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The synthesis of new odorant molecules is still a challenging task for the fragrance chemist, because now as ever it is difficult to predict the odor properties of small organic molecules. Therefore, certain tools, such as, e.g., lead-structure optimization of existing odorants, are helpful techniques. In this article, we describe the synthesis and the odor properties of a new molecule derived by the so-called 'seco' lead-structure optimization of the ambergris compound Ambroxide(®) . Based on these results, more representatives with similar structures have been synthesized and evaluated for their olfactory properties.

In creating new aroma molecules, the fragrance chemist can make use of several tools: receptor or combinatorial research as well as lead structure optimization of existing chemicals or substances from the natural pool. Sometimes, it is also possible to discover new structures via another way: the careful analysis of existing products and their production processes. In analyzing the production process of 1-oxacyclohexadecan-2-one (6), we identified at least two new oxa-bridged macrocyclic molecules. In continuation, these results inspired us to synthesize and evaluate more representatives with similar structures. In this contribution, presented at the RSC/SCI conference ‘flavours & fragrances 2007’ in London, September 24–26, 2007, the synthesis and olfactory properties of several new oxa-bridged macrocycles will be introduced and discussed.

An oil of the piperitone type of Eucalyptus dives produced from trees cultivated in South Africa was analyzed by GC and GC/MS. Seventy-three constituents were characterized with piperitone ranging from 29.2% to 64.9%, depending on whether the oil was produced from dried or fresh leaves. Two novel constituents such as p-menth-5-en-2-one and p-menth-6-en-3-one were characterized as minor constituents of the oil; the former being found in nature for the first time.

Background Worm infestations may play a role in preventing allergic diseases. There is a lack of epidemiologic information from western countries on the association between worm infestation and atopic eczema (AE). The aim of this study was to investigate the association between worm infestation and AE in a proper temporal sequence and under consideration of the intrinsic and extrinsic subtype.

The 3-methyl-4-(tricyclo[5.2.1.02,6]dec-4-en-8-ylidene)butan-2-ols (=Fleursandol®; rac-10), a new class of sandalwood odorants, were synthesized in their enantiomerically pure forms by use of tricyclo[5.2.1.02,6]dec-4-en-8-ones 17 and ent-17 and (tetrahydro-2H-pyran-2-yl)-protected 4-bromo-3-methylbutan-2-ols 22 and ent-22 as starting materials (Schemes 2–4). Only four of 16 possible stereoisomers of rac-10 possess the typical, very pleasant, long-lasting sandalwood odor (Table 1). The (2S,3R,4E,1′R,2′R,6′R,7′R)-isomer ent-10a is by far the most important representative, with an odor threshold of 5 μg/l in H2O.

In 1998, the German Environmental Survey (GerES III) recruited approximately 5000 adults between the ages of 18 and 69 years. The study population for these analyses consisted of 1580 smokers (34% of the total population) and 3126 nonsmokers. Nicotine and cotinine concentrations in urine were determined by HPLC methods with UV-detection and corrected for creatinine. Nicotine and cotinine concentrations differed between smokers and nonsmokers by factors of 10-100. The multiple linear regression models used for the analyses of nicotine detection in the urine of smokers explained 43.2% and 42.3% of the total volume-specific and creatinine-specific variances, respectively. Cigarette smoking was the major factor responsible for 41% of the total variance. The explained variances of the cotinine results were larger, 51.0% and 49.3% of the total variance were volume-specific and creatinine-specific, respectively. More than 20% of nonsmokers in GerES III were exposed to environmental tobacco smoke at home, at work or in other places. The logistic regression analysis approach used for the group of nonsmokers showed the greatest effects for those exposed to tobacco smoke at home (adjusted OR varied between 4 and 6). These results were seen for nicotine as well as for cotinine excretion. Exposure to tobacco smoke in the workplace doubled the risk for the detection of nicotine and cotinine in urine. When other risk factors such as age, sex, social status, community size, season of urine collection, and the consumption of food containing nicotine such as potatoes, cabbage, tea were included, the effect estimates for tobacco smoke exposure remained unchanged. A new federal bill to diminish environmental tobacco smoke (ETS) exposure in the workplace was recently passed in Germany, but protection of nonsmokers from smoking family members at home needs more attention.

The odorous trace constituent iso-β-bisabolol (4) was isolated from East Indian and Western Australian sandalwood oil and synthesized by using the (E/Z)-triene 12 (iso-γ-bisabolene) as a key intermediate. Only one of four stereoisomeric forms of 4, (6R,7R)-4a, is odor active, having a strong floral, muguet-like, very pleasant scent.

Currently, there is ongoing discussion regarding potential protective effects of exposure to pets during early childhood on the development of atopic disorders in children later in life. We used data from three consecutive cross-sectional surveys to study the relationship between contact with dogs, cats and other pets, and allergic diseases in schoolchildren 5-14 years of age. In three study areas of the former East Germany, 7,611 questionnaires were received from 5,360 different children who were examined between 1992 and 1999 as school entrants, or third- or sixth-graders. Allergic sensitization to common aeroallergens (birch, grass, mite, cat) was assessed by specific serum immunoglobulin E (IgE) concentrations [using radioallergosorbent testing (RAST)] for 85% of the children. After adjustment for possible confounders, inverse associations were found between contact with dogs in the first year of life and lifetime prevalences of asthma [odds ratio (OR) = 0.68; 95% confidence interval (CI): 0.43-1.08], hay fever (OR = 0.61; 95% CI: 0.39-0.95), eczema (OR = 0.76; 95% CI: 0.61-0.94), itchy rash (OR = 0.76; 95% CI: 0.61-0.94), and pollen sensitization (RAST >/= 4: OR = 0.56; 95% CI: 0.38-0.82). These effects were more pronounced for children with atopic parents. Similar associations were observed for current contact with dogs. We identified no clear relationships for the other pets (cats, rodents, birds), with the exception that children currently exposed to cats were more likely to be sensitized against cats. In conclusion, this study supports the hypothesis of a potential protective mechanism related to dog exposure in early life, especially for children of atopic parents. However, this association was found only for dogs and not for cats.

Size distribution of particle number concentrations in the geometric equivalent diameter range 0.01–2.5 μm were determined in three communities, Zerbst, Bitterfeld and Hettstedt of the state of Sachsen-Anhalt in Eastern Germany, in the first half of 1993 and 1999. A Mobile Aerosol Spectrometer (MAS) consisting of a differential mobility particle spectrometer (DMPS) and a laser aerosol spectrometer (LAS-X) were used for size-selective particle number concentration measurements from which mass concentrations were derived based on an apparent mean density of the ambient aerosol of the closely situated city of Erfurt. The total number concentration was governed by ultra-fine particles ( −3 , the geometric means of total number concentration showed constant concentration (13.3×10 3 cm −3 in 1993 and 13.3×10 3 cm −3 in 1999, p =0.975) and the geometric means of number concentration of ultra-fine particles (UP) between 10 and 30 nm increased from 5.9×10 3 to 8.2×10 3 cm −3 from 1993 to 1999 ( p =0.016). The temporal changes of number and mass concentrations in the three communities are similar. The clear shift to smaller particle sizes within this six years period was caused by changes of the most prominent sources, traffic and domestic heating, since formerly dominating industries in Bitterfeld and Hettstedt had vanished grossly.

It has been postulated that the prevalence of atopic diseases and their increase over time are associated with regional differences in diet and trends. The results of an ecological correlation study comparing the mean daily intake of selected dietary constituents and the prevalence of allergic sensitization in adults in Europe is presented.Prevalence data from the European Community Respiratory Health Survey (ECRHS) were used. For eight out of 37 ECRHS centres (including 3,872 subjects), comparable dietary data could be obtained. The effect for each dietary constituent was modelled using logistic regression analyses with a term for over dispersion.Inverse associations between the prevalence of allergic sensitization and the energy adjusted intake of fruit were found (odds ratio (OR)=0.68, p=0.034). Furthermore OR for energy adjusted intake of vitamin A (OR=0.73, p=0.057), vitamin C (OR=0.83, p=0.338) and riboflavin (OR=0.72, p=0.077) were consistently These results support the hypothesis that a high intake of monounsaturated fatty acids might promote the development of allergic sensitization.

Purpose To examine whether frequent intake of margarine is associated with allergy prevalence in adults using data of a representative national health survey. Methods Data on 7124 subjects aged 18 to 79 years were obtained from the German National Health Survey 1998. Confounder-adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated by multiple logistic regression, using the frequency of intake of low-fat butter, regular and low-fat margarine as explanatory variable in relation to frequent intake of regular butter as reference group. Results Frequent intake of margarine of any kind was positively associated with current asthma during the past 12 months in young adults aged 18 to 29 years (aOR, 2.33; 95% CI, 1.03–5.26). In subgroup analysis, the positive association was confined to frequent intake of low-fat margarine (4.51; 1.78–11.43) or the combination of low-fat margarine and low-fat butter (4.79; 1.84–12.44). Consumption of margarine of any kind was not related to hay fever, atopic dermatitis, and atopic sensitization to inhalant allergens. Conclusions Frequent intake of margarine rich in n-6 PUFA is not consistently associated with allergic diseases in adults. Other constituents of low-fat margarine or certain dietary habits and lifestyle factors, characterized by use of low-fat margarine, may be related to current asthma.

Measurements of biocontaminants in settled house dust once a year are commonly used to assess long-term exposure. To examine stability over time and seasonal variation, we measured concentrations of mite and cat allergens, endotoxin and mold spores in living room floor dust in 745 German homes collected twice a year in two different seasons. The study population consisted of adults and children living in five different areas in Germany. All dust samples were collected in a standardized manner from the living room floor and taken during the years 1995 to 1998. The median interval between the two dust samplings was approximately 7 months. Mite and cat allergens were measured in settled house dust by monoclonal antibodies, endotoxin by the limulus amebocyte lysate method, and total spore counts by cultural methods. Crude Pearson's correlation coefficients between log-transformed concentrations in the first and second dust samples ranged between 0.65 and 0.75 for allergens, 0.59 for endotoxin and only 0.06 for total spore counts. The strongest and most consistent seasonal effects were observed for fungi with highest levels in July-September. Cat allergen concentrations were found consistently to be increased in January-March. Mite allergens did not show a strong and consistent seasonal pattern. We conclude that repeated measurements of mite and cat allergens and endotoxin in settled house dust improve the estimate for annual mean concentrations. However, even a single observation of these biocontaminants may be a good proxy for a 1-year exposure since repeated measures were highly correlated. However, repeated measurements of fungi levels were only weakly correlated and thus repeated observations for assessment of annual means of total spore counts are needed.

Currently, there is ongoing discussion regarding potential protective effects of exposure to pets during early childhood on the development of atopic disorders in children later in life. We used data from three consecutive cross-sectional surveys to study the relationship between contact with dogs, cats and other pets, and allergic diseases in schoolchildren 5-14 years of age. In three study areas of the former East Germany, 7,611 questionnaires were received from 5,360 different children who were examined between 1992 and 1999 as school entrants, or third- or sixth-graders. Allergic sensitization to common aeroallergens (birch, grass, mite, cat) was assessed by specific serum immunoglobulin E (IgE) concentrations [using radioallergosorbent testing (RAST)] for 85% of the children. After adjustment for possible confounders, inverse associations were found between contact with dogs in the first year of life and lifetime prevalences of asthma [odds ratio (OR) = 0.68; 95% confidence interval (CI): 0.43-1.08], hay fever (OR = 0.61; 95% CI: 0.39-0.95), eczema (OR = 0.76; 95% CI: 0.61-0.94), itchy rash (OR = 0.76; 95% CI: 0.61-0.94), and pollen sensitization (RAST/= 4: OR = 0.56; 95% CI: 0.38-0.82). These effects were more pronounced for children with atopic parents. Similar associations were observed for current contact with dogs. We identified no clear relationships for the other pets (cats, rodents, birds), with the exception that children currently exposed to cats were more likely to be sensitized against cats. In conclusion, this study supports the hypothesis of a potential protective mechanism related to dog exposure in early life, especially for children of atopic parents. However, this association was found only for dogs and not for cats.

The current authors examined whether mite and cat allergen and bacterial endotoxin levels in dust of the mothers' mattresses were associated with cord blood immunoglobulin (Ig)E (CB-IgE) levels in newborns. Data from 1,332 term and normal weight neonates, from an ongoing birth cohort study, Influences of life-style related factors on the immune system and the development of allergies in childhood (LISA), with complete information on exposure to biocontaminants in mattress dust and CB-IgE were analysed. Two thirds of CB-IgE were undetectable (

The use of gas stoves has been associated with respiratory symptoms of chronic airway inflammation and higher rates of respiratory infections. We used data from a 1992/93 survey of 2,198 East German school children (aged 5 to 14) to assess whether gas cooking increases respiratory symptoms and is associated with a chronic inflammatory process reflected by an increase in white blood cell (WBC) count in children who do not exhibit signs of an acute respiratory infection. We found increases for the respiratory symptoms 'cough without cold' [odds ratio (OR) = 1.68; 95% confidence interval (CI), 1.18-2.39], 'cough in the morning' (OR = 1.58; CI, 1.23-2.04) and 'cough during the day or at night' (OR = 1.42; CI, 1.13-1.78) in children living in homes with gas ranges, but lifetime prevalence of asthma, bronchitis, wheeze, and the prevalence of acute infections were not affected. Furthermore, we examined WBC levels in a subgroup of 1,134 children for whom blood samples were available and who did not suffer from an acute infection. We observed small increases in the risk of having WBC counts above the 75th or 90th percentile (8300 or 9800 cell counts per microliter) when children were exposed to gas cooking after adjustment for age, gender, and passive smoking (OR = 1.30; CI, 0.98-1.73, and OR = 1.38; CI, 0.91-2.10). The strongest effect estimates for chronic inflammation were found for those children likely to have been exposed at higher levels, that is when stoves had no fans, in smaller homes, and for children spending more time indoors.