Sesquiterpene Glucosides from Chloranthus japonicus Sieb

A new lindenane sesquiterpene glucoside named yinxiancaoside A (1), a new, rare bidesmosidic megastigmane sesquiterpene glucoside named yinxiancaoside B (5), and three known sesquiterpene glucosides, chloranoside A (2), pisumionoside (3), and sarcaglaboside A (4), were isolated from the whole plant of Chloranthus japonicus Sieb. The structures of the new compounds were established by an extensive study of their spectral data, especially 1D- and 2D-NMR. The cytotoxic activity of the isolated compounds against human hepatoma (Hepg-2), human ovarian carcinoma (OV420), and human breast cancer (MCF-7) cells was investigated.     

Terpenoid and phenolic metabolites from the fungus xylaria sp. associated with termite nests

Three new sesquiterpene acids, xylaric acids A-C (1-3, resp.), and a new tetralone (=3,4-dihydronaphthalen-1(2H)-one) derivative, 4, along with nine known compounds, xylaric acid D (5), hydroheptelidic acid (6), gliocladic acid (7), chlorine heptelidic acid (8), trichoderonic acid A (9), 16-(α-D-mannopyranosyloxy)isopimar-7-en-19-oic acid (10), 16-(α-D-glucopyranosyloxy)isopimar-7-en-19-oic acid (11), 5-carboxymellein (12), and naphthalen-1,8-diol 1-O-α-D-glucopyranoside (13) have been isolated from the solid culture of the ascomycete fungus Xylaria sp. associated with termite nest. The structures of these compounds were elucidated primarily by NMR experiments. The absolute configurations of compounds 1-3 and 5-9 were determined by combination of X-ray data and CD spectral analysis. The absolute configuration of 4 was assigned by Snatzke's method. Compounds 8 and 11 showed slight cytotoxicities against two cell lines A549 and SGC7901.     

Two new antibacterial sesquiterpenoids from Centipeda minima

Two new guaiane-type sesquiterpene lactones, compounds 1 and 2, along with three known guaianolide- or pseudoguaianolides, were isolated from Centipeda minima (whole plant). Their structures were identified by spectroscopic and mass-spectrometric analyses. The configuration at C5 of the guaiane framework of 1 was rationalized by quantum-mechanical calculations (Table 2). All compounds were found to be active against eight different microbial pathogens (Table 3), with MIC values in the range of 6.25-100 microg/ml.     

Sesquiterpene Lactones with COX‐2 Inhibition Activity from Artemisia lavandulaefolia

Two new sesquiterpene lactones, artelavanolides A ( 1 ) and B ( 2 ), and four known sesquiterpene lactones ( 3 – 6 ) were isolated from the leaves of Artemisia lavandulaefolia. Their structures were elucidated based on the analysis of spectroscopic data (1D, 2D‐NMR and HR‐ESI‐MS). The absolute configuration of 1 was determined by the analysis of single‐crystal X‐ray diffraction data. Artelavanolide A ( 1 ) is a rare sesquiterpene lactone possessing an unusual skeleton with the linkage of Me(14)–C(1) that is probably formed through a rearrangement of the guaiane‐type sesquiterpenoids. Artelavanolide B ( 2 ) is a new highly unsaturated guaianolide. Compounds 1 – 6 were tested for activities on the inhibition of COX‐2 enzyme in vitro. All of compounds exhibited inhibitory activity against COX‐2 with IC₅₀ values ranging from 43.29 to 287.07 μm compared with the positive control, celecoxib (IC₅₀ = 18.10 μm ). Among them, 3 showed the best COX‐2 inhibitory activity with an IC₅₀ value of 43.29 μm .     

Flavonoids and terpenoids from Helichrysum forskahlii

Three new flavonoids, namely helichrysone A (1), helichrysone B (2) and helichrysone C (3) were isolated from the aerial parts of Helichrysum forskahlii, together with 10 known flavonoids, three triterpenes, and one sesquiterpene. The structures of the new flavonoids 1-3 were established by 1D and 2D NMR spectral data. In addition, the antimicrobial activities of the isolated compounds were determined.     

Two New Sesquiterpene Derivatives from the Tunisian Endemic Ferula tunetana Pom.

A new sesquiterpene ester, tunetanin A ( 1 ), a new sesquiterpene coumarin, tunetacoumarin A ( 2 ), together with eight known compounds, i.e., coladin ( 3 ), coladonin ( 4 ), isosmarcandin ( 5 ), 13‐hydroxyfeselol ( 6 ), umbelliprenin ( 7 ) propiophenone ( 8 ), β‐sitosterol ( 9 ), and stigmasterol ( 10 ), were isolated from the roots of Ferula tunetana. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D‐ and 2D‐NMR experiments and MS analysis, as well as by comparison with published data. The cytotoxicity of compounds 1 – 7 towards two human colon cancer cell lines, HT‐29 and HCT 116, was evaluated. Compounds 3, 4 , and 6 showed weak cytotoxic activities.     

Sesquiterpene Lactones from Centaurea zuccariniana and Their Antimicrobial Activity

Twenty‐nine compounds were isolated from the aerial parts of the Greek plant C. zuccariniana DC. The structures of the isolated compounds were established by means of NMR‐ (¹H,¹H‐COSY, ¹H,¹³C‐HSQC, HMBC, NOESY, and ROESY) and mass‐spectral analyses. These compounds comprise 13 sesquiterpene lactones, 14 flavonoids, two lignans, and one simple lactone. Among the isolated sesquiterpene lactones, three are new, namely one heliangolide, (1E,4Z)‐15‐hydroxy‐8α‐O‐(4′‐acetoxy‐3′‐hydroxy‐2′‐methylidenebutanoyl)‐6βH,7αH‐germacra‐1,4,11(13)‐trien‐6,12‐olide; and two eudesmanolides, 8α‐(4′,5′‐diacetoxyangeloyl)sonchucarpolide and one unusual eudesmanolide with an oxygenated bridge linking C(1) and C(4), named zuccarinin. The main sesquiterpene lactones were malacitenolide, cnicin, and 4′‐O‐acetylcnicin. These results are in agreement with those obtained from the previously studied Greek Centaurea sp. belonging to the section Acrolophus (Cass .) DC.; this finding could be of chemotaxonomic significance for the genus Centaurea. The in vitro antimicrobial activities of the isolated new sesquiterpene lactones were against eight bacteria and eight fungal species. A 96‐well microbioassay procedure for fast and easy evaluation of antibacterial and antifungal activities was applied to compare these compounds with commercial antibiotic and fungicide standards, and with previously isolated analogous sesquiterpene lactones tested by the same bioassay. All of the compounds tested showed moderate antibacterial, but significant antifungal activities; the present results corroborate with previous data, indicating that these types of compounds exhibit low or moderate antibacterial, but potent antifungal activities. The unusual eudesmanolide zuccarinin proved to be the most potent among the present tested sesquiterpene lactones, as well as among all previously tested eudesmanolides isolated from Greek Centaurea sp.     

A new dihydroagarofuranoid sesquiterpene from Microtropis fokienensis with antituberculosis activity

A new dihydroagarofuran-based sesquiterpene, 8-acetoxymutangin (1), was isolated from the stems of Microtropis fokienensis, together with eight known compounds, including mutangin (2). Their structures were determined through in-depth spectroscopic and mass-spectrometric analyses. Among the isolated compounds, 1 exhibited potent in vitro antituberculosis activity, with an MIC value of 10.0 microg/ml against Mycobacterium tuberculosis 90-221387, which is considerably better than that of mutangin (2). The activity of 1 lies in the same range as that of the clinic drug ethambutol (MIC 6.25 microg/ml), despite completely different chemical structures, which indicates different modes of action.     

Biologically active metabolites from the basidiomycete Limacella illinita (Fr.) Murr

In the course of our search for new bioactive compounds from basidiomycetes, four new compounds were isolated from fermentations of Limacella illinita. Illinitone A (1) exhibited weak phytotoxic and moderate nematicidal activities against Caenorhabditis elegans, illinitone B (2) was moderately cytotoxic, while limacellone (3) exhibited weak cytotoxic and phytotoxic activities. The muurolane sesquiterpene 4a was found to be inactive in the assays performed here. Limacellone (3), which appeared to be related with the illinitones 1 and 2, has a new C15 carbon skeleton. It is possible that compounds 1, 2 and 3 are terpenoids/ secoterpenoids, but their biosyntheses were not investigated.     

Secondary metabolites from two species of Pulicaria and their cytotoxic activity

Two new compounds, the sesquiterpene (1E,5E)-8β-acetoxy-4α-hydroxy-7βH-germacra-1(10),5-dien-14-oic acid (2), and a nor-sesquiterpene, (5E)-8β-acetoxy-4α-hydroxy-7βH-germacr-5-en-10-one (3), were isolated from Pulicaria canariensis ssp. lanata, along with ten known compounds, including the flavonoid 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4). From Pulicaria burchardii, we isolated seven known compounds; the physical and spectroscopic data of the triterpenoid 3β-hydroxytaraxaster-20-en-30-al (1) are reported. The structures of compounds 1-3 were determined on the basis of HR-MS, and 1D- and 2D-NMR studies. The structure of 2 was corroborated by X-ray crystal diffraction. Cell viability experiments revealed that the semisynthetic flavonoid 4b was the most cytotoxic compound against human leukemia cells, and the cytotoxicity was caused by induction of apoptosis, as determined by microscopy of nuclear changes.     

New Nitrogen‐Containing Sesquiterpenoids from the Taiwanese Soft Coral Cespitularia taeniata May

Chemical investigation of the EtOH extract of the soft coral Cespitularia taeniata May collected in Taiwan has resulted in the isolation of two new sesquiterpene lactams, taenialactams A and B ( 1 and 2 , resp.), and a new sesquiterpene lactone, taenialactone A ( 3 ), together with 8β‐methoxyatractylenolide ( 4 ) and atractylenolactam ( 5 ). The structures of these compounds were determined on the basis of spectroscopic analyses. The in vitro cytotoxic activities of the isolated metabolites were tested against KB, Daoy, and WiDr cell lines. A biogenetic pathway for these novel compounds was proposed.     

The chemical constituents of the fungus Stereum sp

Four new compounds, including a sesquiterpene and three aromatic compounds, and a known compound were isolated from a culture broth of the fungus Stereum sp. The novel sesquiterpene was determined to be stereumone A ((+)-2,3,4a,5,6,7,8a,9-octahydro-5-hydroxy-6,6,9-trimethyl-4,8a-epoxynaphtho[2,3-b]furan-8(8H)-one; 1), and the three new aromatic compounds were elucidated as 3,5-dihydroxy-4-(3-methylbut-2-enyl)benzene-1,2-dicarbaldehyde (2), 5,7-dihydroxy-6-(3-methylbut-2-enyl)isobenzofuran-1(3H)-one (3), butyl 2,4-dihydroxy-6-methylbenzoate (4), together with the known compound methyl 2,4-dihydroxy-6-methylbenzoate (5). The structures were established by spectroscopic methods including 2D-NMR techniques. Compounds 2 and 4 showed evident nematicidal activity against nematode Panagrellus redivivus.     

Koanolides B-D,new sesquiterpene lactones from Koanophyllon gibbosum

Three new germacrane-type sesquiterpene lactones, koanolides B–D (1-3) have been isolated from the aerial parts of Koanophyllon gibbosum (Asteraceae), along with the previously reported sesquiterpene lactone koanolide A and the flavonoid eupatorin. The structures of the new compounds were elucidated using spectroscopic and spectrometric data analyses, including 1D and 2D NMR, and by comparison with known spectral data. The antiproliferative activities of the new compounds were evaluated in a panel of six representative human solid tumor cell lines and showed GI₅₀ values ranging from 1.3 to 16 μM for the new molecules.     

New erythroxane-type diterpenoids from Fagonia boveana (Hadidi) Hadidi & Graf

The aerial parts of Fagonia boveana afforded two new erythroxane-type diterpenes, 3beta,15,16-trihydroxy-erythrox-4(18)-ene (2) and 15,16-dihydroxy-cis-ent-erythrox-3-ene (fagonene) (3) together with two known ones; 16-O-acetylfagonone (1) and 7beta-hydroxy fagonene (8). Also a new guaiane sesquiterpene alcohol, 6,10-epoxy-4alpha-hydroxy guaiane type sesquiterpene (4) has been isolated. In addition three 8-methoxy flavonols, 8-methoxy-quercetin-3,7,3'-trimethyl ether (ternatin) (5), gossypetin, 3,8,3',4' tetramethyl ether (6) and herbacetin-3,8-dimethyl ether (7) were also isolated. The structures of the isolated compounds have been determined on the basis of spectroscopic evidences as well as physical and chemical correlation with known compounds. On performing different assays for biological activities, 6 displayed significant cytotoxic activity against KA3IT and NIH3T3 cell lines, 8 was the most active antiviral against Herpes simplex type 1 while 7 was the most active cancer-preventive agent using protein-tyrosine kinase inhibitory method.     

A new neolignan and a new sesterterpenoid from the stems of Picrasma quassioides Bennet

A new dihydrobenzofuran-type neolignan, picrasmalignan A (1), and a new sesterterpene lactone, 2'-isopicrasin A (4), were isolated from the stems of Picrasma quassioides Bennet, along with four known compounds, comprising two neolignans, 2 and 3, a sesterterpene lactone, 5, and a flavonol, 6. The structures of these compounds were determined by detailed analysis of NMR and MS data, and comparison with the literature data. Compounds 1-6 were tested for their anti-inflammatory activity, and 1-3 and 6 showed potent inhibitory activities on nitric oxide, tumor necrosis factor-α, and interleukin-6 production in mouse monocyte-macrophage RAW 264.7 stimulated by lipopolysaccharide (LPS).     

Cytotoxic metabolites from Botryotinia fuckeliana A-S-3: An endophytic fungus from Ajuga decumbens

Available online from an cytotoxic endophytic fungus Botryotinia fuckeliana A-S-3, three cytochalasans phenochalasin B (4), [12]-cytochalasin (5) and one [1,3] dioxacyclotridecino (6), along with two new ent-eudesmane sesquiterpenes, 1-keto-4α,15-epoxyeudesm-11-ol (1), and ent-4(15)-eudesmen-5,6-ol-1-one (2), and one known ent-eudesmane sesquiterpene ent-4(15)-eudesmen-11-ol-1-one (3) were isolated. The structures of these compounds were elucidated by interpretation of spectroscopic data. Among these compounds, two cytotoxic constituents were identified.     

Volatiles and Nonvolatiles in Flourensia campestris Griseb. (Asteraceae), How Much Do Capitate Glandular Trichomes Matter?

The distribution and ultrastructure of capitate glandular trichomes (GTs) in Flourensia species (Asteraceae) have been recently elucidated, but their metabolic activity and potential biological function remain unexplored. Selective nonvolatile metabolites from isolated GTs were strikingly similar to those found on leaf surfaces. The phytotoxic allelochemical sesquiterpene (–)‐hamanasic acid A ((–)‐HAA) was the major constituent (ca. 40%) in GTs. Although GTs are quaternary ammonium compounds (QACs)‐accumulating species, glycine betaine was not found in GTs; it was only present in the leaf mesophyll. Two (–)‐HAA accompanying surface secreted products: compounds 4‐hydroxyacetophenone (piceol; 1 ) and 2‐hydroxy‐5‐methoxyacetophenone ( 2 ), which were isolated and fully characterized (GC/MS, NMR), were present in the volatiles found in GTs. The essential oils of fresh leaves revealed ca. 33% monoterpenes, 26% hydrocarbon‐ and 30% oxygenated sesquiterpenes, most of them related to cadinene and bisabolene derivatives. Present results suggest a main role of GTs in determining the volatile and nonvolatile composition of F. campestris leaves. Based on the known activities of the compounds identified, it can be suggested that GTs in F. campestris would play key ecological functions in plant‐pathogen and plant‐plant interactions. In addition, the strikingly high contribution of compounds derived from cadinene and bisabolene pathways, highlights the potential of this species as a source of high‐valued bioproducts.     

Sesquiterpene constituents from the liverwort Bazzania japonica

The hydrodistillation products of the liverwort Bazzania japonica were separated by preparative gas chromatography (GC) and investigated by spectroscopic methods. Seven unknown compounds were isolated and identified by GC-MS and NMR. Four of them, the norsesquiterpene hydrocarbons 4-epi-11-nor-aristola-1(10),11-diene (1), 4-epi-11-nor-aristola-1,9,11-triene (2), 4-epi-11-nor-aristola-9,11-diene (3), and one oxygenated sesquiterpene, (-)-aristol-1(10)-en-12-ol (5) are new natural compounds, and one, (+)-himachala-2,4-diene (7), has for the first time been isolated from liverworts. The absolute configurations of 5 and 7 were derived by chemical correlation reactions and/or enantioselective GC using cyclodextrin phases. 1, 2 and 3 have identical absolute configuration.     

New antibacterial sesquiterpene aminoquinones from a Vietnamese marine sponge of Spongia sp.

Two new sesquiterpene aminoquinones, langcoquinones A (1) and B (2), together with seven known meroterpenoids (3⿿9), were isolated from the marine sponge Spongia sp. collected in Vietnam. Their structures were determined on the basis of spectroscopic analyses and comparisons with published data. The antibacterial activities of the isolated compounds (1⿿9) were investigated against four bacterial strains. Among these, the new sesquiterpene aminoquinones (1 and 2) and the known related compounds (3, 5, 6, 8, and 9) exhibited significant antibacterial activities against Staphylococcus aureus and Bacillus subtilis, with MICs ranging from 6.25 to 12.5 μM.     

Eudesmanolides and Other Constituents from the Flowers of Wedelia trilobata

Two eudesmane sesquiterpene lactones, wedetrilides B ( 1 ) and C ( 2 ), along with five known analogues ( 3 – 8 ), an ent‐kaurane diterpenoid ( 9 ), a steroid ( 10 ), as well as cinnamic acid derivatives ( 11 – 13 ), were isolated from the flowers of Wedelia trilobata. Their structures were elucidated on the basis of extensive spectroscopic analyses and by comparison of their NMR data with those of related compounds. Furthermore, the structures of 1 and 3 – 5 were confirmed by X‐ray single‐crystal diffraction analyses. Compounds 4 and 5 exhibited weak cytotoxic activities against the MCF‐7, HeLa, and A549 cell lines. Compounds 3 – 5 were also evaluated for their inhibitory effects against HIV lytic replication.