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Warning Odor of the North American Porcupine(Erethizon dorsatum)
Abstract
Volatile compounds in the lipid coating of the lower-back quills of the North American porcupine,Erethizon dorsatum, were collected using headspace trapping on Tenax and analyzed by gas chromatography–mass spectrometry (GC-MS), GC with organoleptic detection, and GC with a chiral stationary phase. Over 50 components were isolated, primarily oxygenated aliphatics, lactones, and isoprenoids. The most abundant constituent was tetradecyl acetate, which does not contribute significantly to the odor of the quill lipids. GC with a wide-bore capillary column and a human nose as detector was used to determine the retention time of the peak with the characteristic porcupine odor. Comparison of this organoleptic chromatogram with those obtained with a flame ionization detector and GC-MS showed the compound to be a -decalactone. The racemic mixture of this optically active substance does not possess the unique odor. Resolution of the enantiomers of -decalactone by GC with a chiral cyclodextrin phase shows that the isomer possessing the characteristic porcupine odor is the(R)--decalactone. We suggest the biological function of this compound is to serve as a warning odor, which, in conjunction with an initial quill strike, produces a conditioned aversion in potential predators.
... Several behavioral and morphological adaptations associated with porcupine mechanisms of defense have already been described for the North American porcupine, Erethizon dorsatum (Chapman et al. 2018;Cho et al. 2012;Roze 2009Roze , 2012Chapman and Roze 1997;Roze 2002). In general, the defense repertoire of this species begins with the erection of omnidirectional quills and the presentation of its back to the potential aggressor, exhibiting an apparently larger body size, aposematic color, and warning odor (Roze 2009(Roze , 2012Li, Roze, and Locke 1997). Among the morphological characteristics involved in this process are the presence of piloerector muscles, a fluorescent and contrasting color in the quill surface, odor glands, and osmetrichia quills (quills with modifications for odor dispersal) in the dorsum region (Roze 2009(Roze , 2012Chapman and Roze 1997;Li, Roze, and Locke 1997). ...
... In general, the defense repertoire of this species begins with the erection of omnidirectional quills and the presentation of its back to the potential aggressor, exhibiting an apparently larger body size, aposematic color, and warning odor (Roze 2009(Roze , 2012Li, Roze, and Locke 1997). Among the morphological characteristics involved in this process are the presence of piloerector muscles, a fluorescent and contrasting color in the quill surface, odor glands, and osmetrichia quills (quills with modifications for odor dispersal) in the dorsum region (Roze 2009(Roze , 2012Chapman and Roze 1997;Li, Roze, and Locke 1997). Erect porcupine quills can penetrate the skin and muscular tissue of an opponent when touched, and the presence of microscopic overlapping, backward-facing barbs in the tip facilitates the penetration (Cho et al. 2012). ...
... Note the high amount of elastic fibers at the arrector muscle insertion area (thin arrows). 1997; Li, Roze, and Locke 1997). The most distinct warning behavior noted was the vibration of the quills, which has not been reported for E. dorsatum. ...
New World porcupines (Erethizontidae) exhibit behaviors and possess integumentary structures, including the quills, that are used for self‐defense. The North American porcupine ( Erethizon dorsatum ) has been well studied regarding these features; however, information is lacking for the South American Coendou species. We describe the defensive behavior and integumentary morphology of Coendou spinosus to understand the defensive strategies of this species and to compare with those reported for other species. We assessed the behaviors related to warning, defense, and escape of eight porcupines, as well as the characteristics of their pelage and quills. Furthermore, we microscopically analyzed skin samples of a roadkill adult male specimen. Similar to E. dorsatum , C. spinosus exhibited omnidirectional quill erection, revealing an aposematic color and, with their backs toward the perceived human threat, they performed quick tail and body movements to strike the hands of the human trying to capture them by the tail. Furthermore, C. spinosus presented an integumentary structure similar to that of E. dorsatum , and mechanisms to facilitate quill release when touched, penetration, and fixation in the opponent. The most distinct warning behavior noted was the vibration of the quills, which has not been reported for Erethizon . Our study confirms that, like other erethizontids, C. spinosus does not attack but exhibits warning, defense, and escape mechanisms and behaviors when threatened or touched. The dissemination of such information helps to counter the negative stigma associated with porcupines, as they can be the victims of attacks by dogs and humans, and to promote their conservation.
... These five VOCs were all higher in relative abundance in males and delta-decalactone and bis(prenyl) sulfide differed by pairing status. Delta-decalactone and delta-dodecalactone have a sweet, coconut odor [80,81] and are primary odor compounds in the warning secretion on porcupine (Erethizon dorsatum) quills [82], and in the marking fluid of the male bengal tiger (Panthera tigris) [83]. Literature references to bis(prenyl) sulfide and prenyl bromide as scent signaling compounds in other species were not found, however bis(prenyl) sulfide may be the result of prenylation of proteins containing terminal sulfides [84] and prenyl bromide forms methyl prenyl sulfide [85], a compound found in maned wolf urine samples in Goodwin et al. [47] and in the present analysis. ...
... This study provides an excellent foundation for selecting VOCs to bioassay that may play a role in ovulation induction in the maned wolf. In particular, delta-decalactone and delta-dodecalactone deserve closer attention in bioassay as they were each four-fold higher in normalized abundance in males than females, higher in intact males than the neutered male, and are known signaling compounds in other mammals [82,83]. Several hemiterpenoid compounds are worthy of further investigation. ...
The maned wolf (Chrysocyon brachyurus) is an induced ovulator. Though the mechanism of ovulation induction remains unknown, it is suspected to be urinary chemical signals excreted by males. This study assessed volatile organic compounds (VOCs) in weekly urine samples across 5 months from 13 maned wolves (6 intact males, 1 neutered male, 6 females) with the goal of identifying VOCs that are differentially expressed across sex, reproductive status, and pairing status. Solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used to extract and separate VOCs that were identified via spectral matching with authentic standards, with spectral libraries, or with new software that further matches molecular fragment structures with mass spectral peaks. Two VOCs were present across all 317 urine samples: 2,5-dimethyl pyrazine and 2-methyl-6-(1-propenyl)-pyrazine. Fifteen VOCs differed significantly (Adj. P < 0.001 and |log2 fold change| >2.0) between intact males and females. Using partial least squares-discriminant analysis, the compounds with the highest importance to the sex classification were delta-decalactone, delta-dodecalactone, and bis(prenyl) sulfide. Sixty-two VOCs differed between intact males and the neutered male. Important classifier compounds were 3-ethyl 2,5-dimethyl pyrazine, 2-methyl-6-(1-propenyl)-pyrazine, and tetrahydro-2-isopentyl-5-propyl furan. Several VOCs established as important here have been implicated in reproductive communication in other mammals. This study is the most robust examination of differential expression in the maned wolf thus far and provides the most comprehensive analysis of maned wolf urinary VOCs to date, increasing the sample size substantially over previous chemical communication studies in this species. New data analysis software allowed for the identification of compounds in the hormone-producing mevalonate pathway which were previously unreported in maned wolf urine. Several putative semiochemicals were identified as good candidates for behavioral bioassays to determine their role in maned wolf reproduction, and specifically in ovulation induction.
... The quills, especially the long quills along the headnape-back and bristle-like spines along the whole body serve the porcupine as an excellent means of protection against predators (Macdonald 1985). Most of the work regarding porcupine behavior and reproductive study is centered on the North American species (Erethizion dorsatum) (Shadle et al. 1946;Edwin and Shadle 1953;Li et al. 1997) but observation on H. indica is quite meager. In H. indica, intraspecific communication and territorial marking occur mainly by anal gland secretion and urine. ...
... For a few years, we are concentrating our work on the ultrastructure and chemical analysis of epidermal structures of mammalian hair like lion mane -porcupine quill -and hedgehog spine to assess their role as putative sources of communicatory signals. Of these, the ultramorphology and chemical analysis of lion mane hair as a putative source of pheromone (Poddar-Sarkar et al. 2008) has been reported earlier, while a hint of greasy appearance of porcupine quill employed for individual recognition (Roze et al. 1990) and functional osmetrichia of the rosette quills of the North American porcupine (Li et al. 1997) also suggest a similar possibility. Certain American bear species rub their back on tree trunks, leaving communicatory (territorial) semiochemicals (Burst and Pelton 1983;Pelton et al.1999). ...
Ultrastructure and lipid chemistry of specialized epidermal structure of Indian porcupines and hedgehog
... The sebaceous glands in the rosette of Erethizon secrete the pungent warning odor released upon quill erection. Quills of the rosette region have osmetrichial specializations, allowing them to disperse the warning odor (Li et al. 1997;Roze 2009). Chaetomys lacks the robust defense system to back up an olfactory warning. ...
This study examines the functional histology of the thin-spined porcupine's (Chaetomys subspinosus (Olfers, 1818)) quills and integument, and compares them with the North American porcupine (Erethizon dorsatum (Linnaeus, 1758)) equivalents. Erethizon quills disseminate warnings to potential predators. An olfactory warning is generated by sebaceous glands of the lower back, disseminated by osmetrichial specializations of lower-back quills. Chaetomys skin lacks functional sebaceous glands, and generates no warning odor. Erethizon quills also carry a visual warning, effective even in dim light. Chaetomys quills carry no warning color. The straight, stiff quills of Erethizon are tipped with one-way barbs and can be elevated to 90°. A protective collagenous spool at the base of the quill prevents back-stabbing on impact. Chaetomys quills lack barbs and the basal collagenous spool is poorly developed. The quill shafts are wavy and angled at the base, allowing them to act as shock absorbers during a fall from a tree. Nevertheless, Chaetomys quills of the head and shoulders can be elevated to 90° to function as stabbing devices. Major defensive quills of Erethizon protect the back; in Chaetomys, the front. Though both species have 1–3 arrector muscles, they differ in the details of quill stabilization. The Chaetomys quill surface has regional cuticular patterns, of which the distal, longest region is highly pitted. The function of the pitted region remains a mystery.
... In mammals, both sebaceous and apocrine glands open into the hair follicle, and it seems that piloerection likely increases the secretion of their odorous products, as well as enabling better air circulation on the skin surface (Flood, 1985). Piloerection appears to be integrally involved in emission of alarm odours in several species, such as the North American porcupine (Li et al., 2004), rat (Kiyokawa et al., 2004 or springbok antelope (Bigalke, 1972). This is not to say that Darwin was unaware of the importance of odours in communication -he clearly was. ...
Recent work has demonstrated that human body odour alters with changing emotional state and that emotionally laden odours can affect the physiology and behaviour of people exposed to them. Here we review these discoveries, which we believe add to a growing recognition that the human sense of smell, and its potential role in social interactions, have been underappreciated. However, we also critically evaluate the current evidence, with particular focus on methodology and interpretation of emotional odour studies. We argue that while the evidence convincingly indicates that humans retain a capacity for olfactory communication of emotion, the extent to which this occurs in ordinary social interaction remains an open question. Future studies should place fewer restrictions on participant selection and lifestyle and adopt more realistic experimental designs. We also need to devote more consideration to underlying mechanisms and to recognise the constraints that these may place on effective communication. Finally, we outline some promising approaches to address these issues, and raise some broader theoretical questions that such approaches may help us to answer.
... The New World porcupines live in South, North and Central America, and few specimens are the Brazilian porcupine, Mexican hairy dwarf porcupine and Canadian porcupine [16]. Spines of New World porcupines are greatly reduced measuring around 10 cm in length, however these perform fair function also. ...
The goal of this article is to inform community regarding porcupines damage, and deliver guidelines for their harmless, real and liable elimination. The utmost apparent attribute of porcupines is their extensive, piercing and shakable quills, which shelter backs of the physiques that make them hit, as a threatening to probable raiders. In general, porcupines occur the maximum in mountainous and gravelly states, however these may adjust in many territories like extremely wet plantations and somewhat territory comprising of prairies, foothills, deserts and tropical forests. Porcupines can become a pest by eating of carrots and other root vegetables, clovers, roots, fruits as well as foraging on the farm crops. A definite indication of porcupine burrow is a mound of feces at entering site of cave or hollow tree. In this global region, Hystrix indica Kerr is most plentiful and scattered species, and has been familiarized as a severe pest of fruit orchards, vegetables, flowering plants, forage grasses in pastures or rangelands and traditional as well as non-traditional crops. When porcupines inflict optimum damage, then their control actions must be adopted. A pest controlling expert can provide skill to recognize the porcupines problematic and decide the superlative promising way out to decide the pest annoyance. Prior to executing a loss managing method, evaluate the porcupines incidence by means of watching for shattered quills, fecal masses beneath nourishing and sleeping plants, or distinctive injury marks to trees in a region. Manipulate habitat to attract more natural predators to control porcupine populations, place aluminum flashing around mature tree trunks and enclose small trees with wire baskets, and enclosure areas with electric or nonelectric fencing, to stop porcupines from gnawing at their bark. Implement forest management practices to reduce food supply and some wood preservatives applied to trees, and use of poison baits may provide partial damage relief. During late spring and summer activity periods, shooting of pest is most effective option, and use steel leg-hold traps lured by salt-soaked ingredients and placing proximate to alive burrows or else frequently used tracks.
Sarcoptic mange causes pruritic and crusting dermatitis in a large number of mammalian species with varying population impacts. Between 2016 and 2022, 15 North American porcupines (Erethizon dorsatum) were diagnosed with sarcoptic mange at Cornell University's Janet L. Swanson Wildlife Hospital in Ithaca, New York. Disease severity varied among individuals but all shared a similar unique presentation with thick, pale tan to yellow crusts limited in distribution to the ventral, nonquilled areas of the body, including the ventral abdomen and thorax, distal limbs, and face. The thick, hard nature of the crusts resulted in additional complications in many individuals, including inability to move the jaw and cracking and fissuring of the crusts and skin over joints of the limbs. Mites were plentiful within the crusts, with some burrowing into the epidermis as deep as the stratum spinosum. Secondary bacterial and/or fungal dermatitis were common, resulting in sepsis and death in three of the porcupines. Treatment with avermectins (ivermectin and/or selamectin) for 4–5 wk was successful in 12 cases in combination with other supportive care measures, including subcutaneous fluids, antimicrobials, and analgesics. Porcupines were hospitalized for an average of 18 d (ranging from 7 to 50 d) prior to transfer to a licensed wildlife rehabilitator for continued treatment and eventual release back into the wild.
Les êtres vivants vivent dans un environnement variable dans le temps et dans l’espace. La manière dont les êtres vivants s'adaptent à leur environnement est une question fondamentale en biologie évolutive, notamment dans le contexte actuel où les activités humaines génèrent des variations rapides de l’environnement. La plasticité transgénérationnelle (abrégée TGP ci-après) pourrait être un processus important dans l’adaptation des organismes à un environnement variable et suscite donc l’intérêt de la communauté scientifique depuis sa première description formelle il y a une vingtaine d’années. La TGP est l’extension au travers des générations de la plasticité phénotypique et se manifeste lorsque l’environnement des parents, ou ancêtres plus lointains, influence le phénotype des descendants, sans passer par une modification de l’ADN des descendants. La TGP pourrait notamment être un processus important dans les interactions prédateur-proie qui concernent la majorité des animaux. En effet, il a été montré que les descendants peuvent produire des défenses en réponse à la détection d’indices (de la présence) de prédateurs par les parents. Ainsi, la TGP permet une préadaptation des descendants à la présence de prédateurs dans leur environnement. L’objectif de cette thèse est d’améliorer la compréhension de la TGP des défenses contre les prédateurs chez les animaux en caractérisant plusieurs facteurs susceptibles de l’influencer. Le premier objectif de cette thèse était de réaliser une synthèse bibliographique sur ce sujet. Ensuite, à travers une succession d’expériences, nous avons caractérisé plusieurs facteurs impactant la TGP des défenses en prenant comme modèle biologique un petit gastéropode d’eau douce, la physe aiguë (Physa acuta). Les résultats principaux sont que : 1. la TGP des défenses n’est pas restreinte à l’environnement parental : les défenses morphologiques et comportementales sont influencées par la présence d’indices de prédateurs dans l'environnement des mères, des pères et des grands-parents ; 2. la TGP est fortement “trait-dépendante” : les effets transgénérationnels de l’exposition à des indices de prédateurs étaient différents entre les différentes défenses mesurées ; 3. la présence d’effets transgénérationnels sur les défenses des descendants dépend d’un grand nombre de facteurs : l’environnement des descendants, le sexe du parent exposé aux indices de prédateurs, de la génération exposée (génération parentale ou grand-parentale) et du moment de l’exposition des parents aux indices de prédateurs pendant leur développement ; 4. la TGP impacte les défenses comportementales à l'échelle moyenne (moyenne phénotypique sur plusieurs descendants), mais aucun effet transgénérationnel sur la variance comportementale entre les descendants n’a été trouvé (personnalité animale) ; 5. la nature adaptative de la TGP reste équivoque. En fonction des expériences et des défenses, l’exposition parentale aux indices de prédateurs a induit l’expression des défenses chez les descendants et a donc pré-adapté les descendants à la présence de prédateurs, ou à l’inverse a diminué l'expression des défenses des descendants. La TGP joue donc un rôle dans l’expression des défenses contre les prédateurs. Ce travail de thèse démontre que la TGP dépend de multiples facteurs qui peuvent interagir entre eux : le trait considéré, l’environnement des descendants, le parent exposé aux indices de prédateurs (mère, père ou grand-parent) et le moment de l’exposition aux indices de prédateurs. Ainsi, en identifiant des facteurs clés de la TGP des défenses contre les prédateurs, ce travail de thèse met en lumière de nombreuses pistes de recherche qui ultimement permettront une compréhension plus globale et intégrative des causes et conséquences de la TGP.
Simple Summary
Many significant human and animal diseases are spread by blood feeding insects and other arthropod vectors. Arthropod pests and disease vectors rely heavily on chemical cues to identify and locate important resources such as their preferred animal hosts. Although there are abundant studies on the means by which biting insects—especially mosquitoes—are attracted to humans, this focus overlooks the veterinary and medical importance of other host–pest relationships and the chemical signals that underpin them. This review documents the published data on airborne (volatile) chemicals emitted from non-human animals, highlighting the subset of these emissions that play a role in guiding host choice by arthropod pests. The paper exposes some of the complexities associated with existing methods for collecting relevant chemical features from animal subjects, cautions against extrapolating the ecological significance of volatile emissions, and highlights opportunities to explore research gaps. Although the literature is less comprehensive than human studies, understanding the chemical drivers behind host selection creates opportunities to interrupt pest attack and disease transmission, enabling more efficient pest management.
Abstract
Many arthropod pests of humans and other animals select their preferred hosts by recognising volatile odour compounds contained in the hosts’ ‘volatilome’. Although there is prolific literature on chemical emissions from humans, published data on volatiles and vector attraction in other species are more sporadic. Despite several decades since the identification of a small number of critical volatiles underpinning specific host–vector relationships, synthetic chemicals or mixtures still largely fail to reproduce the attractiveness of natural hosts to their disease vectors. This review documents allelochemicals from non-human terrestrial animals and considers where challenges in collection and analysis have left shortfalls in animal volatilome research. A total of 1287 volatile organic compounds were identified from 141 species. Despite comparable diversity of entities in each compound class, no specific chemical is ubiquitous in all species reviewed, and over half are reported as unique to a single species. This review provides a rationale for future enquiries by highlighting research gaps, such as disregard for the contribution of breath volatiles to the whole animal volatilome and evaluating the role of allomones as vector deterrents. New opportunities to improve vector surveillance and disrupt disease transmission may be unveiled by understanding the host-associated stimuli that drive vector-host interactions.
Scanning electron microscopy shows that the quill surface from the thin-spined porcupine (Chaetomys subspinosus (Olfers, 1818)) has several regional cuticular patterns of which the most expansive is highly pitted with 4 μm wide pores leading to pits, which in turn communicate circumferentially via tunnels to neighboring pits. The cell unit of the pitted layer is a hexagonal or pentagonal prism, the “pitted fibrillous cuticular cell” (PFCC), which has a superficial pitted cuticular scale derived part with an underlying part packed with fine fibrils and the nucleus. The scaled part has about six scales, which swell and fuse except where raised cuticular scales from the inner root sheath intervene. This unique and complicated cell soon dies even while below the skin’s surface during its development. The raised scale-bearing cells of the inner root sheath leave their imprints on the PFCC’s surface, thus indicating that the quill’s pitted layer is at one time soft. Histochemistry, energy dispersive X-ray spectrometry, and Fourier transform infrared spectrometry show that the PFCC is keratinous.
A number of studies concerning the analysis of axillary odors have assumed that the characteristic odor produced in the axillae is due to volatile steroids and isovaleric acid. Organoleptic evaluation of Chromatographic eluants from axillary extracts was employed to isolate the region in the chromatogram where the characteristic odor eluted. The odor of the dissolved eluant was eliminated when it was treated with base, suggesting that acids make up the characteristic axillary odor. Subsequent extraction of the pH-adjusted axillary extract in conjunction with organoleptic evaluation of the Chromatographic eluant, preparative gas chromatography, and analysis by GC-MS as well as GC-FTIR showed the presence of a number of C6 to C11 straight-chain, branched, and unsaturated acids as important contributors to the axillary odor. The major odor component is (E)-3-methyl-2-hexenoic acid. Three homologous series of minor components are also important odor contributors; these consist of the terminally unsaturated acids, the 2-methyl-C6 to -C10 acids and the 4-ethyl-C5 to -C11 acids. These types of acids have not been reported previously as components of the human axillary secretions and have not been proposed previously as part of the principal odor components in this area.
The histology of the porcupine's skin and subcutis is described. The functional relationships of the thoracic skin during elevation of the quills involve a smooth arrector muscle attached to quill sets, one set behind the other, with the muscle at a slant usually from a single root tip of one set to the distal part of the follicles in the caudal set. Stretched elastin returns the quills to their resting position. There is a low-resistance pathway for the tilting quill roots through lease connective tissue and fat until a collagenous strand attached to the quill set stops further tilt. The lumbosacral region (rosette) has a two-layered arrector, but it attaches to only its own quill set and inserts into the dermis. Both regions have a varied and complicated system of transverse and oblique muscles associated with the roots in a set. (The occurrence of obliques is variable in the thoracic region.) A hypothesis is presented concerning the mechanism of quill detachment from the porcupine after the quill is rammed into a predator. This involves the shearing of the conical root tip along its adherent follicular cells and a stopping device (spool) to prevent the root from self-stabbing.
Porcupine quills possess antibiotic properties. The antibiotic activity is associated with free fatty acids (but not neutral lipids) coating the quills. Extracts of quill fatty acids strongly inhibited the growth of six grampositive bacterial strains. No growth inhibition was observed against four gram-negative strains. Free fatty acids made up 18.6% of total quill lipids in samples collected in the summer, and 5.5% of total lipid in samples collected in the winter. The fatty acids were separated and identified (as the methyl esters) by gas-liquid chromatography and mass spectroscopy. Major components of a complex mixture included 14-methylpentadecanoic, 9-hexadecenoic, hexadecanoic, and 9-octadecenoic acids. It is suggested that porcupines benefit from the quill fatty acids: evidence from healed fractures of major skeletal components (35.1% incidence in 37 skeletons examined) suggests that porcupines fall relatively frequently from trees. Quill antibiotics may limit self-injury suffered in such falls.
The volatile components in the musk of the striped skunk (Mephitis mephitis) were analyzed by GC-MS. Several thiols (mercaptans), thioethers (sulfides), and disulfides were identified.
Analytical results from enantiomeric and isotopic analyses of four typical raspberry aroma compounds, α- and β-ionones, δ-decalactone and raspberry ketone, are reported. Different raspberry cultivars and commercial raspberry flavoured products were analysed, and a principal component analysis was carried out on the results. Using these methods, a cultivar discrimination was possible and significant information was obtained on the flavour of different cultivars. It was also possible to discriminate between natural and adulterated samples.
POLYMORPHIC mimicry in butterflies requires that their potential
predators, either birds, lizards or monkeys, should be able to exercise
Gestalt perception. We here describe a simple experiment showing that
wild birds are indeed able to perceive a pattern as a whole, rather than
responding only to single elements of it.
THE tarsal organ of deer of the genus Odocoileus is located, medially on the ankle (Fig. 1) and consists of sebaceous and apocrine sudoriferous glands as well as greatly enlarged arrector pili smooth muscle bundles1, which effect the erection of a long tuft of bright, stiff hairs. The hairs in the centre of the tuft are covered with a lipid film carrying the scent. The glands and urine are the possible sources of the tarsal scent. Tarsal organs are found only in tele-metacarpal deer (Odocoileinae); that is, in the New World genera Odocoileus, Blastocerus and Mazama, and in the Holarctic genera Alces and Rangifer
2.
(S)-delta-Decanolide (4) was isolated from cultures of Cladosporium suaveolens after the microorganism was fed either (S)- or (R,S)-coriolic acid (1). Feeding (R,S)-10-hydroxyoctadec-(8E)-enoic acid (2) to Yarrowia lipolytica produced (S)-gamma-dodecanolide. When (S)-homocoriolic acid (3) was fed to C.suaveolens, gamma-nonalide slightly enriched in the S enantiomer was produced. At some stage in the biodegradation of 3, an inversion of configuration, from S to R, occurred and was accompanied by the loss of the hydrogen atom originally present on C-14, as GLC/MS analysis of the products of feeding C. suaveolens with dideuterated 10 showed.
Volatile constituents of fresh apricots (Prunus armeniaca) of the Blenheim variety were analyzed by capillary gas chromatography and gas chromatography-mass spectrometry. The fruit was sampled by simultaneous vacuum steam distillation-extraction. A total of 49 components were identified in the extract, including 25 constituents reported for the first time in apricot. Linalool, lactones, and C6 lipid peroxidation products were the major constituents in the extract. Odor unit values, calculated from concentration and odor threshold data, indicate that the following compounds are major contributors to blended apricot aroma: β-ionone, linalool, γ-decalactone, hexanal, (E)-2-hexenal, (E,E)-2,4-decadienal, (E)-2-nonenal, and γ-dodecalactone. Headspace analyses of the intact fruit led to the identification of 83 components, 60 of which had not been previously reported in apricot. Esters were the dominant constituents in the headspace samples.