Structure of onchidione, a bis-γ-pyrone polypropionate from a marine pulmonate mollusk

The chemical investigation of the marine pulmonate Onchidium sp. and of its defensive mucous secretion led us to the isolation of a novel polypropionate, onchidione (4), containing two γ-pyrone rings. The structure of 4 was elucidated by spectroscopic methods, mainly NMR techniques, and secured by X-ray analysis on a single crystal.     

Asperpyrone F,a new dimeric naphtho-γ-pyrone from the edible fungus Pleurotus ostreatus

A new dimeric naphtho-γ-pyrone, asperpyrone F (1), along with six known ones, asperpyrones B (2) and C (3), fonsecinones A (4) and B (5), aurasperones A (6) and E (7), have been isolated from the solid culture of the edible fungus Pleurotus ostreatus. The structures of 1–7 were determined mainly by NMR and MS experiments. The absolute configuration of compound 1 was assigned via the circular dichroism (CD) data analysis. Compounds 1–7 showed modest antioxidant and immunomodulatory activities. All compounds were isolated from the fungus P. ostreatus for the first time.     

Bioactive α-pyrone meroterpenoids from mangrove endophytic fungus Penicillium sp.

Five α-pyrone meroterpenoids, including one new 3-epiarigsugacin E (1) and four known compounds, arisugacin D (2), arisugacin B (3), territrem C (4) and terreulactone C (5) were obtained from the marine fungus Penicillium sp. SK5GW1L. Their structures were identified by MS and NMR experiments, and the absolute configuration of compound 1 was further confirmed by low temperature (150 K) single crystal X-ray diffraction with Cu Kα radiation. Compounds 3, 4 and 5 showed strong inhibitory activities against acetylcholinesterase (AchE) with IC₅₀ values of 3.03, 0.23 and 0.028 μM, respectively.     

Preparation of bis-(γ-trifluoropropyl)dichloro

Summary It was shown that (CF₃CH₂CH₂)₂SiCl₂, along with Cl₃SiCH₂CH₂CF₃ and CH₃Si(Cl)₂CH₂CH₂CF₃ may easily be prepared without danger by the addition of H₂SiCl₂ and HSiCl₃ or CH₂SiHCl₂ in the presence of platinohydrochloric acid.     

A new family of Mn₆ SMMs using phosphinate ligands

A new family of hexametallic [Mn(III)?] Single-Molecule Magnets with general formula [Mn?O?(R-sao)?(X)?(MeOH)???] (R= H, Me, Et or Ph; X = O?PHPh or O?P(Ph)?) have been synthesised and characterised. The molecules are new members of the [Mn?] family of SMMs in which the carboxylate ligands have been replaced with phenyl- and diphenylphosphinate. The magnetic cores remain largely unaltered meaning that structural distortions of the Mn-N-O-Mn torsion angles in the [Mn?O] subunits can be used to tune the magnetic properties, switching pairwise exchange interactions from antiferromagnetic to ferromagnetic. The results suggest that the Mn? building block, be it ferro- or antiferromagnetically coupled, could be an important building block for the formation of novel, functional 0-3D materials.     

A new naphtho-<Emphasis Type="Italic">γ</Emphasis>-pyrone from mangrove endophytic fungus ZSU-H26

A new naphtho-γ-pyrone, 5-hydroxy-6,8-dimethoxy-2-benzyl-4H-naphtho[2,3-b]-pyran-4-one (1), together with three known compounds 5,7-dihydroxy-2-methylbenzopyran-4-one (2), 3,5-dihydroxy-2,7dimethylbenzopyran-4-one (3) and cyclo(Tyr-Tyr) (4) were isolated from the mangrove endophytic fungus Phomopsis sp. ZSU-H26 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR spectroscopic techniques. Primary bioassays showed that 1 exhibited cytotoxicity against HEp-2 and HepG2 cells with IC₅₀ values of 10 and 8 μg/mL, respectively.     

The in vivo anti-plasmodial activity of haliclonacyclamine A, an alkaloid from the marine sponge, Haliclona sp

The compound haliclonacyclamine A was isolated from the Haliclona sponge at Solomon Islands. It acts as a powerful in?vitro and in?vivo anti-plasmodial agent against the chloroquine-resistant Plasmodium falciparum strain FCB1and Plasmodium vinckei petteri-infected mice, respectively.     

Acrepyrone A,a new γ-pyrone derivative from an endophytic fungus,Acremonium citrinum SS-g13

Abstract

A new γ-pyrone derivative, acrepyrone A (1), and three known sorbicillinoids, trichodimerol (2), dihydrotrichodimerol (3) and tetrahydrotrichodimerol (4) were isolated from an endophytic fungus, Acremonium citrinum SS-g13, harboured in the roots of the Chinese medicinal plant Fructus mori. Their structures were determined by analysing MS, NMR, and ECD data. Compound 1 was evaluated for its cytotoxic effect, antibacterial activity and quorum sensing inhibitory potential.     

A new naphthoquinoneimine derivative from the marine algal-derived endophytic fungus Aspergillus niger EN-13

Cultivation of an endophytic fungus Aspergillus niger EN-13 that was isolated from the inner tissue of the marine brown alga Colpomenia sinuosa resulted in the characterization of a new naphthoquinoneimine derivative,namely,5,7-dihydroxy-2-[1-(4- methoxy-6-oxo-6H-pyran-2-yl)-2-phenylethylamino]-[1,4]naphthoquinone.The structure of the new compound was established on the basis of various NMR spectroscopic analyses including 2D NMR techniques,EI-MS,and HR-ESI-MS.This compound displayed moderate antifungal activity.     

A new cyclodipeptide from the cultures of Geotrichum candidum

A new cyclodipeptide,cyclo(phenylalanyl-N-methyltyrosyl)1,was isolated from the mycelial solid cultures of Geotrichum candidum.Its structure was elucidated by spectroscopic methods.The antifungal activity of the new compound against Peronophythora litchii was assessed by microplate Alamar blue assay(MABA).     

Two new diterpenoids from the marine Soft coral Clavularia viridis

Two new dolabellane diterpenoids named clavudiol B(2)and clavirolide F(5),have been iso-lated from the soft coral Clavularia viridis,collected from Xisha Islands in the South China Sea.Theirstructures have been determined as 2 and 5 by spectral analysis and chemical reactions.     

A stereoselective synthesis of bis-β-amino acids

Enantiopure bis-β-amino acids (5a–c) were prepared from chiral bis-sulfinimines (3a–c) in >97% ee via stereoselective addition of the sodium enolate of methyl acetate followed by hydrolysis.     

(−)-Wistarin from the marine sponge Ircinia sp.: the first case of enantiomeric sesterterpenes

The sestertepene (−)-wistarin has been isolated from a Red Sea sponge of the genus Ircinia. This metabolite is the enantiomer of (+)-wistarin, a tetracyclic metabolite previously isolated from the sponge Ircinia wistarii. The enantiomeric relationship was proved by comparison of the CD spectrum of (−)-wistarin with that of a synthetic sample of the (+)-isomer. A hypothetical biosynthesis of (−)-wistarin is discussed starting from a putative linear precursor.     

A new method of the synthesis of bis-μ-[(methylenedicyclopentanone-2,2′-dioximato)-triphenylantimony]

Bis-μ-[(methylenedicyclopentanone-2,2′-dioximato)triphenylantimony] is prepared by the reaction of triphenylantimony with methylenedicylopentanone-2,2′-dioxime in the presence of hydrogen peroxide. According to the data of X-ray structural analysis, this compound has centrosymmetric structure with two Ph₃Sb fragments connected with each other via dioxime bridges. The antimony atoms have screwed trigonalbipyramidal coordination, the Sb-C bond lengths vary in the range of 2.097(6)–2.122(4) Å, the Sb-O distances equal to 2.073(3) and 2.064(3) Å. There are short Sb—N intramolecular contacts in the molecule [2.876(4), 2.905(4) Å].     

A new triterpenoid saponin from the roots of Platycodon grandiflorum

A new triterpenoid saponin, 3-O-β-D-glucopyranosyl 16-oxo-platycodigenin 28-O-β-D-apiofuranosyl-(1→3)-β-D-xylopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyra-nosyl ester, was isolated from the roots of Platycodon grandiflorum, together with three known saponins, including platycodin D, deapio platycoside E and platycoside E. The structure of the new compound, named 16-oxo-platycodin D, was elucidated on the basis of spectroscopic data.     

A new veratramine alkaloid from the bulbs of Fritillaria hupehensis

A new highly conjugated alkaloid of veratramine type, 225,25S,5α-veratramine-7(8),12(14)-diene-3β,13β,23β-triol-6-one (1), was isolated from the bulbs of Fritillaria hupehensis Hsiao et K.C. Hsia. Its structure was determined on the basis of spectroscopic evidences.     

A new neuroprotective bakkenolide from the rhizome of Petasites tricholobus

A new bakkenolide-type compound, bakkenolide-Va（1）, was isolated from the rhizome of Petasites tricholobus. The structure was characterized on the basis of various NMR （1H, 13C, 1H-1H COSY, HMQC, HMBC and NOESY） and mass spectrometry data. The neuroprotective activity of bakkenolide-Va was investigated in primarily cultured neurons treated by hypoxia-ghicose deprivation and various types of oxidative insults.     

A new sesquiterpene from Caragana intermediia

A new alloaromadendrane-type sesquiterpene,(-)-alloaromadendrane-3β,9β-diol(1),has been isolated from the aerial part of Caragana intermediia.The structure of (-)-alloaromadendrane-3β,9β-diol(1)was established by spectroscopic methods, including X-ray analysis that provided its relative stereochemistry.Bioassay showed that (-)-alloaromadendrane-3β,9β-diol (1)possesses anti-pyricularia oryzae P-2b activity with MIC value of 10μg/mL.     

A new iridoid from Incarvillea delavayi

A new iridoid was isolated from the 80% ethanol extract of the whole plant of Incarvillea delavayi. Its structure was defined, and named incarvillic acid, on the basis of spectral evidences.     

A new tetrastilbene from Caragana sinica

A new tetrastilbene named carasinol D （1） was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B （2） by an acid-catalyzed conversion.