STUDIES ON THE SYNTHESIS OF RABDOSIA DITERPENOID Ⅱ,PREPARATION OF A KEY BUILDING BLOCK,α,β-UNSATURATED LACTONE

The main half molecule(4a)of the trichorabdal B(1) was synthesized from pentadienol(6).The key step is the intramolecular Diels-Alder reaction of 8.

Two new α,β-unsaturated butyrolactone derivatives from Pleione bulbocodioides

Two new α,β-unsaturated butyrolactone derivatives, 4-(4″-hydroxybenzyl)-3-(3′-hydroxy-phenethyl)furan-2(5H)-one (1) and 3-(3′-hydroxyphenethyl)furan-2(5H)-one (2), together with one known phenolic compound (3), were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structures were elucidated by analysis of spectroscopic data.

Histone Deacetylation Modifier Induced One New Resorcylic Acid Lactone 7′(Z)-zeaenol from the Zoanthid-Derived Fungus Cochliobolus lunatus

Chemical epigenetic manipulation was applied to the zoanthid-derived fungus Cochliobolus lunatus(TA26-46)with a histone deacetylation modifier(100μmol L^(−1) nicotinamide),resulting in the isolation of a new 14-membered resorcylic acid lactone named 7′(Z)-zeaenol(1),together with six known analogues(2−7)from the treated broth.The planar structure of 1 was determined by comprehensive NMR spectroscopy and HRESIMS data.The absolute configuration of 1 was elucidated by ECD spectrum,^(13)C NMR shift calculations,and on the basis of biogenetic considerations.Compound 5 exhibited cytotoxic activity against the human tumor cell lines A549,HCT-116,HT-29,Hela,MCF-7,and K562 with the IC_(50) values ranging from 2.54 to 7.44μmolL^(−1).

Degradation of N-Acyl Homoserine Lactone Quorum Sensing Signals by Bacillus thuringiensis AHL Lactonase

Bacterial cells rely on signaling molecules to communicate with others from the same species and induce certain genes in a process known as quorum sensing (QS). A common molecule is N-acyl homoserine lactone (AHL) which is responsible for the expression of virulence and other factors that allow the organisms to compete in a given environment. On the other hand, other bacteria produce certain enzymes such as AHL-lactonase that break down AHL molecules and prevent gene expression of these factors. The aim of this work was to examine the level of degradation of AHL molecules by AHL-lactonase in 62 Bacillus thuringiensis (Bt) strains isolated from Middle Tennessee, Mississippi, and Alabama. N-hexanoyl-homoserine lactone (C6-HSL) and N-3-oxo-hexanoyl homoserine lactone (3-oxo-C6-HSL), which cause Chromobacterium violaceum (CV026) to produce a purple pigment were tested at different concentrations to view the Bt lactonase activity. In addition, PCR was used to test for the presence of the lactonase gene. The results showed that among the 62 Bt strains, there were 58 that possessed the AHL-lactonase (aiiA) gene and 48 strains were able to degrade C6-HSL. At high concentrations of AHL, only 13 strains were able to completely degrade C6-HSL. In addition, degradation of 3-oxo-C6-HSL was weak compared to C6-HSL. The results also revealed that AHL lactonase was thermostable, and it was concluded that the level of degradation varies in Bt strains. Only 13 of the strains studied have potent inhibitory activity against C6-HSL, which may be good to be used in field applications to control agricultural pest.

Copper-Catalyzed C-C(O)C Bond Cleavage of Monoalkylated β-Diketone: Synthesis of α,β-Unsaturated Ketones

A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K3PO4) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .

前列腺素关键中间体——手性Corey Lactone的合成研究进展

综述了前列腺素的关键手性中间体———Corey lactone的制备方法,重点阐述了Corey lactone的外消旋体拆分法,不对称合成法及手性源原料法的最新研究进展。参考文献28篇。

Sesquiterpene Lactones from Elephantopus scaber

A new germacranolide sesquiterpene lactone, isoscabertopin, was isolated from Elephantopus scaber together with the known scabertopin. Their structures were determined by spectroscopic methods.

A new cassane diterpenoid lactone from the seed of Caesalpinia minax

A new cassane diterpenoid lactone was isolated from the seed of Caesalpinia minax. On the basis of spectral evidences, its structure was established as 12α-methoxyl, 5α, 14β-dihydroxy-1α, 6α, 7β-triacetoxycass-13（15）-en-16, 12-olide.

A New Sesquiterpene Lactone from Ainsliaea bonatii

A new sesquiterpene lactone, Ainsliaolide A, was isolated from Ainsliaea bonatii. Thestructure was determined on the basis of spectral data.

Eupatoranolide, a New Sesquiterpene Lactone from Eupatorium adenophorum

A new sesquiterpene lactone eupatoranolide was isolated from the flowers of Eupatorium adenophorum, its structure was elucidated as 2 beta-acetoxy-(7 alpha, 9 beta H)-3.6(11)-cadinadien-12(7)-olide by spectral analysis.

A new ent-labdane diterpenoid lactone from Andrographis paniculata

A new ent-labdane diterpenoid lactone was isolated from Andrographis paniculata.Its structure was identified on the basis of spectral data including 2D NMR.

Fenugreek lactone attenuates palmitate-induced apoptosis and dysfunction in pancreatic β-cells

AIM: To investigate the effect of fenugreek lactone(FL) on palmitate(PA)-induced apoptosis and dysfunction in insulin secretion in pancreatic NIT-1 β-cells. METHODS: Cells were cultured in the presence or absence of FL and PA(0.25 mmol/L) for 48 h. Then, lipid droplets in NIT-1 cells were observed by oil red O staining, and the intracellular triglyceride content was measured by colorimetric assay. The insulin content in the supernatant was determined using an insulin radioimmunoassay. Oxidative stress-associated parameters, including total superoxide dismutase, glutathione peroxidase and catalase activity and malondialdehyde levels in the suspensions were also examined. The expression of upstream regulators of oxidative stress, such as protein kinase C-α(PKC-α), phospho-PKC-α and P47 phox, were determined by Western blot analysis and real-time PCR. In addition, apoptosis was evaluated in NIT-1 cells by flow cytometry assays and caspase-3 viability assays.RESULTS: Our results indicated that compared to the control group, PA induced an increase in lipid accumulation and apoptosis and a decrease in insulin secretion in NIT-1 cells. Oxidative stress in NIT-1 cells was activated after 48 h of exposure to PA. However, FL reversed the above changes. These effects were accompanied by the inhibition of PKC-α, phosphoPKC-α and P47 phox expression and the activation of caspase-3. CONCLUSION: FL attenuates PA-induced apoptosis and insulin secretion dysfunction in NIT-1 pancreatic β-cells. The mechanism for this action may be associated with improvements in levels of oxidative stress.

A new nor-sesquiterpene lactone from Ainsliaea fulvioides

A new nor-sesquiterpene lactone ainsliatone A （1） was isolated from the aerial parts of Ainsliaeafulvioides. Its structure was established by the basis of spectroscopic methods and single-crystal X-ray diffraction analysis.

A new nine-membdered lactone from a marine fungus Cladosporium sp.F14

A new nine-membered lactone,cladospolide E（1）,was isolated from a culture broth of a marine fungus Cladosporium sp.F14. The structure of compound 1 was determined on the basis of extensive spectroscopic analysis,including 1D and 2D NMR data.

A new ent-labdane eiterpenoid lactone from Andrographis paniculata

A new ent-labdane diterpenoid lactone with a new natural product was isolated from Andrographis paniculata. Their structures were elucidated on the basis of spectral evidences including 2D NMR.

New Sesquiterpene Lactones from Carpesium Lipskyi

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Corrosion inhibition of α,β-unsaturated carbonyl compounds on steel in acid medium

Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.

Effects of coriaria lactone-activated,astrocyte-conditioned medium on estrogen receptor and progesterone receptor expression in rat cortical and hippocampal neurons

BACKGROUND： Coriaria lactone-activated astrocytes released bioactive substances that eventually caused epilepsy. OBJECTIVE： It has been suggested that activated astrocytes alter the expression of the estrogen receptor and progesterone receptor by releasing bioactive substances during epilepsy, thereby affecting neuronal activity in the brain. This study was designed to observe the expression of the estrogen receptor and the progesterone receptor in rat brain following lateral ventricle injection of coriaria lactone-activated, astrocyte-conditioned medium. DESIGN AND SETTING： This immunohistochemical, randomized, controlled, animal study was conducted at the Department of Pathology, Hospital Affiliated to Binzhou Medical College, China. MATERIAL： Coriaria lactone was provided by Huaxi Pharmaceutical Factory, China. METHODS： Forty adult, healthy, male, Sprague Dawley rats were randomly assigned into two groups. Astrocyte-conditioned medium （10 μ L） was injected into rat lateral ventricle in the control group （n = 8）. Coriaria lactone-activated, astrocyte-conditioned medium （10 μL） was infused into the rat lateral ventricle in the coriaria lactone group （n = 32）. At 2, 4, 8 and 12 hours following injection, rats were sacrificed and subjected to immunohistochemistry. Eight rats were studied at each time point. MAIN OUTCOME MEASURES： Behavioral changes were observed in rats of both groups. Expression of the estrogen receptor and the progesterone receptor in rat cortical and hippocampal neurons was measured using immunohistochemistry. RESULTS： Four hours after injection, estrogen receptor levels in rat cortical and hippocampal neurons were significantly higher in the coriaria lactone group than in the control group （P 〈 0.05）. Progesterone receptor levels were significantly lower in the coriaria lactone group than in the control group （P 〈 0.05）. Seizures were not observed in the control group. In the coriaria lactone group, convulsions appeared 30 minutes after injection; seizures reached grade Ⅲ at 45 minutes rat behavior was nearly normal at 2 hours. CONCLUSION： Activated astrocytes can induce seizures in the rat by enhancing estrogen receptor expression and decreasing progesterone receptor expression in cerebral cortical and hippocampal neurons.

Gallium trichloride-catalyzed conjugate addition of indole and pyrrole to α,β-unsaturated ketones in aqueous media

Michael addition of indole and pyrrole to a variety of α, β-unsaturated ketones was efficiently promoted by a catalytic amount of GaCl3 in aqueous media to afford the corresponding products in good to excellent yields.

Sesquiterpene Lactone Glycosides from Carpesium macrocephalum

Two new sesquiterpene lactone glycosides were isolated from the seeds of Carpesium macrocephalum. Their structures were elucidated as 2-O--D-glucopyranosy-5? 11?H- eudesma-4 (15)-en-12, 8?olide and 2 ?O--D-glucopyranosy-5?H-eudesma-4 (15), 11 (13)- dien-12, 8?olide by spectral methods (HRMS, 1 D and 2 D NMR).