The antifungal metabolites from coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica.

One new cyclohexenone derivative, asperfumtone A (1) along with six known compounds were obtained from the coculture of Aspergillus fumigatus and Alternaria alternata associated with Coffea arabica. The configuration of 2 was first reported in the research. The structures were determined by extensive spectroscopic analyses, and ECD calculation. Compounds 3, 4 and 7 showed significant antifungal activities against coffee phytopathogens A. alternata and Fusarium incarnatum with MICs of 1 µg/mL. Compounds 1 and 2 showed weak antifungal activities against A. alternata and F. incarnatum with MICs of 32-64 µg/mL.

Global Isomeric Survey of Elusive Cyclopropanetrione: Unknown but Viable Isomers.

Despite the great interest in energy storage application, stable neutral CnOn (n > 1) structures either in thermodynamics or kinetics have yet been largely limited due to the rather high tendency to release the very stable CO molecule. The neutral cyclopropanetrione (C3O3) cluster has long remained elusive since no isomer with sufficient kinetic stability has been found either experimentally or theoretically. In this work, we constructed the first global potential energy surface of singlet C3O3 at the CCSD(T)/aug-cc-pVTZ//B3LYP/aug-cc-pVTZ level, from which the kinetic stability of a wide range of C3O3 isomers can be determined by investigating their isomerization and fragmentation pathways. Amongst, a three-membered ring structure 01 is the global C3O3 isomer with a barrier of 10.6 kcal/mol at the sophisticated W1BD level. In particular, two carbene-type isomers 02 and 04 possess appreciable destruction barriers of 20.3 and 24.7 kcal/mol at W1BD, respectively. Thus, 02 and 04 can be useful building blocks for constructing larger high-energy density carbon-oxygen clusters. Moreover, with the carbene center, both might effectively functionalize various nano-materials while retaining the electrochemical active carbonyl and epoxyl moieties that are very desirable in alkali metal-ion batteries.

The factors affecting a native obligate parasite, Cuscuta australis, in selecting an exotic weed, Humulus scandens, as its host.

In weed management, using native parasites to control exotic weeds is considered a better alternative than classical biological control. But the risk must be assessed because of the potential damage caused by these agents. We conducted this project to investigate the mechanism driving the choice of a native obligate parasite, Cuscuta australis, between the exotic, Humulus scandens, and native plants as its host through field and pot experiments. The results showed that C. australis preferred the exotic weed over native (naturalized) hosts and caused a notable reduction in the biomass of H. scandens in the field. In contrast, the results of the pot experimentindicated that C. australis preferred a mix of native (naturalized) hosts over the exotic weed. Both texperiments indicated that the parasitic preference of C. australis was induced more by light irradiance than plant water, carbon (C), nitrogen (N) and phosphorus (P) contents, indicating that the native parasite can only be used to control H. scandens when the exotic weed forms mono-cultures or dominates the community. Accordingly, induction and release of C. australis to control H. scandens should be conducted with great caution.

Isomerization Pathways of ONCNO: Unstable or Metastable?

Fulminates containing the CNO(-) ion have been widely utilized as high-energy density materials (HEDMs) for more than 120 years. Yet no purely covalently bound CNO molecule, i.e., nitrile oxide, is known to behave as an HEDM. In this study, we performed a thorough investigation of the potential energy surface of nitrile oxide ONCNO and related isomers, applying various sophisticated methods including G4, CBS-QB3, W1BD, CCSD(T)/CBS, and CASPT2/CBS. The Gibbs free energy calculations showed that the decomposition of ONCNO to the considerably endothermic products CNO + NO is favored compared to that into the highly exothermic products CO2 + N2. Thus, ONCNO fails to be the long expected nitrile oxide HEDM. However, with the rate-determining barrier of 23.3 kcal mol(-1) at the W1BD level, ONCNO should be experimentally accessible.

Screening Allelochemical-Resistant Species of the Alien Invasive Mikania micrantha for Restoration in South China.

To screen allelochemical-resistant species of the alien invasive weed Mikania micrantha, we studied the allelopathic inhibition effects of the leaf aqueous extract (LAE) of Mikania on seed germination and seedling growth of the 26 species native or naturalized in the invaded region in South China. Seed germination was more strongly negatively affected by LAE than seedling growth. Responses of seed germination and seed growth to LAE differed differently among the target species. LAE more strongly negatively affected seed germination, but less strongly negatively affected seedling growth, in non-legume species than in legume species. LAE more strongly negatively affected seed germination and seedling growth in native species than naturalized exotic species. Therefore, naturalized exotic non-legume seedlings are more suitable than seeds of native legume species for restoration of Mikania-invaded habitats.

Ethyl 2-[1,3-dioxo-6-(piperidin-1-yl)-2,3-dihydro-1H-benz[de]isoquinolin-2-yl]acetate.

In the title compound, C(21)H(22)N(2)O(4), the naphthalimide unit is almost planar (r.m.s. deviation = 0.081Å). The carboximide N atom and the five C atoms of the eth-oxy-carbonyl-methyl substituent also lie close to a common plane (r.m.s. deviation = 0.119Å), which subtends an angle of 71.06 (8)° to the naphthalamide plane. The piperidine ring adopts a chair conformation. In the crystal, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into zigzag chains along the a axis.

2-Methyl-4-(2-methyl-benzamido)-benzoic acid.

In the crystal structure of the title compound, C(16)H(15)NO(3), inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains parallel to the b axis and pairs of inter-molecular O-H⋯O hydrogen bonds between inversion-related carb-oxy-lic acid groups link the mol-ecules into dimers. The dihedral angle between the two benzene rings is 82.4 (2)°.

Methyl 4-(3-chloro-prop-oxy)benzoate.

In the crystal structure of the title compound, C(11)H(13)ClO(3), inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into zigzag chains along the c axis.

Methyl 5-chloro-2-(4-methyl-benzene-sulfonamido)-benzoate.

In the title compound, C(15)H(14)ClNO(4)S, the benzene rings are oriented at a dihedral angle of 85.42 (1)°. An intra-molecular N-H⋯O hydrogen bond results in the formation of a five-membered ring and an intramolecular C-H⋯O inter-action also occurs.

Methyl 5-chloro-2-[N-(3-eth-oxy-carbonyl-prop-yl)-4-methyl-benzene-sulfonamido]-benzoate.

In the title compound, C(21)H(24)ClNO(6)S, the benzene rings are oriented at a dihedral angles of 41.6 (2)°. In the crystal structure, weak inter-molecular C-H⋯O inter-actions link the mol-ecules.

2,2,2-Trifluoro-ethyl 4-methyl-benzene-sulfonate.

In the crystal structure of the title compound, C(9)H(9)F(3)O(3)S, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules along the c-axis direction. Also present are slipped π-π stacking inter-actions between phenyl-ene rings, with perpendicular inter-planar distances of 3.55 (2) Šand centroid-centroid distances of 3.851 (2) Å.

Methyl 2-amino-5-chloro-benzoate.

The title compound, C(8)H(8)ClNO(2), is almost planar, with an r.m.s. deviation of 0.0410 Šfrom the plane through the non-hydrogen atoms. In the crystal structure, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains along the b axis. An intra-molecular N-H⋯O hydrogen bond results in the formation of a six-membered ring.