Crystal structure characterization, Hirshfeld surface analysis, and DFT calculation studies of 1-(6-amino-5-nitro-naphthalen-2-yl)ethanone.

The title compound, C12H10N2O3, was obtained by the de-acetyl-ation reaction of 1-(6-amino-5-nitro-naphthalen-2-yl)ethanone in a concentrated sulfuric acid methanol solution. The mol-ecule comprises a naphthalene ring system bearing an acetyl group (C-3), an amino group (C-7), and a nitro group (C-8). In the crystal, the mol-ecules are assembled into a two-dimensional network by N⋯H/H⋯N and O⋯H/H⋯O hydrogen-bonding inter-actions. n-π and π-π stacking inter-actions are the dominant inter-actions in the three-dimensional crystal packing. Hirshfeld surface analysis indicates that the most important contributions are from O⋯H/H⋯O (34.9%), H⋯H (33.7%), and C⋯H/H⋯C (11.0%) contacts. The energies of the frontier mol-ecular orbitals were computed using density functional theory (DFT) calculations at the B3LYP-D3BJ/def2-TZVP level of theory and the LUMO-HOMO energy gap of the mol-ecule is 3.765 eV.

Diethyl 4-[4-(dimethyl-amino)phen-yl]-2,6-dimethyl-1,4-dihydro-pyridine-3,5-dicarboxyl-ate.

In the title compound, C(21)H(28)N(2)O(4), the dihydro-pyridine ring adopts a flattened boat conformation. The mean plane of the dihydro-pyridine ring and the attached benzene ring form a dihedral angle of 85.1 (1) Å. One of two ethyl fragments is disordered between two conformations in a 0.67 (4):0.33 (4) ratio. In the crystal structure, mol-ecules related by translation along the a axis are linked into chains via inter-molecular N-H⋯O hydrogen bonds.

Bioactive metabolites produced by Chaetomium globosum, an endophytic fungus isolated from Ginkgo biloba.

A novel cytotoxic chlorinated azaphilone derivative named chaetomugilin D (1), together with three known metabolites, chaetomugilin A (2), chaetoglobosins A (3) and C (4), has been isolated by a bioassay-guided fractionation from the EtOAc extract of the cultures of Chaetomium globosum, an endophytic fungus found in the leaves of Ginkgo biloba. Structure of 1 was established by analyses of spectroscopic methods, including 2D-NMR experiments (COSY, NOESY, HMQC, and HMBC). Compounds 1-4 displayed significant growth inhibitory activity against the brine shrimp (Artemia salina) and Mucor miehei.

Diethyl 2,6-dimethyl-4-phenyl-1,4-dihydro-pyridine-3,5-dicarboxyl-ate.

The title mol-ecule, C(19)H(23)NO(4), was synthesized by the reaction of benzaldehyde, ethyl acetoacetate and NH(4)HCO(3). The dihydro-pyridine ring adopts a flattened boat conformation and the plane of the base of the boat forms a dihedral angle of 88.78 (9)° with the phenyl ring. The packing is stabilized by strong inter-molecular N-H⋯O and weak inter-molecular C-H⋯O hydrogen bonds.

Antioxidant polyketide phenolic metabolites from the edible mushroom Cortinarius purpurascens.

Phytochemical investigation of the ethyl acetate extract of the edible macrofungus, Cortinarius purpurascens, led to the isolation of nine anthraquinone-related pigments, citreorosein 6,8-dimethyl ether (1), physcione (2), rufoolivacin (3), rufoolivacin C (4), rufoolivacin D (5), leucorufoolivacin (6), verbindung cr11 (7), verbindung cr60 (8) and 1-Hydroxy-3-methyl-2-isopropanyl-6,8-dimethoxyanthraquinone (9). The structures of these isolated compounds were characterised by spectroscopic methods and comparison with published data. Among the tested compounds, 3-6 exhibited potent DPPH radical-scavenging activity with IC50 values in the range of 3-8 µg/ml. The results indicated that the fungus is a possible source of natural products with potential antioxidant activity.

Polyhydroxylated steroids from an endophytic fungus, Chaetomium globosum ZY-22 isolated from Ginkgo biloba.

A novel polyhydroxylated C(29)-sterol, 25xi-methyl-22-homo-5alpha-cholest-7,22-diene-3beta,6beta,9alpha-triol, designated globosterol (1), together with one known tetrahydroxylated ergosterol (22E, 24R)-ergosta-7,22-diene-3beta,5alpha,6beta,9alpha-tetraol (2) has been isolated from the cultures of an endophytic fungus, Chaetomium globosum ZY-22 originated from the plant Ginkgo biloba. The structures and relative configurations of 1 and 2 were established on the basis of extensive spectroscopic analyses including 1D and 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and NOESY) experiments and comparison with the literature. Globosterol (1) possesses an unprecedented 25-methyl Delta(22)-C(10)-side chain and Delta(7)-3beta,6beta,9alpha-hydroxy-steroid nucleus, which represents the first example for C(29)-steroids of the group.

Metabolites from an endophytic fungus sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach.

Two new natural compounds, a symmetrical disulfide dimer didodecyl 3,3''-dithiodipropionate (1) and a pregnane steroid 5,16-pregnadien-3beta-ol-20-one acetate (2), were isolated together with two known compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) and ergosterol peroxide (4), from the ethyl acetate soluble extract of fermentation broth of an endophytic fungus, Sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach L. and grown in pure culture. Their structures were determined on the basis of spectroscopic methods including 1D and 2D nuclear magnetic resonance spectroscopy (NMR) experiments and by mass spectrometric measurements (MS). These fungal metabolites were isolated for the first time from the genus Sphaceloma. The structure of 1 was also confirmed by chemical synthesis.