A new sexual signal in rutting male red deer: Age related chemical scent constituents in the belly black spot

Rutting behaviour of red deer stags (Cervus elaphus) includes an extensive repertoire of visual and acoustic signals directed either to rival males or to females. As in other mammals, olfactory communication is expected to play a central role in these rutting interactions too, but this has rarely been investigated. Only during the rutting season, red deer males show a conspicuous black spot area throughout most of their underbelly produced by the impregnation of substances with a strong scent. Here, we examined the origin of these compounds and their potential role as chemical signals. By using gas chromatography–mass spectrometry (GC–MS), we identified 67 compounds in the hair from the belly black spot of red deer stags, mainly heterocyclic aromatic organic compounds, such as m-cresol, benzoic acid, cyclohexanecarboxylic acid and ethylphenol, but we also found steroids, such as cholesterol and androstane-3,17-dione, carboxylic acids and their esters between n-C₆ and n-C₂₂, alcohols, squalene and other minor compounds. Many of these compounds are found in the belly black spot but not in other hair areas, and may have originated from several sources, such as the urine or the sebaceous glands of the skin, which impregnated the belly. Moreover, we found differences in chemical profiles depending on age, with older males having higher proportions of benzoic acid and androstane-3,17-dione, but lower proportions of m-cresol. Because most of these compounds are strongly odoriferous, and appear related to male characteristics, our data indicate that scent from the hairs forming the black spot of the belly may be regarded as an overlooked new sexual chemical signal in red deer in the context of competition for mates during the rutting season.     

Lipids in femoral gland secretions of male lizards, Psammodromus hispanicus

Many lizards produce chemical secretions that may be used as pheromones in reproductive behavior, but only a few studies have identified chemical compounds in secretions. By using GC–MS, we found only 20 lipophilic compounds in femoral glands secretion of male lizards, Psammodromus hispanicus. Main compounds were six steroids (mainly cholesterol and campesterol) and seven n-C₉ to n-C₁₈ carboxylic acids (especially dodecanoic acid), and minor components were six alcohols between C₁₆ and C₂₉ and squalene. We compared these chemicals with those previously found in secretions of the closely related sister species Psammodromus algirus and other lizard species.     

Lipophilic compounds in femoral secretions of males and females of the El Hierro giant lizard Gallotia simonyi (Lacertidae)

Many lizards use femoral gland secretions in reliable intraspecific communication. Based on mass spectra, obtained by GC–MS, we found 57 lipophilic compounds in femoral secretions of males and females of El Hierro giant lizards, Gallotia simonyi (fam. Lacertidae). Compounds included steroids (mainly cholesterol) and fatty acids ranging between n-C₁₆ and n-C₂₂ (mainly hexadecanoic and octadecanoic acids), followed by aldehydes, alcohols, ketones, squalene and waxy esters. There were important intersexual differences in the presence, abundance and number of compounds (more numerous in males). Males had higher proportions of the most odoriferous compounds (fatty acids and aldehydes), while females had higher proportions of more stable compounds (steroids, waxy alcohols, waxy esters and terpenoids). This suggests sexual differences in function of femoral secretions. In addition, some compounds could reflect the physiological state, allowing monitoring health of lizards from secretions samples, which is especially important given the critical conservation status of this lizard.     

Age-related variation in lipophilic chemical compounds from femoral gland secretions of male lizards Psammodromus algirus

In spite of the importance of chemoreception in social organization of lizards, only a few studies have examined chemical composition of secretions of lizards. The secretion of the femoral glands of male lizards Psammodromus algirus contains 59 lipophilic compounds, mainly carboxylic acids between n-C₉ and n-C₂₀, and steroids (mainly campesterol, ergosterol and cholesterol), and minor components such as five alcohols, six aldehydes, squalene, α-tocopherol, ketones, and a furanone. These compounds were identified on the basis of mass spectra, obtained by GC–MS. Secretions of adult males of different age were different. Older lizards had secretions with relatively lower proportions of octadecadienoic, oleic and eicosatetraenoic acids, and higher proportions of campesterol, ergosterol, ergostenol, 4,4-dimethy-cholest-7-en-3-ol, and ergosta-5,22-dien-3-ol. These differences might allow conspecifics to get information on the age of the sender based on chemicals alone, which may have an important role in social behavior of this lizard.     

Relative Contributions of Urine and Anal-Sac Secretions in Scent Marks of Large Felids

SYNOPSIS. A hypothesis generated from field observations oflions and tigers was tested in a zoo setting. The presence ofa whitish material in urine marks, detected by visual inspection,led to the surmise that analsac secretions were expelled alongwith urine. This hypothesis was evaluated by labelling anal-sacsecretions of various felids with an inert dye. The animalswere monitored thereafter for signs of dye in urine-marks, onfeces or in their enclosures. The failure to find anal-sac secretionsin urine or on feces led to a search for an alternate explanationfor the whitish material. A likely answer was found in the confirmationof considerable lipid in the bladder urine of lions and tigers,which separates to form a visible, whitish layer. Relative levelsof urinary lipid reflect general condition of an animal as theycorrelate with kidney fat reserves (Hewer et al., 1948), sothe amount of lipid in a scent mark could serve as an indicatorof condition. Furthermore, because lipid retards the releaseof volatile compounds (Regnier and Goodwin, 1976), lipid ina scent mark will extend release time of a pheromonal message.     

Resorcinol and m-guaiacol alkylated derivatives and asymmetrical secondary alcohols in the leaves from Tamarix canariensis

We have discovered that leaves from the halotolerant plant saltcedar (Tamarix canariensis [Willd.]) are a source of resorcinols and guaiacols. Specifically, the waxes of the saltcedar leaves contained high amounts of 5-n-alkylresorcinols (ARs; 17 g/kg dry weight), 5-n-alkyl-m-guaiacols (AGs; 14 g/kg dw) and secondary alcohols (44 g/kg dw). Herein we provide the report of 5-n-alkylresorcinols with long side-alkyl chains as natural compounds in Tamaricaceae. These compounds are homologous to ones previously reported almost exclusively in cereals. The ARs span the formulas n-C₁₄ to n-C₂₇, the most abundant of which is n-C₂₁. Although the odd-C-numbered compounds dominate, there are non-negligible amounts of the even-numbered homologs. We also provide, the first-ever report of 11 homologs of 5-n-alkyl-m-guaiacols (AGs) as natural compounds from the sample plant, which we characterized as the corresponding trimethylsilyl (TMS)-ether derivatives. The AGs contain a hydroxyl group at carbon 1 of the phenolic nucleus, a methoxy group at position 3, and a (predominantly odd-C-numbered) linear alkyl chain linked to the benzene ring at position 5. They span the formulas n-C₁₃ to n-C₂₇, the most abundant of which is n-C₂₁. Finally, we also isolated from saltcedar a series of eight asymmetric secondary alcohols, whose formulas range from n-C₂₅ to n-C₃₅ and whose major homolog is n-hentriacontan-12-ol.     

Chemical composition of femoral secretions of oviparous and viviparous types of male common lizards Lacerta vivipara

In spite of the importance of chemoreception in intraspecific communication of lizards, only a few studies have examined chemical composition of secretions of lizards. The secretion of the femoral glands of adult male lizards Lacerta vivipara contains a relatively low number (18) of lipophilic compounds in comparison with other related lacertid lizards. These compounds were identified on the basis of mass spectra, obtained by GC-MS. Chemicals included ten steroids (mainly cholesterol) and four carboxylic acids between n-C₁₂ and n-C₁₈, and minor components such as squalene, α-tocopherol, and two waxy esters, which may contribute to avoid oxidation of other lipophilic components in the fairly humid environments occupied by this lizard. Secretions of adult males from oviparous and viviparous populations did not differ in the numbers and quality of chemical compounds, but there were some differences in the relative proportion of some compounds. Males from oviparous populations had lower proportions of hexadecanoic acid and cholestan-3-one, and higher proportions of squalene than viviparous males. These differences might be explained by either small genetic differences between types or due to different microclimatic conditions in the original populations.     

Lanostane triterpenes of Canscora decussata

From the aerial parts of Canscora decussata Schult (Gentianaceae), five triterpenes, viz. gluanone, canscoradione, friedelin, fridelan-3-β-ol, and β-amyrin, three sterols, viz. sitosterol, stigmasterol, and campesterol, besides liberal amount of a mixtures of n-alkanes (C₂₇-C₃₁) and n-alkanols (C₂₆-C₃₂) have been isolated. The identity of the compounds has been established by chemical transformations, spectral evidence, and by direct comparison, where possible, with authentic reference materials. Gluanone and canscoradione have not been encountered before in nature.     

Flavanone and other constituents from Onychium siliculosum

Two new compounds, onitinoside and onysilin along with the known compounds, pinostrobin, onitin, onitisin, campesterol, sitosterol and n-alkanes (C₂₅-C₃₃) were isolated from Onychium siliculosum. Onitinoside and onysilin were identified by spectral and chemical methods as 4-O-glucosyl-6-(2′-hydroxyethyl)-2,2,5,7-tetramethylindan-1-one and 5-hydroxy-6,7-dimethoxyflavanone, respectively.     

The scent of the reticulated giraffe (Giraffa camelopardalis reticulata)

The giraffe (Giraffa camelopardalis) emits a scent that can be detected by humans over considerable distances. Dichloromethane extracts of hair samples from adult male and female reticulated giraffes (G. c. reticulata) were analysed by gas chromatography–mass spectrometry. Two highly odoriferous compounds, indole and 3-methylindole, identified in these extracts appear to be primarily responsible for the giraffe’s strong scent. Other major compounds identified were octane, benzaldehyde, heptanal, octanal, nonanal, p-cresol, tetradecanoic acid, hexadecanoic acid, and 3,5-androstadien-17-one; the last compound has not previously been identified from a natural source. These compounds may deter microorganisms or ectoparasitic arthropods. Most of these compounds are known to possess bacteriostatic or fungistatic properties against mammalian skin pathogens or other microorganisms. The levels of p-cresol in giraffe hair are sufficient to repel some ticks.     

Effects of biosurfactants produced by Candida antarctica on the biodegradation of petroleum compounds

The effects of biosurfactants on the biodegradation of petroleum compounds were investigated. Candida antarctica T-34 could produce extracellular biosurfactant mannosylerythritol lipids (MELs) when it was cultured in vegetable oil. In addition, in our previous study, it was found that this strain could also produce a new type of biosurfactant while it grew on n-undecane (C₁₁H₂₄), and the biosurfactant was named as BS-UC. In flask culture of Candida antarctica, the addition of BS-UC could improve the biodegradation rate of some n-alkanes (e.g. 90.2% for n-decane, 90.2% for n-undecane, 89.0% for dodecane), a mixture of n-alkanes (82.3%) and kerosene (72.5%). By comparing the effects of the biosurfactants BS-UC and MEL and chemical surfactants on the biodegradation of crude oil, it was found that biosurfactants could be used to enhance the degradation of petroleum compounds instead of chemical surfactants. In a laboratory scale immobilized bioreactor, the addition of biosurfactant improved not only the emulsification of kerosene in simulated wastewater but also its biodegradation rate. The highest degradation rate of kerosene by addition of MEL and BS-UC reached 87 and 90% at 15 h, respectively. The results showed that the biosurfactant BS-UC was highly promising for work on biodegradation of hydrophobic contaminants.     

Isoflavone,wax and triterpene constituents of Wyethia mollis

The hexane extract of Wyethia mollis contains the n-alkanes C₁₅-C₁₈, C₂₀-C₂₅, C₂₇ and C₂₉. Linoleic acid was the only detectable acidic component. A mass spectral analysis of the wax ester fraction indicated that it was a mixture of homologues, the saturated even-carbon acids n-C₁₆-C₃₀ esterfield with the saturated even-carbon alcohols n-C₁₈-C₂₆. The chloroform extract yielded the known isoflavones santal and 3′-O-methylorobol along with a new lanostane-type triterpene, 22,25-epoxy-lanosta-7:9(11)-dien-3-one. The wide distribution of n-alkanes and the decreased odd-even carbon ratio are consistent with the proposed primitive nature of this plant.     

Emulsifying and surface active agents from Corynebacterium hydrocarboclastus

A Corynebacterium hydrocarboclastus culture isolated in our laboratory (see, Zajic and Knettig, Developments in Industrial Microbiology, 1971, p. 87) has been shown to produce an extracellular biopolymer with emulsifying properties when grown on a mixture of linear hydrocarbons. This microorganism was found to grow well on a variety of carbohydrates and hydrocarbons. However, the best substrates were pure linear hydrocarbons and particularly, n-C₁₂, n-C₁₃, and n-C₁₄. The substrates supporting good growth gave good polymer production. Maximum cell mass of 10–11 g/liter and a maximum amount of polymer of 5–6 g/liter were recorded. The polymers recovered from the different substrates were found to be complex molecules or mixtures with a protein, a lipid, and a carbohydrate moiety. All the polymers are surface active and have two critical micelle concentrations.     

Assessment of dominance hierarchy through urine scent marking and its chemical constituents in male blackbuck Antelope cervicapra, a critically endangered species

In ungulates the process of chemical communication by urinary scent marking has been directly related to reproductive dominance, territorial defense and proximity to resources. The differences in the frequency of urine marking and chemical composition of urine of males Antelope cervicapra before, during and after the dominance hierarchy period were assessed. The variations in the urine marking and its chemical profiles of dominant males (n = 9), bachelors (n = 5) and sub-adult males (n = 5) were compared to find out how the dominance hierarchy influences the confined blackbuck herd under semi-natural captive conditions. The frequency of urine marking is significantly higher (p < 0.001) in dominant males. Twenty-eight major constituents were identified in the urine of dominant males (before, during and after the dominance hierarchy period), bachelor and sub-adult males. Among these, three specific compounds namely, 3-hexanone (I), 6-methyl-5-hepten-2-one (II) and 4-methyl-3-heptanone (III) were seen only in dominant males urine during the dominance hierarchy period. Based on the behavioural observation and the unique chemical constituents in the urine, it is concluded that the dominant male scent odor suppresses aggression, scent marking, scent production and territorial patrolling activities of subordinate males, through which the dominant male establish their hierarchy and attains success in reproduction.     

Dependence of the hydrocarbon constituents of the leaf waxes of Khaya species on leaf age

The hydrocarbon constituents of the leaf waxes of eight species of Khaya were analysed for taxonomic purposes using GLC. The leaf waxes contained neither isoalkanes nor alkanes and the bulk of the n-alkanes were in the range of C₂₅ to C₃₃, odd-carbon number compounds predominating. It was found that the percentage composition of the n-alkane constituents of the leaf waxes varied with the age of leaves, young leaves having n-C₂₉ as the most abundant alkane, whereas older leaves had n- C₃₁.     

The Abiotic Formation of Hydrocarbons from Dissolved CO2 Under Hydrothermal Conditions with Cobalt-Bearing Magnetite

Conversion of CO₂ to organic compounds in hydrothermal systems is important in understanding prebiotic chemical evolution leading to the origin of life. However, organic compounds with carbon number of more than 3 have never been produced from dissolved CO₂ in simulated hydrothermal experiments. In this paper, we report that not only CH₄, C₂H₆ and C₃H₈, but also n-C₄H₁₀ and n-C₅H₁₂ could be produced from dissolved CO₂ and H₂ in the presence of cobalt-bearing magnetite at 300°C and 30 MPa. It is shown that unbranched alkanes in Anderson–Schulz–Flory distribution were the dominant hydrocarbon products produced from dissolved CO₂ catalyzed by cobalt-bearing magnetite under certain hydrothermal conditions. It is proposed that magnetite with other transition metals may act potentially as effective mineral catalysts for abiotic formation of organic compounds from dissolved CO₂ in hydrothermal systems.     

The role of olfactory cues in mother–pup,groupmate, and sex recognition of lesser flat‐headed bats,Tylonycteris pachypus

Tylonycteris pachypus is a gregarious bat species with tens of individuals in a colony. The mechanisms by which mother bats recognize their pups and adult bats recognize each other are not clear. We hypothesized that such recognition is achieved by chemical discrimination and performed experiments to test the hypothesis. Results showed that mother bats were much more attracted to the scent from their own pups. For adult bats, females were attracted to the scent from both male and female groupmates but had a higher preference to the scent from female than from male groupmates. Male bats were much more attracted to the scent from male groupmates while showed no preference to the scent from female groupmates. Within a group, both female and male bats had no difference in preference to the scent from the same or opposite sex. These results suggest that mother–pup and groupmate recognition of T. pachypus can be achieved by olfactory cues.     

Floral scent chemistry of mangrove plants

The flowers of mangrove plants are pollinated by a variety of pollinators including birds, bats, and insects. This study analyzed the floral scent chemistry of mangroves on Iriomote Island (located near Taiwan) including Bruguiera gymnorrhiza (L.) Lamk. (Rhizophoraceae), Kandelia candel (L.) Druce (Rhizophoraceae), Rhizophora stylosa Griff. (Rhizophoraceae), Sonneratia alba J. Smith (Sonneratiaceae), Nypa fruticans (Thunb.) Wurmb. (Palmae), Lumnitzera racemosa Willd. (Combretaceae), Avicennia marina (Forsk.) Vierh. (Avicenniaceae or Verbenaceae), and Pemphis acidula Forst. (Lythraceae). A total of 61 chemicals (fatty acid derivatives, terpenoids, carotenoid derivatives, benzenoids, nitrogen-containing compounds, 13 unknown chemicals) were detected in the floral scents of the various species. The species displayed a distinct chemical profile ranging from only two chemicals in the floral scent of Kandelia candel to more than 25 chemicals in the floral scent of Nypa fruticans. All of the identified chemicals have been found in the floral scents of other angiosperms. The chemical profile of some species can be correlated with their floral morphology and pollinators. Received: August 18, 2001 / Accepted: October 9, 2001     

Organic chemistry of Protosalvinia (Foerstia) from the Chattanooga and New Albany Shales

Vertical samplings of Protosalvinia, a thalloid Upper Devonian alga from the Chattanooga and New Albany Shales, are chemically analyzed and correlated with the organic chemical constituents isolated from associated shale matrices. Normal, saturated acids (n-C₈ to n-C₃₆n-paraffins (C₁₀ to C₃₆), showing an odd carbon-number preference, branched-chain alkanes, and vanadyl porphyrins isolated from Protosalvinia vary in their concentrations with depth of burial and with the dominant associated morphology of Protosalvinia, i.e., P. arnoldii, P. ravenna, P. furcata. Organic constituents of shales, in general, reflect those detected in thalli; relative concentrations, molecular diversity, carbon chain-lengths and maxima of compounds extracted from both shale and fossil material are similar. Pristane, phytane and porphyrins are probably derived from a chlorophyllous organism, while δ¹³C data corroborate a photosynthetic system operating in the primary biosynthesis of shale geochemistry. Crude-oil extracts of Protosalvinia-rich strata contain higher alkane and lower aromatic hydrocarbon concentrations than those of an average crude oil. Chemical variations among forms of Protosalvinia suggest biochemical differences in original plant composition rather than diagenetic transitions; field observations of morphological trends seen in vertical samplings may be used in crude extrapolations of the organic chemical compositions of shale strata.     

Electronic property of Group IV phthalocyanine dimers: SiPcMPc

A series of Group IV phthalocyanine (Pc) dimers, (n-C₆H₁₃)₃SiOSiPcOSiPcOSi(n-C₆H₁₃)₃ (SiPcSiPc), (n-C₆H₁₃)₃SiOSiPcOGePcOSi(n-C₆H₁₃)₃ (SiPcGePc), and (n-C₆H₁₃)₃SiOSiPcOSnPcOH (SiPcSnPc), was characterized by cyclic voltammetry and DFT calculation. Two oxidations and two reductions were observed for (n-C₆H₁₃)₃SiOSiPcOSiPcOSi(n-C₆H₁₃)₃ and (n-C₆H₁₃)₃SiOSiPcOGePcOSi(n-C₆H₁₃)₃, while there were two oxidations and three reductions for (n-C₆H₁₃)₃SiOSiPcOSnPcOH. The Pc with a bigger size of the central metal in one part of the dimeric compound is more difficult to be oxidized but it is easier to be reduced at the same time: i.e., both oxidation and reduction potentials showed a positive shift with the increase of the size of the central metal atom. Density functional theory was used to optimize the structures of the Pc dimers and to understand the electrochemical properties. The optimized structures of HOSiPcOSiPcOH, HOSiPcOGePcOH and HOSiPcOSnPcOH as model compounds for SiPcSnPc, SiPcGePc, SiPcSiPc, respectively, show that all the Pc dimers are staggered, the plane-to-plane distances are 3.394, 3.538 and 3.722 Å, respectively. Tin generates a saddle-type structure of phthalocyanine, but silicon or germanium does not greatly distort the ring structure, and yields a planar ring structure. A large plane-to-plane distance and a high degree of plane distortion yield a red-shift of Q-band, a low ring current, high oxidation and low reduction potentials and high ionization energies.