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Two new 1,3-benzodioxole derivatives, leucandioxoles A and B (1–2), together with two known related compounds (3–4), have been isolated from the South China Sea sponge Leucandra sp. The structures ...

Two new 1,3-benzodioxole derivatives, leucandioxoles A and B (

Biodiesel is prepared from waste cooking oil and methanol. The ester exchange reaction is conducted under ultrasonic conditions with alkali as the catalysts. Five factors influencing on the transesterification reaction of biodiesel production are discussed in this study, including the reaction time, reaction temperature, catalyst amount, methanol to oil molar ratio, ultrasonic power. A series of laboratory experiments were carried out to test the conversion of biodiesel under various conditions. The process of biodiesel production was optimized by application of orthogonal test obtain the optimum conditions for biodiesel synthesis. The results showed that the optimum reaction conditions were:molar ratio of oil to methanol 8:1,catalysts 1.2g KOH/100g oil,reaction temperature 70°C, reaction time 50 min,Ultrasonic power 400W. The conversion may up to 96.48%.

Copper (II) imprinted polymer particles were prepared by surface molecular imprinting technique in toluenewith 1-hy-droxy-4-(prop-2-enyloxy)-9, 10-anthraquinone (AQ) as the functional monomer, silica gel as the carrier.The effect of adsorption time, acidity, temperature and concentration on adsorption capacity was investigated by atomic absorption spectrometry. Selectivity for Cu2+ of the prepared polymer was also studied in mixed aqueous solution, the ion imprinted polymer were applied to the determination of Cu2+ in river and tap water samples, the concentration of Cu2+ in water samples were determined and the recoveries of Cu2+ in river and tap water samples were 110.7% and 109.2%, respectively.

A one-step extraction/transesterification process was developed to directly convert microalgae into biodiesel in the presence of catalyst, KOH using ultrasonic irradiation. The influences of various parameters on the transesterification reaction, including the reaction time, temperature, catalyst concentration, methanol to microalgae mass ratio and ultrasonic power, were investigated. And the optimum conditions for the transesterification process have been obtained as mass ratio of methanol to microalgae as 4:1, catalyst concentration of 7wt.%, temperature as 70oC and ultrasonic power as 100W with an irradiation time of 30 min by orthogonal experiments L9(34 )．Under these conditions, the conversion of fatty acid methyl esters was up to 4.0%.

Cu2+-imprinted polymers (Cu(II)–IIPs) were prepared by thermal precipitation polymerization method with Cu2+ion as the template, 1,4-dihydroxyanthraquinone (AQ) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker. In synthesis processes,The functional monomer AQ, there is only one functional groups that can selectively recognize Cu2+ ion, is set in highly cross-linked polymer net, not to form covalent-linkage with polymer net. The imprinted polymer particles were characterized by UV-visible spectra, FT-IR, scanning electron microscopy and colorimetry. The sorption and selectivity capacity of Cu(II)–IIPs for Cu2+ ion were studied．The results showed that the imprinted polymer had good affinity for Cu2+. The maximum sorption capacity was 11.4 mg/g．The sorption equilibrium time was 50 min and the optimum pH for quantitative copper retention was 7.0. Competitive sorption of Cu2+, Co2+, Zn2+, Mg2+, Ca2+ from their mixture was also studied in a batch system. The relatively selective factor of copper to other metal ions were greater than 1. The Cu(II)–IIPs could be repeatedly used with high selectivity and stability for Cu2+.This Cu(II)–IIPs has been successfully applied to the separation and determination of the trace Cu2+ in real water samples.

Three new aaptamine derivatives (1–3), together with six known related compounds (4–9), have been isolated from the South China Sea sponge Aaptos aaptos. The structures of all compounds were unambiguously elucidated on the basis of spectroscopic analyses. Compounds 1, 4, 5, 7, and 9 showed cytotoxic activities against HeLa, K562, MCF-7, and U937 cell lines with IC50 values in the range of 0.90–12.32 μM.

A chiral copper complex, generated from a C 2 -symmetric bis(hydroxycamphorsulfonamide) ligand (8 mol%) and Cu(OTf) 2 , has been discovered to effect high enantioselectivities in the addition of alkynylzinc to a series of simple ketones. The alkynylation of a variety of aromatic and aliphatic ketones resulted in excellent yields and enantioselectivities (83-98% ee). Even when the loadings of the catalyst is 5 mol%, up to 94% ee was obtained.

New chiral oxazolidine ligands have been derived conveniently from natural amino acids in good yields. Their use in the enantioselective addition of phenylacetylene to aromatic ketones has been tested with the best ee being up to 88%. We provide a simple, practical and inexpensive method to generate chiral tertiary propargylic alcohols.

( S )-(−)-2-Amino-1,1,3-triphenylpropanol 3c , which is readily available from l -Phe, was found to be effective in catalyzing the addition reaction of an alkynylzinc reagent to aromatic ketones with up to 80% ee of the thus produced chiral tertiary propargylic alcohols. Unlike previous reports, 3c does not require the use of an additional central metal (other than zinc itself) and the pre-preparation of an alkynylzinc. This has greatly simplified the experimental procedure for this reaction.

The bifunctional ligand 2a showed a more enhanced reactivity than that of the corresponding amino alcohol ligand in the asymmetric addition of alkynylzinc to benzaldehyde. The bifunctional ligand 2a can catalyze the addition of phenylacetylene to various types of aldehydes including aromatic aldehydes, aliphatic aldehydes, and α,β-unsaturated aldehydes with high enantioselectivity (81–98% ee). The conditions of this catalytic process are both mild and simple.

The readily available and inexpensive (S)-BINOL ligand in combination with Ti(O(i)Pr)(4) is an effective chiral catalyst for the catalytic asymmetric addition of alkynylzinc to unactivated simple ketones. Good to excellent enantioselectivities were achieved. No previous case has been reported successfully using BINOL to catalyze the addition of phenylacetylene to unactivated ketones, and thus the utility of BINOL in asymmetric catalysis is expanded.

To investigate the epidemiological and clinical characteristics of acute bacterial dysentery in recent years in Beijing so as to provide scientific reference for prevention and control of enteric infectious diseases.The data of age, occupation, symptoms, signs, pathogen detection of 652 patients with acute bacterial dysentery diagnosed clinically from April 2007 to October 2007 were analyzed retrospectively.The occupations of the 652 patients included office workers and functionaries (31.4%), students (29.4%), retirees (9.8%), unemployed and housewives (7.1%), commercial attendants (6.3), workers (4.8%), teachers (4.1%), and others (7.1%). Diarrhea, stomach ache, and fever were the main symptoms. Tenesmus and tenderness of left lower quadrant abdomen were infrequent. The positive rate of fecal bacterial culture was 17.7%. 8.9% of the patients were diagnosed as with bacterial dysentery by fecal bacterial culture.Most of the patients with bacterial dysentery in Beijing are young adults. The positive rate of fecal bacterial culture is low. It is difficult to differentiate bacterial dysentery from other diarrheal diseases.

The chiral oxazolidine ligand can catalyze the enantioselective addition of diethylzinc to aromatic aldehydes at room temperature with high enantioselectivity (98–99% ee). The conditions for this catalytic process are both mild and simple as compared with the same kind catalyst.

New chiral oxazolidines were conveniently synthesized from natural amino acids in three simple steps with good yields. The use of chiral oxazolidine ligands for the enantioselective alkynylation of aldehydes provides a simple, practical and inexpensive method to generate chiral propargyl alcohols with 85–99% ee.

( S )-(−)-2-Amino-1,1,3-triphenylpropanol 3c , which is readily available from l -Phe, was found to be effective in catalyzing the addition reaction of an alkynylzinc reagent to aromatic ketones with up to 80% ee of the thus produced chiral tertiary propargylic alcohols. Unlike previous reports, 3c does not require the use of an additional central metal (other than zinc itself) and the pre-preparation of an alkynylzinc. This has greatly simplified the experimental procedure for this reaction.

The bifunctional ligand 2a showed a more enhanced reactivity than that of the corresponding amino alcohol ligand in the asymmetric addition of alkynylzinc to benzaldehyde. The bifunctional ligand 2a can catalyze the addition of phenylacetylene to various types of aldehydes including aromatic aldehydes, aliphatic aldehydes, and α,β-unsaturated aldehydes with high enantioselectivity (81–98% ee). The conditions of this catalytic process are both mild and simple.

The catalytic asymmetric addition of phenylacetylene to aromatic ketones is reported. The catalyst, generated from commercially available Cinchona alkaloids and industrially available triethylaluminum, gives the expected tertiary alcohols with good enantiomeric excess (70-89%) and yields (60-83%). No previous case has been reported successfully using triethylaluminum as a Lewis acid in the asymmetric alkynylation of carbonylic derivatives, and thus we provide a new method to obtain optically active tertiary propargyl alcohols.