Chemosystematic Studies Research Articles

Phytochemical and Chemotaxonomic Investigations on Coussapoa Microcarpa (Cecropieae, Urticaceae)

Background: The Coussapoa genus (Urticaceae, tribe Cecropiae) contains 50 species mainly distributed throughout the Neotropical Region. Although some genera belonging to the Cecropiae tribe have been well-assessed, the chemical profile of Coussapoa members has not yet been investigated. Objective: In this context, the aim of the present study was to characterize phenolic substances present in a methanol extract obtained from Coussapoa microcarpa leaves employing UPLC-DAD-ESI-MS analyses Methods: Several condensed tannins (epi-afzelechin-epi-catechin, B-type and C-type procyanidins), flavan-3-ols ((+) -catechin and (-) - epicatechin), phenolic acid (O-caffeoylquinic acid) and C-glycosyl flavones (orientin, isoorientin, vitexin, isovitexin, isoorientin-2″-O-rhamnoside,vitexin-2″-O-hexoside, vitexin-2″-O-xyloside and isovitexin-2″-O-xyloside) were identified. Results: The determined chemical profile observed for C. microcarpa exhibits chemo-taxonomic significance compared to other neotropical genera. Conclusion: Structural variability of the identified secondary metabolites is of significant value for chemosystematic studies concerning the Coussapoa genus and the Cecropiae tribe, both still unexplored regarding their chemodiversity.

Untargeted Metabolomics Sheds Light on the Diversity of Major Classes of Secondary Metabolites in the Malpighiaceae Botanical Family.

Natural products produced by plants are one of the most investigated natural sources, which substantially contributed to the development of the natural products field. Even though these compounds are widely explored, the literature still lacks comprehensive investigations aiming to explore the evolution of secondary metabolites produced by plants, especially if classical methodologies are employed. The development of sensitive hyphenated techniques and computational tools for data processing has enabled the study of large datasets, being valuable assets for chemosystematic studies. Here, we describe a strategy for chemotaxonomic investigations using the Malpighiaceae botanical family as a model. Our workflow was based on MS/MS untargeted metabolomics, spectral searches, and recently described in silico classification tools, which were mapped into the latest molecular phylogeny accepted for this family. The metabolomic analysis revealed that different ionization modes and extraction protocols significantly impacted the chemical profiles, influencing the chemotaxonomic results. Spectral searches within public databases revealed several clades or genera-specific molecular families, being potential chemical markers for these taxa, while the in silico classification tools were able to expand the Malpighiaceae chemical space. The classes putatively annotated were used for ancestral character reconstructions, which recovered several classes of metabolites as homoplasies (i.e., non-exclusive) or synapomorphies (i.e., exclusive) for all sampled clades and genera. Our workflow combines several approaches to perform a comprehensive evolutionary chemical study. We expect it to be used on further chemotaxonomic investigations to expand chemical knowledge and reveal biological insights for compounds classes in different biological groups.

Comparative assessment of the amino acids content of some legumes species in Southern Ukraine

The data on the composition and amount of amino acids have been analyzed in the raw materials of five legume species. All of them grow in Southern Ukrainian flora (Securigera varia (L.) Lassen, Vicia cracca L., Lupinus luteus L., Melilotus officinalis (L.) Pall., Melilotus albus Medic.) and may be used as a source of amino acids, especially essential, whose resource has to be replenished from the outside. Aim. We have studied and compared the amino acid profile of some species of the Ukrainian South Legumes, and used the multidimensional statistical cluster analysis to construction of histograms based on the amino acids content and composition of such plants as: Securigera varia (L.) Lassen, Vicia cracca L., Lupinus luteus L., Melilotus officinalis (L.) Pall., Melilotus albus Medic. Materials and methods. The raw materials were harvested at the South of Ukraine and were investigated by gas-liquid chromatography. The amino acid analyzer has been used after hydrochloric acid hydrolysis at elevated temperature. Results. 19 amino acids have been identified, of which nine are essential or partially interchangeable. The non-polar amino acid proline is in the lead in terms of quantity among the essential amino acids. Its amount was 6932 mg/100 g and the ability to accumulate it was noted in Melilotus officinalis (2276 mg/100 g). The smallest proline amount was found in Lupinus luteus (388 mg/100 g). The sulfur-containing non-polar amino acid methionine is in the smallest amount in the selected plants (506 mg/100 g). Our attention was drawn to the absence of the polar amino acid glutamine among the non-essential amino acids in some plants. Securigera varia, Vicia cracca, and Melilotus officinalis did not contain glutamine. In this subgroup, the polar aspartic acid was found in the highest amount (6824 mg/100 g) with the highest content in Vicia cracca and the lowest – in Melilotus albus (2660 mg/100 g and 385 mg/100 g, respectively). Conclusions. The analysis of the presence and number of amino acids was the basis for our multidimensional statistical cluster analysis and histograms of the presentation of the amino acid profile of the studied plant members of the family Fabaceae L. In constructing the dendrogram, three clusters were identified, and representatives of one genus (Melilotus L.) were attributed to different clusters which is significant for further chemosystematic studies.

Chemosystematically valuable triterpenoid saponins from Glandularia x hybrida

Phytochemical investigation of the ethanolic extract of Glandularia x hybrida roots resulted in the isolation and identification of five previously undescribed saponins, 3-O-β-ᴅ-xylopyranosyl-hederagenin-28-O-β-ᴅ-glucopyranosyl (1→2)-O-β-ᴅ-glucopyranosyl ester, 3-O-β-ᴅ-xylopyranosyl-hederagenin-28-O-β-ᴅ-glucopyranosyl (1→2)-[β-ᴅ-glucopyranosyl (1→6)]-β-ᴅ-glucopyranosyl ester, hederagenin-28-O-β-ᴅ-glucopyranosyl (1→2)-[β-ᴅ-glucopyranosyl (1→6)]-β-ᴅ-glucopyranosyl ester, 23-O-acetyl-3-O-β-ᴅ-xylopyranosyl-pomolic acid-28-O-β-ᴅ-glucopyranosyl ester, and 23-O-acetyl-pomolic acid-3-O-β-ᴅ-xylopyranoside, along with eleven structurally diverse compounds. The structural characterizations of the isolated compounds were determined using physical data, comprehensive 1D and 2D NMR spectral analysis, and HRESIMS. All isolated saponins are hederagenin or pomolic acid glycosides conjugated with differentiable sugar units bound to C-3 and/or C-28 of the aglycone through ether and/or ester glycosidic linkages, respectively. Structural diversity of these isolated secondary metabolites would have a great impact on the future chemosystematic studies of this plant. Four saponins, obtained in good yield were evaluated for their anti-inflammatory activities in a rat model using the carrageenan-induced paw edema protocol. Two of these exhibited significant anti-inflammatory activities demonstrated through inhibition of the paw edema by 64 and 60%.

The ethnobotany and major essential oil compounds of anise root (Annesorhiza species, Apiaceae)

A comprehensive review of indigenous knowledge about a traditional Cape, San and Khoi food item called anise root or anyswortel (genus Annesorhiza) is presented. The first accurate record was by Thunberg in 1772 at the Berg River near Vlermuisdrift (now Bridgetown) in the Western Cape and applied to A. grandiflora. Four species have recorded food uses as root vegetables (A. grandiflora, A. macrocarpa, A. nuda and an as yet undescribed species from Namaqualand) and two species (A. nuda and A. flagellifolia) as leaf vegetables. Essential oils of this genus were studied for the first time. Hydro-distilled oil from the fleshy roots, leaves and fruits of three species recorded as edible (A. grandiflora, A. macrocarpa and A. nuda) were chemically characterized using GC–MS and NMR spectroscopy. Noteworthy differences were found between plant parts as well as species. Estragole and a small amount of anethole occur in the roots of A. nuda (but not in any of the other two species). The major components of A. grandiflora fruits were dillapiole, nothoapiole and limonene, while elemicin was identified in the roots of the same species. Fruits of A. macrocarpa contained methyleugenol, the leaves ethyl-benzenes and α-terpineol, whereas the roots yielded nerolidol and an unidentified sesquiterpene. In contrast, leaves and roots of A. nuda were quite similar with the exception of the occurrence of estragole and anethole in roots only and not in the leaves. This partially explains the reported anise flavor of the edible roots of this species. The main compound of both roots and leaves of A. nuda was butan-2-yl (2Z)-3-(methylsulfanyl) prop-2-enoate, a new trans-β-methylthioacrylate derivative. This α, β-unsaturated methylsulfanyl ester, colloquially named (−)-nudaic ester, was characterized and assigned using 2D-NMR spectroscopy. The pronounced chemical differences between the examined species require further chemosystematic studies and the differences between roots, leaves and fruits may reflect the distinct vegetative (winter) and reproductive (summer) growth phases in these summer-deciduous plants.

Phytochemical Analysis of Podospermum and Scorzonera n-Hexane Extracts and the HPLC Quantitation of Triterpenes.

Previously tested n-hexane extracts of the Scorzonera latifolia showed promising bioactivity in vivo. Because triterpenes could account for this activity, n-hexane extracts were analyzed by HPLC to identify and quantify the triterpenes as the most abundant constituents. Other Scorzonera and Podospermum species, potentially containing triterpenic aglycones, were included in the study. An HPLC method for simultaneous determination of triterpene aglycones was therefore developed for analysis of Podospermum and Scorzonera species. n-Hexane extracts of root and aerial parts of S. latifolia, ten other Scorzonera species and two Podospermum species were studied to compare the content of triterpenes. HPLC was used for the qualitative and quantitative analysis of α-amyrin, lupeol, lupeol acetate, taraxasteryl acetate, 3-β-hydroxy-fern-7-en-6-one acetate, urs-12-en-11-one-3-acetyl, 3-β-hydroxy-fern-8-en-7-one acetate, and olean-12-en-11-one-3-acetyl. Limits of detection and quantification were determined for each compound. HPLC fingerprinting of n-hexane extracts of Podospermum and Scorzonera species revealed relatively large amounts of triterpenes in a majority of investigated taxa. Lupeol, lupeol acetate, and taraxasteryl acetate were found in a majority of the species, except S. acuminata. The presence of α-amyrin, 3β-hydroxy-fern-7-en-6-one-acetate, urs-12-en-11-one-3-acetyl, 3β-hydroxy-fern-8-en-7-one-acetate, and olean-12-en-11-one-3-acetyl was detected in varying amounts. The triterpene content could correlate with the analgesic and anti-inflammatory activity of Scorzonera, which was previously observed and Scorzonera species that have been determined to contain triterpenes in large amounts and have not yet been tested for their analgesic activity should be tested for their potential analgesic and anti-inflammatory potential. The presented HPLC method can be used for analysis of triterpene aglycones, for example dedicated to chemosystematic studies of the Scorzonerinae.

GC/MS Fingerprinting of Solvent Extracts and Essential Oils Obtained from Liverwort Species

Studies concerning chemical profiling of the volatiles present in the solvent extracts from liverworts help to determine inter- and intraspecific relationships in this plant group. Due to the fact that the liverworts are morphologically very small and it is difficult to collect their sufficient amounts, there are still a few data concerning the chemistry of essential oils. The available data indicate however, that the components present in the essential oils can be used in chemosystematic studies of these spore-forming plants. Compounds occurring in the essential oils constitute a powerful tool for studying chemical differences between or within liverwort species for which the characteristic components are mono- and sesquiterpenoids. Good results were obtained for the liverworts species from the genera Asterella, Conocephalum, Diplophyllum, Jungermannia, Lepidozia, Radula, Reboulia or Scapania.

Chemotaxonomic value of essential oil components in liverwort species. A review

AbstractA number of liverwort species are known to emit volatile terpenoids and simple aromatic compounds when crushed. The characteristic odour of these spore‐forming plants is associated with oil body constituents. Secondary metabolites, which constitute the oil bodies, are also of value for taxonomic investigations. Liverworts have yielded a rich array of secondary metabolites. Many of these compounds are characterized by unique structures, and some of them have not been found in any other plants, fungi, or marine organisms. Gas chromatographic profiling of the volatile extracts obtained from the liverworts has been applied with success in differentiating liverworts species, and also used to resolve the taxonomic problems at genus and family level. Due to the fact that liverworts are morphologically very small and it is difficult to collect a sufficient amount of plant material, there are few research data on the composition of the essential oils obtained from these plants. Nevertheless, the available data indicate that, as in the case of aromatic plants, the components present in essential oils obtained from the liverworts can be used in chemosystematic studies of this plant group. The aim of this paper is to show whether: (i) there are differences in the essential oils composition between different liverwort species; (ii) it is possible to find chemical markers characteristic for the analysed liverwort species; and (iii) the data derived from an analysis of the essential oils are in accordance with the data received from volatile extracts. Copyright © 2015 John Wiley & Sons, Ltd.

Saccharopolyspora indica sp. nov., an actinomycete isolated from the rhizosphere of Callistemon citrinus (Curtis)

A novel actinomycete strain, designated VRC122T, was isolated from a Callistemon citrinus rhizosphere sample collected from New Delhi, India, and its taxonomic status was determined by using a polyphasic approach. Strain VRC122T was a Gram-stain-positive, aerobic, non-motile, non-acid-alcohol-fast strain. Phylogenetic analysis based on 16S rRNA gene sequences showed the strain was placed in a well-separated sub-branch within the genus Saccharopolyspora. The highest levels of 16S rRNA gene sequence similarity were found with Saccharopolyspora hirsuta subsp. kobensis JCM 9109T (98.71%), Saccharopolyspora antimicrobica I05-00074T (98.69%) and Saccharopolyspora jiangxiensis W12T (98.66%); 16S rRNA gene sequence similarities with type strains of all other species of the genus Saccharopolyspora were below 98%. Chemosystematic studies revealed that it contained meso-diaminopimelic acid. Arabinose and galactose were the predominant whole-cell sugars. Diagnostic polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylcholine. MK-9(H6) was the predominant menaquinone. C14:0, C16:0, iso-C15:0, iso-C16:0, iso-C17:0, anteiso-C15:0, anteiso-C17:0, C17:0 cyclo and summed feature 3 (C16:1ω7c and/or C16:1ω6c) were the major cellular fatty acids. The G+C content of the genomic DNA was 69.5 mol%. The results of DNA-DNA hybridization (30%, 22% and 25%, respectively) with type strains of the above-mentioned species, in combination with differences in physiological and biochemical data supported that strain VRC122T represents a novel species of the genus Saccharopolyspora, for which the name Saccharopolyspora indica sp. nov., is proposed. The type strain is VRC122T (=KCTC 29208T=MTCC 11564T=MCC 2206T=ATCC BAA-2551T).

Temporal characteristics of a natural products in-house database

In the era of Big Data it is necessary to transform data into knowledge so that information has high value gain. In this context, our research group AsterBioChem wishes to contribute for this Big Data in the field of natural products. A newly developed in-house database of plants from South American Asteraceae called AsterDB (AsterBioChem Database) comprises diverse chemical structures and additional information of compounds isolated by AsterBioChem members. The AsterDB has taxonomic information, biological activities and structural information. This database can be used for chemosystematic studies, extract dereplication, QSAR and QSRR studies. In this work we describe a QSRR study involving sesquiterpene lactones from AsterDB. The chromatographic information comprises logarithm of retention factor obtained from experimental retention times using reversed phase analytical C-18 column in isocratic elution (MeOH-H2O 1:1 and 3:7 MeCN-H2O). The 2D and 3D descriptors were calculated using softwares PaDEL, Adriana. Code, Dragon and MOE. Pre-processing of the descriptors was carried out with the Caret's package from R. Four procedures for descriptor selection were used: genetic algorithm (GA), forward selection, best first and greedy stepwise. Artificial neural networks (ANN) with the backpropagation algorithm and partial least squares (PLS) were used as modeling tools. More than 300 models were built using different combinations of training and test sets. The best models were selected and those with overfitting and external validation with Q2ext< 0.7 were discarded. The best model for MeCN was obtained by PLS/GA using 2D descriptors (R2= 0.96, Q2= 0.92 and Q2ext = 0.91) and that for MeOH was obtained by ANN/GA using 3D descriptors (R2= 0.91, Q2= 0.88 and Q2ext = 0.80). This QSRR modeling showed that AsterDB is able to transform data into knowledge for future use in dereplication of secondary metabolites from plant extracts.

Phytochemistry reviews: special issue on high altitude plants

The underlying theme of a the joint symposium organised by the Austrian Pharmaceutical Society and the Phytochemical Society of Europe was the highly specialised plants, lichens and fungi from distinct habitats at high altitudes. This symposium took place at the University of Innsbruck Centre in Obergurgl, Tyrol, Austria, April 26–29, 2009 at a time of year where there was still considerable snow in the village and on the upper slopes. The organisms that live in this harsh environment are influenced in their development by ecological factors including a short vegetation period, low temperatures and extensive temperature extremes, high UV-light impact, increased winds and of course considerable snow pressure. These factors lead to a high degree of biodiversity and a high diversity of unique secondary metabolites as a chemical response to these challenges. An international group of experts in the fields of phytochemistry, biology and pharmacology met in Obergurgl to discuss ‘‘Plants from High Altitude— Phytochemistry and Bioactivity’’ and this covered phytochemical, chemo-ecological, ethnomedicinal and pharmacological aspects as well as cultivating and breeding issues of high mountain plants and related organisms. This special issue of Phytochemistry Reviews resulted from this symposium and presents recent work and provides views of this exciting research area from different angles which has rarely been covered before. Chemosystematic studies on Scorzonera, Arnica and Matricaria species (Asteraceae) provided highly interesting insights into the trends and causes of altitudinal variation of phenolic compounds. Due to its vertical spread, comparative studies on samples of Calluna vulgaris collected from wild populations at different altitudes were possible and investigations of markers of altitudinal variation among flavonoids and phenolic acids could be performed. More than 40 species of Mallotus, a genus of high medicinal potential of the Euphorbiaceae family, are found in mountainous regions of Vietnam. An up-todate picture concerning their phytochemistry and biological properties has been drawn in the review included in this special issue. In contrast to widely used Hypericum perforatum—St. Johns Wort, Hypericum species of the Paramos regions of Central and South America are rarely studied. In addition to an analysis of their phytochemistry, the viable and sustainable collection The authors Franz Bucar and Simon Gibbons contributed equally.

Chemosystematic studies of Nitraria retusa and selected taxa of Zygophyllaceae in Egypt

Nitraria retusa (Forssk.) Asch. was subjected to botanical and chemical studies and compared against four selected taxa of Zygophyllaceae viz., Fagonia arabica L., Peganum harmala L., Tribulus terrestris L. and Zygophyllum album L.f. The botanical section included the study of morphological and anatomical characters of both vegetative and reproductive organs using LM and scanning electron microscope. The chemical section included a detailed study of the flavonoids present in N. retusa. Twelve compounds were isolated and identified as flavone, flavonol O-glycosides and flavone C-glycosides. Flavonoid patterns from N. retusa (Forssk.) Asch. of the selected taxa Zygophyllaceae were surveyed through HPLC and correlated with morphological and anatomical criteria.

Terpenoids as chemosystematic markers in selected fossil and extant species of pine (Pinus, Pinaceae)

The compositions of terpenoids from the seed cones and resins of selected fossil and modern species of pine (Pinus, Pinaceae) were analysed using gas chromatography-mass spectrometry (GC-MS) to study the preservation of chemosystematic markers (biomarkers) in fossil conifers. Diterpenoids of the abietane, pimarane, isopimarane, and labdane types are the major components in the solvent extracts of all fossil and extant pines. Mono- and sesquiterpenoids of the bornane and cadalane classes and two phytosterols were also identified. The terpenoid patterns of the fossil species largely match the terpenoids observed in modern pines. The characteristic features of the fossil and extant Pinus species are abietane-, pimarane-, and isopimarane-type diterpenoids with a high abundance of abietic acids. Several biomolecules were preserved unaltered in the Eocene and Oligocene pine cones. In addition to the biomolecules, the fossil pines contain a series of degradation products (geomolecules) that were generated from their biological precursors before and after burial. The generation of the geomolecules is governed by various oxidative and reductive processes, such as microbial degradation and clay catalysis. In conclusion, the comparative analysis of solvent-extractable biomarkers in fossil and related extant species is a valuable tool for (palaeo)chemosystematic studies of conifers. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 154, 129–140.

ビブサン型ジテルペンの化学と生物活性

Plants producing natural products remain one of the few sources of drug discovery, yielding unorthodox and often unexpected chemical structures. Since some classes of plant-derived natural products are frequently concentrated on the same genus, the extensive chemosystematic studies of the specific plants serve as a chemical library to discover candidates for drugs or biological probes for physiological studies. Vibsane-type diterpenes belong to rarely occurring natural products since they have been elaborated solely in Viburnum species such as V. awabuki, V odoratissimum, and V. suspensum. These diterpenes are further classified into 11-membered ring, 7-membered ring and rearranged (neovibsanin) types, thus putting their chemical diversity into a unique chemical library. We describe a variety of vibsanes, chemical correlations between three subtypes, and synthetic studies of vibsanin F, the simplest 11-membered ring vibsane, as well as neurotrophic activities of neovibsanins A-B.

Altitudinal variation of secondary metabolite profiles in flowering heads of Arnica montana cv. ARBO

The altitudinal variation on the contents of secondary metabolites in flowering heads of Arnica montana was assessed. Plants of A. montana cultivar ARBO were grown in nine experimental plots at altitudes between 590 and 2230 m at Mount Patscherkofel near Innsbruck/Austria. The total contents of sesquiterpene lactones and flavonoids were not positively correlated with the altitude of the growing site. However, the proportion of flavonoids with vicinal free hydroxy groups in ring B to flavonoids lacking this feature significantly increased with elevation. Additionally, the level of caffeic acid derivatives also positively correlated with the altitude of the growing site. In particular amounts of 1-methoxyoxaloyl-3,5-dicaffeoylquinic acid significantly increased in higher sites and samples from the summit region contained 85% more of this compound than samples from valley sites. These results are discussed with regards to chemosystematic studies comparing samples collected in different altitudes as well as in the light of a UV-B protective and radical scavenging function of phenolics and their significance for plant life in environments with elevated UV-B radiation.

144 Use of Fourier Transform Infrared (FT IR) Diffuse Reflectance Spectroscopy and Hamming Distances to Study the Phycocolloid Chemosystematics of the Red Algae (Rhodophta)

The use of red algal polysaccharide cell wall structures as taxonomic indicators has been a recurring theme in the literature for over 58 years. Traditionally the polymeric phycocolloids of the red algal cell walls have been classified into definite structures (carrageenans and agars) based on the phycocolloids present. However, this method has some obvious shortcomings, such as its inability to assign hybrid structures (carragars), or the appearance of agarocolloids in traditional ‘carrageenophytes’. Thus, there is a need to develop an unbiased method of examining phycocolloid structures without assigning them names. Fourier transform infrared diffuse reflectance spectroscopy was used to analyze the spectra of a large number of red algal species, belonging to several orders. The spectra for each species resulted in a series of ‘peaks’ corresponding to certain wavenumbers (cm−1), which in term correspond to phycocolloid bonds. On the basis of shared/similar peaks, irrespective of their combinations to describe polymeric units, a series of matrices were developed for each family. These were coded as a 0 and 1, indicating the presence or absence of a peak, respectively. Using the concept of vector addition and Hamming distances, a methodology was formulated for analyzing ordinal and familial level groupings. Initial analysis on 173 species, representing 39 families and 12 orders of the Rhodophyta, proved to be promising. Some results corroborated previous studies, while others proved to be informative and raised the need for further chemosystematic studies. This provides the impetus for continuing to develop this method as a contribution to red algal systematics.

Chemosystematic studies of natural compounds isolated from Asteraceae: characterization of tribes by principal component analysis

This work describes an application of principal component analysis (PCA) on a database of secondary metabolites from the Asteraceae family. The numbers of occurrences of metabolites in 11 chemical classes for the different tribes of the family were used as variables. PCA allows the identification of chemical classes that contribute most to the subgroups classification within the family. Relationships between chemical composition and botanical classification were made.

Determination of Monoterpenes in Oleoresin: A Chemosystematic Study of the Interaction between Fraser Fir (Abies fraseri) and Balsam Woolly Adelgid (Adelges piceae)

The Fraser fir (Abies fraseri), a conifer native to high elevation sites in the southern Appalachians, has suffered severe mortality attributed to an exotic insect, the balsam woolly adelgid (BWA) (Adelges piceae). Fraser fir, like many other plants, produce volatile organic compounds called monoterpenes in a variety of tissues, including the cortical oleoresin found in blisters on the bark. The purpose of this study was to perform a chemosystematic study to evaluate whether differences in monoterpene composition of Fraser fir oleoresin were observed as a function of the season sampled, the presence or absence of BWA infestation, the health of a tree, and the susceptibility of trees to BWA, based on geographic location. Oleoresin was collected in September and December, 1994, at two mountains, Mount Rogers, where the fir were relatively healthy, and Roan Mountain, where heavy to moderate mortality has been observed. The oleoresin samples were dissolved in methylene chloride, and the monoterpenes were determined by gas chromatography. This method was shown to have acceptable precision for chemosystematic studies for five monoterpenes and the total of all monoterpenes. The levels of monoterpenes in oleoresin were statistically the same for most compounds in September and December, although the total monoterpenes were higher in September at Mount Rogers and α-pinene was higher in December at Roan Mountain. Infested and uninfested fir had the same levels of oleoresin monoterpenes at both mountains. No differences in monoterpene levels were observed at Mount Rogers with healthy and unhealthy fir, but at Roan Mountain, the total monoterpene concentrations were different in these categories. A comparison of monoterpene concentrations in oleoresin from Mount Rogers and Roan Mountain showed statistically significant differences for 3-carene, β-phellandrene, and total monoterpenes.

Les composés phénoliques et la caractérisation des niveaux taxonomiques inférieurs du monde végétal

Summary The chemical markers such as phenolic compounds, have been extensively used in botanical chemosystematic studies; these last mainly concerned the high taxonomic levels: order, family, genus. In consequence of new more sensitive and automatic analytical procedures, it is possible to approach the metabolic (phenolic) profile of individual genotypes: so the Micromolecular Biology is born, concerned with the organisation and functioning of plant populations. Three examples will give support to this proposal: Dactylis glomerata, Rosa x hybrida, Lotus corniculatus.

Epicuticular Hydrocarbon Composition of Wild and Laboratory-reared Drosophila mojavensis Patterson and Crow (Diptera: Drosophilidae)

Epicuticular hydrocarbons of Drosophila mojavensis (Patterson & Crow) were identified and quantified as a preliminary to an investigation into the involvement of epicuticular hydrocarbons in the behavioral and physiological ecology of catiphilic Drosophila Epicuticular hydrocarbons of D. mojavensis contain 23 to 39 carbon atoms, with >96% of the total hydrocarbon containing 29 to 37 carbons. Odd-chain lengths predominate. Alkanes consist almost entirely of C 29 , C 33 2-methyl-branched molecules. Alkenes are mostly C 31 to C 37 and are unusual in that a significant proportion consist of methyl-branched molecules. The n-alkenes are mostly (Z)-10- and (Z)-12-, but lesser amounts of (Z)-9-, 13-, 14-, 15-, and 16- also occur. The 2-methyl-branched alkenes are predominantly (Z)-8-, 10-, 12-, and 14-. The predominant alkadiene positional isomers (7,23- and 8,24-C 33.2 , 7,25- and 8,26- C 35.2 , 7,27- and 8,28-C 37.2 ) represent a symmetric arrangement of double bonds that has not heretofore been reported for insects. Ontogeny is accompanied by a doubling in total hydrocarbon per fly, primarily because of increases in the amount of alkadienes. Sexual dimorphism in epicuticular hydrocarbon profile was detected in the percentage abundance of many components and in the relative amounts of C 35.2 and C 37.2 . Ontogenic patterns for many individual hydrocarbon components also are sexually dimorphic. Flies in nature have significantly less total hydrocarbon than laboratory-reared flies and differ in the relative amounts of several olefinic components as well, leading to the suggestion that epicuticular hydrocarbon synthesis and deposition in wild flies may be affected by compounds in the rotting tissue of their host cacti. Finally, we suggest that insect chemosystematic studies using epicuticular hydrocarbon might take advantage of the diversity in olefin positional isomers that apparently exists in a number of insect groups