Canadian beaver

Kontak, D.J. Smith, P.K. 1989. Sulphur isotopic composition of sulphides from the Beaver Dam and other Meguma Group-hosted gold deposits, Nova Scotia implioations for genetic models. Canadian Journal of Earth Sciences, 26, 1617-1629. 

The majority of biological monitoring studies to date have focused on PFOSA, PFSAs and PFCAs. FTCAs and FTUCAs have been observed in some species, including seabirds and seals from the Canadian Arctic [107, 197], suggesting that FTOHs may be a source of the observed PFCAs. Two studies have also investigated the presence of other FSAs in biological samples. Tomy et al. [87] have observed NEtFOSA in an Eastern Arctic marine food web, while Taniyasu et al. [182] have observed NEtEOSA in beaver fiver samples. 

Furyl)-8-methyloctahydroindolizine (12) has been isolated from the scent-gland of the Canadian beaver Castor fiber L.), together with (-)-castoramine and a series of related quinolizidines and other alkaloids. The alkaloid (12) is only a minor... 

The previous review on Nuphar (water-lily) alkaloids in this treatise appeared in Volume 35, and covered the period 1974-1987 (7). It overlapped in part with the treatment of simple bicyclic Nuphar metabolites in Volume 28 (7). Nuphar alkaloids include sesquiterpenoid monomeric (C15) piperidine and quinolizidine alkaloids as well as more complex dimeric (C30) sulfur-containing metabolites. Related metabolites isolated from the scent glands of the Canadian beaver, Castor fiber, also include a unique indolizidine alkaloid 944 606). Only the indolizidine and simple quinolizidine alkaloids are relevant to the present review. Compounds mentioned in the ensuing discussion are illustrated in Fig. 18. 

The chemistry shown in Eq. (21) uses a / -amino selenide as a radical precursor. /S-Amido radical cyclizations in which y -amido selenides served as the radical precursors have also been reported. One example has been described within the context of an approach to the ABC-ring system of manzamine A [47]. Another appears in an efficient synthesis of indolizidine 72, a component of castoreum derived from the Canadian beaver scent gland (Eq. 22) [48]. It is notable that allylic strain plays a role in the latter free-radical cyclization, as the furyl residue undoubtedly occupies an axial site on the incipient tetrahydropiperidone ring. 

Novosad, J.J. and lonescu, E.E. (1987) Eoam forming surfactants for beaver-hill lake carbonates and gilwood sands reservoirs, in Proceedings of CIM Annual Technical Meeting, Canadian... 

The original structure of (— )-deoxynupharidine (15) was not correct and much of the earlier literature concerning these alkaloids contains erroneous structures. The compound has a l/ ,4/f,7/f,9a/ configuration, as indicated in Fig. 36.4 (Howard and Michael, 1986). Similar alkaloids have been isolated from the scent glands of the Canadian beaver. Castor fiber (Fig. 36.4). The oil of this gland or castoreum is used as a fixative in the perfumery industry. (— )-Deoxynu-pharidine (15) is one of the components of the complex mixture of compounds found in this oil. Although it is not clear. 

Common/vernacular names Secretion of Canadian beaver (C. canadensis) and Siberian or European beaver (C. fiber). 

Beavers are large pale brown to chestnut-brown rodents. The Canadian beaver inhabits lakes and rivers of Canada and northern United States, while the Siberian beaver is found in Europe and Siberia. Castoreum is the secretion accumulated in glands located near the pubis (between anus and sex organs) of these animals. These scent glands with their secretion (castoreum) are collected and dried, from which extracts (absolute, tincture etc.) are prepared by solvent extraction. Canadian castoreum is considered superior in quality to the Siberian castoreum. ... 

Related C15 quinolizidines and one indolizidine alkaloid have also been found in the exudate from the scent glands of the Canadian beaver Castor fiber) (castoreum, previously used as a fixative in perfumery). For convenience, these animal alkaloids wiU be included in the present discussion. 

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