Volatile attractants for the common bluebottle, Graphium sarpedon nipponum, from the host, Cinnamomum camphora

Floral scent has been shown to elicit behavioral responses by butterflies which forage for flowers after receiving appropriate signals. In comparison with investigations about the role of floral scent, those of foliar odor are, however, very few. In this study, the foliar volatiles of Cinnamomum camphora (Lauraceae), which had been collected by air entrainment, exhibited activities toward Graphium sarpedon nipponum (Papilionidae) in both electrophysiological and behavioral tests. The volatiles were analyzed by capillary gas chromatography with electro-antennographic detection (GC-EAD). Two electrophysiological active compounds were found which were determined as nonanal and decanal by using gas chromatography-mass spectrometry (GC-MS). Female butterflies generally tend to show a greater EAG response than males to the headspace volatiles and EAG-active aldehydes. Two EAG-active aldehydes were found in attractant tests to be attractive to both sexes of the butterfly when treated individually. Although the difference between the sexes was not significant, the female butterflies' preference tended to be more active than that of the males.     

Novel scheme for biosynthesis of aryl metabolites from L-phenylalanine in the fungus Bjerkandera adusta

Aryl metabolite biosynthesis was studied in the white rot fungus Bjerkandera adusta cultivated in a liquid medium supplemented with L-phenylalanine. Aromatic compounds were analyzed by gas chromatography-mass spectrometry following addition of labelled precursors ((14)C- and (13)C-labelled L-phenylalanine), which did not interfere with fungal metabolism. The major aromatic compounds identified were benzyl alcohol, benzaldehyde (bitter almond aroma), and benzoic acid. Hydroxy- and methoxybenzylic compounds (alcohols, aldehydes, and acids) were also found in fungal cultures. Intracellular enzymatic activities (phenylalanine ammonia lyase, aryl-alcohol oxidase, aryl-alcohol dehydrogenase, aryl-aldehyde dehydrogenase, lignin peroxidase) and extracellular enzymatic activities (aryl-alcohol oxidase, lignin peroxidase), as well as aromatic compounds, were detected in B. adusta cultures. Metabolite formation required de novo protein biosynthesis. Our results show that L-phenylalanine was deaminated to trans-cinnamic acid by a phenylalanine ammonia lyase and trans-cinnamic acid was in turn converted to aromatic acids (phenylpyruvic, phenylacetic, mandelic, and benzoylformic acids); benzaldehyde was a metabolic intermediate. These acids were transformed into benzaldehyde, benzyl alcohol, and benzoic acid. Our findings support the hypothesis that all of these compounds are intermediates in the biosynthetic pathway from L-phenylalanine to aryl metabolites. Additionally, trans-cinnamic acid can also be transformed via beta-oxidation to benzoic acid. This was confirmed by the presence of acetophenone as a beta-oxidation degradation intermediate. To our knowledge, this is the first time that a beta-oxidation sequence leading to benzoic acid synthesis has been found in a white rot fungus. A novel metabolic scheme for biosynthesis of aryl metabolites from L-phenylalanine is proposed.     

The ectomycorrhizal fungus Tricholoma matsutake biosynthesizes benzoic acid and benzaldehyde independently

Metabolism of benzoic acids and benzaldehydes are crucial to produce hormones, defense compounds and attractants for pollinators in plants. Tricholoma matsutake contains benzoic acid and benzaldehyde, but their roles have not been fully studied. First we conducted tracer experiments to gain insight into benzoic acid and benzaldehyde biosynthesis in T. matsutake. ¹³C and ²H were incorporated into benzoic acid from uniformly ¹³C- and ²H- labelled l-phenylalanine and (E)-cinnamate 1?d after supplementation of the precursors without any substitution of ¹³C and ²H. In contrast, no ¹³C and ²H were incorporated into benzaldehyde from these precursors 10?d after the supplementation. The results indicate that T. matsutake has a metabolic pathway to biosynthesize benzoic acid from l-phenylalanine and (E)-cinnamate in which benzaldehyde is not a metabolic intermediate. However, 30?d after the supplementation of ¹³C- and ²H- labelled l-phenylalanine, ¹³C and ²H were incorporated into all the carbon and hydrogen atoms of benzaldehyde. In addition, ²H was not incorporated into benzaldehyde from exogenously supplemented ²H-labelled benzoic acid. This result indicates that T. matsutake has a metabolic pathway to biosynthesize benzaldehyde from l-phenylalanine in which benzoic acid is not an intermediate. Taken together, our results strongly suggest that T. matsutake biosynthesizes benzoic acid and benzaldehyde in separate pathways.     

直立百部的非生物碱化学成分研究(英文)

从直立百部(Stemona sessilifolia)根中首次分离到十四个非生物碱成分.依据波谱数据,它们鉴定为豆甾醇(1)、4-甲氧基苯甲酸(2)、苯甲酸(3)、3,4-二甲氧基苯酚 (4)、4-甲氧基苯甲酸(5)、4-羟基苯甲酸(6)、4-羟基-3-甲氧基苯甲酸(7)、4-羟基-3,5-二甲氧基苯甲酸(8)、3,3′-bis(3,4-dihydro-4-hydroxy-6-methoxy)-2H-1-benzopyran(9)、4-羟基-3-甲氧基苯甲醛(10)、羽扇豆烷-3-酮 (11)、绿原酸(12)、胡萝卜苷(13),3-feruoyl-chinasueure (14).化合物5～14为首次从百部属植物中分离得到.     

The antioxidant activity of aqueous spinach extract: chemical identification of active fractions

In previous studies we have elucidated the presence of powerful, natural antioxidants (NAO) in water extracts of spinach leaves and demonstrated their biological activity in both in vitro and in vivo systems. In the present study, the chemical identity of several of these antioxidant components is presented. Spinach leaves were extracted with water and the 20,000 g supernatant which contained the antioxidant activity was extracted with a water:acetone (1:9) solution. The 20,000 g supernatant obtained was further purified on reverse phase HPLC using C-8 semi-preparative column. Elution with 0.1% TFA resulted in five hydrophilic peaks. Elution with acetonitrile in TFA resulted in seven additional hydrophobic peaks. All the peaks were detected at 250 nm. All the fractions obtained showed antioxidant activity when tested using three different assays. Based on 1H and 13C NMR spectroscopy four of the hydrophobic fractions were identified as glucuronic acid derivatives of flavonoids and three additional fractions as trans and cis isomers of p-coumaric acid and others as meso-tartarate derivatives of p-coumaric acid. The present study demonstrates for the first time the presence of both flavonoids and p-coumaric acid derivatives as antioxidant components of the aqueous extract of spinach leaves.     

Metabolism of cinnamic, p-coumaric, and ferulic acids by Streptomyces setonii

Streptomyces setonii strain 75Vi2 was grown at 45 degrees C in liquid media containing yeast extract and trans-cinnamic acid, p-coumaric acid, ferulic acid, or vanillin. Gas chromatography, thin-layer chromatography, and mass spectrometry showed that cinnamic acid was catabolized via benzaldehyde, benzoic acid, and catechol; p-coumaric acid was catabolized via p-hydroxybenzaldehyde, p-hydroxybenzoic acid, and protocatechuic acid; ferulic acid was catabolized via vanillin, vanillic acid, and protocatechuic acid. When vanillin was used as the initial growth substrate, it was catabolized via vanillic acid, guaiacol, and catechol. The inducible ring-cleavage dioxygenases catechol 1,2-dioxygenase and protocatechuate 3,4-dioxygenase were detected with an oxygen electrode in cell-free extracts of cultures grown in media with aromatic growth substrates and yeast extract.     

On the chemical stability of beta-hydroxyphenylalkylhydroxylamines and its relevance to the metabolism of amphetamines and ephedrines.

β, N-bis (hydroxy) phenylalkylamines rapid oxidative decomposition to benzaldehyde and an oxime in the presence of small quantities of Cu(II). The reaction occurs in aqueous solution at pH 7.4 so that products of metabolic transformation reactions involving the oxidation of such hydroxylamines would be expected to decompose in this way. N-Oxidation of norephedrine would result in benzaldehyde by this mechanism, and since benzaldehyde is a precursor to benzoic acid, it is proposed that the N-hydroxylation pathway of arylalkylamine metabolism instead of carbon oxidation could lead to benzoic acid. This acid is a major metabolite of compounds such as amphetamine and ephedrine in some species.     

Trianthenol: an antifungal tetraterpenoid from Trianthema portulacastrum (Aizoaceae)

An antifungal tetraterpenoid named trianthenol 1 has been isolated from the chloroform extract of Trianthema portulacastrum. Its structure was established as 15-hydroxymethyl-2,6,10,18,22,26,30-heptamethyl-14-methylene- 17-hentriacontene on the basis of spectroscopic data including high resolution mass and two-dimensional NMR techniques. A benzaldehyde derivative 2, a pentacyclic triterpenoid 3 and benzoic acid derivatives 4-5 are also reported for the first time from Trianthema portulacastrum.     

No oral-cavity-only discrimination of purely olfactory odorants

The purely olfactory odorants coumarin, octanoic acid, phenylethyl alcohol, and vanillin had been found to be consistently identified when presented retronasally but could not be identified when presented oral-cavity only (OCO). However, OCO discrimination of these odorants was not tested. Consequently, it remained possible that the oral cavity trigeminal system might provide sufficient information to differentiate these purely olfactory odorants. To evaluate this, 20 participants attempted to discriminate vapor-phase coumarin, octanoic acid, phenylethyl alcohol, and vanillin and, as a control, the trigeminal stimulus peppermint extract, from their glycerin solvent, all presented OCO. None of the purely olfactory odorants could be discriminated OCO, but, as expected, peppermint extract was consistently discriminated. This inability to discriminate clarifies and expands the previous report of lack of OCO identification of purely olfactory odorants. Taken together with prior data, these results suggest that the oral cavity trigeminal system is fully unresponsive to these odorants in vapor phase and that coumarin, octanoic acid, phenylethyl alcohol, and vanillin are indeed purely olfactory stimuli. The OCO discrimination of peppermint extract demonstrated that the absence of discrimination for the purely olfactory odorants was odorant dependent and confirmed that the oral cavity trigeminal system will provide differential response information to some vapor-phase stimuli.     

孜然种子提取物枯茗醛和枯茗酸抑菌作用研究

以番茄早疫病菌、棉花黄萎病菌、小麦纹枯病菌、烟草赤星病菌、小麦全蚀病菌、油菜菌核病菌、辣椒疫霉病菌、水稻纹枯病菌、小麦白粉病菌和番茄灰霉病菌等为供试菌种,采用离体与活体相结合的方法系统地测定了枯茗醛和枯茗酸的抑菌活性。离体抑菌活性测定结果表明,枯茗醛和枯茗酸对多种病原菌具有一定的抑制效果,其中对油菜菌核病菌菌丝生长的抑制效果高于其它供试病原菌,有效中浓(EC50)分别为2.1和7.3 mg/L;枯茗醛和枯茗酸对小麦白粉病的防治实验结果表明,供试浓度为1000 mg/L时,两种药剂的保护防效均高于50%;相同处理浓度下,枯茗酸对油菜菌核病的保护防效与速克灵处理相当,达到57.52%。     

Fecal volatile components elicit aggregation in the oriental migratory locust,Locusta migratoria manilensis (Orthoptera: Acrididae)

Abstract The aggregation components from fecal volatiles of the oriental migratory locust, Locusta migratoria manilensis were identified with gas chromatographic/electroantennographic detector (GC‐EAD), GC‐MS (mass spectrometry) analyses and behavioral bioassays. Both last instar nymphs and adults of the oriental migratory locust have similar aggregation pheromones in their volatiles. A total of 11 electrophysiologically active compounds, namely, hexanal, cyclohexanol, heptanal, phenol, 2,5‐dimethyl‐pyrazine, benzyl alcohol, benzaldehyde, guaiacol, nonanal, 2,6,6‐trimethyl‐2‐cyclohexene‐1,4‐dione and decyl aldehyde were identified in the fecal volatiles of 2‐day‐old immature adult male locusts. Only hexanal, nonanal, benzaldehyde, cyclohexanol and 2,5‐dimethyl‐pyrazine elicited significant aggregation responses in immature 2‐day‐old adult males. However, adult males had significantly lower behavioral responses to synthetics of five single compounds than the blend of cyclohexanol, 2,5‐dimethyl‐pyrazine, benzaldehyde, nonanal, hexanal in ratios of 100: 100: 2: 60: 30 in the range of 30–60 μg/mL. We propose that it is the blend of these five compounds that plays a key role in eliciting and sustaining aggregation in gregarious oriental migratory locusts. These results also showed that the aggregation pheromones of the oriental migratory locust are significantly different from those found in the desert locust.     

Broad activation of the glomerular layer enhances subsequent olfactory responses

Early olfactory experience with a specific odorant enhances the subsequent response of the glomerular layer of the rat olfactory bulb to that same odorant. Because different odorants activate different glomerular layer regions, it seemed plausible that experience with a large number of odorants might result in enhanced glomerular activation during subsequent exposure to both the previously experienced odorants and the novel odorants evoking activity in regions that overlapped with those previously stimulated by different odorants. To this end, 7 odorants were selected using our glomerular response data archive that together stimulated much of the glomerular layer (alpha-phellandrene, benzaldehyde, L-carvone, decanal, pentanol, santalol, and valeric acid). Young rats were exposed to a different odorant each day for 7 days, and this cycle was repeated 3 times from postnatal days 1-21. The [(14)C]2-deoxyglucose technique was used to measure neural activity in response to both previously experienced and novel odorants. The 2 novel odorants (alpha-ionone and L-menthone) activate regions of the glomerular layer that overlap with those stimulated by the 7 enrichment odorants. Our results indicate that early experience with multiple odorants results in increased responsiveness both to previously experienced odorants and to novel odorants that stimulate previously activated regions of the bulb.     

A new enzymatic activity from elicitor‐treated pear cell cultures converting trans‐cinnamic acid to benzaldehyde

Cell cultures of Asian pear (Pyrus pyrifolia) are known to produce benzoate‐derived biphenyl phytoalexins upon elicitor treatment. Although the downstream pathway for biphenyl phytoalexin biosynthesis is almost known, the upstream route of benzoic acid biosynthesis in pear has not been completely elucidated. In the present work, we report benzaldehyde synthase (BS) activity from yeast extract‐treated cell suspension cultures of P. pyrifolia. BS catalyzes the in vitro conversion of trans‐cinnamic acid to benzaldehyde using a non‐oxidative C₂‐side chain cleavage mechanism. The enzyme activity was strictly dependent on the presence of a reducing agent, dithiothreitol being preferred. C₂‐side chain shortening of the cinnamic acid backbone resembled the mechanisms catalyzed by 4‐hydroxybenzaldehyde synthase (HBS) activity in Vanilla planifolia and salicylaldehyde synthase (SAS) activity in tobacco and apple cell cultures. A basal BS activity was also observed in the non‐elicited cell cultures. Upon yeast extract‐treatment, a 13‐fold increase in BS activity was observed when compared to the non‐treated control cells. Moreover, feeding of the cell cultures with trans‐cinnamic acid, the substrate for BS, resulted in an enhanced level of noraucuparin, a biphenyl phytoalexin. Comparable accumulation of noraucuparin was observed upon feeding of benzaldehyde, the BS product. The preferred substrate for BS was found to be trans‐cinnamic acid, for which the apparent K_m and V_max values were 0.5 mM and 50.7 pkat mg^?1 protein, respectively. Our observations indicate the contribution of BS to benzoic acid biosynthesis in Asian pear via the CoA‐independent and non‐β‐oxidative route.     

Dynamics of odorant binding to thin aqueous films of rat-OBP3

Uptake, retention and release of 5 selected odorants (benzaldehyde, 2-methylpyrazine, 2-isobutyl-3-methoxypyrazine, 2-isobutylthiazole, and 2,4,5-trimethylthiazole) by recombinant rat odor-binding protein 3 (rat-OBP3) were measured in a model system under nonequilibrium conditions. Gaseous odorants were introduced into a 100 mm section of a polar deactivated capillary in which aqueous rat-OBP3 films were formed to mimic the olfactory epithelium (OE), and the change in the gas-phase concentration of the outflow gas was monitored in real time using atmospheric pressure chemical ionization-mass spectrometry (APCI-MS). The 5 odorants were chosen because they exhibited a broad range of dissociation constants with rat-OBP3 and because they were amenable to detection by on-line APCI-MS. All 5 odorants were quantitatively bound by rat-OBP3, which resulted in an effective concentration of the odorants in the aqueous layer (about 50?000-fold). Odorant release from the rat-OBP3-odorant complex into the gas phase showed that odorant release was governed by the dissociation constant of the complex and the flow rate of odorant-free air. When 2 odorants were introduced into the system, odorant uptake and release were influenced by the method of introduction and their relative affinities for the protein. Because rat-OBP3 exhibits typical odorant-binding characteristics, the results not only provide fundamental information on the kinetics of odorant mass transfer induced by the presence of OBPs in the olfactory mucus layer but also support the possibility that vertebrate OBPs may facilitate the accumulation of odorants in the OE.     

Purification and characterisation of TOL plasmid-encoded benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase of Pseudomonas putida

Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, two enzymes of the xylene degradative pathway encoded by the plasmid TOL of a Gram-negative bacterium Pseudomonas putida, were purified and characterized. Benzyl alcohol dehydrogenase catalyses the oxidation of benzyl alcohol to benzaldehyde with the concomitant reduction of NAD+; the reaction is reversible. Benzaldehyde dehydrogenase catalyses the oxidation of benzaldehyde to benzoic acid with the concomitant reduction of NAD+; the reaction is irreversible. Benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase also catalyse the oxidation of many substituted benzyl alcohols and benzaldehydes, respectively, though they were not capable of oxidizing aliphatic alcohols and aldehydes. The apparent Km value of benzyl alcohol dehydrogenase for benzyl alcohol was 220 microM, while that of benzaldehyde dehydrogenase for benzaldehyde was 460 microM. Neither enzyme contained a prosthetic group such as FAD or FMN, and both enzymes were inactivated by SH-blocking agents such as N-ethylmaleimide. Both enzymes were dimers of identical subunits; the monomer of benzyl alcohol dehydrogenase has a mass of 42 kDa whereas that of the monomer of benzaldehyde dehydrogenase was 57 kDa. Both enzymes transfer hydride to the pro-R side of the prochiral C4 of the pyridine ring of NAD+.     

Identification of volatiles from differently aged red clover (Trifolium pratense) root extracts and behavioural responses of clover root borer (Hylastinus obscurus) (Marsham) (Coleoptera: Scolytidae) to them

Root extracts from 1.5 and 2.5-year-old red clover (Trifolium pratense) were obtained using supercritical fluid extraction (SFE). GC–MS analysis and Kovats indices allowed identification of the volatile compounds as butyl acetate, E-2-hexenal, α-pinene, benzaldehyde, 6-methyl-5-hepten-2-one, limonene, acetophenone, methyl benzoate, nonanal, octanoic acid and decanal.     

Antioxidant and antimicrobial potential of two extracts from Capparis spinosa L. and Rumex nervosus and molecular docking investigation of selected major compounds

The present study examined the phytochemical composition, antioxidant, antimicrobial properties, and molecular docking of different solvents extracts (methanol and water) of two medicinal plants, namely, Capparis spinosa L (CS) and Rumex nervosus (RN). Phytochemical analysis showed that total phenol, flavonoids, alkaloids, and vitamin C were significantly (P ≤ 0.05) higher in the methanolic extract of both plants than in other solvents. However, tannin content was significantly (P ≤ 0.05) high in the water extract for both plants. Chloroform and acetone extracts were significantly lower in phytochemicals than other solvents, therefore excluded in this study. GC–MS analysis showed one dominant compound in CS (isopropyl isothiocyanate) and two in RN (pyrogallol and palmitic acid). The antioxidant methods applied (DPPH, ABTS, β-Carotene/linoleic acid assay, and reducing the power) showed that the methanolic extract of CS exerted higher activity in methanolic extract but lower than that of BHA standard. The methanolic extract of both plants inhibited the bacterial pathogens when a minimum inhibitory concentration (MIC) method was applied, compared to water extract with RN-methanolic extract had a lower inhibition concentration than CS-methanolic extract. The molecular interactions study revealed that the palmitic acid and pyrogallol interacted with the receptors' active site. This work concluded that CS and RN showed a remarkable antioxidant and antibacterial effect with the high antimicrobial activity of RN extract.     

Hydrogen-peroxide-producing system ofPleurotus eryngii involving the extracellular enzyme aryl-alcohol oxidase

The effect of benzyl alcohol, benzaldehyde and benzoic acid on the production of extracellular hydrogen peroxide (H₂O₂) by the ligninolytic fungusPleurotus eryngii was investigated. It was found that an equilibrium between oxidative and reductive reactions of these compounds is established, leading to the continuous production of H₂O₂. A multienzymatic cyclic system is proposed in which H₂O₂ is produced extracellularly by the action of aryl-alcohol oxidase on benzyl alcohol, the most abundant compound after redox reactions, and to a lower extent on benzaldehyde. The oxidation products of these reactions, benzaldehyde and benzoic acid, are reduced by intracellular dehydrogenases.     

The Volatile Profiles of a Rare Apple (Malus domestica Borkh.) Honey: Shikimic Acid‐Pathway Derivatives,Terpenes, and Others

The volatile profiles of rare Malus domestica Borkh . honey were investigated for the first time. Two representative samples from Poland (sample I) and Spain (sample II) were selected by pollen analysis (44–45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid‐phase microextraction (HS‐SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid‐pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H‐indole‐3‐acetate. The main compounds of the honey headspace were (sample I; sample II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car‐2‐en‐4‐one (10.2%). CH₂Cl₂ and pentane/Et₂O 1 : 2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9–3.9%), benzoic acid (2.0–11.2%), terpendiol I (0.3–7.4%), coumaran (0.0–2.8%), 2‐phenylacetic acid (2.0–26.4%), methyl syringate (3.9–13.1%), vomifoliol (5.0–31.8%), and methyl 1H‐indole‐3‐acetate (1.9–10.2%). Apple honey contained also benzyl alcohol, 2‐phenylethanol, (E)‐cinnamaldehyde, (E)‐cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles.     

Studies on the Browning of Kori-tofu

Properties of ether extract of browned Kori-tofu were investigated. More than half amount of neutral glycerides of Kori-tofu changed into weak-acidic substances after browning, in which most of extracted brown pigments were contained. These weak-acidic substances showed properties of carbonyl and reductone, and mainly contained glycerides, whose constitutional fatty acids were palmitic, oleic, and linoleic acids as well as a little amount of azelaic and stearic acids.

From the ether extract of browned Kori-tofu were isolated and identified azelaic acid and carbonyls. The carbonyls identified were benzaldehyde, methylethylketone, crotonal, acetaldehyde, α-ketoaldehydes of C₂, C₃, C₄, C₅, C₇ and C₉, and hexane-2,3-dione. Two nitrogeneous carbonyl compounds were isolated. Formation mechanisms of these compounds and their roles in browning of Kori-tofu were discussed.