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This recommended practice enables the quantification of volatile compounds in flavourings to be made by gas chromatography with flame-ionization detection, without having authentic compounds available, and also in many cases it can avoid time-consuming calibration procedures. The relative-response factors (RRF) can be predicted from the molecular formula of the compound, and this approach can be applied to compounds containing the atoms C, H, O, N, S, F, Cl, Br, I, and Si, providing that the molecular formula and number of benzene rings in the analytes are known. The purity of chemically-defined flavouring substances or chromatographic standards can also be estimated using these predicted RRF, and this procedure can also be used to quantify (poly)hydroxylated compounds, after their derivatization into trimethylsilyl ethers or esters. Copyright © 2016 John Wiley & Sons, Ltd.

The leaves of Pogostemon cablin (Blanco) Benth. (Lamiaceae) are the source of patchouli essential oil, which is - with an annual production of about 1300 tonnes - an important and unique commodity in the fragrance industry. All the literature pertaining to patchouli was critically reviewed with an emphasis on the qualitative and quantitative chemical analysis of the oil but also harvesting, fermentation, drying, distillation, used analytical techniques, sensory aspects including molecules responsible for the odour, adulteration and toxicological aspects, i.e., skin sensitisation, are discussed. In total 72 constituents have been convincingly identified in the oil and another 58 tentatively. The main constituent is the sesquiterpene patchoulol. For this review over 600 papers were consulted and in the supplementary information all patchouli-related references not relevant enough to be cited in the paper itself are listed.

A comprehensive and critical compilation of the volatile constituents of vetiver root (Chrysopogon zizanioides L.) is presented, including those present in its essential oil. This extremely complex material has stimulated analytical research for many decades in the hope of unravelling the secrets of its composition. Up to now, more than 300 molecules have been reported, mostly sesquiterpenoids possessing a large variety of skeletons, together with their norterpenic counterparts. This review attempts to clarify some of the discrepancies related to the characterization of these constituents, which were often due to the misuses of analytical methods without enough critical consideration of the literature. The identification of the main odour impact components of vetiver is also discussed, because much contradictory information appears in the literature on this subject. Copyright © 2014 John Wiley & Sons, Ltd.

Many flavour regulations around the world contain a list of so-called ‘restricted substances’ (RS), i.e. substances that occur naturally in source materials for flavourings and food ingredients with flavouring properties, but whose presence in certain foods is restricted and/or for which maximum levels are set, for example, the European regulation 1334/2008. Only a few publications refer to the determination of RS in compound flavourings or their raw materials, and the latter only concern the analysis of one or two individual RS in single essential oils. The Working Group on Methods of Analysis of the International Organization of the Flavor Industry (IOFI) has developed a method for the rapid routine determination of β-asarone, coumarin, menthofuran, methylchavicol, methyleugenol, pulegone, safrole and α- and β-thujones in flavourings and their raw materials by gas chromatography-mass spectrometry (GC-MS), using selected-ion monitoring and internal standards. The method has been evaluated by nine flavour-industry laboratories using a complex surrogate flavouring containing all of the above analytes, at concentrations that would be likely to produce levels in finished foods of around typical maximum limits for these RS. Results were obtained from a total of 15 columns and sets of analytical conditions, using 11 GC/MS instruments, with in each case a determination of the analyte in two versions of the flavouring. With reproducibility relative standard deviations (RSDR) of less than about 20%, and recoveries of 80–120%, the method performance can be considered as satisfactory for rapid routine checks on the levels of restricted substances in compound flavourings. The method is intended for flavour-industry laboratories in order for them to fulfil their obligation to inform food-industry clients of the amounts of these substances in commercial flavourings, but is not intended for their analysis in finished foods. Copyright © 2014 John Wiley & Sons, Ltd.

Previous publications investigated different data treatment strategies for quantification of volatile suspected allergens by GC/MS. This publication presents the validation results obtained on “ready to inject” samples under reproducibility conditions following inter-laboratory ring-testing. The approach is based on the monitoring of three selected ions per analyte using two different GC capillary columns. To aid the analysts a decisional tree is used for guidance during the interpretation of the analytical results. The method is evaluated using a fragrance oil concentrate spiked with all suspected allergens to mimic the difficulty of a real sample extract or perfume oil. At the concentrations of 10 and 100 mg/kg, imposed by Directive 76/768/EEC for labeling of leave-on and rinse-off cosmetics, the mean bias is +14% and −4%, respectively. The method is linear for all analytes, and the prediction intervals for each analyte have been determined. To speed up the analyst's task, an automated data treatment is also proposed. The method mean bias is slightly shifted towards negative values, but the method prediction intervals are close to that resulting from the decisional tree.

Simultaneous distillation-extraction (SDE) combines, in a single step, hydro-distillation of volatiles from a sample with continuous solvent extraction of the solutes dissolved in the aqueous distillate. The solvent extract containing the isolated flavour volatiles can be subsequently analysed by gas chromatography. The technique is applicable to compounds possessing a wide range of volatility, but it is suitable neither for compounds of low volatility (e.g. vanillin), nor for highly volatile materials (e.g. methanethiol). The present guidelines concern the isolation of flavouring substances by simultaneous distillation-extraction (SDE), based on the experience of the authors in laboratories of the flavour industry. Copyright © 2014 John Wiley & Sons, Ltd.

A comprehensive review is presented on the constituents of the heartwood from fragrant sandalwood species, including Santalum album, S. spicatum and S. austrocaledonicum, which are important raw materials in the fragrance industry, and S. insulare, a closely related species. Analytical aspects are discussed in detail, both on qualitative and quantitative standpoints, and sensory properties are also reviewed. It is shown that more than 230 constituents have been identified so far in the heartwood of these sandalwood species. These components belong to many different chemical classes and are mainly terpenoids, but some other families are also represented. Copyright © 2010 John Wiley & Sons, Ltd.

This is a comprehensive review of extracts from the lichen Pseudevernia furfuracea (treemoss) that are used in the fragrance industry. Qualitative and quantitative analytical aspects are critically reviewed and the results are compared to those of the related oakmoss extracts. It is shown that more than 90 constituents have been identified so far in treemoss extracts, including 42 depsides, depsidones or depside-derived compounds, and 42 triterpenes or steroids. Constituents of certain host trees, mainly Pinus species, generate specific analytical and toxicological issues which need to be considered in addition to those related to the known degradation products of lichen compounds. A new classification of lichen extracts used as raw materials in fragrance compounding is proposed. Copyright © 2009 John Wiley & Sons, Ltd.

Volatile extracts of two wild cabbages, Brassica cretica and Brassica insularis, were studied by GC–MS, GC/FID, and GC–olfactometry/aroma extract dilution analysis (GC–O/AEDA). Major compounds were 3-butenyl cyanide (70% of the total GC/FID area) and 3-butenyl isothiocyanate (29%) in B. cretica and 2-phenylethyl cyanide (53%) and 2-phenylethyl isothiocyanate (21%) in B. insularis. AEDA revealed the impact of five heteroatomic trace compounds (diacetyl, methional, furfuryl thiol, 1-octen-3-one and skatole) with moderate to high flavour dilution (FD) factors that were detected only due to GC–O analyses. Copyright © 2008 John Wiley & Sons, Ltd.

International audience; Indian cress (Tropaeolum majus L.) absolute was studied by GC-olfactometry (VIDEO-Sniff method) in order to identify odor-active aroma compounds. Because of its fruity-sulfury odor note, a compound that has never been identified in plant extracts before stood out: O,S-diethyl thiocarbonate, present at 0.1% (percentage of the total GC/FID area) in the extract. GCxGC-TOFMS allowed for a clean mass spectrum to be obtained, and isolation by preparative GC followed by NMR studies allowed its identification. Here, we report on the first detection of O,S-diethyl thiocarbonate in Indian cress absolute by GC-olfactometry/VIDEO-Sniff and on its isolation and identification. The synthesis and odor evaluation of its homologues are presented.

For a long time, exotic scents from the islands of the South Pacific have universally been appreciated. Most frequently, fragrant flowers (e.g., frangipani, jasmine sambac, tiaré, pua kenikeni) are used locally for ornamental purposes such as flower garlands (leis). Despite their powerful and delightful fragrance, very few of these flowers have been commercially employed in this part of the world for perfume manufacturing. Creative perfumers are nevertheless strongly interested to better understand these fragrances and to use them, either genuine or artificially reconstituted. Analytical results on the fragrance of these flowers are reported, together with some economical considerations.

New, odorant nitrogen- and sulfur-containing compounds are identified in cress extracts. Cress belongs to the botanical order Brassicales and produces glucosinolates, which are important precursors of nitrogen- and sulfur-containing compounds. Those compounds often present low perception thresholds and various olfactive notes and are thus of interest to the flavor and fragrance chemistry. When the study of organonitrogen and organosulfur compounds is undertaken, Brassicale extracts are one of the matrices of choice. Cress extracts were studied by analytical (GC-MS, GC-FPD) and chemical (fractionation) means to identify new interesting odorant compounds. Two compounds that have never been reported in cress extracts, containing both nitrogen and sulfur, were discovered: N-benzyl O-ethyl thiocarbamate and N-phenethyl O-ethyl thiocarbamate. These two molecules being of organoleptic interest, their homologues were synthesized and submitted to organoleptic tests (static and GC-sniffing). Their odors evolve from garlic and onion over green, mushroom- and cress-like to fresh, spearmint-like. This paper presents the origin, chemical synthesis, and organoleptic properties of a series of O-alkyl thiocarbamates.

A method is described for the analysis of suspected volatile allergens in products containing high molecular weight or non-volatile compounds such as plant extracts, solid and liquid detergents, shampoos, etc. The method is based on dissolution/extraction of the sample followed by direct injection in a programmed temperature vaporizing inlet, the liner of which contains PDMS foam to retain the high molecular weight non-volatile material. The liner is automatically replaced after each injection, by an automated liner exchange device. Analysis is done by GC-MS operated in the retention-time locked mode. The figures of merit are illustrated with the analysis of some real samples.

The volatile flavor components of Mobola plum (Parinari curatellifolia), a native fruit of Southern Africa, have been isolated by a vacuum headspace concentration method. The concentrate was analyzed by hyphenated gas chromatographic techniques, including gas chromatography (GC)/mass spectrometry (MS) and GC/Fourier transform infrared (FTIR), together with other GC-coupled detection devices for the specific and selective detection of nitrogen- and sulfur-containing compounds. A total of 88 components were identified. Of these compounds, 12 contain nitrogen, including 2-aminobenzaldehyde and phenylacetaldoxime, which are detected for the first time in an edible fruit. In addition, two unusual nitrated compounds have been identified, including optically active (2-nitrobutyl)benzene, which is a new natural product. Quantitative and sensory data of the new compounds are provided.

Recent changes in European legislation require monitoring of 24 volatile compounds in perfumes as they might elicit skin sensitization. This paper reports a GC-MS quantitation procedure for their determination in fragrance concentrates. GC and MS conditions were optimized for a routine use: analysis within 30 min, solvent and internal standard selection, and stock solution stability. Calibration curves were linear in the range of 2-100 mg/L with coefficients of determination in excess of 0.99. The method was tested using real perfumes spiked with known amounts of reference compounds.

(-)-2,6-Dimethyl-10-(p-tolyl)-2,6(E)-undecadiene (1) is a major constituent in the essential oil of Cistus monspeliensis, an aromatic shrub common in Mediterranian countries. 1 was isolated by column chromatography, subjected to ozonolyses, and the absolute configuration was determined by enantioselective gas chromatographic correlation with the ozonolysis product of the sesquiterpene hydrocarbon ar-curcumene with known absolute configuration.

The synthesis of 2-mercapto-p-menth-8-ene (3) and 1-mercapto-p-menth-8-ene (4) are described, starting, respectively, from thioepoxydation of (+)-trans-limonene 1,2-epoxide (1a) and (+)-cis-limonene 1,2-epoxide (1b) via hydride reduction of episulphides 2a and 2b. Structural determination of these sulphur-containing terpenoids was achieved by one- and two-dimensional NMR spectroscopy. The odours of these two new monoterpene thiols were described, respectively, as reminescent of grapefruit juice and as being typically alliaceous. Copyright © 2002 John Wiley & Sons, Ltd.

Photochemical acetylthiolation of (-)-sabinene 1 afforded 10-acetylthiothujane 2 and an unexpected cyclopentenyl methyl thioacetate 3 in moderate yield (24%). Hydride reduction of these two latter compounds gave two monoterpenoid thiols ( 2a and 3a ) in excellent yield (95%). The odour of the major sulfur-containing compounds 2 and 2a was respectively described as being typically anisic and as reminiscent of cooked leek. Structural determination of these derivatives was achieved by one- and two-dimensional NMR spectroscopy.

Photochemical thioacetylation of (s−)- i -cadinene 1 afforded 5-acetylthio-cadinene 1a which was further reduced into 5-mercapto-cadinene 1b in good yield (80%). Thioepoxydation of trans -1,10-cadinene oxide 1c , prepared from m -CPBA oxidation of 1 , was also investigated. Structural determination of these derivatives was achieved by one- and two dimensional NMR spectroscopy.

The components in essential oils of Dalmatian sage, Salvia officinalis L., were identified by 1 H- and 13 C-NMR spectroscopy and by GC-MS. The diterpene manool was identified for the first time in steam-distilled oil from Dalmatian sage. Several sesquiterpenes were also identified for the first time in Dalmatian sage oils. A rapid GC method was developed and used to analyse 13 oils from a preliminary study of Dalmatian sage accessions. Oil yields from pilot-scale distillations in summer were significantly higher from non-flowering accessions than from flowering accessions. Oils from flowering and non-flowering accessions had different compositions, with significantly higher levels of thujones, β-caryophyllene and viridiflorol in oils from flowering accessions

Yeast extract-mediated reduction of 4-(4-hydroxyphenyl)-but-3-en-2-one 3 to raspberry ketone 1 occurs with transfer β to the carbonyl group of HR from NADPH and of an hydrogen atom from the solvent at α position, as indicated by experiments with (4R) and (4S) [4-2H]-NADPH and with deuterated solvent. The same extract converts 3 in 1 in the presence of NADH, but much less efficiently. In this latter case HS and not HR is transferred from the reduced cofactor to position 4 of 1. Horse liver alcohol dehydrogenase-mediated reduction of 1, bearing deuterium labelling at positions 1, 3 and 4 and obtained from 3 using the whole-cell system in the presence of D2O, gave an S carbinol possessing 0.95 ee, shown by 2H NMR studies onto the diacetate 7 to contain an excess of the (3S,4S) diastereoisomer, thus suggesting a prevalent β re-face.syn addition of hydrogen across the double bond of 3 in the whole-cell mediated conversion into 1

Feeding experiments in Beauveria bassiana (ATCC 7159) of (2R,3S)-[2,3-2H2]-4-(4-hydroxyphenyl)butan-2-ol (15) and (2R,3R)-[1,3-2H4]-4-(4-hydroxyphenyl)-butan-2-ol (16) afford (1S)- and (1R)-[1-2H]tyrosol (17) and (18), respectively, as indicated by NMR studies on the (+)-MTPA esters 21 and 23 and comparison with an authentic sample of the (S) enantiomer. These results indicate that the C-2, Baeyer-Villiger-type, chain shortening of the C-6−C-4 framework of the intermediate raspberry ketone 1 to give the C-6−C-2 tyrosol (4) occurs with retention of configuration. The asymmetrically labeled substrates 15 and 16 have been obtained by enzymic resolution of derivatives of (2SR,3RS)-6 and (2SR,3SR)-12, prepared, in turn, by syn catalytic reduction with deuterium and with hydrogen gas, respectively, of the (Z) enol acetates 5 and 11.

In growing cultures of the fungus Beauveria bassiana (ATCC 7159) the incubation of 4-(4‘-hydroxyphenyl)but-3-en-2-one (p-hydroxybenzylidenacetone, 3), of 4-(4‘-hydroxyphenyl)butan-2-one (raspberry ketone, 1), and of the S and R,S forms of 4-(4‘-hydroxyphenyl)butan-2-ol (2) yields 2-(4‘-hydroxyphenyl)ethanol (tyrosol, 4) as a final product. The experiments support the view that the actual substrate for the Baeyer−Villiger-type degradation is raspberry ketone (1) and that there is a kinetic preference in the microbial enzymatic system for the oxidation to 1 of the S form of the 4-(4‘-hydroxyphenyl)butan-2-ol (2). Keywords: Raspberry ketone; tyrosol; degradation; Beauveria bassiana; Baeyer−Villiger oxidation; stereochemistry

The absolute prepared from an Indian commercial concrete from flowers of Jasminum auriculatum Vahl was examined. Column and molecular distillations, column chromatography and chemical function separations were carried out. GC-MS and GC-FTIR of numerous fractions thus obtained allowed the identification of 198 compounds. Among them, methyl, ethyl, (Z)-hex-3-enyl, benzyl, 2-phenylethyl and (E,E)-farnesyl esters were found, in addition to phenols and nitrogen compounds.

International audience; Indian cress (Tropaeolum majus L.) has been consumed in salad or soup for decades, but its odor's detailed molecular composition is still unknown. Here we report on the study of the odorant profile and odor-impact compounds of Indian cress absolute by GC-olfactometry/vocabulary-intensity-duration of elementary odors by sniffing (GC-O/VIDEO-Sniff) on an eight-way multiport system, combined with GCxGC-MS analyses for the identification of odorant trace constituents. Odor impact compounds of Indian cress absolute were determined by GC-O, and the overall influence of sulfury and fruity notes stood out. Forty-four odorant compounds were identified among which 22 (50% of the identified odorant molecules) were identified by using comprehensive two-dimensional GC coupled to a time-of-flight-mass spectrometer (TOFMS). These trace compounds were not detected by 1D-qMS or could only be found with specific searches once they were detected by comprehensive 2D-GC, although they were well perceived by the judges in GC-O. This was amongst others the case for the two molecules having the highest odor impact, (E)-hex-2-enal (fruity) and diethyl trisulfide (alliaceous, sulfury, cabbage). A powerful sulfur-containing odor compound whose first identification in cress was recently reported by the authors was detected by GC-O: O,S-diethyl thiocarbonate (fruity/red fruit and sulfury odor)

A comprehensive review is presented on extracts of a lichen, oakmoss (Evernia prunastri), that are used in the fragrance industry. Analytical aspects are discussed in detail, from both qualitative and quantitative standpoints, mainly in relation to the industrial processing of the lichen. It is shown that more than 170 constituents have been identified so far in oakmoss extracts, including 47 depsides or depside-derived compounds and 25 triterpenes or steroids. A survey of industrially relevant synthetic products with an oakmoss odour is included. Toxicology issues related to the use of oakmoss extracts in cosmetics and fragrance formulations are critically reviewed.

International audience; Odor impact compounds of Tagetes minuta L. essential oil were studied by gas chromatography (GC)-olfactometry using aroma extract dilution analysis (AEDA) and vocabulary-intensity-duration of elementary odors by sniffing (VIDEO-Sniff). AEDA was conducted by direct injection and revealed the presence of 43 odorant zones. Highest flavor dilution (FD) values were obtained for ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, (E)-ocimenone, two tentatively identified thiols, and two yet unknown compounds. VIDEO-Sniff was realized by dynamic headspace sampling (D-HS) combined with 8W-GC-olfactometry where eight sniffers simultaneously detect volatile compounds obtained from a single chromatographic separation and revealed the presence of 42 odorant zones. Odorant trace compounds detected by GC-O that were present in quantities inferior to the GC-qMS system’s detection limit and those subject to coelutions were identified by GC×GC-time-of-flight mass spectrometry (TOFMS). A total amount of 37 odorant components could be identified by VIDEO-Sniff, and the strong influence of the fruity notes of numerous esters stood out. Highest olfactory signals were obtained for ethyl 2-methylpropanoate, ethyl 2- and 3-methylbutanoate, and oct-1-en-3-one. Both methods hence come to the conclusion that ethyl 2-methylpropanoate and ethyl 2- and 3-methylbutanoate are among the main odorants in Tagetes minuta L. essential oil. Differences, advantages, and drawbacks of both GC-O methods are discussed.

Different 3-alkyl-p-methan-3-ol derivatives provide a strong physiological cooling effect with potential application as food and cosmetic additives. In order to investigate the influence of the chemical structure on the cooling sensation, the stereoselective syntheses of 29 different 3-alkyl-p-methan-3-ol derivatives were accomplished. All the compounds obtained are odorless and were evaluated by taste, considering two sensations: a cooling effect and bitterness. The results of this structure–activity relationship study highlight that compounds with a (1R,4S)-configuration are the isomers with the more intense cooling effect and lower bitterness. In addition, the structure of the 3-alkyl chain affected the latter properties. Increasing the chain length over two carbon atoms does not change the cooling power, but enhances the bitterness with the additional feature that the branched isomers are considerably more bitter than the linear ones. Overall, the 3-alkyl-p-menthan-3-ol isomers with the best quality in terms of high cooling power and low bitterness are (1R,4S)-3-(hydroxymethyl)-p-menthan-3-ol diastereoisomers (−)-38 and (−)-42.

This article reviews papers published during the period 1982-88 on the headspace of medicinal and aromatic plants and flowers. Articles reported in Chemical Abstracts, the bibliography section of the Journal of Chromatography and Analytical Abstracts are discussed. Considering the large number of publications on this topic which have appeared in the literature over this period, we apologize in advance for any articles which may have been overlooked. Flower headspace analysis is treated as an especially dedicated subject, considering the peculiarity and specificity of this topic.

The performances of the GC-MS determination of suspected allergens in fragrance concentrates have been investigated. The limit of quantification was experimentally determined (10 mg/L), and the variability was investigated for three different data treatment strategies: (1) two columns and three quantification ions; (2) two columns and one quantification ion; and (3) one column and three quantification ions. The first strategy best minimizes the risk of determination bias due to coelutions. This risk was evaluated by calculating the probability of coeluting a suspected allergen with perfume constituents exhibiting ions in common. For hydroxycitronellal, when using a two-column strategy, this may statistically occur more than once every 36 analyses for one ion or once every 144 analyses for three ions in common.

The first part of this study first aims at validating a method to identify suspected allergens limited by EU regulations in fragrances by comprehensive two-dimensional gas chromatography (GC x GC) coupled with rapid scanning quadrupole MS (GC x GC-qMS). The effectiveness of the quadrupole MS operating at different scanning speed (1000 and 11,111 amu/s) was evaluated in identifying (full scan mode acquisition--TIC) and in quantifying (single ion monitoring--SIM) the target analytes in complex mixtures. In full scan acquisition mode the mass range was reduced to 40-240 amu to increase the scan acquisition rate while in SIM mode the influence of different dwell-times (40, 10 and 5 ms) was tested. The number of scans for each single modulated chromatographic GC x GC peak and the total number of scans for the 2D peak, together with half height peak width (referred to apex) of each allergen in the standard mixture in both TIC and SIM modes were determined. Moreover, the match quality of the spectra obtained by GC/MS at 1000 and 11,111 amu/s and by GC x GC-MS at 11,111 amu/s were compared and the occurrence of spectral skewing verified. In the second part of this work quantitative methods by GC x GC-SIM/qMS and GC x GC-FID were validated on the basis of Eurachem/CITAC protocols through which the following performance parameters were determined: confirmation of identity, selectivity and specificity, limit of detection (LOD), limit of quantitation (LOQ), linearity (working and linear range), precision and accuracy and uncertainty. Suspected allergens were spiked in a concentration range between 2 and 25 ppm (microg/mL) on a Test fragrance taken as a reference, while 1,4 dibromo-benzene and 4,4'-dibromodiphenyl were used as internal standards.

The mode of reduction through fermenting baker's yeast and Hansenula anomala CBS 110 of 4-phenylbut-3-en-2-ones 7-9 has been studied. The ratio between saturated ketones 1-3, saturated carbinols 4-6 and starting materials 7-9 depends upon the microorganism used and the incubation period. When using as substrate ketone 7, obtained from natural precursors and baker's yeast as reducing agent, up to 80.5% of natural raspberry ketone 1 is obtained.

(-)-2,6-Dimethyl-10-(p-tolyl)-2,6(E)-undecadiene (1) is a major constituent in the essential oil of Cistus monspeliensis, an aromatic shrub common in Mediterranian countries. 1 was isolated by column chromatography, subjected to ozonolyses, and the absolute configuration was determined by enantioselective gas chromatographic correlation with the ozonolysis product of the sesquiterpene hydrocarbon ar-curcumene with known absolute configuration.

The site-specific natural abundance deuterium distribution of raspberry ketone 3 obtained through a variety of methods has been determined through (2)H NMR spectroscopy. This technique provided a means of distinguishing between "natural" raspberry ketones biogenerated from 4-hydroxybenzalacetone (2), obtained from 4-hydroxybenzaldehyde of extractive botanical origin and acetone produced by sugar fermentation by reduction using baker's yeast and other microorganisms, and other raspberry ketone samples obtained in different "non-natural" ways. Of natural origin is also a commercial sample obtained in an unspecified manner. A mechanistic interpretation has been proposed to explain the difference of site-specific deuterium content between the examined samples.

Forty-one compounds have been identified in the essential oil of Ruta angustifolia. Besides the already known compounds, seven derivatives possessing the 3,4-methylenedioxyphenyl moiety were identified, including piperonyl acetone and a novel olefinic derivative 8-(3,4-methylenedioxyphenyl)-1-octene.

Four sesquiterpenes (1-4) with the africanane skeleton [of which only 5-africanene (1) has been previously reported] and the new asteriscane derivative asterisca-3(15),6-diene (5) were isolated from the essential oil of Lippia integrifolia. A further new compound, african-2(6)-ene (7), was obtained as a semisynthetic product by derivatization of isoafricanol (6). The structures of the new compounds were assigned on the basis of spectroscopic data, enantioselective gas chromatography, and by chemical correlations.

A targeted search for heliotropin (or piperonal) in the flower fragrance of heliotrope and in cured vanilla beans of Tahitian origin is reported. Heliotropin is not detected in the fragrance emitted by heliotrope, using dynamic headspace SBSE sampling, followed by thermal desorption and analysis by conventional GC-MS. Main constituents are anisaldehyde and benzaldehyde, which confirms previous findings. Less than one part per million of heliotropin is accurately detected in authentic Tahitian vanilla bean, in using both GC-MS and LC-MS/MS. This confirms previous observations, which had shown that 4-methoxyaromatic compounds are the characteristic elements in the flavor of Tahitian vanilla, with p-anisaldehyde as the the main aroma donator. We suggest that heliotropin was named after the discovery of piperonal by degradation of piperine, the odor of which was reminiscent of the heliotrope flower. Later, its identification in vanilla extracts was the result of either a wrong interpretation of analytical data, or, much more probably, adulterations of these extracts. As a result, heliotropin should not be cited any longer as a characteristic consituent of Tahitian vanilla.

Among the character-donating components of the fragrance of Wisteria sinensis flowers, two new β-chromenes were detected by GC-MS and GC-FTIR of

The essential oil of Ruta graveolens produced in Malaysia was subjected to analysis by GC/MS. Thirty compounds representing ca. 82% of the oil were identified. The major compounds were 2-undecanone (30.73%), 2-nonanone (18.06%) and 2-nonyl acetate (11.03%). Psoralen (1.28%) and bergaptene or xanthotoxin (7.24%) also were identified in the oil.

The fragrance given off by certain springtime flowers was the subject of a previous communication. We now present the results from further analyses of flower headspaces from cultivated and wild plants (including trees), which bloom at the end of spring and in summer in the Grasse region: Sambucus nigra L. (elder), Ligustrum ovalifolium (privet), Ligustrum vulgare L. (common-privet), Ailantus glandulosa Desf., Magnolia grandiflora L. and Trachelospermum jasminoides. We bring further information about the composition of the headspace from Philadelphia coronarius L. flowers (seringat), which were only briefly reported in our first communication. We confirm that the odoriferous emissions from flowers contain some chemical substances which are not readily detected in the corresponding extraction or hydrodistillation products. Such constituents include, for example, terpenoids and aliphatic amino acid derivatives, some of which may be considered as new natural products.