The origin of mentha — gracilis (Lamiaceae). II. essential oils

Essential oils were eamined in nine clones of Mentha arvensis, four clones of M. spicata, and 20 clones of M. gracilis. An F₁ hybrid of M. arvensis M. spicata, selected on the basis of morphology and chromosome number, was matched with one clone of M. Gracilis. Genes for the inheritance of limonene, 1,8-cineole, linalool, isomenthone, carvone, and piperitenone oide were identified in one clone of M. arvensis and two clones of M. spicata. The range of essential oil compounds detected indicates that no one character can be used to identify M. gracilis, but the critical compounds of the oil of M. gracilis can be derived from crosses of M. arvensis M. spicata.     

Micromorphological traits and essential oil of Micromeria longipedunculata Bräuchler (Lamiaceae)

Micromeria longipedunculata Bräuchler (syn. M. parviflora (Vis.) Rchb.) is an endemic Illyric-Balkan plant species from Bosnia and Herzegovina, Montenegro, and Albania. We investigated types and distribution of trichomes, pollen morphology, and chemical composition of essential oil (analysed by GC and GC-MS) in M. longipedunculata. Non-glandular trichomes, peltate trichomes, and two types of capitate trichomes (type 1 composed of one basal epidermal cell, and one head cell with subcuticular space; type 2 composed of one basal epidermal cell, two or three stalk cells, and one head cell with subcuticular space) were observed on leaves, bracteoles, the calyx, corolla, and the stem. The pollen grains had six apertures which were set in the equatorial pollen belt and showed medium reticulate ornamentation. A phytochemical analysis of essential oils from four different localities is characterized by similar chemical composition with spathulenol (23.7–39.5%), piperitone oxide (7.7–12.1%) and piperitone (7.3–8.9%) as the major compounds.     

Plant volatiles providing additional evidences to the occurence of a wild-growing population of Calamintha vardarensis (Greuter et Burdet) Šilić outside of its natural habitat

The essential‐oil profile of a Calamintha species, wild‐growing in the urban settings of the city of Ni? (South Serbia) and botanically tentatively identified as C. vardarensis (endemic species native to FYR Macedonia and East Serbia), has been statistically (multivariate statistical analyses) compared with those of other Calamintha species, including two previously investigated C. vardarensis populations, as a means of corroboration of the surprising occurence of this Calamintha population outside of its natural distributional range. Agglomerative hierarchical clustering reveals a close link of C. vardarensis from Ni? (with neo‐menthol (40.0%), menthone (21.8%), and pulegone (27.2%) as its major oil contributors) and C. vardarensis from FYR Macedonia.     

Inhibitory effects of the essential oils α-longipinene and linalool on biofilm formation and hyphal growth of Candida albicans

Candida albicans is one of the most common fungal pathogens, and causes systemic and invasive infections in humans. C. albicans biofilms are composed of yeast and hyphal and pseudohyphal elements, and the transition of yeast to the hyphal stage could be a virulence factor. In this study, diverse essential oils were initially investigated for anti-biofilm activity against C. albicans strains, and cascarilla bark oil and helichrysum oil and their components α-longipinene (a major constituent of both) and linalool were found to markedly inhibit biofilm formation without affecting planktonic cell growth. Moreover, α-longipinene and linalool were found to synergistically reduce biofilm formation. Notably, treatments with cascarilla bark oil, helichrysum oil, α-longipinene, or linalool clearly inhibited hyphal formation, and this appeared to be largely responsible for their anti-biofilm effect. Furthermore, the two essential oils, α-longipinene and linalool, reduced C. albicans virulence in Caenorhabditis elegans.     

Interactions of two endophytic fungi colonizing Atractylodes lancea and effects on the host’s essential oils

We investigated interactions between endophytic fungi infecting the same host; Gilmaniella sp. AL12 and Cunninghamella sp. AL4 are endophytes of Atractylodes lancea (Asteraceae). We studied the effect on the host’s essential oils of the single inoculation of one fungus and the mixed inoculation of both. We also observed the effects of these inoculations on endophytic fungal colonization and distribution. Single inoculation included two groups: single inoculation of AL12 (AL12 group), and single inoculation of AL4 (AL4 group). Mixed inoculation included three groups: AL4 inoculation first, followed by AL12 (AL4/AL12), simultaneous inoculation of AL4 and AL12 (AL4_VS_AL12), and AL12 inoculation first, followed by AL4 (AL12/AL4). The control (CK) did not include any fungi. AL4 was observed to prefer to colonize rhizomes, and AL12 to colonize blades of plants. The isolation rate of each fungus in the mixed inoculation group was lower than in the single inoculation group; this may have been due to niche competition. When we inoculated AL12 first and then AL4, the isolation rate of AL4 in stems, leaves, and roots decreased. Similarly, when we inoculated AL4 first and then AL12, the isolation rate of AL12 decreased in the stems and leaves. However, in the roots it appeared that the invasion of AL4 changed the volatile oil levels and that this helped the colonization of AL12; the colonization rate of AL12 following single inoculation was slightly lower than in the AL12/AL4 group and the AL4_VS_AL12 group. This may illustrate that these endophytes have a long history of mutual colonization of roots, and thus have synergies with each other. We used tissue staining to observe inoculated plant tissue. No hyphae were observed intruding into plant cells, and the hyphae of the two fungi were not observed intertwining; meaning that there was no physical interaction between them. However, we found hyphae colonizing the interspaces of leaf tissues and between root cortical cells. These hyphae were single bend fold and unbranched. These mycelia exhibited adaptive morphology compared with those in in vitro pure culture. Transmission electron microscopy (TEM) allowed us to more clearly observe endophytic colonization between root cortical cells. Gas chromatography showed that both single and mixed inoculation significantly increased levels of atractylone and atractylodin in the essential oils of A. lancea. In particular, the relative percentage of atractylodin in groups AL12/AL4 and AL4/AL12 was twice as much as in the control group, and the relative percentage of atractylone in AL4_VS_AL12 was more than three times that of the control. The gas chromatograph of the host’s essential oil was more complex following mixed inoculation than it was in the control.     

Studies on the chemical constituents of Kalimeris indica(Ⅱ)

采用冷渗漉提取的方法提取马兰的化学成分.经硅胶柱色谱和Sephadex LH-20进行分离纯化,通过理化方法和波谱数据分析进行结构鉴定.从80%乙醇冷渗漉提取物的水不溶物中分离并鉴定了12个化合物,分别为正十六烷酸(1)、6-羟基-桉烷-4(14)-烯(2)、β-谷甾醇(3)、α-菠菜甾醇(4)、香草醛(5)、β-20(21),24-二烯-达玛烷-3-酮(6)、豆甾醇(7)、木栓酮(8)、羽扇豆酮(9)、α-香树脂醇(10)、表木栓醇(11)、神经酰胺(12).化合物2、6、9、12均为首次从该种植物中分得.     

Effect of dietary supplementation with sea buckthorn (Hippophaë rhamnoides) seed and pulp oils on the fatty acid composition of skin glycerophospholipids of patients with atopic dermatitis

Sea buckthorn (Hippopha? rhamnoides) seed and pulp oils have traditionally been used for treating skin diseases in China and Russia, but are not widely used in other countries. A placebo-controlled, parallel study was carried out to investigate the effects of these oils on the fatty acid composition of skin glycerophospholipids of patients with atopic dermatitis. Sixteen patients ate 5 g of sea buckthorn seed oil, pulp oil, or paraffin oil daily for 4 months. Skin fatty acids were analyzed with gas chromatography before and after treatment. The seed oil slightly increased the proportion of docosapentaenoic acid (22:5n-3) and decreased the proportion of palmitic acid (16:0) in skin glycerophospholipids (0.05 < P < 0.1). The levels of the other fatty acids remained stable. The results show that the fatty acid composition of skin glycerophospholipids is well buffered against short-term dietary modification.     

Micro-structure and chemical composition of vateritic deformities occurring in the bivalve Corbicula fluminea (Müller, 1774)

Vateritic deformities occurring in the invasive heterodont bivalve Corbicula fluminea from several locations in the UK were characterised in detail for the first time using scanning electron microscopy, X-ray diffraction and different geochemical techniques (electron microprobe, ICP-AES, and mass spectrometry). Large volumes of vaterite are produced abnormally in the animals' shells in the form of yellow-green bulges. These are distinguished from the aragonitic parts of the shell by their characteristic micro-structures, content of organic material, trace elemental composition and carbon stable isotope signatures. The most commonly observed micro-structures include columnar vaterite, lamellar vaterite and different irregular structures occurring in all parts of the shell. There are indications that organic material is present largely as intracrystalline impurities or nano-scale phases and not as envelopes around microstructural units. These micro-structures are novel, nothing equivalent having yet been described for other vateritic systems. Euhedral vaterite crystals also occur occasionally. The vaterite has generally higher Mg/Ca and lower Na/Ca, K/Ca than the aragonite. In addition, δ13C is also always lower. Microstructural characteristics would suggest loss of biological control probably due to physiological stress(es) inducing the switch to vaterite production. The vaterite might be stabilised by its higher content of organic material and magnesium.     

Acidification of lakes in Šumava (Bohemia) and in the High Tatra Mountains (Slovakia)

Acidification of lakes takes place when pH of rainwater is less than 4.5 and the catchments lie on sensitive geology. Both conditions are met for most lakes in Bohemia and Slovakia. Since 1978 we have studied mountain lakes in the Sumava and in the High Tatra Mountains. In Šumava the three lakes under study are of glacial origin. The catchments are small, with steep sides covered by spruce. The bedrocks are biotite-rich paragneiss, together with gneiss, quartzite and granite. In summer 1936 surface pH was 5.7–6.9 in the Lake Čertovo and 6.9–7.0 in the Lake Černé. Now the pH values are 4.3–4.8 in the two lakes and in the Lake Prášilské as well. Old reports on zooplankton are from the years 1871, 1892–96, 1935–37, 1947 and 1960. Since 1979 we have not found any planktonic Crustacea in the lakes Černé and Čertovo. Lake Prášilské is inhabited by Daphnia longispina and Cyclops abyssorum. In July 1989 the pH values were 4.4, 4.7 and 4.7, concentrations of labile monomeric Al were 0.83, 0.68 and 0.24 mg l^-1 in the lakes Čertovo, Černé and Prašilské, respectively. High levels of toxic Al compounds might be responsible for the extinction of planktonic Crustacea in the lakes Čertovo and Černé. All the three lakes are void of fish at present. In the High Tatra Mts. we examined more than 40 lakes above timberline in altitudes 1612–2145 m. They are all clearwater, naturally fishless lakes. The bedrock is granite. Owing to different levels of calcium the lakes are now in different stages of acidification. According to recent changes in the zooplankton they can be divided into three groups: (1) Species composition of planktonic Crustacea has not changed. (2) Planktonic Crustacea were present until 1973 but are absent now. (3) From the original species of Crustacea only Chydorus sphaericus is present. The three groups are well separated along the gradients of calcium, ANC and pH. They can be identified with the Henriksen's bicarbonate (our group 1), intermediate (our group 2) and acid (our group 3) lakes. We suppose that in the process of acidification the lakes of the group (2) have been shifted from oligotrophy to ultraoligotrophy.     

Distribution of total and organic lead in the Šibenik region (Eastern Adriatic)

Abstract

The distribution of inorganic and organic lead species in atmospheric and surface waters from the ?ibenik area (central part of the Eastern Adriatic coast) was investigated. The concentration range of lead compounds in rainwater was 12,000 to 57,000 ng Pb L^?1 for total lead, and 10 to 96 ng Pb L^?1 for ionic alkyllead compounds (mostly in the form of trialkyl derivatives). In seawater, trialkyllead compounds were detected in concentration from <0.5 to 12.5 ng Pb^?1 L, which represented 0.5 to 6.8% of the total lead. These results were compared with data obtained elsewhere, and the influence of lead compounds emitted from leaded gasoline (from automobiles and gasoline stations) on the adjacent water body is elucidated.     

Differential expression of limonene synthase gene affects production and composition of essential oils in leaf and floret of transgenic lavandin (Lavandula × intermedia Emeric ex Loisel.)

Transgenic lavandin (Lavandula × intermedia) expressing the limonene synthase gene (LIMS) cDNA of true lavender (L. angustifolia) driven by a constitutive 35S promoter was generated from leaf-derived callus inoculated with disarmed Agrobacterium tumefaciens. Only three LIMS regenerants could be acclimatized and their transgenes confirmed. Of them, LM-3, showed closed internodes and short stalks with small spikes, similar to the morphological characters of dwarfism. These results might be attributable to depleted geranyl diphosphate, the monoterpene precursor, which is required for the production of gibberellin. LIMS was differentially expressed in leaves and florets of the transgenic plant, which affected the production of several monoterpenes and therefore essential oil production. In vegetative leaves, overexpressed LIMS increased not only limonene but also total essential oil production, although no alteration in fragrance was observed. Conversely, suppression of LIMS expression in florets of the reproductive stage reduced their total essential oil production, including the dramatic decrease of limonene, linalool, and linalyl acetate. These results suggest that the constitutive promoter acts as a suppressor in tissues in which endogenous targeted gene expression is strong. Consequently, a slight change in fragrance at weak intensity in florets of the transgenic plants, producing a camphoraceous odor, was apparent when compared with non-transgenic plants, because the relative proportions of camphoraceous compounds such as 1,8-cineole, camphor, and borneol were increased in the transgenic plants. These results suggest that the suppression of terpene synthase gene expression is an effective way to alter fragrance, despite a dramatic reduction in total essential oil production.     

Effects of road salts on the composition of seasonal pond communities: can the use of road salts enhance mosquito recruitment?

Road deicing agents can enter nearby wetlands and alter the composition of aquatic communities by directly eliminating salt-intolerant species and modifying ecological interactions between tolerant species. We conducted field experiments to examine the sensitivity of taxa that inhabit seasonal wetlands and to determine whether salt contamination could increase the production of ovipositing insects. In two outdoor mesocosm experiments, cladocerans and copepods rarely survived concentrations of commercial road salt >1,200 mg L⁻¹, while wood frog eggs and hatchlings (Lithobates sylvaticus) were not strongly impacted until concentrations exceeded 4,500 mg L⁻¹. Shore flies (Ephydridae), mosquitoes (Culex restuans; Anopheles punctipennis) and midge larvae (Chironomidae) were more salt tolerant than macrozooplankton. These taxa tended to be absent or relatively rare in experimental mesocosms with low salinities, but abundant in mesocosms with intermediate to high salinities. We conducted two additional experiments to examine whether adult choice of oviposition sites may in part explain the rarity of Cx. restuans in pools with low salinity. These revealed that Cx. restuans reduced oviposition rates in water-filled containers with cladocerans, and reduced clutch size in the presence of Lithobates larvae. However, salt concentration per se did not influence the propensity of Cx. restuans to oviposit. Collectively, our results suggest that aquatic habitats that are biologically compromised by deicing agents favor salt-tolerant insects, and that the use of road salts could increase the production of adult mosquitoes that are pests and vectors of disease.     

Comparison of essential oils and genetic relationship of Origanum × intercedens to its parental taxa in the island of Crete

Plants of the taxa Origanum onites and Origanum vulgare were allowed to cross-pollinate under natural open field conditions and to produce a mixed population of putative hybrid Origanum × intercedens and parent genotypes. Randomly collected plants were classified as putative hybrids or parent genotypes by inspection of their inflorescence. They were then subjected to analysis of their essential oil composition and were fingerprinted by randomly amplified polymorphic DNA (RAPD) fragments. DNA primers identifying the genotype as well as showing the distance of a particular putative hybrid plant from the parent genotypes were found. Alone or in combination with the essential oil composition they can be used as reliable tools for the genetic identification of the two parental taxa and the putative hybrid plants in natural populations.     

Environmental and seasonal variation in the diet of Elachistocleis bicolor (Guérin-Méneville 1838) (Anura: Microhylidae) from northern Uruguay

We studied the diet of Elachistocleis bicolor captured in pine, eucalypt, and unmodified environments in Uruguay. Comparisons between seasons (active, inactive) and among three environments (pine, eucalypt, unmodified), were made using rarefaction analyses, importance indices, and non-parametric tests. Elachistocleis bicolor has a specialized diet composed mainly of Pheidole and Solenopsis ants and termites. The diet of E. bicolor includes a high number of prey per individual, suggesting active search as a foraging strategy. The consumption of myrmicine ants (i.e., Solenopsis) represents a source for potential toxic skin secretions that in E. bicolor may be used to avoid being attacked in the ant nests used for shelter during aestivation, as occurs in the microhylid Phrynomantis microps. Diets in forested environments were richer in both periods, which may reflect the colonization of opportunistic ant species in these environments. Ants were more important in the eucalyptus plantations, particularly in the inactive period, whereas termites were more important in the pine plantations mainly in the inactive period. These environmental and seasonal differences in diet are consistent with the temperature and humidity tolerances of ants and termites, which are the main prey of E. bicolor.     

Evaluation of species composition and seasonal dynamics of mosquito larvae in the Košice Basin during 2010 and 2011

In six sites in the Ko?ice Basin we collected 17,520 larvae of 15 mosquito species during the seasons (April–August) of 2010 and 2011. They were: Aedes vexans (Meigen, 1830), Ae. cinereus (Meigen, 1818) [or Ae. rossicus (Dolbeskin, Gorickaja & Mitrofanova, 1930], Ochlerotatus geniculatus (Olivier, 1791), Oc. refiki (Medschid, 1928), Oc. rusticus (Rossi, 1790), Oc. sticticus (Meigen, 1838), Oc. punctor (Kirby, 1837), Oc. cataphylla (Dyar, 1916), Oc. cantans (Meigen, 1818)[or Oc. annulipes (Meigen, 1830)], Oc. communis (De Geer, 1776), Oc. flavescens (Müller, 1764), Oc. leucomelas (Meigen, 1804), Culiseta annulata (Schrank, 1776), Culex pipiens (L., 1758) [or Cx. torrentium (Martini, 1925)] and Anopheles maculipennis s.l. The objective of the present research was to identify the mosquito larvae species diversity and compare their distribution and density in urban and suburban localities of the monitored territory.     

A critical review on the impacts of β-glucans on gut microbiota and human health

The β-glucans are the glucose polymers present in the cells walls of yeast, fungi and cereals. β-Glucans are the major compositions of various nutritional diets such as oats, barley, seaweeds and mushrooms. Various biological activities of β-glucans have been reported such as anticancer, antidiabetic, anti-inflammatory and immune-modulating effects. The importance of β-glucans in food processing industries such as bread preparation, yogurt and pasta have been well elucidated. In recent findings on food science research gut microbiota plays a significant role and vastly studied for its intermediate role in regulating health. Several reports have suggested that β-glucans should have a significant impact on the gut microbiota changes and in turn on human health. The review was aimed to accumulate the evidence on types of β-glucans, their functional properties and the mechanism by how the β-glucans regulate the gut microbiota and human health. The various in vitro, in vivo and clinical studies, have been summarized, in particular, the changes happening upon the β-glucans supplementation on the gut microbiota. Overall, this review updates the recent studies on β-glucans and gut microbiota and also inputs the demanding questions to be addressed in β-glucans–microbiota research in the future.     

The pristine rain forest? Remnants of historical human impacts on current tree species composition and diversity

Abstract Aim Tropical rain forests are often regarded as pristine and undisturbed by humans. In Central Africa, community‐wide disturbances by natural causes are rare and therefore current theory predicts that natural gap phase dynamics structure tree species composition and diversity. However, the dominant tree species in many African forests recruit poorly, despite the presence of gaps. To explain this, we studied the disturbance history of a species‐rich and structurally complex rain forest. Location Lowland rain forest in Southern Cameroon. Methods We identified the recruitment conditions of trees in different diameter classes in 16 ha of species‐rich and structurally complex ‘old growth’ rain forest. For the identification of recruitment preference we used independent data on the species composition along a disturbance gradient, ranging from shifting cultivation fields (representing large‐scale disturbance), to canopy gaps and old growth forest. Results In nine of sixteen 1‐ha forest plots the older trees preferred shifting cultivation fields for recruitment while younger trees preferred gaps and closed forest conditions. This indicates that these nine sites once experienced large‐scale disturbances. Three lines of evidence suggest that historical agricultural use is the most likely disturbance factor: (1) size of disturbed and undisturbed patches, (2) distribution of charcoal and (3) historical accounts of human population densities. Main conclusions Present‐day tree species composition of a structurally complex and species‐rich Central African rain forest still echoes historical disturbances, most probably caused by human land use between three to four centuries ago. Human impact on African rain forest is therefore, contrary to common belief, an issue not of the last decades only. Insights in historical use will help to get a more balanced view of the ‘pristine rain forest’, acknowledging that the dualism between ‘old growth’ and ‘secondary’ forest may be less clear than previously thought.     

Effect of γ irradiation on the fatty acid composition of soybean and soybean oil

Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.     

Volcanic impacts on the Holocene vegetation history of Britain and Ireland? A review and meta-analysis of the pollen evidence

Volcanic ash layers show that the products of Icelandic volcanism reached Britain and Ireland many times during the Holocene. Historical records suggest that at least one eruption, that of Laki in a.d. 1783, was associated with impacts on vegetation. These results raise the question: did Icelandic volcanism affect the Holocene vegetation history of Britain and Ireland? Several studies have used pollen data to address this issue but no clear consensus has been reached. We re-analyse the palynological data using constrained ordination with various representations of potential volcanic impacts. We find that the palynological evidence for volcanic impacts on vegetation is weak but suggest that this is a case of absence of evidence and is not necessarily evidence of absence of impact. To increase the chances of identifying volcanic impacts, future studies need to maximise temporal resolution, replicate results, and investigate a greater number of tephras in a broader range of locations, including more studies from lake sediments.