Acetone, methyl ethyl ketone, ethyl acetate, acetonitrile and other polar aprotic solvents are strong inducers of aneuploidy in Saccharomyces cerevisiae

A diploid yeast strain D61.M was used to study induction of mitotic chromosomal malsegregation, mitotic recombination and point mutation. Several ketones (including acetone and methyl ethyl ketone) and some organic acid esters (including the methyl, ethyl and 2-methoxyethyl esters of acetic acid) and acetonitrile strongly induced aneuploidy but not recombination or point mutation. Only diethyl ketone induced low levels of recombination and point mutation in addition to aneuploidy. Related compounds were weak inducers of aneuploidy: methyl n-propyl ketone, the methyl esters of propionic and butyric acid, acetic acid esters of n- and iso-propanol and ethyl propionate. No mutagenicity was found with n-butyl and isoamyl acetate, ethyl formate, acetyl acetone (2,5-dipentanone) and dioxane. Methyl isopropyl ketone induced only some recombination and point mutation but no aneuploidy. Efficient induction was only observed with a treatment protocol in which growing cells were exposed to the chemicals during a growth period of 4 h at 28 degrees C followed by incubation in ice for more than 90 min, usually overnight for 16-17 h. Aneuploid cells could be detected in such cultures during a subsequent incubation at growth temperature if the chemical was still present. Detailed analysis showed that there was a high incidence of multiple events of chromosomal malsegregation. It is proposed that the mutagenic agents act directly on tubulin during growth so that labile microtubules are formed which dissociate in the cold. When cells are brought back to temperatures above the level critical for reassembly of tubulin and allowed to grow, faulty microtubules are formed.     

Attractiveness of 79 compounds and mixtures to wild Ceratitis capitata (Diptera: Tephritidae) in field trials

Seventy-nine volatile compounds chosen from those emitted by Mediterranean fruit fly males, fruits and food baits, were tested for their attractiveness to females of Ceratitis capitata (Wiedemann) in field trials with a wild population. To correct for density fluctuations, the results were presented as a percentage of males caught in the same type of traps baited with trimedlure, a known male attractant. The mixtures of corn steep liquor with ammonia compounds and amines were the most effective attractants for females. Other compounds exhibiting C. capitata attraction were a mixture ethyl acetate+acetic acid+ethanol for both sexes, and p-cymene, 1,3-diethylbenzene and borneol for females.     

Captures of pest fruit flies (Diptera: Tephritidae) and nontarget insects in BioLure and torula yeast traps in Hawaii

MultiLure traps were deployed in a Hawaiian orchard to compare the attraction of economically important fruit flies and nontarget insects to the three-component BioLure and torula yeast food lures. Either water or a 20% propylene glycol solution was used to dissolve the torula yeast or as capture fluid in BioLure traps. Torula yeast in water was more attractive than BioLure for male and female Bactrocera cucurbitae (Coquillett) and Bactrocera dorsalis (Hendel) and as attractive for Ceratitis capitata (Wiedemann), and the addition of propylene glycol significantly inhibited the attractiveness of torula yeast. The known synergistic effect of propylene glycol with BioLure, resulting in increased captures of Anastrepha flies, was not observed with Bactrocera. Nontarget Drosophilidae, Neriidae, Phoridae, Calliphoridae, Sarcophagidae, and Muscidae were more strongly attracted to BioLure, and both lures collected Chloropidae equally. As with fruit flies, propylene glycol in torula yeast significantly decreased nontarget captures. The results therefore suggest that torula yeast in water is a more effective attractant than BioLure for pest Bactrocera while minimizing nontarget captures.     

A Quick-Mixed Aluminum Hematoxylin Stain

Two stock solutions are composed as follows: A) aluminum sulfate, sodium iodate and acetic acid in aqueous propylene glycol and B) hematoxylin in pure propylene glycol. When combined in specified proportions the stock solutions yield aluminum-hematein dissolved in nontoxic propylene glycol. The ready-to-use stain, prepared in small volumes as needed, performs well in paraffin sections of plant tissues.     

Candida rugosa lipase-catalysed kinetic resolution of 2-substituted-aryloxyacetic esters with dimethylsulfoxide and isopropanol as additives

Candida rugosa lipase-catalysed hydrolysis of three different 2-substituted-aryloxyacetic esters was performed in aqueous buffer containing dimethyl sulphoxide and isopropanol from 0 to 80% v/v as additives, in order to obtain an enhancement of the enantioselectivity. For 2-(p-chlorophenoxy)acetic acid and 2-n-butyl-2-(p-chlorophenoxy)acetic acid ethyl esters, DMSO enhanced enzyme enantioselectivity more than IPA with an opposite enzymatic enantiopreference. The cosolvents moderately improved Candida rugosa lipase enantioselectivity for 2-phenyl-2-(p-chlorophenoxy)acetic acid ethyl ester.     

Attraction of Bactrocera dorsalis (Diptera: Tephritidae) and nontarget insects to methyl eugenol bucket traps with different preservative fluids on Oahu Island, Hawaiian Islands

Attraction of oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), and nontarget insects to preservative fluids ethylene glycol antifreeze, propylene glycol antifreeze, or mineral oil in bucket traps that contained captured decaying male oriental fruit flies, a male lure (methyl eugenol), and a toxicant (DDVP vapor insecticidal strip) were compared with dry control traps. Significantly (P < 0.05) greater numbers of B. dorsalis were captured in propylene glycol antifreeze traps than in other attractant trap types. Among attractant trap types with lowest negative impacts on nontarget insects, control traps captured significantly lower numbers of three species and one morphospecies of scavenger flies, one species of plant-feeding fly, and one species each of sweet-and lipid-feeding ants. Mineral oil traps captured significantly lower numbers of two species of scavengers flies and one morphospecies of plant-feeding fly, and one species of sweet-feeding ant. Because of the fragile nature of endemic Hawaiian insect fauna, the propylene glycol antifreeze bucket trap is best suited for use in environments (e.g., non-native habitats) where endemic species are known to be absent and mineral oil traps are more suited for minimizing insect captures in environmentally sensitive habitats.     

Effect of Fixatives on Silver Impregnation of Plant Cells

The kind of fixative and duration of fixation modify the affinity of plant cell structures, as shown by a 10-15 hr impregnation at 70 C in 2% aqueous AgNO₂, and a 1-2 hr reduction at room temperature by a 1:1 mixture of 10% formalin and 1% hydroquinone. Cytoplasmic staining was enhanced by fixing in salts of heavy metals, in buffered 6.5% glutaraldehyde, and in 0.5% picric acid. Nuclear staining was prominent after mixtures of glutaraldehyde and hydroquinone, after formalin and pyrogallol, and after acetone, propylene glycol or ether. Nucleolar staining was favored by fixing in 10% formalin, in 5% formalin containing 0.5% hydroquinone, in 50% ethanol containing 0.5% pyrogallol, or in ethylene glycol. Chromosome staining was favored by fixation in 50% acetic or propionic acid, in 2% trichloroacetic acid, and in methanol or ethanol. The best morphological preservations were seen after 50% acetic acid, 6.5% glutaraldehyde, or the 5% formalin-0.5% hydroquinone mixture.     

Transesterification of canola oil in mixed methanol/ethanol system and use of esters as lubricity additive

Transesterification of canola oil was carried out with methanol, ethanol, and various mixtures of methanol/ethanol, keeping the molar ratio of oil to alcohol 1:6 and using KOH as a catalyst. Mixtures of alcohol increased the rate of transesterification reaction and produced methyl as well as ethyl esters. The increased rate was result of better solubility of oil in reaction mixture due to better solvent properties of ethanol than methanol and equilibrium due to methanol. With 3:3 molar ratio of methanol to ethanol {MEE (3:3)} the amount of ethyl ester formed was 50% that of methyl ester. Properties (acid value, viscosity, density) of all esters including mixed esters were within the limits of ASTM standards. Lubricities of these esters are in the order: ethyl ester>methyl ethyl ester>methyl ester.     

Synthesis and immunomodulating activity of new diglycopeptides of of glycyrrhizinic acid and it's 30-methyl ester

New amino acid derivatives of glycyrrhizic acid and its methyl ester were selectively synthesized using active N-succinimide esters. The compounds with residues of glycine ethyl ester and alanine methyl and butyl esters increased the level of agglutinins and hemolysins in blood serum of mice two- to threefold in comparison with the control upon parenteral administration at a dose of 2 mg/kg for 14 days. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru.     

Initiation of spore germination in Bacillus subtilis: relationship to inhibition of L-alanine metabolism

The inhibitory effects of anthranilic acid esters (methyl anthranilate and N-methyl anthranilate) on the l-alanine-induced initiation of spore germination was examined in Bacillus subtilis 168. Methyl anthranilate irreversibly inhibited alanine initiation by a competitive mechanism. In its presence, the inhibition could be reversed only by the combined addition of d-glucose, d-fructose, and K(+). Both l-alanine dehydrogenase and l-glutamate-pyruvate transaminase, enzymes which catalyze the first reaction in l-alanine metabolism, were competitively inhibited by methyl anthranilate. The K(i) values for germination initiation (0.053 mM) and of l-glutamate-pyruvate transaminase (0.068 mM) were similar, whereas that for l-alanine dehydrogenase (0.4 mM) was six to seven times higher. Since a mutant lacking l-alanine dehydrogenase activity germinated normally in l-alanine alone, it is speculated that the major pathway of l-alanine metabolism during initiation may be via transmination reaction.     

Glucuronic acid conjugates of bilirubin-IXα in normal bile compared with post-obstructive bile. Transformation of the 1-O-acylglucuronide into 2-, 3-, and 4-O-acylglucuronides

Structures have been determined for bilirubin-IXalpha conjugates in freshly collected bile of normal rats, dogs and man and in post-obstructive bile of man and rats. The originally secreted conjugate has been characterized as azopigment (I), i.e. a 1-O-acyl-beta-d-glucopyranuronic acid glycoside. Conversion of the acetylated methyl ester of azopigment (I) into methyl 2,3,4-tri-O-acetyl-1-bromo-1-deoxy-beta-d-glucopyranuronate (V) indicates the pyranose ring structure for the carbohydrate and a C-1 attachment for the bilirubin-IXalpha acyl group. Alternative procedures for deconjugation of azopigment (I) and its derivatives are also described. In post-obstructive bile, the 1-O-acylglucuronide is converted into 2-, 3- and 4-O-acylglucuronides via sequential intramolecular migrations of the bilirubin acyl group. The following approach was utilized. (1) The tetrapyrrole conjugates were cleaved to dipyrrolic aniline and ethyl anthranilate azopigments, and the azopigments were separated as the acids or methyl esters. (2) The isomeric methyl esters were characterized by mass spectral analysis of the acetates and silyl ethers. (3) The free glycosidic function was demonstrated by 1-oxime and 1-methoxime derivative formation. (4) The position of the dipyrrolic O-acyl group was determined for the methyl esters by protecting the free hydroxyl groups of the glucuronic acid moieties as the acetals formed with ethyl vinyl ether and by further conversion of the carbohydrates into partially methylated alditol acetates. These were analysed by using g.l.c.-mass spectrometry. The relevance of the present results with regard to previous reports on disaccharidic conjugates is discussed. Details of procedures for the formation of chemical derivatives for g.l.c. and mass spectrometry have been deposited as Supplementary Publication SUP 50081 (15 pages) at the British Library Lending Division, Boston Spa, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978), 169, 5.     

Contribution of fatty acids to olfactory host finding of female Aedes aegypti

Single carbon to 18 carbon n-aliphatic carboxylic acids were tested for their attractive effects on female Aedes aegypti in a Y-tube olfactometer. Each acid was tested over a wide range of concentrations together with L-(+)-lactic acid, the indispensable synergist for other attractive components emitted from human hosts. The attractiveness of lactic acid was significantly augmented when combined with fatty acids of chain length C(1)-C(3), C(5)-C(8) and C(13)-C(18), respectively. The addition of the C(9) and C(11) acids reduced the attractive effect of lactic acid. According to experiments showing a further increase of attractiveness by adding a second fatty acid, we suggest two groups of attractive carboxylic acids: C(1)-C(3) and C(5)-C(8). The addition of a fatty acid from one group to a mixture of lactic acid and an acid from the other group augmented the attraction to the mixture. Together with ammonia, a previously demonstrated attractant for Aedes aegypti, lactic acid plus two fatty acids from the different groups formed the hitherto most attractive, artificially composed blend. Two of the carboxylic acids which were found to be attractive together with lactic acid were also tested alone and in combination with CO(2), the major attractant in human breath. In both cases no attractive effect of the carboxylic acids could be observed.     

橘小实蝇植物源引诱活性物质的生物测定

植物源引诱物质可显著提高橘小实蝇Bactrocera dorsalis(Hendel)蛋白饵剂的应用效果,本文测试了柑橘、番木瓜、芒果、番石榴、杨桃的叶片浸提物、果实以及已知植物次生物质对橘小实蝇的引诱效果。植物浸提物的生物测定结果表明,杨桃的二氯甲烷浸提物的引诱效果最佳,平均引诱率为20.83%,对于不同的萃取剂而言,二氯甲烷、乙醇浸提物效果明显优于石油醚,三者浸提的平均引诱率分别为15.67%、15.17%和10.50%;对于不同寄主植物而言,柑橘浸提物的效果最佳,3种有机溶剂浸提物的平均引诱率为18.33%,其中石油醚、二氯甲烷和乙醇浸提物的引诱率分别为20.00%、15.83%和19.17%,其他植物浸提物的引诱效果为杨桃>番木瓜>芒果>番石榴,3种有机溶剂浸提物的平均引诱率分别为17.22%、11.67%、11.11%和10.56%。寄主果实的生物测定结果表明,柑橘的平均引诱率为65.83%,其中雌虫和雄虫的引诱率分别为61.67%和70.00%,明显高于杨桃、番石榴和番木瓜,三者的引诱率分别为31.67%、31.67%和21.67%,与柑橘引诱率差异显著(P<0.05)。已知植物次生物质的生物测定结果表明,甲基丁香酚的引诱效果最佳,平均引诱率为45.00%,其中雄虫和雌虫的引诱率分别为86.67%和3.33%;乙酸乙酯和番石榴香精的引诱效果次之,平均引诱率分别为32.50%和28.33%,其中雌虫的引诱率均为36.67%;杨桃香精和柠檬酸的引诱效果较差,平均引诱率分别为25.00%和26.67%。     

Induction of chromosome loss by mixtures of organic solvents including neurotoxins

Twenty-three aprotic polar solvents - 3 nitriles, 8 organic esters, 10 ketones and 2 lactones - and LiCl were tested in combination with propionitrile alone or a mixture of ethyl acetate and propionitrile for the induction of mitotic chromosome loss in the D61.M strain of the yeast Saccharomyces cerevisiae. Propionitrile and ethyl acetate are very potent inducers of chromosome loss. Mixtures of propionitrile and ethyl acetate induced chromosome loss at much higher frequencies than was observed with the pure chemicals. To test the potentiating effects of propionitrile or mixtures of propionitrile with ethyl acetate on other chemicals, they were used in concentrations that were at or below the level for induction of chromosome loss. Twenty chemicals when tested in pure form were negative or only marginally active in the test for chromosome loss. Except for amyl propionate and benzyl acetate, the same chemicals showed strong induction in combination treatments with the potentiating chemicals. All the ketones including the neurotoxic methyl ethyl ketone, 2-hexanone and 2.5-hexanedione induced high frequencies of chromosome loss. Only methyl ethyl ketone is capable of inducing high levels of chromosome loss when tested in the pure form at much higher concentrations. 1-Methyl-2-pyrrolidinone and gamma-valerolactone had previously been shown to induce chromosome loss only when the treatment at a growth-supporting temperature was interrupted by a cold shock within a narrow range of low temperatures which prevented growth. Both gave very strong induction in combination treatment performed at a continuous growth-supporting temperature. LiCl is a weak inducer of chromosome loss: strong induction can be achieved in combination treatments.     

Serial Sections of Cooked Rice Embedded in Carbowax

Serial sections of cooked rice kernels may be obtained by following either of two dehydration schedules and embedding in Carbowax. In the first schedule the cooked, rinsed and drained kernels are immersed several days in a nonaqueous fixative composed of: isopropyl alcohol, 10 ml; propionic acid, 30 ml; acetone, 10 ml; methylal, 40 ml; dioxane, 30 ml; and propylene glycol, 30 ml (Newcomer's, modified), followed by 7 or 8 days in equal parts of propylene glycol, dioxane and glycerol (changed once), and 4 days on a warming table in the same mixture with 5% Carbowax added. The dehydrated kernels are then infiltrated 4-24 hr with a Carbowax embedding mixture. In the second schedule they are immersed several days in an aqueous solution consisting of: propylene glycol, 12.5 ml; polyethylene glycol 400, 12.5 ml; either with 75 ml of water containing 0.1% thymol, or with a mixture of water, 65 ml; formalin, 10 ml; CaCl₂, 1 gm; and CdCl₂, 1 gm; followed by 3 or 4 days in 50% propylene glycol, and 3 or 4 days on a warming table in 80% propylene glycol with 5% Carbowax added. Infiltration is as above. The composition of the embedding mixture is varied according to the temperature and humidity likely to prevail during sectioning. The texture of the wax may be improved by adding small amounts of gum arabic, spermaceti, and glycerol. Serial sections 3-10 μ thick are placed on clean dry slides, and adhesive dropped at the edges of the ribbon of Carbowax until it is dissolved. The adhesive consists of water-glass (concentrated solution), 1 ml; concentrated ammonia, 1 ml; Carbowax, 5 gm; and water, 98 ml. After the slides are dry they are stored, or immersed 10 min in chloroform, collodionized, and passed to staining solutions. Atmospheric conditions affect not only the Carbowax, but also the response to reagents of cooked rice and of sections.     

Effects of alcoholic solvents on antiradical abilities of protocatechuic acid and its alkyl esters

DPPH radical scavenging reactions of protocatechuic acid and its methyl ester were investigated in various solvents. In alcoholic solvents, methyl protocatechuate rapidly scavenged more than four equivalents of the radical, whereas approximately two equivalents were consumed in aprotic solvents. Methyl, ethyl, butyl, isopropyl, and tert-butyl protocatechuates were examined for their DPPH radical scavenging abilities in methanol or ethanol. As a result, the radical scavenging equivalence of sterically bulky esters tended to decrease compared to that of methyl or ethyl ester. The ABTS radical scavenging ability of those esters in water also showed the same tendency. Since 2-methoxy derivatives were detected in the reaction mixture of methyl protocatechuate and DPPH radical in methanol, a nucleophilic attack of an alcoholic molecule on the o-quinone intermediate, which is sensitive to steric hindrance from alkyl groups of both esters and alcoholic solvents, must be crucial for total radical scavenging abilities.     

Separation and structural analysis of vinyl- and isovinyl-azobilirubin derivatives

The coupling reaction of bilirubin with the diazonium salts of ethyl anthranilate or of aniline yields two isomeric azopigments. These can be separated by t.l.c. as their methyl esters. The mass spectra of each pair of azopigments are very similar, showing that they are isomers. Proton-magnetic-resonance spectrometric studies show that they differ in the positions of the substituents on the pyrrolenone end ring; in one compound the methyl and vinyl groups are interposed compared with the other compound. These azo compounds were used as reference standards for determination of the site of conjugation in bilirubin monoglucuronide prepared enzymically. Analysis showed that conjugation occurs at the carboxyethyl side chain of both sides of the bilirubin molecule. During the preparation of the ethyl anthranilate reference compounds a series of minor azopigments were isolated by t.l.c. Analysis of the mass spectra of many of these showed that three side reactions can occur: (1) methylation of the imide carbonyl group; (2) addition of methanol or water to the vinyl substituent; (3) transmethylation of the ethoxycarbonyl group.     

Monte Carlo simulations of vapour–liquid phase equilibrium and microstructure for the system containing azeotropes

Abstract

Phase equilibrium data of the mixtures including alcohols, esters and organic acids are of first interest particularly to design and optimise biodiesel production and reactive distillation processes. In this work, vapour–liquid phase equilibrium of these systems was simulated at low pressure using Gibbs ensemble Monte Carlo method. All Lennard–Jones parameters of pseudo-atoms involved in the systems were derived from previous parametrisations of TraPPE-UA force field. The Fourier coefficients of dihedrals encountered in ethyl acetate molecule have been obtained from the quantum calculations. Using this force field, temperature-composition diagrams are well reproduced for ethyl acetate + ethanol, ethyl acetate + methanol at 70.00 kPa and ethyl acetate + acetic acid mixtures at 77.33 kPa. The transferability of this force field to mixtures in these systems is noticeable. Analysis of the microstructure for the ethyl acetate + ethanol and ethyl acetate + acetic acid mixtures was presented. We found that the hydrogen bond networks consist of autoassociation and cross-association and autoassociation occupies the main position as compared with cross association in the ethyl acetate + ethanol mixture. OC_HAc–H_HAc and OC_EtOAc–H_HAc hydrogen bond interactions play a significant role in the phase behaviours or structures of ethyl acetate + acetic acid mixture.     

Trapping social wasps (Hymenoptera: Vespidae) with acetic acid and saturated short chain alcohols

Nineteen compounds were evaluated in combination with a solution of acetic acid as baits for trapping the German yellowjacket, Vespula germanica (F.), the western yellowjacket Vespula pensylvanica (Sausssure), and the golden paper wasp Polistes aurifer Saussure. Compounds with three to six carbon chains or branched chains and with a hydroxy functional group were selected for testing based on their similarity to isobutanol. They were compared with isobutanol with acetic acid, which is a known wasp attractant. None of the compounds tested were superior to isobutanol when presented with acetic acid as a lure for these species of wasps. However, traps baited with either the S-(-)- or the racemic mixture of 2-methyl-1-butanol in combination with acetic acid captured similar numbers of both species of yellowjackets, compared with isobutanol with acetic acid. Polistes aurifer responded strongly to the S-(-)-enantiomer and to the racemic mixture of 2-methyl-1-butanol with acetic acid and not to the R-(+)-enantiomer with acetic acid.