Discovery of novel sesquiterpenoids from a gorgonian Menella sp.

A novel sesquiterpenoid, menelloide A (1), which was found to possess a new carbon skeleton, and a new guaiane-type sesquiterpenoid, menelloide B (2), along with (+)-chloranthalactone B (3), an enantiomer of the known sesquiterpenoid, chloranthalactone B (4), were isolated from a gorgonian coral identified as Menella sp. The structures of sesquiterpenoids 1-3 were established by spectroscopic methods and by comparison of the data with those of related metabolites. Sesquiterpenoids 1 and 3 displayed inhibitory effects on the generation of superoxide anion by human neutrophils.     

Feroniellins A-C, novel cytotoxic furanocoumarins with highly oxygenated C10 moieties from Feroniella lucida

Three new furanocoumarins, named feroniellins A (1), B (2), and C (3), were isolated from the roots of Feroniella lucida. Compounds 1-3 are novel structures having an oxolane, oxane, and oxepane moiety. Their overall structures and configurations were determined by spectral and chemical methods. The cytotoxicities of 1-3 were evaluated against human KB and HeLa carcinoma cells.     

Novel cyclopropyl diketones and 14-membered macrolides from the soil fungus Hamigera avellanea BCC 17816

Two novel cyclopropyl diketones, hamavellone A (1) and B (2), and two new 14-membered nonaketide macrolactones, hamigeromycin A (3) and B (4), together with six known compounds, 89-250904-F1 (radicicol analogue A, 5), pseurotin A (6), emodin (7), ω-hydroxyemodin (8), and emodin bianthrones (9 and 10) were isolated from the soil fungus Hamigera avellanea BCC 17816. The structures of the new compounds were defined by analysis of NMR and MS data. The absolute stereochemistry of 3 was addressed by chemical correlation to 5. Hamavellone B (2) exhibited antimalarial activity with an IC₅₀ of 5.2 μg/mL, whereas it also showed comparable cytotoxicity.     

Three novel pregnane glycosides from Epigynum auritum

Three novel pregnane glycosides with an unusual aglycone (Epigynumgenane), named Epigynosides A (1), B (2) and C (3), were isolated from the aerial part of Epiginum auritum. Their structures were elucidated by spectral means and confirmed by X-ray diffraction analysis.     

Isolation and characterization of miscellaneous terpenoids of Schisandra chinensis

Two new bisnortriterpenoids with 18-norschiartane skeleton, wuweizidilactones G (1) and H (2), four new highly oxygenated nortriterpenoids based on a schisanartane skeleton, schindilactones D-G (3-6), a pre-schisanartane skeleton, pre-schisanartanin B (7), and a novel 3,4-seco-21,26-olide-artane triterpenoid wuweizilactone acid (8), along with 24 known terpenoids with different carbon frameworks, have been isolated from the acetone extract of the stems and leaves of Schisandra chinensis. The terpenoids produced by this plant have chemical diversity. The structures of new compounds 1-8 have been characterized by spectroscopic data interpretation. The cytotoxicity and anti-HIV-1 activity of all the Schisandra nortriterpenoids were evaluated.     

Melicodenines A and B, novel Diels-Alder type adducts isolated from Melicope denhamii

Two novel Diels-Alder type adducts, melicodenines A (1) and B (2), were isolated from the leaves of Melicope denhamii (Seem.) T. G. Hartley and their structures were established by spectroscopic analyses, including extensive 2D NMR experiments. Compound 1 is a bisquinolinone alkaloid comprised of two N-methylflindersines (3), while compound 2 is the first naturally occurring quinolinone-acetophenone conjugate composed of 3 and an evodionol methyl ether (4).     

Cyclooxygenase-2 enzyme inhibitory withanolides from Withania somnifera leaves

Four novel withanolide glycosides and a withanolide have been isolated from the leaves of Withania somnifera. The structures of the novel compounds were elucidated as physagulin D (1→6)-β-d-glucopyranosyl-(1→4)-β-d-glucopyranoside (1), 27-O-β-d-glucopyranosyl physagulin D (2), 27-O-β-d-glucopyranosyl viscosalactone B (3), 4,16-dihydroxy-5β, 6β-epoxyphysagulin D (4), and 4-(1-hydroxy-2,2-dimethylcyclo-propanone)-2,3-dihydrowithaferin A (5) on the basis of 1D-, 2D NMR and MS spectral data. In addition, seven known withanolides withaferin A (6), 2,3-dihydrowithaferin A (7), viscosalactone B (8), 27-desoxy-24,25-dihydrowithaferin A (9), sitoindoside IX (10), physagulin D (11), and withanoside IV (12) were isolated. These withanolides were assayed to determine their ability to inhibit cycloxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes and lipid peroxidation. The withanolides tested, except compound 9, showed selective COX-2 enzyme inhibition ranging from 9 to 40% at 100 μg/ml. Compounds 4, 10 and 11 also inhibited lipid peroxidation by 40, 44 and 55%, respectively. The inhibition of COX-2 enzyme by withanolides is reported here for the first time.     

Two novel diterpenoids from Isodon rubescens var. lushanensis

Two novel diterpenoids, luanchunins A (1) and B (2), along with their precursor, kamebakaurin (3), had been isolated from the stems and leaves of Isodon rubescens var. lushanensis. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compounds 1 and 2 showed potent cytotoxic activity against HL-60 with IC₅₀ values of 4.81 μM and 3.52 μM, respectively. Plausible pathways for the biosynthesis of 1 and 2 were also postulated.     

New briaranes from the octocorals Briareum excavatum (Briareidae) and Junceella fragilis (Ellisellidae)

Six 12-hydroxybriaranes, including four new diterpenoids, briaexcavatins I-L (1-4), and two known metabolites, excavatolides C (5) and E (6), have been isolated from the cultured scleraxonia Briareum excavatum. In addition, the gorgonian coral Junceella fragilis yielded a new chlorinated briarane, fragilide C (10). The structures of above compounds were determined by spectroscopic methods and the structures of 5 and 6 were further confirmed by X-ray data analysis for the first time. The absolute configuration of 6 was elucidated by chemical conversion. Some of these briaranes have displayed inhibitory effects on superoxide anion generation by human neutrophils.     

New pyridoacridine alkaloids from the purple morph of the ascidian Cystodytes dellechiajei

Two new pyridoacridine alkaloids, 13-didemethylaminocycloshermilamine D (1) and demethyldeoxyamphimedine (2), were isolated from the purple chromotype of the Western Mediterranean ascidian Cystodytes dellechiajei. This morph also contained the known shermilamine B (3), kuanoniamine D (4), N-deacetylshermilamine B (5), N-deacetylkuanoniamine D (6), styelsamines C (7), and D (8). The structures of new compounds were elucidated on the basis of spectroscopic data. A hypothetic biosynthetic pathway from the tetracyclic styelsamine D (8) was proposed for both compounds 1 and 2 and their antimicrobial potential was evaluated.     

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).     

Bioactive meroditerpenes and indole alkaloids from the soil fungus Neosartorya fischeri (KUFC 6344), and the marine-derived fungi Neosartorya laciniosa (KUFC 7896) and Neosartorya tsunodae (KUFC 9213)

Two new metabolites including a new aszonalenin analogue (1c) and a new meroditerpene (3) were isolated, together with aszonalenin (1a), acetylaszonalenin (1b), 13-oxofumitremorgin B (2), aszonapyrone A (4b) and helvolic acid, from the culture of the soil fungus Neosartorya fischeri (KUFC 6344). While the ethyl acetate extract of the culture of the diseased coral-derived fungus Neosartorya laciniosa (KUFC 7896) furnished aszonapyrone B (4a), aszonapyrone A (4b), tryptoquivaline L and 3′-(4-oxoquinazolin-3-yl) spiro[1H-indole-3,5′-oxolane]-2,2′-dione, the ethyl acetate extract of the culture of the marine sponge-associated fungus Neosartorya tsunodae (KUFC 9213) yielded a new analogue of chevalone C (5) and helvolic acid. The structures of the new compounds were established based on 1D and 2D NMR spectral analysis as well as HR-ESIMS. Compounds 1a–c, 2, 3, 4a, 4b and 5 were evaluated for their in vitro growth inhibitory activity on the MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and A375-C5 (melanoma) cell lines by the protein binding dye SRB method.     

Kehokorins A-C, novel cytotoxic dibenzofurans isolated from the myxomycete Trichia favoginea var. persimilis

Kehokorins A (1)-C (3), three novel dibenzofurans, have been isolated from field-collected fruit bodies of the myxomycete, Trichia favoginea var. persimilis, and their structures were elucidated by spectral data. Kehokorin A (1) was a α-l-rhamnopyranoside of kehokorin B (2), while kehokorin C (3) was a 1-demethoxy analog of 2. Kehokorin A (1) was cytotoxic against HeLa cells with an IC₅₀ value of 1.5 μg/mL.     

Induced production of novel prenyldepside and coumarins in endophytic fungi Pestalotiopsis acaciae

Concomitant supplementation of a histone deacetylase inhibitor, suberoylanilide hydroxamic acid, and a DNA methyltransferase inhibitor, 5-azacytidine, to the culture medium of a plant endophytic fungus, Pestalotiopsis acaciae, dramatically altered its metabolic profiles. As a result, three novel aromatic compounds, 2′-hydroxy-6′-hydroxymethyl-4′-methylphenyl-2,6-dihydroxy-3-(2-isopentenyl)benzoate (1), 4,6-dihydroxy-7-hydroxymethyl-3-methylcoumarin (2) and 4,6-dihydroxy-3,7-dimethylcoumarin (3), were isolated, along with five known polyketides, endocrocin (4), pestalotiollide B (5), pestalotiopyrone G (6), scirpyrone A (7) and 7-hydroxy-2-(2-hydroxypropyl)-5-methylchromone (8).     

Cytotoxic dimeric sesquiterpenoids from Curcuma parviflora: isolation of three new parviflorenes and absolute stereochemistry of parviflorenes A, B, D, F, and G

Three novel dimeric sesquiterpenoids, named parviflorenes G-I (1-3), have been isolated from Curcuma parviflora (Zingiberaceae), and their structures were elucidated by means of spectroscopic studies. Absolute stereochemistry of parviflorene G (1) as well as previously isolated related compounds, parviflorenes A (4), B (5), D (6), and F (7), was revealed by CD spectral data and chemical means. Parviflorenes G (1) and I (3) were cytotoxic against HeLa cells, while parviflorenes A (4) and F (7) were cytotoxic against all tested tumor cell lines in the human cancer cell line panel assay.     

Seven new alkaloids from the roots of Stemona tuberosa

Seven new alkaloids, named as 1,9-epoxy-9a-hydroxystenine (1), tuberostemoline A (2), tuberostemoline B (3), tuberostemoninol C (4), oxotuberostemonine A (5), the mixture of bisdehydrotuberostemonine D (6), and bisdehydrotuberostemonine E (7), together with four known alkaloids neotuberostemonine (8), sessilifoline B (9), stemoxazolidinone F (10), and tuberostemoninol A (11), were isolated from the roots of Stemona tuberosa. The structures of 1–7 were elucidated through extensive spectroscopic analysis, and the relative configurations of 1–6 and 8 were further confirmed by X-ray crystallographic data. Compounds 8, 9 and the mixture of 6 & 7 exhibited potential acetylcholinesterase (AChE) inhibitory activities.     

Briaexcavatins C-F, four new briarane-related diterpenoids from the Formosan octocoral Briareum excavatum (Briareidae)

Four new briarane-related diterpenoids, designated as briaexcavatins C-F (1-4), were isolated from the Formosan octocoral Briareum excavatum, collected off southern Taiwan coast. The structures of these new metabolites were elucidated by the interpretation of spectroscopic and chemical methods. The configuration of 1 was further supported by molecular mechanics calculations. Briarane 1 has been shown to exhibit mild cytotoxicity toward MDA-MB-231 human breast tumor cells and briarane 3 was found to show activity to inhibit neutrophil elastase release in humans.     

Three novel nortriterpenoids from Notochaete hamosa Benth. (Labiatae)

Three nortriterpenoids, notohamosin A (1), B (2) and C (3) with novel skeleton, and eight known compounds were isolated from the ethanol extract of the whole plants of Notochaete hamosa Benth. (Labiatae). On the basis of spectral evidence including 1D, 2D NMR, IR and MS data, their structures were elucidated. The relative configurations of compounds 1, 2 and 3 were determined according to NOESY experiments.     

Five novel norcembranoids from Sinularia leptoclados and S. parva

Three new norcembrane-based diterpenoids, leptocladolides A (1), B (4) and C (5), along with five known metabolites 6-10, have been isolated from the dichloromethane extract of a Taiwanese soft coral Sinularia leptoclados. Furthermore, a chemical investigation on the dichloromethane extract of S. parva has resulted in the isolation of two new related isomers, 1-epi-leptocladolide A (2) and 7E-leptocladolide A (3), in addition to 1 and 7. The structures of new metabolites 1-5 were elucidated on the basis of extensive spectroscopic analyses and their relative stereochemistries were determined by NOESY experiments. The new metabolites 1 and 3 have been shown to exhibit significant cytotoxic activity against KB and Hepa59T/VGH cancer cell lines.     

Excavatoids A-D, new polyoxygenated briaranes from the octocoral Briareum excavatum

Three polyoxygenated briaranes, including two new compounds, excavatoids A (1) and B (2), and a known metabolite, briaexcavatin I (3), were isolated from the cultured octocoral Briareum excavatum. Moreover, the wild type B. excavatum, collected off southern Taiwan coast, yielded two new 5,6-epoxybriaranes, excavatoids C (4) and D (5). The structures of new compounds 1, 2, 4, and 5 were determined by spectroscopic methods and the structure of 1 was further confirmed by X-ray diffraction data analysis. The X-ray structure for briaexcavatin I (3) was also reported for the first time. Excavatoid A (1) is the first briarane which possesses six hydroxy groups and a 17-methoxy group. Excavatoid C (4) is the first 12,13-secobriarane which possesses a novel pentacyclic skeleton with an ?-lactone. Excavatoid D (5) displayed moderate inhibitory effects on superoxide anion generation and elastase release by human neutrophils.