An analysis of the volatile flavour compounds in a soft raw goat milk cheese

The major components of the musty cow rind cheeses were identified in a soft raw goat milk cheese as heptan-2-one, nonan-2-one, their corresponding secondary alcohols, some esters and sulfur compounds. Their production was associated with the manufacturing process and its influence on the microbial activity. However a specificity in goat cheese compounds was displayed concerning in particular limonene and some ketones, alcohols and aldehydes.     

Plant growth retardant activity of polycycloalkanols structurally related to 4-howoisotwistanols

Various polycycloalkanols structurally related to the plant growth retardants, 4-homoisotwistanols, were prepared and their effect on the growth of cucumber seedlings in complete darkness investigated in order to obtain information on structure-activity relationships. 4-Homobrendan-2-ols, bicyclo[3.3.1]-nonan-1-ol and adamantan-1-ol showed almost the same inhibitory activity as the 4-homoisotwistanols, but 4-homobrendan-3-ol and bicyclo-[3.3.1]nonan-2-ol were only moderately active or almost inactive. No simple relationship was apparent between structure and activity.     

Alkaloids from Ruta montana

Two known and four new quinoline and 4-quinolone type alkaloids were isolated from Ruta montana collected from Rommani (Morocco). The known compounds were 1-methyl-4-methoxy-2-quinolone and evolitrine. The structures of the new compounds were established from 1D and 2D NMR experiments including HMQC, HMBC and MS spectral methods as 2-(nonan-8-one)-(1H)-4-quinolone, 2-(nonan-8-one)-4-methoxy-quinoline, 2-(nonan-8-one)-N-methyl-4-quinolone and 2-(decan-9-one)-N-methyl-4-quinolone.     

Diarylheptanoids from the rhizomes of Zingiber officinale

Seven new diarylheptanoids, i.e., (3S,5S)-3,5-diacetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane, (3R,5S)-3-acetoxy-5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptane, (3R,5S)-3,5-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane, (5S)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one, 5-hydroxy-1-(3,4-dihydroxy-5-methoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptan-3-one, 5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(3,4-dihydroxy-5-methoxy-phenyl)heptan-3-one and 1,5-epoxy-3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane were isolated from the rhizomes of Chinese ginger (Zingiber officinale Roscoe), along with 25 known compounds, i.e., 8 diarylheptanoids, 14 gingerol analogs, a diterpene and 2 steroids. Their structures were elucidated by spectroscopic and chemical methods.     

Sesquiterpenoids and diarylheptanoids from Nidus vespae and their inhibitory effects on nitric oxide production

Two coriamyrtin-type sesquiterpenes, fengfangin A (1) and tutin (2), and six diarylheptanoids, namely alnusone (3), centrolobol (4), muricarpone B (5), 1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptan-3-one (6), (3S)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptan-3-ol (7), and (3S)-1-(4-hydroxyphenyl)-7-(3,4-dihydroxyphenyl)heptan-3-ol (8), were isolated from the 95% EtOH extract of nidus vespae, the nest of Polistes species. Their structures were identified by spectroscopic methods. Compounds 1 and 8 are new products. The absolute configuration of 1 was determined by single-crystal X-ray diffraction analysis using Flack parameter. The biological tests showed that compounds 5, 6, and 8 could inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells with IC(50) values in the range of 13-17 μM, whereas the sesquiterpenes were inactive in this assay (>25 μM). In addition, the ecological significance of the presence of neurotoxic sesquiterpene lactones in nidus vespae is briefly discussed.     

Behavioural and electrophysiological responses of the bark beetle, Ips typographus, to potential pheromone components

ABSTRACT. Field tests showed ( S )-(-)- cis -verbenol and ( R )-(+)- trans -verbenol in combination with a second pheromonal component, 2-methyl-3-buten-2-ol, more attractive than the combination with their optical antipodes. Inhibition of response to the attractant component, ( S )-(-)- cis -verbenol, by high concentrations of its optical antipode did not occur. No significant differences were noted for response to the attractant, ( S )-(-)- cis -verbenol and 2-methyl-3-buten-2-ol, with the addition of either ipsdienol enantiomer or a racemic mixture of ipsdienol enantiomers. Electroantennogram (EAG) studies correlated well with the behavioural studies. EAGs recorded from male and female beetles revealed both sexes to have a lower threshold for the pheromone, ( S )-(-)- cis -verbenol, than its host terpene precursor, (-)- alpha -pinene. EAGs showed a greater number of acceptors for (-)- alpha-pinene in males than in females. EAGs at acceptor saturation to the enantiomers of alpha -pinene and the verbenol isomers showed males more responsive to (-)- alpha -pinene, (±)- cis -verbenol, and ( R )-(+)- trans -verbenol. Significantly greater EAGs were elicited in females than in males to (-)- alpha -pinene, and (±)- and ( S )-(-)- cis -verbenol. No significant differences in EAGs of females to the enantiomers of trans -verbenol were noted. EAGs showed similar thresholds in males and females to the pheromone component, 2-methyl-3-buten-2-ol; however, female response at threshold was significantly greater than male response. The results are discussed with regard to olfactory acceptor evolution.     

(1S,3S,7R)-3-methyl-alpha-himachalene from the male sandfly Lutzomyia longipalpis (Diptera: Psychodidae) induces neurophysiological responses and attracts both males and females

Lutzomyia longipalpis adult males form leks on or near hosts and release (1S,3S,7R)-3-methyl-alpha-himachalene from their tergal glands to lure females to the same site for mating and feeding. Here we have examined whether the male-produced attractant could also serve as a male aggregation stimulus. High resolution chiral capillary gas chromatography analysis of male tergal gland extracts, synthetic (1S,3S,7R)-3-methyl-alpha-himachalene, and a synthetic mixture of all isomers of 3-methyl-alpha-himachalene, was coupled to electrophysiological recordings from ascoid sensillum receptor cells in antennae of male and female sandflies. Receptor cells of both sexes responded only to the main component of the male tergal gland extract that eluted at the same retention time as (1S,3S,7R)-3-methyl-alpha-himachalene. Furthermore, of the eight 3-methyl-alpha-himachalene isomers in the synthetic mixture only the fraction containing (1S,3S,7R)-3-methyl-alpha-himachalene, co-eluting with an isomer of (1S*,3S*,7S*)-3-methyl-alpha-himachalene, elicited an electrophysiological response from male and female ascoid sensillum receptor cells. Both males and females flew upwind in a wind tunnel towards a filter paper disk treated with either 4-6 male equivalents of the tergal gland extract, pure (1S,3S,7R)-3-methyl-alpha-himachalene or the synthetic mixture of eight isomers. This indicates that (1S,3S,7R)-3-methyl-alpha-himachalene derived from L. longipalpis males may have a dual function in causing male aggregation as well as serving as a sex pheromone for females.     

Acaricidal activities of bicyclic monoterpene ketones from Artemisia iwayomogi against Dermatophagoides spp.

The acaricidal properties of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one isolated from Artemisia iwayomogi and its structural analogues were evaluated against Dermatophagoides farinae and D. pteronyssinus, and their effects were compared with that of the commercial acaricide benzyl benzoate. Based on the 50 % lethal dose (LD₅₀) values against D. farinae, 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (0.82 μg/cm²) was 9.71 times more effective than benzyl benzoate (7.96 μg/cm²), followed by (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.03 μg/cm²), (1S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one (1.58 μg/cm²), and (1R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-one oxime (3.05 μg/cm²) in a filter paper bioassay. The acaricidal activities of 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues against D. pteronyssinus were similar to those against D. farinae. These results demonstrate that naturally occurring A. iwayomogi-isolated 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one and its structural analogues are suitable for the production of natural acaricides against house dust mites.     

Electrophysiological responses of antennal receptor neurons in female Australian sheep blowflies,Lucilia cuprina,to host odours

Studies were conducted to investigate the electrophysiological responses of receptor neurons on the antennae of female Lucilia cuprina to putative stimulants. Three distinct types of olfactory neurons were identified. Tests with 25 compounds showed 27 out of the 75 neurons examined responded best to racemic 1-octen-3-ol (Oct-best neuron), nine to dimethyldisulphide (DMDS-best neuron) and seven to 2-phenylethanol (PE-best neuron). The remaining cells were not stimulated by any chemical stimulus presented in this study. The olfactory neurons showed low spontaneous activities, 2.2 ~ 2.7 impulses/s, which increased significantly on stimulation with test compounds. Dose-dependent responses were observed with Oct-best neurons. Another type of neuron that had a much higher spontaneous activity (26 impulses/s) was observed. This neuron did not respond to any of the candidate compounds tested but showed a decrease in activity with increased airflow over the antennae and was termed the Airflow-sensitive neuron. The spontaneous activities of Oct-, DMDS-, PE-best and Airflow-sensitive neurons were inhibited by butanoic, pentanoic, hexanoic acids, and 3-methylindole.     

Identification of volatile emissions from Platypus mutatus (=sulcatus) (Coleoptera: Platypodidae) and their behavioral activity

We report here the identification and behavioral activity of volatile compounds emitted by male Platypus mutatus (=sulcatus) Chapuis while boring galleries in living poplar, Populus deltoides Marshall, trees. Headspace analysis using solid phase microextraction techniques showed the presence of 6-methyl-5-hepten-2-ol (sulcatol) and 6-methyl-5-hepten-2-one (sulcatone). Only one enantiomer of sulcatol, retusol, was found to be part of the volatile emission. Behavioral assays showed that females are more attracted than males to galleries with boring males inside. Both sulcatol and sulcatone elicited electroantennographic responses by female P. mutatus. Furthermore, behavioral bioassays showed that both sulcatol and sulcatone elicit behaviorally attractive responses by females. These results suggest that male P. mutatus releases a sex pheromone composed mainly of retusol and sulcatone.     

Sex pheromone of the cotton leafworm, Spodoptera littoralis

cis-9,trans-11-Tetradecadien-1-ol acetate (A) and cis-9,trans-12-tetradecadien-1-ol acetate (B), the same compounds as the female sex pheromone of Spodoptera litura, were identified as major components of the female sex pheromone of the cotton leafworm, Spodoptera littoralis. Compounds A and B were individually active, but the activity was synergistically enhanced by mixing the two compounds. The male response was optimal with mixture ranging from 5 : 1 to 20 : 1 of compounds A and B, respectively. Fifty per cent of the male moths of S. littoralis responded to the 20 : 1 mixture at the 10^?7 μg level; they responded at a concentration 100-fold lower than did male moths of S. litura. A partially purified extract of females of S. litura stimulated male moths of S. littoralis. Similarly a partially purified extract of S. littoralis was also active for the male moths of S. litura. The extract of females of S. litura, however, was 1000 times less active for male moths of S. littoralis than was the exrtact of females of S. littoralis, suggesting that a compound(s) is present in the extract of S. litura that inhibits the response of males of S. littoralis.     

Design and synthesis of 6-substituted amino-4-oxa-1-azabicyclo[3,2,0]heptan-7-one derivatives as cysteine proteases inhibitors

A series of 6-substituted amino-4-oxa-1-azabicyclo[3,2,0]heptan-7-one compounds was designed and synthesized as a new class of inhibitors for cysteine proteases cathepsins B, L, K, and S. One compound (5S,6S)-6-(N-benzyloxycarbonyl-L-phenylalanyl) amino-4-oxa-1-azabicyclo[3,2,0]heptan-7-one showed excellent cathepsin L and K inhibition activity with IC(50) at a low nanomolar range.     

陆地革菌的化学成分研究

从陆地革菌(Thelephora terrestris)子实体中分离得到9个已知化合物,经波谱学分析鉴定为:(22E,24R)-麦角甾-7,22-二烯-3β -醇 (1),(22E, 24R)-麦角甾-7, 22-二烯-3β ,5α,6β -三醇 (2),(22E,24R)-麦角甾-4,6,8(14),22-四烯-3-酮 (3),24-亚甲基羊毛甾-8-烯-3β -醇 (4),熊果酸 (5),木栓酮 (6),cerebroside B (7),(2S,3S,4R,2'R)-2-(2'-羟基二十二碳酰氨基)-十八碳烷-1,3,4-三醇 (8),(2S,3S,4R,2'R)-2-(2'-羟基二十三碳酰氨基)-十八碳烷-1,3,4-三醇 (9)。     

蓝柄丽齿菌的化学成分

从担子菌亚门蓝柄丽齿菌(Calodon suaveolens)中首次分离得到8个化合物,通过波谱学技术并借助必要的化学方法最终确定结构,它们是：(22E,24R)-麦角甾-7,22-二烯-3β-醇(1),(22E,24R)-5α,8α-过氧麦角甾-6,22-二烯．3β-醇(2),(22E,24R)-麦角甾．5,7,22-三烯-3β-醇(3),(22E,24R)-3β-羟基麦角甾-5,22-二烯-7-酮(4),对羟基苯甲酸(5),尿嘧啶(6),polyozellin(7),(4E,BE）-2-N-(2’-羟基棕榈酰)-1-O-β-D-吡喃葡萄糖基-9-甲基-4,8-sphingadienine(8)。     

Tuning breadth and sex-specific sensitivity in chemosensory neurons of male and female Uca pugnax

Chemosensory neurons of female fiddler crabs (genus Uca) display greater sensitivity to mixtures of food-related stimuli than do neurons in males. This phenomenon represents an interesting contrast to other sex-specific systems, which tend to be in response to cues associated with mating and parental care. This study examined the responses of chemosensory neurons in males and females to ten individual stimuli to determine if sex-specific responses were restricted to a few key compounds, or if the heightened sensitivity of females was broadly distributed. Neurons in males and females responded well to all stimuli, and although fiddler crabs are primarily herbivorous, highly efficacious physiological stimulants included amino acids and amines as well as carbohydrates most closely associated with plant material. The chemosensory neurons are characterized by broad tuning and relatively high response thresholds, when compared to other crustaceans. Most importantly, the investigations revealed a robust pattern in which female neurons displayed elevated responses to all stimuli. Tuning breadth was not shown to be sex-specific, nor were there detectable differences in over-all response profiles. The most likely explanation for these patterns is that the broad sex-specificity in Uca is produced via fundamental alterations in cellular properties associated with chemosensory transduction. Accepted: 29 June 1999     

Selective inhibitors of GABA uptake: synthesis and molecular pharmacology of 4-N-methylamino-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol analogues

A series of lipophilic diaromatic derivatives of the glia-selective GABA uptake inhibitor (R)-4-amino-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol [(R)-exo-THPO, 4] were synthesized via reductive amination of 3-ethoxy-4,5,6,7-tetrahydrobenzo[d]isoxazol-4-one (9) or via N-alkylation of O-alkylatedracemic 4. The effects of the target compounds on GABA uptake mechanisms in vitro were measured using a rat brain synaptosomal preparation or primary cultures of mouse cortical neurons and glia cells (astrocytes), as well as HEK cells transfected with cloned mouse GABA transporter subtypes (GAT1-4). The activity against isoniazid-induced convulsions in mice after subcutaneous administration of the compounds was determined. All of the compounds were potent inhibitors of synaptosomal uptake the most potent compound being (RS)-4-[N-(1,1-diphenylbut-1-en-4-yl)amino]-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol (17a, IC50 = 0.14 microM). The majority of the compounds showed a weak preference for glial, as compared to neuronal, GABA uptake. The highest degree of selectivity was 10-fold corresponding to the glia selectivity of (R)-N-methyl-exo-THPO (5). All derivatives showed a preference for the GAT1 transporter, as compared with GAT2-4, with the exception of (RS)-4-[N-[1,1-bis(3-methyl-2-thienyl)but-1-en-4-yl]-N-methylamino]-4,5,6,7-tetrahydrobenzo[d]isoxazol-3-ol (28d), which quite surprisingly turned out to be more potent than GABA at both GAT1 and GAT2 subtypes. The GAT1 activity was shown to reside in (R)-28d whereas (R)-28d and (S)-28d contributed equally to GAT2 activity. This makes (S)-28d a GAT2 selective compound, and (R)-28d equally effective in inhibition of GAT1 and GAT2 mediated GABA transport. All compounds tested were effective as anticonvulsant reflecting that these compounds have blood-brain barrier permeating ability.     

Rat cheek gland compounds: behavioural response to identified compounds

Cheek gland secretions from sexually mature and reproductively active male and female laboratory rats (Wister strain), Rattus norvegicus albinus were analysed by gas chromatography/mass spectroscopy. Alkanes, aliphatic acids esters and alcohols were identified in the secretions. Cheek gland preparation from males contained predominantly three compounds, viz. di-n-octyl phthalate (I); 1,2-benzene diacarboxylic acid butyl (2-ethyl hexyl) ester (II); and 1,2 benzene dicarboxylic acid (2-methylpropyl) ester (III) whereas in the cheek gland of females two compounds, viz, 1,2-benzene dicarboxylic acid (2-methylpropyl) ester (I); and 2,6,10 dedecatrien-1-ol, 3,7,11-trimethyl-(Z, E) (II) were the major fractions. The identified compounds were tested for odour preferences. Compounds II and III of males and I and II of females attracted both male and female conspecifics. By contrast, compound I from males only attracted females. The level of attraction also varied from compound to compound. The results suggest that cheek gland secretions have pheromonal functions.     

Olfactory receptors on the antennae of the malaria mosquito Anopheles gambiae are sensitive to ammonia and other sweat-borne components

Electrophysiological studies on female An. gambiae s.s. mosquitoes revealed a receptor neuron within a subpopulation of the antennal grooved-peg sensilla sensitive to the odour of incubated sweat, but not responding to fresh sweat. This receptor neuron was sensitive to ammonia as well, a sweat-borne component which attracts female An. gambiae in a windtunnel bioassay. Neurons innervating a different subpopulation of grooved-peg sensilla did not show a response to incubated sweat. In the latter sensilla, however, one type of neuron responded to water or water containing solutions, while another receptor neuron was inhibited when stimulated with dry air, ether or ethanol. Neurons innervating sensilla trichodea, a more abundant antennal type of olfactory sensillum, did not respond to fresh or incubated sweat at the doses offered. However, receptor neurons within the sensilla trichodea responded with excitation to several sweat-borne components. A subpopulation of the sensilla trichodea was innervated by neurons sensitive to geranyl acetone. A second subpopulation housed receptor neurons sensitive to indole. 3-Methyl-1-butanol and 6-methyl-5-hepten-2-one evoked excitation of receptor neurons within both subpopulations of sensilla trichodea. Neurons were most sensitive to indole and geranyl acetone with a threshold of 0.01%. These findings are discussed in the context of host-seeking behaviour.     

不同营养层次挥发物对燕麦蚜茧蜂寄主搜寻行为的影响

“Ｙ”型管嗅觉计及风洞测定试验明,小麦植株,麦长管蚜（Sitobion avenae),禾谷缢管蚜（Rhopalosiphum padi)对燕麦蚜蜂（Aphidius avenae)雌蜂的吸引作用较小,而有蚜植株及蚜害植株对其吸引作用较大,并以麦长管蚜有蚜植株的吸引作用最强,尽管该蜂对禾谷缢管蚜的寄生率极你,工作量 由其危害诱导产生的挥发性信息化僵物对该蜂仍具有较强的吸引作用,GC－MS鉴定结果表明,麦蚜取食诱导的挥发性信息化合物主要是2－莰烯,6－甲基－5－已烯－2－酮,顺－3－已酰酸酯有水杨酸甲酯,其中6－甲基－5－已烯－2－酮和6－甲基－5－已烯－2－醇对燕麦蚜划蜂的吸引作用最强,水杨酸酯无明显吸引作用。