14-dihydro-desacylcynaropicrin) and 3beta-D-glucopyranosyloxy-8beta-(p-hydroxyphenylacetyloxy)-guaia-4(15),10(14),11(13)-trien-1alpha,5alpha,6beta,7alphaH-12,6-olide (8-epicrepioside) were identified. The structures were determined on the basis of spectral analyses, especially 1- and 2D NMR. Compound 1 exhibited significant cytotoxicity against human PC-3 tumor cells.     

Conformationally constrained dipeptide surrogates with aromatic side-chains: synthesis of 4-aryl indolizidin-9-one amino acids by conjugate addition to a common alpha,omega-diaminoazelate enone intermediate

Four methyl 9-oxo-8-(N-(Boc)-amino)-4-phenyl-1-azabicyclo[4.3.0]nonane carboxylates (11, 4-Ph-I(9)aa-OMe) were synthesized from (2S,8S,5E)-di-tert-butyl-4-oxo-5-ene-2,8-bis[N-(PhF)amino]azelate [(5E)-7, PhF = 9-(9-phenylfluorenyl)] via a seven-step process featuring a conjugate addition/reductive amination/lactam cyclization sequence. Various nucleophiles were used in the conjugate addition reactions on enone (5E)-7 as a general route for making alpha,omega-diaminoazelates possessing different substituents in good yield albeit low diastereoselectivity except in the case of aryl Grignard reagents (9/1 to 15/1 drs). 6-Phenylazelates (6S)-8d and (6R)-8d were separated by chromatography and diastereoselective precipitation and independently transformed into 4-Ph-I(9)aa-OMe. From (6S)-8d, (2S,4R,6R,8S)-4-Ph-I(9)aa-OMe 11 was prepared selectively in 51% yield. Reductive amination of (6R)-8d provided the desired pipecolates 9 along with desamino compound 10, which was minimized by performing the hydrogenation in the presence of ammonium acetate. Subsequent ester exchange, lactam cyclization, and amine protection provided three products (2R,4S,6S,8R)-, (2R,4S,6S,8S)-, and (2S,4S,6R,8S)-4-Ph-I(9)aa-OMe 11 in 10, 6, and 6% yields, respectively, from (6R)-8d. Ester hydrolysis of (2S,4R,6R,8S)-11 furnished 4-phenyl indolizidin-9-one N-(Boc)amino acid 3 as a novel constrained Ala-Phe dipeptide surrogate for studying conformation-activity relationships of biologically active peptides.     

Two new sesquiterpenes from Chloranthus japonicus Sieb

Two new sesquiterpenes, namely, 1β,10β-dihydroxy-eremophil-7(11), 8-dien-12,8-olide (1) and 8,12-epoxy-1β-hydroxyeudesm-3,7,11-trien-9-one (2), together with three known sesquiterpenoids, shizukolidol (3), 4α-hydroxy-5α(H)-8β-methoxy-eudesm-7(11)-en-12,8-olide (4), and neolitacumone B (5), and two known monoterpenes, (3R,4S,6R)-p-menth-1-en-3,6-diol (6) and (R)-p-menth-1-en-4,7-diol (7), were isolated from the whole plant of Chloranthus japonicus Sieb. Their structures were elucidated on the basis of spectroscopic data analysis and comparison with those of related known compounds. Compounds 4–7 were isolated from this plant for the first time.     

New Eremophilenolides from Senecio dianthus

From the aerial parts of Senecio dianthus, four new eremophilenolides ( 1 – 4 , resp.) and one new eremophilenolide alkaloid ( 5 ), of the relatively uncommon eremophilenoid‐type sesquiterpenoid lactones, were isolated together with three known sesquiterpenoid lactones, 10β‐hydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 6 ), 8β,10β‐dihydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 7 ), and 10α‐hydroxy‐1‐oxoeremophila‐7(11),8(9)‐dien‐12,8‐olide ( 8 ). On the basis of IR, MS, and NMR data, particularly 2D‐NMR analyses, the structures of the new compounds were established as: 2β‐(angeloyloxy)‐10β‐hydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 1 ), 6β‐(angeloyloxy)‐10β‐hydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 2 ), 2β‐(angeloyloxy)‐8β,10β‐dihydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 3 ), 2β‐(angeloyloxy)‐8α‐hydroxyeremophila‐7(11),9(10)‐dien‐12,8β‐olide ( 4 ), and 8β‐amino‐10β‐hydroxyeremophil‐7(11)‐en‐12,8α‐olide ( 5 ). In addition, the relative configuration of 1 was corroborated by X‐ray diffraction analysis.     

Sesquiterpenes from the Roots of Ligularia duciformis

Two new sesquiterpenes named liguducin-A ( 1 ) and -B ( 4 ) were isolated from a Chinese medicinal plant, the dried roots of Ligularia duciformis, together with four known sesquiterpenes, 4α, 10β-dihydroxy-1β,5α-H-guai-6-ene ( 2 ), 4α-hydroxy-1β,5α,11α-H-guai-9-en-12,8α-olide ( 3 ), 1β-hydroxyeudesm-4,11-dien-3-one ( 5 ) and 1β,6α-dihydroxyeudesm-4(15)-ene ( 6 ). On the basis of the spectral evidence, their structures were determined.     

Two new terpenoids from endophytic fungus Periconia sp. F-31

Two new terpenoids, (+)-(3S,6S,7R,8S)-periconone A (1) and (-)-(1R,4R,6S,7S)-2-caren-4,8-olide (2), have been isolated from an endophytic fungus Periconia sp., which was collected from the plant Annona muricata. Their structures were elucidated on the basis of extensive spectroscopic analyses. In the in vitro assays, the two compounds showed low cytotoxic activities against six human tumor cell lines (HCT-8, Bel-7402, BGC-823, A549, A2780 and MCF-7) with IC(50)>10(-5) M.     

A New Eudesmanolide and a New Aromatic Derivative from Carpesium cernuun

Carpesium cernuun L. has long been used as chinese folk medicine for its anti-inflammatory, pain-relief, and detoxication properties1. Up to now, no phytochemical studies of Carpesium cernuun has been carried out. Here we report the structure elucidation of a new eudesmanolide 1 and a new aromatic derivative 2, which were obtained from this plant. Compound 1 was isolated as colorless gum, [(]+128.4 (c 0.43, CHCl3). Its EIMS revealed a molecular ion peak m/z 248. Together with the support …     

Wedelolides A and B: novel sesquiterpene delta-lactones, (9R)-eudesman-9,12-olides, from Wedelia trilobata

Two new sesquiterpene lactones, wedelolides A (1) and B (2), were isolated by bioassay-guided fractionation from the leaves of Wedelia trilobata, together with known trilobolides 6-O-isobutyrate (3) and 6-O-methacrylate (4). The compounds 1 and 2 were the first examples of an unprecedented framework: a novel sesquiterpene delta-lactone, (9R)-eudesman-9,12-olide. The structures of the antimalarial wedelolides A (1) and B (2) were determined on the basis of MS and 2D NMR spectral analysis. The absolute configuration of eight carbon stereocenters of compounds 1 and 2 was determined to be 1S,4S,5S,6R,7S,8S,9R,10S by mean of auxiliary chiral MTPA derivatives.     

Unusual sesquiterpene lactones from Ligularia virgaurea spp. oligocephala

[structure: see text] [structure: see text] Sesquiterpene lactones, ligulolide A (1) and 6beta,8alpha-dihydroxy-1-oxoeremophila-7(11),9(10)-diene-12,8-olide (2), were isolated from Ligularia virgaurea spp. oligocephala. Their structures were established by analysis of one- and two-dimensional NMR data. The relative stereostructures were determined on the basis of NOESY and single-crystal X-ray experiments. 1 represents a novel sesquiterpene carbon framework, and a possible biosynthetic process is proposed. 2 is a novel eremophilane-type sesquiterpene.     

Antimicrobial sesquiterpenoids from Laurus nobilis L

Activity-guided fractionations of leaf extracts from Laurus nobilis L. led to the isolation of a known sesquiterpene lactone, deacetyl laurenobiolide (1). Compound 1 showed antimicrobial activity against periopathic pathogens (Actinomyces viscosus, Porphyromonas gingivalis, Prevotella intermedia and Actinobacillus actinomycetemcomitans), opportunistic Gram-positive bacteria (Staphylococcus aureus and Streptococcus pyogenes) and fungi (Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus). Furthermore, acetylation and cyclisation of deacetyl laurenobiolide (1) yielded laurenobiolide (2) and a new compound, (5S,6R,7S,8S,10R)-6,8-dihydroxyeudesma-4(15),11(13)-dien-12-oic acid 12,8-lactone (3), respectively. Compounds 2 and 3 also showed antimicrobial activities. All compounds 1-3 demonstrated growth inhibitory effects with minimum inhibitory concentrations ranging from 31 to 1000?μg?mL(-1). This is the first report of compounds 1-3 showing antimicrobial activities.     

Structure determination of ramosine, a guaianolide, by NMR spectroscopy

Ramosine, a new sesquiterpene lactone, was isolated from the chloroform fraction of Amberboa ramosa and the structure was assigned as 4beta-(hydroxymethyl)-3beta,4alpha-dihydroxy-8alpha-[(S)-3-hydroxy-2-ethylenepropionyloxy]-1alphaH, 5alphaH,6betaH,7alphaH,11betaH,11alpha-methylguaia-10(14)-en-6, 12-olide by extensive NMR studies.     

An Unusual Occurrence in the Reaction of 4-Azasteroid Derivatives with N-Fluorodibenzenesulfonimide and Lithium Diisopropylamide

The reaction of N,N-diethyl-3-oxo-4-methyl-4-aza-5-androstane-17β-carboxamide(1) with N-fluorodibenzenesulfonimide(NFA) and lithium diisopropylamide(LDA) was studied.Under absolute anhydrous and anaerobic conditions,the formation of 5(2α-fluoro-4-methyl-3-oxo-4-aza-5α-androstane-17β-carboxylic acid methyl ester) can be rationalized by participating in the expected nucleophilic substitution reaction.Not in absolute anhydrous and anaerobic conditions,the formation of 10(N-di-isopropyl-N'-aryl-sulfonamides(C12H20N2O2S) and 11(N-diethyl-3-oxo-4-methyl-4-aza-5-androstene-17β-carboxamide) can be rationalized by assuming that the situ genera-ted carbanion 2 followed by a single electron transfer mechanism.5,10 and 11 were characterized.10 was a new compound and determined by X-ray single-crystal diffraction.Crystal data for 10:space group C2/c with a = 14.783(2),b = 7.6193(11),c = 24.663(3) ,β = 98.688(3)o,V = 2746.1(7) nm3,Mr = 256.36,Z = 8,Dc = 1.240 g/cm3,μ = 0.229 mm-1,F(000) = 1104,R = 0.0511 and wR = 0.1268.There exist intramolecular H-bonds which result in a supramolecular framework of the title compound.The formation mechanisms of 10 and 11 were also discussed briefly.     

Terpenoids of Crepis tectorum. Molecular and crystal structure of the sesquiterpene lactone 8-epideacylcynaropicrin

Sesquiterpene lactones of the guaianolide type — isolipidiol (I) and 8-epideacylcynaropicrin (II) — have been isolated from narrow-leaf hawk's-beard,Crepis tectorum L. On the basis of the results of an x-ray experiment the structure of (1R, 3S, 5R, 6R, 7R, 8R)-3,8-dihydroxy-cis,trans-guaia-4(15),10(14),-11(13)-trien-6,12-olide is proposed for (II).     

Terpenoids from the Roots of Ligularia muliensis

Three new eremophilane‐type sesquiterpenes, (6β,8α)‐6‐(acetyloxy)‐8‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 1 ), (6α,8α)‐6‐hydroxyeremophil‐7(11)‐en‐12,8‐olide ( 2 ), and (6α,8α)‐6‐(acetyloxy)eremophil‐7(11)‐en‐12,8‐olide ( 3 ) ((8α)‐eremophil‐7(11)‐en‐12,8‐olide = (4aR,5S,8aR,9aS)‐4a,5,6,7,8,8a,9,9a‐octahydro‐3,4a,5‐trimethylnaphtho[2,3‐b]furan‐2(4H)‐one), besides the recently elucidated eremoligularin ( 4 ) and bieremoligularolide ( 5 ), as well as a new highly oxygenated monoterpene, rel‐(1R,2R,3R,4S,5S)‐p‐menthane‐1,2,3,5‐tetrol ( 12 ), together with six known constituents, i.e., the sesquiterpenes 6 and 7 , the norsesquiterpenes 8 – 10 , and the monoterpene 13 , were isolated from the roots of Ligularia muliensis. In addition, an attempt to dimerize 1 to a bieremophilenolide (Scheme) resulted in the generation of the new derivative (6β,8β)‐6‐(acetyloxy)‐8‐chloroeremophil‐7(11)‐en‐12,8‐olide ( 11 ). The new structures were established by means of detailed spectroscopic analysis (IR, FAB‐, EI‐, or HR‐ESI‐MS as well as 1D‐ and 2D‐NMR experiments). Compounds 4 and 5 were evaluated for their antitumor effects in vitro (Table 3).