Mandibular gland secretions of workers of Myrmica rugulosa and M.schencki: comparison with four other Myrmica species

ABSTRACT. The mandibular glands of the two species of ant, Myrmica schencki Em. and Myrmica rugulosa Nyl., contain mixtures of similar compounds, but in different proportions. M.rugulosa produces 3-pentanol, 3-hexanone, 3-hexanol, 3-heptanone, 3-heptanol, 3-octanone (by far the most abundant component), 3-octanol, 3-nonanol, 3-decanone and 6-methyl-3-octanone, in addition to small amounts of ethanal, acetone and methylpropanal. M.schencki produces most of these (though much less 3-octanone and much more 3-octanol), but also produces significant amounts of 3-nonanol, 3-decanol and 6-methyl-3-octanol, while producing no detectable 3-pentanol or 3-hexanone. The mandibular gland secretions of these two species attract the workers, increase their linear speed, and reduce their sinuosity of movement. In M.schencki these behavioural activities are caused by 3-octanol and 3-octanone, the effect of a synthetic mixture of the two being exactly like that of an isolated mandibular gland; the two compounds act together to cause attraction and increase linear speed, and in synergy to reduce the workers' sinuosity of movement. In M.rugulosa , 3-octanol, 3-octanone and 6-methyl-3-octanone are the major active constituents. 3-Octanone attracts the workers, its effect being enhanced by 3-octanol; it also increases the ants' linear speed, this effect being moderated slightly by the 3-octanol. Presented together these two substances act synergistically to decrease the workers' sinuosity of movement, and reproduce exactly the overall behavioural activity of an isolated mandibular gland. The chemical and behavioural results are combined with those previously reported to explain the responses of M.rubra, M.ruginodis, M.rugulosa, M.sabuleti, M.schencki and M.scabrinodis workers to isolated mandibular glands of these species.     

A comparison of mandibular gland volatiles from ants of the bull horn acacia,Acacia collinsii

GC–MS analyses of dichloromethane extracts of the mandibular glands from three obligate symbiotic Psuedomyrmex ant species of Acacia collinsii from Costa Rica: Pseudomyrmex flavicornis (synonym Pseudomyrmex belti), Psuedomyrmex spinicola, and Psuedomyrmex nigrocincta, showed distinct differences in the 16 ketones, 15 alcohols, 2 aldehydes and 2 carboxylic acids that were identified. Different compounds were the major component from each species: P. flavicornis, 3-octanone; P. spinicola, 4-methyl-3-heptanone; and P. nigrocincta, 3-methyl-2-hexanol. The secretion of P. flavicornis contained 10 compounds not found in the other species, including the two terpene alcohols, citronellol and geraniol. The secretions of P. spinicola and P. nigrocincta had 12 compounds in common, that were not found in P. flavicornis' secretion. The similarity of the mandibular gland secretion of P. spinicola and P. nigrocincta may indicate that they are more closely related to each other than either is to P. flavicornis. The components from the mandibular gland of Crematogaster rochai, another ant associated with this acacia, are 2- and 3-methylbutanoic acid, 3-octanone, 3-octanol, 6-methyl-3-octanol and 3-nonanone.     

Phéromones agrégeant les ouvrières de Myrmica rubra

The workers of Myrmica rubra aggregate around a source of one of their secretions, which can be called ‘alarm pheromone’, and also around workers of Lasius flavus. The mechanism of these aggregations differ.Both L. flavus workers and a solution in liquid paraffin of 3-octanol, one of the mandibular gland compounds, act as an arrestant for the workers of M. rubra. Both Dufour's gland secretion and a source of 3-octanone, the major compound of the mandibular gland secretion, are true attractants.The poison gland secretion, a mixture of 3-octanone and 3-octanol in liquid paraffin and a solution in liquid paraffin of 3-nonanone, a minor mandibular gland compound, all induce klinokinesis. The secretion of the mandibular glands and the secretion of the venom apparatus both cause positive klinokinesis and taxis. These locomotory reactions increase the probability that an object, marked by nest mates with these secretions, will be detected by several workers.When presented alone, 3-octanone is the only attractive compound in the mandibular gland secretion. However, a mixture of 3-octanone and 3-octanol (15 per cent of 3-octanol in the vapour phase) is detected more easily by the ants. The diffusion coefficients of the two compounds are different, and a mixture of these substances creates not only a quantitative but also a qualitative odour gradient. This may explain the synergy of the mixture.     

Comparative study of the mandibular gland secretion of four species of Myrmica ants

The mandibular glands of the two species of ant, Myrmica ruginodis and Myrmica sabuleti contain a similar mixture of compounds, but the proportions are different. M. sabuleti produces ethanol, propanone, methylpropanal, 3-hexanone, 3-hexanol, 3-heptanone, 3-heptanol, 3-octanone, 3-octanol, 6-methyl-3-octanone, 6-methyl-3-octanol and 3-decanone. With the exception of 3-decanone these compounds were also found in M. ruginodis. These compounds were also found in M. rubra and M. scabrinodis.In both species now studied, the mandibular gland contents attract the workers and cause a large increase in their linear speed. In M. sabuleti these behavioural activities are due to 3-octanone and 3-octanol: the attraction of these two compounds in a synthetic mixture is exactly like that of an isolated mandibular gland; the compounds act in synergy to cause an increase in the ants' linear speed. Workers of M. ruginodis specifically respond to a mixture of ethanol, 3-octanone and 3-octanol: the alcohol only moderates the ethological action of the ketone, which is a true attractant and causes a very large increase in the ants' velocity; ethanol also attracts workers, acting in this respect in synergy with 3-octanone.These chemical and behavioural results are combined with those previously reported (Cammaerts-Tricot, 1973; Morganet al., 1978) to explain the responses of M. rubra, M. ruginodis, M. sabuleti and M. scabrinodis workers to isolated mandibular glands from each of these four species.     

Volatile constituents of Trichothecium roseum

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.     

Field trapping of Metamasius hemipterus with synthetic aggregation pheromone

The five synthetic pheromone components of the West Indian sugarcane borer (WISB), Metamasius hemipterus (L.) (Coleoptera, Curculionidae) were tested in the field. The combination of sugarcane (SC) and the major pheromone compound, 4-methyl-5-nonanol (1) was attractive. However, the addition of 2-methyl-4-heptanol (2) or 2-methyl-4-octanol (3) was required to reach high catch levels while 5-nonanol (4) or 3-hydroxy-4-methyl-5-nonanone (5) did not enhance WISB attraction. The redundancy phenomenon, here reported for the first time in rhynchophorinous species, was observed between compounds 2 and 3. SC +1 +3 was more attractive than living male baits, however, the sex-ratio of the catches was equivalent between both treatments. The sex-ratio of catches was affected by the qualitative composition of the pheromone formulation. Compound 3 had a sexual role, attracting more females while 5 seemed to play an aggregation role, luring both sexes in the same proportion.     

The volatile components of the mandibular gland secretion of workers of the ants Myrmica lobicornis and Myrmica sulcinodis

The mandibular glands of workers of M. lobicornis produce a mixture of 3-alkanones and 3-alkanols in the C₆–C₁₀ carbon chain length range, in addition to nanogram amounts of acetone, ethanal and 2-methylpropanal. Ethological studies have shown that the three major constituents, 3-octanol, 3-octanone and 3-decanol, are also the major pheromonally active components. When presented together they stimulate an alarm response in the workers similar to that induced by a worker's crushed head.In M. sulcinodis the mandibular gland secretion is composed of a mixture of the same ketones and alcohols, but in different proportions.     

Synthesis of (4R,6S,7R)-7-hydroxy-4,6-dimethyl-3-nonanone and (3R,5S,6R)- 6-hydroxy-3,5-dimethyl-2-octanone,the pheromone components of the bostrychid beetle,Dinoderus bifoveolatus

(4R,6S,7R)-7-Hydroxy-4,6-dimethyl-3-nonanone and (3R,5S,6R)-6-hydroxy-3,5-dimethyl-2-octanone, the pheromone components of the bostrychid beetle, Dinoderus bifoveolatus, as well as their (4R,6S,7S)- and (3R,5S,6S)-isomers were synthesized from (2R,4S,5R)- and (2R,4S,5S)-2,4-dimethyl-5-heptanolide, respectively.     

高分子膜载体固定化酵母催化2-辛酮不对称还原

以戊二醛交联尼龙6膜载体固定化面包酵母DX213,采用固定化酵母细胞催化2-辛酮不对称还原得到(R)-2-辛醇。系统考察了有机溶剂、反应时间、pH、底物、辅助底物和热处理等因素对反应的产率和光学选择性的影响。结果表明,上述因素对酵母细胞催化不对称合成(R)-2-辛醇反应均有显著影响。二氯甲烷为该反应最适有机溶剂,在固定化细胞57 g/L(50℃预热50 min),水相与有机溶剂相体积比4/1,pH 7.0,初始2-辛酮浓度为60 mmoL/L(分别在反应0,10,17 h等分添加),蔗糖5.7 g/L和28℃条件下反应48 h,(R)-2-辛醇的产率和e.e.值分别达到89.3%和96.8%。     

Estimation of volatile constituents in the fish flesh from wild and farmed Cirrhina mrigala and Cyprinus carpio

Analysis of fish meat using gas chromatography is described. Flavor is the sensation arising from the interplay of the signals of sensing smell, taste and irritating stimuli from food stuff. For human, flavor and nutrition are inseparable. In fish, trace amount of volatile organic compounds (VOCs) are the major compounds to affect consumer’s preference, which are produced during storage and spoilage. In the present study, volatile compounds were extracted by Likens-Nickerson concurrent distillation apparatus from wild and farmed Cirrhina mrigala and Cyprinus carpio. The quantitative and qualitative estimation of volatiles was made by gas chromatography. Wild and farmed fish of different fish sizes were compared for these compounds (appearing in the form of peaks), which were identified from their retention time by comparing with the standards. Fifteen major VOCs were found in these species which included hexadecane, 3-octanol, hexanal, decane, 3-hexene-1-ol, 2-undecanone, 2-heptanone, butanal, 2-nonanone, 1- heptanal, furaldehyde, 3-methyl-1-butanal, trans-3-hexene-1-ol, octanal and decanal. These compounds varied qualitatively and quantitatively in both wild and farmed fish of different fish sizes.     

Purification and characterization of an anti-Prelog alcohol dehydrogenase from <Emphasis Type="Italic">Oenococcus oeni</Emphasis> that reduces 2-octanone to (<Emphasis Type="Italic">R</Emphasis>)-2-octanol

An anti-Prelog alcohol dehydrogenase from Oenococcus oeni that reduces 2-octanone to (R)-2-octanol was purified by 26-fold to homogeneity. The enzyme had a homodimeric structure consisting of 49 kDa subunits, required NADPH, but not NADH, as a cofactor and was a Zn-independent short-chain dehydrogenase. Aliphatic methyl ketones (chain length ≥6 carbon atoms) and aromatic methyl ketones were the preferred substrates for the enzyme, the best being 2-octanone. Maximum enzyme activity with 2-octanone was at 45°C and at pH 8.0.     

Isolation, identification, synthesis and biological activity of volatile compounds from the heads of Atta ants

S-(+)-4-methyl-3-heptanone has been identified as the principal alarm pheromone of Atta texana and Atta cephalotes. Both enantiomers of 4-methyl-3-heptanone have been synthesized and their biological activities have been compared on both species of ants. Comparison of the geometric averages of response ratios, at threshold concentration levels on A. texana, showed S-(+)-4-methyl-3-heptanone to be about 100 times more active than the (?) enantiomer. A similar analysis also showed no inhibition of the activity of S-(+)-4-methyl-3-heptanone by the (?) enantiomer. A less rigorous study on A. cephalotes showed S-(+)-4-methyl-3-heptanone to be about 210 times more active than R-(?)-4-methyl-3-heptanone.Both ant species produce 3-octanone, possible trace amounts of 3-octanol, and both diastereomers of 4-methyl-3-heptanol. A. texana also produces (+)-2-heptanol, 2-heptanone, and 3-heptanol. A. cephalotes contains trace amounts of 2-heptanone.     

Alarm pheromones of the Attini: Their phylogenetic significance

The volatile components present in the mandibular glands of a number of species of the attine genera Cyphomyrmex (1 species), Trachymyrmex (3 species), and Acromyrmex (2 species) were investigated and compared with those present in Atta. The extracts were found to consist of mixtures of a number of compounds. All but one of these mixtures contained some or all of the following compounds: 3-octanone, 4-methyl-3-heptanone, 3-octanol, and 4-methyl-3-heptanol. The behavioural responses of Trachymyrmex and Cyphomyrmex workers to these compounds were tested. A common chemical heritage based on 3-ketones and 3-alcohols appeared to exist among the genera studied. The chemical data were compared with an accepted phylogeny of these genera to see whether it supported the phylogeny.     

Comprehensive volatile organic compounds profiling of Bacillus species with biocontrol properties by head space solid phase microextraction with gas chromatography-mass spectrometry

The eight Bacillus strains, used as biocontrol agents with proven antagonistic effect against plant pathogens, produced antifungal volatile organic compounds (VOCs). Bioassay in sealed dishes revealed that the VOCs from each Bacillus strain significantly inhibited the mycelial growth (56–82%) of Fusarium solani. The effective antifungal VOCs were extracted using headspace solid phase microextraction and further identified by gas chromatography-mass spectrometry technique. The detected volatile compounds could be chemically grouped into ketones, alcohols, aldehydes, pyrazines, acids, esters, pyridines and benzene compounds. The ketones and alcohols were predominant in the VOCs from eight Bacillus strains whereas the ketones, including 3-methyl-2-pentanone, 2-heptanone, 2-octanone, 2-decanone, 5-methyl-2-hexanone, 2-nonanone, 2-dodecanone, 2-undecanone, 5-methyl-2-heptanoneand2-pentanone, were the most common and principal components in all strains. Present results showed that the eight Bacillus strains are rich resources of bioactive volatiles, which may play an important role in the inhibition on F. solani. Studies are under the way to determine effects of those compounds against plant pathogens and to find the possible action mechanisms.     

Pheromonal blends: Certain components may only convey gross information

Certain insect secretions contain 3-octanone and 3-octanol, or 2-heptanone and 2-heptanol. It is shown that the vapour phase composition of each of these binary mixtures may be very different from the liquid phase composition with which it is in equilibrium. It is suggested that there may be little need for biosynthetic exactness in the ratio of some components of pheromone blends and, further more, that certain components of a pheromone blend may be able to convey only gross information rather than subtleties in communication.     

Anti-Prelog Reduction of Prochiral Carbonyl Compounds by Oenococcus oeni in a Biphasic System

An aqueous-organic biphasic system was established and used with whole cells of Oenococcus oeni to reduce 2-octanone to (R)-2-octanol. The conversion reached 99% when the Tris/borate buffer was increased from 50 mM to 300 mM in the aqueous phase. In addition, the conversion increased as the log P value of the organic solvent changed from 0.5 to 6.6. Under optimized conditions, the conversion of (R)-2-octanol reached 99% from 0.5 M 2-octanone with an optical purity of 99% e.e. The biphasic system allows the anti-Prelog reduction of aliphatic and aromatic ketones to furnish (R)-configurated alcohols in high optical purity as well.     

A comparative analysis of mandibular gland secretions in the ant tribe tetramoriini

Chemical analysis of the mandibular gland secretion of seven ant species in the tribe Tetramoriini showed that 3-octanone was the major component in Tetramorium sericeiventre (70%), T. caespitum (71%) and T. guineense (87%), and 3-octanol in Decamorium uelense (96%). 2-Undecanol, was the major component in T. termitobium (80%), but in two members of the subgenus Xiphomyrmex, T. angulinode and an unidentified species (D), the sesquiterpene furan, perillen, was predominant (91% and 98% respectively). Ants in this subgenus also contained 2-nonanol, 2-undecanol and 2-undecanone in their mandibular glands.     

8-Carbon oxylipins inhibit germination and growth, and stimulate aerial conidiation in Aspergillus nidulans

Germination of Aspergillus nidulans conidia in liquid cultures was progressively inhibited at inoculum loads above 1 × 10⁵ conidia mL^?1. High conidial densities also inhibited growth of neighbouring mycelia. The eight-carbon oxylipin 1-octen-3-ol was identified as the main inhibitor in a fraction also containing 3-octanone and 3-octanol.These three oxylipins also increased the conidiation rate of dark-grown surface cultures, but had no effect on liquid cultures. 3-octanone was the most conidiogenic compound. The action of 3-octanone required functional forms of developmental activators fluG, flbB-D and brlA, and was not additive to the conidiogenic effect of stress stimuli such as osmotic stress or carbon starvation.Oxylipins were produced shortly after hyphae made contact with the atmosphere and were most effective on aerial mycelia, indicating that they perform their signalling function in the gas phase.     

Identification of the Predominant Volatile Compounds Produced by Aspergillus flavus

A culture of Aspergillus flavus grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH(2)Cl(2), and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and cis-2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the cis designation to 2-octen-1-ol. Both oct-1-en-3-ol and cis-2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.     

Induction of conidiation by endogenous volatile compounds in Trichoderma spp

Light and starvation are two principal environmental stimuli inducing conidiation in the soil micromycete Trichoderma spp. We observed that volatiles produced by conidiating colonies of Trichoderma spp. elicited conidiation in colonies that had not been induced previously by exposure to light. The inducing effect of volatiles was both intra- and interspecific. Chemical profiles of the volatile organic compounds (VOCs) produced by the nonconidiated colonies grown in the dark and by the conidiating colonies were compared using solid-phase microextraction of headspace samples followed by tandem GC-MS. The conidiation was accompanied by increased production of eight-carbon compounds 1-octen-3-ol and its analogs 3-octanol and 3-octanone. When vapors of these compounds were applied individually to dark-grown colonies, they elicited their conidiation already at submicromolar concentrations. It is concluded that the eight-carbon VOCs act as signaling molecules regulating development and mediating intercolony communication in Trichoderma.