Lilac Alcohol Research Articles

Metabolomics Analysis Reveals the Accumulation Patterns of Flavonoids and Volatile Compounds in Camellia oleifera Petals with Different Color

To systematically and comprehensively investigate the metabolic characteristics of coloring substances and floral aroma substances in Camellia oleifera petals with different colors, ultrahigh-performance liquid chromatography–mass spectrometry (UPLC–MS/MS) and headspace solid phase microextraction and gas chromatography–mass spectrometry (HS–SPME–GC–MS) metabolomics methods were applied to determine the metabolic profiles of white, candy-pink and dark-red petals. The results revealed that 270 volatile organic compounds were detected, mainly terpenoids, heterocyclic, esters, hydrocarbons, aldehydes, and alcohols, in which phenylethyl alcohol, lilac alcohol, and butanoic acid, 1-methylhexyl ester, hotrienol, alpha-terpineol and 7-Octen-4-ol, 2-methyl-6-methylene-, (S)-, butanoic acid, 2-methyl-, 2-methylbutyl ester, 2,4-Octadienal, (E,E)- could act as the floral scent compounds. A total of 372 flavonoid compounds were identified, and luteolin, kaempferol, cyanidin and peonidin derivatives were considered as the main coloring substances for candy-pink and dark-red petal coloration. In conclusion, this study intuitively and quantitatively exhibited the variations in flower color and floral scent of C. oleifera petal with different colors caused by changes in variations of flavonoids and volatile organic compound composition, and provided useful data for improving the sensory quality and breeding of C. oleifera petals.

In Silico Evaluation of Bioactive Compounds of Artemisia pallens Targeting the Efflux Protein of Multidrug-Resistant Acinetobacter baumannii (LAC-4 Strain).

Acinetobacter baumannii (A. baumannii) is one of the major representative aetiologies of recalcitrant nosocomial infections. Genotypic and phenotypic alterations in A. baumannii have resulted in a significant surge in multidrug resistance (MDR). Of all the factors responsible for the development of antimicrobial resistance (AMR), efflux protein pumps play a paramount role. In pursuit of a safe alternative for the prevention and control of A. baumannii infections, bioactive compounds from the aerial parts of the medicinal plant Artemisia pallens were studied. GC-MS analysis of the ethanol extract of A. pallens detected five major compounds: lilac alcohol A, spathulenol, lilac alcohol C, n-hexadecanoic acid, and vulgarin. In silico examinations were performed using the Schrödinger suite. Homology modelling was performed to predict the structure of the efflux protein of A. baumannii-LAC-4 strain (MDR Ab-EP). The identified bioactive compounds were analysed for their binding efficiency with MDR Ab-EP. High binding efficiency was observed with vulgarin with a glide score of −4.775 kcal/mol and stereoisomers of lilac alcohol A (−3.706 kcal/mol) and lilac alcohol C (−3.706 kcal/mol). Our molecular dynamic simulation studies unveiled the stability of the ligand–efflux protein complex. Vulgarin and lilac alcohol A possessed strong and stable binding efficiency with MDR Ab-EP. Furthermore, validation of the absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties of the ligands strongly suggested that these compounds could serve as a lead molecule in the development of an alternate drug from A. pallens.

Honey Bee Foraging Decisions Influenced by Pear Volatiles

The interactions between plants and pollinators are complex. Flower volatiles as special olfactory cues could influence the foraging choices of pollinators. Here, we conducted bioassays to evaluate the role of flower volatiles on the attraction of honey bees (native Apis cerana and exotic Apis mellifera) to pears (native Pyrus bretschneideri and exotic Pyrus communis). Chemical and electrophysiological approaches were used to determine flower volatiles and evaluate the antennal responses of honey bees to volatiles from pear flowers. Bioassays demonstrated that flower volatiles were crucial for the attraction of honey bees to pear flowers; honey bees preferred to forage on P. communis flowers (p > 0.05), with approximately 64.37 ± 0.02% (A. mellifera) and 62.10 ± 0.02% (A. cerana) foraging on P. communis. Flowers of P. communis and P. bretschneideri yielded 27 and 31 compounds, respectively, with 17 of them being common. Honey bee antennae responded to 16 chemicals, including 5 contained in both pear species: 1-nonanol, linalool, methyl 2-hydroxy-3-methylpentanoate, methyl L-isoleucinate, and α-farnesene. In addition, there were 8 electrophysiologically active compounds in P. bretschneideri: methyl L-valine ester, benzaldehyde, 6-methyl-5-hepten-2-one, isophorone, 2-methyl octane, longicyclene, longifolene, and caryophyllene; and 3 electrophysiologically active compounds in P. communis: β-ocimene, 4-oxoisophorone and lilac alcohol D. In conclusion, our study demonstrated the significant impact of pear flower volatiles on honey bee foraging choices. This knowledge provides a basis for the selection of honey bees for pear pollination and lays a foundation for further study of the chemical communication of pear attractiveness to honey bees.

Comprehensive Evaluation of the Volatomic Fingerprint of Saffron from Campania towards Its Authenticity and Quality.

The volatile profiles of eight saffron samples (seven cultivated and one spontaneous) grown in different geographical districts within the Campania region (southern Italy) were compared. Using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME/GC-MS), overall, 80 volatiles were identified in the eight landraces. Among them, safranal and its isomers and other related compounds such as isophorones, which are not only key odorants but also pharmacologically active metabolites, have been detected in all the investigated samples. Principal Component Analysis performed on the volatiles’ compounds revealed that the spontaneous sample turned out to be an outlier. In particular, the volatile organic compounds (VOCs) profile of the spontaneous saffron presented four lilac aldehydes and four lilac alcohol isomers, which, to the authors’ knowledge, have never been identified in the volatile signature of this spice. The multivariate statistical analysis allowed the discrimination of the seven cultivate saffron ecotypes in four well-separated clusters according to variety. Moreover, 20 VOCs, able to differentiate the clusters in terms of single volatile metabolite, were discovered. Altogether, these results could contribute to identifying possible volatile signature metabolites (biomarkers) or patterns that discriminate saffron samples grown in Campania region on a molecular basis, encouraging future biodiversity programs to preserve saffron landraces revealing valuable genetic resources.

Identification of VOCs in essential oils extracted using ultrasound- and microwave-assisted methods from sweet cherry flower

The floral fragrance of plants is an important indicator in their evaluation. The aroma of sweet cherry flowers is mainly derived from their essential oil. In this study, based on the results of a single-factor experiment, a Box–Behnken design was adopted for ultrasound- and microwave-assisted extraction of essential oil from sweet cherry flowers of the Brooks cultivar. With the objective of extracting the maximum essential oil yield (w/w), the optimal extraction process conditions were a liquid–solid ratio of 52 mL g−1, an extraction time of 27 min, and a microwave power of 435 W. The essential oil yield was 1.23%, which was close to the theoretical prediction. The volatile organic compounds (VOCs) of the sweet cherry flowers of four cultivars (Brooks, Black Pearl, Tieton and Summit) were identified via headspace solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). The results showed that a total of 155 VOCs were identified and classified in the essential oil from sweet cherry flowers of four cultivars, 65 of which were shared among the cultivars. The highest contents of VOCs were aldehydes, alcohols, ketones and esters. Ethanol, linalool, lilac alcohol, acetaldehyde, (E)-2-hexenal, benzaldehyde and dimethyl sulfide were the major volatiles, which were mainly responsible for the characteristic aroma of sweet cherry flowers. It was concluded that the VOCs of sweet cherry flowers were qualitatively similar; however, relative content differences were observed in the four cultivars. This study provides a theoretical basis for the metabolism and regulation of the VOCs of sweet cherry flowers.

Перспективи розширеного функціонального використання деяких декоративних кущових культур

The authors present the results of the collection’s formation of some ornamental shrubs, long-term phenological observations of them and the selection of the best forms and breeding hybrids in the Left-Bank Lisosteppe of Ukraine. In particular, the characteristic of the vegetation of 20 varieties of common lilac collection is given. The estimation of the terms and duration of the crop flowering enable to divide its varieties into groups of early, average and late flowering. The high decorative value of most of the strains has been described as well as their resistance to low temperatures and pests. The additional analysis of the latest literature data has shown the significant yield of aromatic substances in the common lilac plant, with the predominance of alkanes and lilac alcohol. The results have been presented of 70 rose cultivars of adaptation to the growing zone conditions. There are 20 promise varieties of the crop, which are characterized by high decorative value, resistance to pathogens and low temperatures and duration of flowering. The characteristics of the new variety of roses of the floribunda group – Olexandra has been given created by the authors. Along side with the high decorative value, different types of the rose plant provide the significant yield of aromatic substances with the domination of alkanes, monoterpenes and 2-phenylethanol. The analysis of the literature data also has shown the presence of aromatic substances in the jasmine and mock-orange plants. The first is characterized with esters based on benzene, cis-jasmon and isophytol, the second – with some sesquiterpenes and epi-13-manol. The further research included the phenological evaluation of the of white cedar and juniper collection. The best selected forms were characterized with decorativeness, resistance to frost, pests and pathogens. The literature data have shown, that the aromatic complex of the crops cultures includes mainly monoterpenes and their derivatives – alcohols and ketones. As a result, it was concluded that it is necessary to expand research with ornamental bushy crops in the direction of evaluating of their aromatic properties.

Chemical components of male and female flowers of Schisandra chinensis

Schisandra chinensis (Turcz.) Baill. is one of the important traditional medicinal plants in East Asia. It is a dioecious plant with aromatic flowers. The female and male flowers of S. chinensis possess slightly different fragrance characteristics. The overall scent of S. chinensis flowers is quite similar to that of Syringa dilatata (Korean lilac) flowers. Hence, this study aimed to understand the aromatic profile of the hexane extract from female and male flowers of S. chinensis and to compare their profile with the hexane extract of Korean lilac flowers. The chemical composition of hexane extract was determined by gas chromatography and mass spectrometry (GC-MS) analysis. In total, 67 different components were detected in the hexane extract of female (48) and male flowers (51) of S. chinensis; 32 of which were common to both female and male flowers. In regards to gender difference, 16 components were found only in female flowers, and 19 components were found only in male flowers. The results revealed that the most abundant components in the hexane extract of both female and male flowers were lilac alcohol C (9.53 and 7.00%), lilac alcohol A (6.55 and 5.71%), n-hexadecanoic acid (6.21 and 6.96%), linoleic acid (5.14 and 7.61%), β-elemene (5.12 and 1.99), and lilac aldehyde D (4.13 and 4.97%). The data suggest that the major compounds in the hexane extract of S. chinensis flowers were generally similar, but they varied quantitatively according to gender. The presence of 10 components in both S. chinensis and Korean lilac flowers may be responsible for their similar fragrance characteristics. It could be concluded that the different fragrance characteristics of these flowers may be due to the presence of several gender-specific aromatic compounds in minor percentages.

Chemical Composition of Aerial Parts Essential Oils from Six Endemic Malagasy Helichrysum Species.

The essential oils of six endemic Malagasy Helichrysum species were investigated by GC (RI), GC–MS and 13C NMR spectrometry. In total, 153 compounds were identified accounting for 90.8% to 99.9% of the total composition. The main constituents were α-pinene for H. benthamii, 1,8-cineole for H. dubardii, (E)-β-caryophyllene for H. indutum, and H. bojerianum. H. diotoides essential oil was characterized by the presence of two lilac alcohols and four lilac acetates whereas H. hirtum essential oil exhibited an atypical composition with 7β-H-silphiperfol-5-ene, 7-epi-subergorgiol, and 7-epi-silphiperfol-5-en-13-oic acid as major components.

Fragrance components of Platanthera bifolia subsp. osca and Platanthera chlorantha collected in several sites in Italy

Platanthera bifolia subsp. osca sample collected at Grisolia showed as main components linalool (17.8%), benzyl benzoate (55.8%), and benzyl 2-hydroxybenzoate (6.7%). Four samples of P. bifolia subsp. osca were collected at Pignola: the main components of the aroma are lilac derivatives (49.02–79.00%), mainly lilac alcohols B (7.41–13.52%), C (10.10–18.45%), and D (7.50–34.28%). Three samples were analyzed from the site of Marsico Nuovo. The main components of the scent found in this site were linalool (1.54–10.00%), lilac aldehydes (3.98–11.15%), and mainly lilac alcohols (50.68–61.51%). The main components of the sample collected at Palena were methyl benzoate (9.04%) and benzyl benzoate (74.72%). The analysis of the composition of the aroma of a Platanthera chlorantha plant has been performed. The main components were lilac derivatives. The reported behavior could be explained admitting an adaptive modification of the scent considering the nature of possible pollinating agents due to different habitats.

Comparative Studies of Chemical Compostion, Antimicrobial and Antioxidant Activity of Essential Oil of Some Species from Genus Artemisia

Background and Objective: Some species from genus Artemisia were used in ancient medicine since Pharaonic civilization, most species of this genus are grown in arid or desert zones in Egypt. The present study aimed to evaluate and compare the chemical constituents, antimicrobial and antioxidant potential of the essential oils of three species of Artemisia ( Artemisia sieberi , Artemisia judaica and Artemisia monosperma ) grown in Egypt. Materials and Methods: Chemical constituent of the essential oils of these species were analysed by GC-MS, antibacterial activities were carried out using disc-diffusion test and antioxidant properties were investigated with Iron, Fe (III) to Fe (II) reduction and DPPH radical scavenging capacity. Results: The results of chemical analysis revealed similarity between the three species in 20 compounds, the major compounds identified in essential oils were verbenol, (7.5 % and 11.51%) in A. sieberi and A. monosperma , I²-caryophyllene oxide (1.25 % – 0.78%) and Methyl jasmonate (0.9 % and 1.21 %) in A. sieberi and A. judaica , respectively. While the major compound in A. judaica was Lilac alcohol C (9.6%) and camphor (4.5%). The antibacterial investigation exhibited significant and broad-spectrum antibacterial efficacy of A. monosperma and A. judaica against different strains of Gram-positive and Gram-negative bacteria. Whereas, A. sieberi showed higher antibacterial efficacy against the gram-positive bacteria but weak or no effect against the Gram-negative bacteria. The results of the antioxidant investigation showed that A. sieberi present the higher reduction capacity with an IC 50 of 0.17 ± 0.03g/L, followed by A. judaica with an IC 50 of 0.58 ± 0.04g/L and A. monosperma with an IC 50 of 6.35 ± 0.41g/L. However, the reducing capacity of ascorbic acid and quercetin were 0.091 ± 0.002g/L and 0.026 ± 0.002g/L respectively. Conclusion: The present study revealed that the essential oils of A. sieberi , A. judaica and A. monosperm a possesses significant antioxidant and antibacterial activity, which attributed to the plenty of varied chemical compounds in these medicinal plants.

Fragrance components of Platanthera bifolia subsp. osca

SPME-GC-MS analysis of the scent of Platanthera bifolia subsp. osca collected during the night showed as main components lilac alcohols B, C and D and lilac aldehydes A, B and C. Other significant chemical components were linalool and caryophyllene. Some differences were found in comparison with previously reported analyses of the scent of P. bifolia and Platanthera chlorantha. The most important difference found was in the composition of the ester fraction.

Floral scents of typical Buddleja species with different pollination syndromes

Floral scents from Buddleja lindleyana, Buddleja loricata, Buddleja cordata and Buddleja tubiflora were evaluated using the dynamic headspace adsorption method and identified with coupled gas chromatography and mass spectrometry. In total, 13 compounds were identified from the flowers of B. cordata, 19 from B. lindleyana and 29 from B. loricata, representing 95.5%, 93.1% and 96.2% of the total floral scents in the three species, respectively. No floral scents were recorded from B. tubiflora. Main volatile compounds in B. cordata were trans-beta-ocimene (53.4%), lilac alcohol (9.6%) and lilac aldehyde (5.6%). Main volatile compounds in B. lindleyana were beta-caryophyllene (17.6%), alpha-farnesene (16.0%) and 3-octanone (9.8%). Main volatile compounds in B. loricata were 4-oxoisophorone (27.1%), alpha-farnesene (17.9%) and linalool (10.6%). The study suggested that the floral scents may have evolved in conjunction with the sensory capabilities of different visitors as a specific group of pollinators in representative Buddleja species. (C) 2012 Elsevier Ltd. All rights reserved.

Volatile Composition Screening of Salix spp. Nectar Honey: Benzenecarboxylic Acids, Norisoprenoids, Terpenes, and Others

Salix spp. nectar honey volatiles of Croatian origin were analyzed by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry (GC, GC/MS). Isolated volatiles were found in the honey headspace and extracts with almost exclusive distribution of several abundant compounds (e.g., phenylacetic acid, pinocembrin, 8-hydroxy-4,7-dimethylcoumarin, and 3-hydroxy-trans-β-damascone in the extracts, or safranal and lilac alcohols in the headspace). Comparison with Croatian Salix spp. honeydew honey revealed similarities regarding distribution of important shikimate pathway derivatives (e.g., high percentage of phenylacetic acid) and several norisoprenoids (α-isophorone and 4-oxoisophorone). On the other hand, distinct features of this honey were occurrence of compounds such as pinocembrin, 8-hydroxy-4,7-dimethylcoumarin, phenylacetonitrile, norisoprenoids (major ones: 3-hydroxy-trans-β-damascenone and trans-β-damascone), more pronounced variability of linalool-derived compounds, as well as the abundance of 3-methylpropanoic acid, 3-methylbutanoic acid, 2-methylpentanoic acid, and 3-methylpentan-1-ol.

Characterisation of an (S)-linalool synthase from kiwifruit (Actinidia arguta) that catalyses the first committed step in the production of floral lilac compounds

Kiwifruit (Actinidia spp. Lindl.) flowers and fruit contain many compounds of interest to the flavour and fragrance industries. In particular, Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. flowers produce β-linalool and important derivatives thereof, including linalool oxides, lilac aldehydes, alcohols and alcohol epoxides. Dynamic headspace sampling of whole A. arguta flowers showed that the peak emission rate of linalool, lilac alcohols and lilac aldehydes occurred around 0800 hours. After solvent extraction, linalool levels remained constant throughout the day and night, but lilac alcohol levels peaked at noon. In whole flowers, linalool was found predominantly in pistils and petals, and the lilac compounds were found mainly in petals. Two highly homologous (96.6% nucleotide identity) terpene synthase cDNA sequences, AaLS1 and ApLS1, were isolated from A. arguta and Actinidia polygama (Sieb. et Zucc.) Maxim flower EST libraries respectively. Real-time PCR analysis revealed that AaLS1 was expressed constitutively throughout the day and night, and primarily in petal tissue. Functional analysis in Escherichia coli showed that AaLS1 and ApLS1 each encoded a linalool synthase which was confirmed by transient expression in planta. Enantioselective gas chromatography revealed that both terpene synthases produced only (S)-(+)-linalool. AaLS1, therefore, is likely to be the key enzyme producing the (S)-linalool precursor of the lilac alcohols and aldehydes in A. arguta flowers.

Fungal Biotransformation of (±)-Linalool

The biotransformation of (+/-)-linalool was investigated by screening 19 fungi. Product accumulation was enhanced by substrate feeding and, for the first time, lilac aldehydes and lilac alcohols were identified as fungal biotransformation byproduct using SPME-GC-MS headspace analysis. Aspergillus niger DSM 821, Botrytis cinerea 5901/02, and B. cinerea 02/FBII/2.1 produced different isomers of lilac aldehyde and lilac alcohol from linalool via 8-hydroxylinalool as postulated intermediate. Linalool oxides and 8-hydroxylinalool were the major products of fungal (+/-)-linalool biotransformations. Furanoid trans-(2 R,5 R)- and cis-(2 S,5 R)-linalool oxide as well as pyranoid trans-(2 R,5 S)- and cis-(2 S, 5 S)-linalool oxide were identified as the main stereoisomers with (3 S,6 S)-6,7-epoxylinalool and (3 R,6 S)-6,7-epoxylinalool as postulated key intermediates of fungal (+/-)-linalool oxyfunctionalization, respectively. With a conversion yield close to 100% and a productivity of 120 mg/L.day linalool oxides, Corynespora cassiicola DSM 62485 was identified as a novel highly stereoselective linalool transforming biocatalyst showing the highest productivity reported so far.

Floral Odors of Silene otites: Their Variability and Attractiveness to Mosquitoes

Inflorescence scent samples from nine populations of dioecious Silene otites, a plant pollinated by moths and mosquitoes, were collected by dynamic headspace extraction. Sixty-three scent samples were analyzed by gas chromatography-mass spectrometry. Out of 38 found, 35 compounds were identified, most of which were monoterpenoids, fatty acid derivatives, and benzenoids. Phenyl acetaldehyde was the most dominant compound in the majority of samples. The variability in scent composition was high, and population and sex differences were found. Nevertheless, wind tunnel experiments proved similar attraction of Culex pipiens pipiens biotype molestus mosquitoes to the inflorescence odor of S. otites of different populations, indicating that different blends are similarly attractive to mosquitoes. The electrophysiological responses of mosquitoes to the 12 most common and abundant odor compounds of S. otites differed. Linalool oxide (furanoid) and linalool evoked the strongest responses in male and female mosquitoes, and (Z)-3-hexenyl acetate was strongly active in females. Medium responses were evoked in males by (Z)-3-hexenyl acetate, in females by benzaldehyde and methyl salicylate, and in both sexes by lilac aldehyde, lilac alcohol, and linalool oxide (pyranoid).

Chirality and biosynthesis of lilac compounds in Actinidia arguta flowers

Biosynthesis of lilac compounds in ‘Hortgem Tahi’ kiwifruit ( Actinidia arguta) flowers was investigated by treating inflorescences with d 5-linalool. The incorporation of the deuterium label into 8-hydroxylinalool, 8-oxolinalool, the lilac aldehydes, alcohols, and alcohol epoxides was followed by GC-MS and enantioselective GC-MS. Both ( R)- and ( S)-linalool were produced naturally by the flowers, but 8-hydroxylinalool, 8-oxolinalool, and the lilac aldehydes and alcohols occurred predominantly as the ( S) and 5′( S)-diastereoisomers, respectively. The enantioselective step in the biosynthesis of the lilac aldehydes and alcohols was concluded to be the oxidation of linalool to ( S)-8-hydroxylinalool. In contrast, the lilac alcohol epoxides had a 5′( R):( S) ratio, the same as for linalool, which suggests that either these compounds are not synthesised from the 5′( S)-configured lilac aldehydes and alcohols, or that if indeed they are, then it is by an enantioselective step that favours utilisation of the 5′( R)-configured compounds.

Volatiles of the Inflorescences of the Madeiran Orchids, Goodyera macrophylla Lowe and Gennaria diphylla (Link) Parl. and Their Role in Pollination

Goodyera macrophylla, considered a rare endemic, and Gennaria diphylla are two native terrestrial Orchidaceae species that can be found mainly in Madeiran Laurisilva. The volatile compounds contributing to the floral scent of these two Madeiran orchids were analysed and compared for the first time. The volatiles, isolated by distillation-extraction in a Likens-Nickerson-type apparatus, and those extracted by headspace sorption, were analysed by GC and GC-MS. The main volatile components isolated by distillation-extraction were γ-terpinene (13%) and n-nonanal (11%) in G. macrophylla and n-octacosane (19%) and n-heptacosane (13%) in G. diphylla. The main volatile components isolated by headspace sorption were p-cymene (21%), α-pinene (15%) and linalool (14%) in G. macrophylla and cis-arbusculone (28%) and lilac alcohol (26%) in G. diphylla. The importance of the volatiles in the pollination of these orchids is discussed.

Aroma composition and new chemical markers of Spanish citrus honeys

Sixty six volatile compounds were detected in Spanish citrus honeys by GC–MS. Certain compounds appeared to be characteristic of this floral source, particularly high concentrations of terpenes and derivatives, such as linalool, ( Z) ( E)-linalool oxide, α-terpineol, terpineal and isomers of lilac aldehyde and lilac alcohol. Sinensal isomers are also proposed as new chemical markers for citrus honeys, since these compounds are present only in this floral source. OAV values suggested that these compounds contributed strongly to the characteristic aroma of citrus honeys.

Linalool and lilac aldehyde/alcohol in flower scents: Electrophysiological detection of lilac aldehyde stereoisomers by a moth

The stereoisomers of linalool and lilac aldehyde/alcohol were determined in the flower scent of 15 plant species using enantioselective multidimensional gas chromatography/mass spectrometry (enantio-MDGC/MS). Both linalool and all 8 stereoisomers of lilac alcohol and lilac aldehyde were detected, and there was a species-specific pattern. Single stereoisomers were collected by micropreparative-enantio-MDGC and were electrophysiologically tested on antennae of the noctuid moth Hadena bicruris, a species known to rely on lilac aldehyde for finding its host plant. The moth responded to all 8 stereoisomers, though only four stereoisomers were found in the scent of its host plant. The moth was less sensitive to some isomers than to others.