Synthesis of Indole-Fused Bicyclo[3.1.1]heptanes through (3+3) Cycloaddition of 2-Indolylmethanols with Bicyclo[1.1.0]butanes.

A variety of indole-fused bicyclo[3.1.1]heptanes were prepared in good yields with high regioselectivity through organocatalyzed umpolung (3+3) cycloaddition of 2-indolylmethanols and bicyclo[1.

Bifunctional Sodium Dithionite Promoted Radical-Polar Crossover Cyclization: Diversified Synthesis of Functionalized Cyclic Sultines.

A catalyst-free reductive radical-polar crossover cyclization with alkenes and sodium dithionite to construct densely functionalized cyclic sultines was described. The key to the success of this practical protocol relies not only on a bifunctional role of sodium dithionite, that is, serving as radical initiator and SO source, but also on the diversified conversions (RPCC/SO insertion/S2 cyclization and RPCC/SO insertion/1,4-addition cyclization processes), which enabled efficient construction of target compounds with the high efficiency and atom- and step-economy under mild conditions.

Multicomponent Cyclization with an Inorganic Sulfur Dioxide Surrogate: Straightforward Construction of Difluorinated Benzosultams.

A straightforward three-component transformation for the preparation of functionalized benzosultams under TM-free and mild reaction conditions was described, in which easy-to-handle NaSO, available bromodifluoroalkyl reagent, and (2-haloaryl) cyanamide were employed. NaSO was essential to the generation of difluoroalkyl radical, SO fixation, and cyclization, which enabled efficient construction of target products in a sustainable manner. A broad substrate scope and modular feature made this protocol attractive for exploring the chemical space of the construction of cyclic sulfonamides.

Trophodynamics and health risk assessment of toxic trace metals in the food web of a plateau freshwater lake.

The trophodynamics of toxic trace metals is significant for assessing the threat of toxic trace metals to the aquatic ecosystem and human safety. However, due to the difficulty of accurately calculating the trophic positions of freshwater aquatic organisms in the food web, the comprehensive process of trophodynamics of toxic trace metals in freshwater ecosystems was still rarely known. By integrating the compound-specific nitrogen stable isotopic analysis of amino acids (CSIA-AAs) and the Bayesian stable isotope mixing model (SIMM) as a novel approach, the present study investigated the trophodynamics of five toxic trace metals (Zn, As, Cr, Cu, and Hg) in the food web of the YangZong Lake, a plateau freshwater lake that was once heavily polluted by arsenic in Yunnan Province, China.

Decreased cpg15 augments oxidative stress in sleep deprived mouse brain.

Sleep deprivation (SD) has detrimental effects on the physiological function of the brain. However, the underlying mechanism remains elusive. In the present study, we investigated the expression of candidate plasticity-related gene 15 (cpg15), a neurotrophic gene, and its potential role in SD using a REM-SD mouse model.

Design, Synthesis, and Fungicidal Evaluation of Novel Pyrazole-furan and Pyrazole-pyrrole Carboxamide as Succinate Dehydrogenase Inhibitors.

The identification of novel succinate dehydrogenase (SDH) inhibitors represents one of the most attractive directions in the field of fungicide research and development. During our continuous efforts to pursue inhibitors belonging to this class, some structurally novel pyrazole-furan carboxamide and pyrazole-pyrrole carboxamide derivatives have been discovered via the introduction of scaffold hopping and bioisosterism to compound 1, a remarkably potent lead obtained by pharmacophore-based virtual screening. As a result of the evaluation against three destructive fungi, including Sclerotinia sclerotiorum, Rhizoctonia solani, and Pyricularia grisea, a majority of them displayed potent fungicidal activities.

Discovery of Novel Succinate Dehydrogenase Inhibitors by the Integration of in Silico Library Design and Pharmacophore Mapping.

Succinate dehydrogenase (SDH) has been demonstrated as a promising target for fungicide discovery. Crystal structure data have indicated that the carboxyl "core" of current SDH inhibitors contributed largely to their binding affinity. Thus, identifying novel carboxyl "core" SDH inhibitors would remarkably improve the biological potency of current SDHI fungicides.

Synthesis, antifungal activity, and QSAR study of novel trichodermin derivatives.

In an attempt to discover more potential antifungal agents, in this study, 21 novel trichodermin derivatives containing conjugated oxime ester (5a-5u) were designed and synthesized and were screened for in vitro antifungal activity. The bioassay tests showed that some of them exhibited good inhibitory activity against the tested pathogenic fungi. Compound 5a exhibited better activity against Pyricularia oryzae and Sclerotonia sclerotiorum than trichodermin, and compound 5j showed particular activity against P.

Synthesis and biological evaluation of novel trichodermin derivatives as antifungal agents.

To discover more potential antifungal agents, 17 novel trichodermin derivatives were designed and synthesized by modification of 3 and 4a. The structures of all the synthesized compounds were confirmed by (1)H NMR, ESI-MS and HRMS. Their antifungal activities against Ustilaginoidea oryzae and Pyricularia oryzae were evaluated.

3-(2,5-Di-methyl-phen-yl)-8-meth-oxy-2-oxo-1-aza-spiro-[4.5]dec-3-en-4-yl 3-(2-bromo-4-fluoro-phen-yl)acrylate.

In the title compound, C27H27BrFNO4, which is an inhibitor of acetyl-CoA carboxyl-ase, the cyclo-hexane ring displays a chair comformation with the spiro-C and meth-oxy-bearing C atoms deviating by 0.681 (7) and -0.655 (1) Å, resppectively, from the mean plane formed by the other four C atoms of the spiro-C6 ring.

Structure, bioactivity and implications for environmental remediation of complexes comprising the fungicide hexaconazole bound to copper.

Background: In agricultural areas excessive amounts of toxic heavy metals are a growing threat to the environment and human health. Measures should be taken to minimise the risk of adverse health effects. Hence, we investigated the possibilities of hexaconazole (a commercial fungicidal) as a dual-function ligand that has heavy metal ions chelating and fungicidal activities.

(1'S,4'S)-5-(2,5-Dimethyl-phen-yl)-4'-meth-oxy-6-oxa-3-aza-spiro-[bicyclo-[3.1.0]hexane-2,1'-cyclo-hexa-n]-4-one.

In the title compound, C18H23NO3, the cyclo-hexane ring has a chair conformation. The oxirane plane (OCC) makes a dihedral angle of 76.15 (13)° with that of the pyrrolidine ring to which it is fused.

Metabolism-based synthesis, biological evaluation and structure-activity relationship analysis of spirotetramat analogues as potential lipid biosynthesis inhibitors.

Background: In previous studies, scientists found that, when spirotetramat was introduced into plants or animals, it was mainly metabolised at positions C-4 and C-8. That is to say, these two functional positions potentially played an important role in spirotetramat's bioactivities. In order to develop novel insecticides or miticides, the present authors designed and synthesised 35 spirotetramat analogues based on metabolite structures.

8-{[(E)-3-(2-Chloro-phen-yl)acrylo-yloxy]imino}-12,13-ep-oxy-trichethec-9-en-4-yl (E)-3-(2-chloro-phen-yl)acrylate.

In the title compound, C(33)H(31)Cl(2)NO(6), the five-membered ring displays an envelope conformation, whereas the two six-membered rings both exhibit a chair conformation. As for the seven-membered ring, the dihedral angle between the mean planes formed by the four C atoms of the envelope unit and the three C and one O atoms of the six-membered chair is 69.08 (4)°, and these two mean planes are nearly perpendicular to the ep-oxy ring, making dihedral angles of 87.

3-tert-Butyl-2-oxo-1-oxaspiro-[4.5]dec-3-en-4-yl 4-chloro-benzoate.

The title tetronic acid derivative, C(20)H(23)ClO(4), which is a spiro-diclofen analogue, has two crystallographically independent mol-ecules in the asymmetric unit (Z' = 2). The cyclo-hexane rings in the respective mol-ecules A and B adopt chair conformations [four C atoms are planar with mean deviations of 0.013 (2) and 0.

Synthesis and bioactivity evaluation of novel spiromesifen derivatives.

Background: The development of environmentally friendly and novel structural pesticides is now an area of intense research in the agriculture field. Spirocyclic tetronic acids such as spiromesifen are typical compounds of this kind. In order to discover novel compounds with improved and broader-spectrum insecticidal activities, a series of spiromesifen derivatives were synthesised and bioassayed.

Design, synthesis, and biological activities of milbemycin analogues.

Milbemycins have received considerable interest in agricultural chemistry due to a special action mode, extremely high activity against arachnoide pests, low toxicity to mammals, and environmentally benign characteristics. Two series of novel milbemycin analogues (4Ia-6IIc) containing alkyl and aryl groups at the 4'- and 13-positions were designed and synthesized by five schemes. These analogues were identified by (1)H NMR, (13)C NMR, and elemental analysis (or HRMS).

Trichodermin (12,13-ep-oxy-trichethec-9-en-4β-yl 4-fluoro-benzoate).

IN THE TITLE TRICHODERMIN COMPOUND (SYSTEMATIC NAME: 12,13-ep-oxy-trichothec-9-en-4β-yl 4-fluoro-benzoate), C(22)H(25)FO(4), the five-membered ring displays an envelope conformation, whereas the two six-membered rings show the different conformations, viz. chair and half-chair. As for the seven-membered ring, the dihedral angle between the mean planes formed by the four C atoms of the envelope unit and the three C and one O atoms of the six-membered chair is 68.

4-Hydr-oxy-3-mesityl-1-oxaspiro-[4.4]non-3-en-2-one.

In the title compound, C(17)H(20)O(3), the five-membered cyclo-pentyl ring displays an envelope conformation, with the atom at the flap position 0.538 (3) Å out of the mean plane formed by the other four atoms. The dihedral angle between the benzene and furan rings is 63.

Dihalogenated trichodermin (4β-acet-oxy-9,10-dibromo-12,13-epoxy-tri-chothec).

In the title dihalogenated trichodermin mol-ecule, C(17)H(24)Br(2)O(4) (systematic name: 9,10-dibromo-12,13-epoxy-trichothec-9-en-4β-yl acetate), the five-membered ring displays an envelope conformation, whereas the two six-membered rings show the same conformation, viz. chair. As for the seven-membered ring, the dihedral angle between the mean planes formed by the four C atoms of the envelope unit and the three C and one O atoms of the six-membered chair is 69.

3-(2,4-Dichloro-phen-yl)-2-oxo-1-oxaspiro-[4.5]dec-3-en-4-yl acetate.

In the title compound, C(17)H(16)Cl(2)O(4), the cyclo-hexyl ring displays a chair conformation [the four C atoms are planar with a mean deviation of 0.001 (2) Å and the two C atoms at the flap positions deviate by 0.625 (2) and -0.

3-(2,4-Dichloro-phen-yl)-2-oxo-1-oxa-spiro-[4.5]dec-3-en-4-yl 4-chloro-benzoate.

In the title spiro-diclofen derivative, C(22)H(17)Cl(3)O(4), the cyclo-hexane ring adopts a chair conformation [four C atoms are planar with a mean deviation of 0.018 Å and the two C atoms at the flap positions deviate by 0.613 (4) and -0.

Trichodermol (4α-hydr-oxy-12,13-epoxy-trichothec-9-ene).

In the title compound, C(15)H(22)O(3), the five-membered ring displays an envelope conformation, whereas the two six-membered rings show different conformations, viz. chair and half-chair. In the crystal, mol-ecules are linked through inter-molecular O-H⋯O hydrogen bonds, forming chains running along the b axis.

2-(4-Chloro-phen-yl)-3-methyl-N-(5-methyl-thia-zol-2-yl)butanamide.

In the title compound, C(15)H(17)ClN(2)OS, the thia-zole ring, which is essentially planar with a maximum deviation of 0.044 (3) Å, makes a dihedral angle of 54.76 (8)° with the benzene ring.