Felinine stability in the presence of selected urine compounds.

The stability of felinine, an amino acid present in feline urine, was investigated. Synthetic felinine was unstable in the urine of a selection of mammals. Felinine was found to stable in feline urine in which urea had been degraded. Synthetic felinine was found to react specifically with urea and did not react with urea analogues such as biuret or thiourea or other nucleophilic compounds such as ammonia which is more nucleophilic or acetamide and water which are less nucleophilic than urea. The reaction of urea and felinine was independent of pH over the range of 3-10. Urea did not react with N-acetyl-felinine suggesting a felinine N-terminal interaction with urea. Mass spectral analysis of the reaction products showed the presence of carbamylated felinine and fragmentation ions derived from carbamyl-felinine. The physiological relevance of felinine carbamylation is yet to be determined.

Use of capillary (zone) electrophoresis for determining felinine and it's application to investigate the stability of felinine.

A rapid capillary electrophoresis method was established to quantify felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid) in cat urine and used to investigate felinine stability. Synthetic felinine was stable in the presence of oxygen while 11% of the natural felinine in urine disappeared after 4 days exposure to air. Both synthetic felinine and the natural felinine (in urine) were stable for up to 3 months when stored at -5 degrees C and 20 degrees C. Thirty percent of the synthetic felinine was lost after 5 hours at 100 degrees C while 95% of the natural felinine disappeared after only 2 hours at the same temperature. The recovery of felinine under certain conditions was greater than 100%. It is possible that acetyl-felinine may be present in the urine and that it is deacetylated during incubation. Overall synthetic felinine was found to be stable but the felinine in cat urine much less so. Other compounds present in the urine may contribute to the decomposition of felinine.

Thermal and optical properties of polymer hosts for solid-state dye lasers.

We present measurements of thermal and optical properties of poly(methyl methacrylate) (PMMA), PMMA modified by the addition of ethanol (MPMMA), and copolymers of methyl methacrylate with 2-hydroxyethyl methacrylate [P(HEMA:MMA)]. Spectral transmission of the polymers is excellent (alpha = 0.5 cm(-1) at 400 nm, decreasing to 0.04 cm(-1) at 633 nm). Measured laser damage thresholds of MPMMA and P(HEMA:MMA) show at least a twofold increase over PMMA. Thermal lensing measured in these hosts doped with Rhodamine 6G is shown to be similar (f = -450 mm for pump power of 200 mW in a 2-mm-diameter spot, scaling with pump intensity). Compared with MPMMA, P(HEMA:MMA) offers an improved surface quality and a more uniform dye distribution.

Felinine: a urinary amino acid of Felidae.

Felinine (2-amino-7-hydroxy-5,5-dimethyl-4-thiaheptanoic acid) has been identified in the urine of several members of the Felidae family including the cat (Felis catus). Rates of excretion of 95 mg/day have been recorded for entire male cats with entire female cats excreting around 19 mg/day. These high excretion rates in entire male cats may have a significant effect on the daily sulphur amino acid requirement. The isoamyl moiety of felinine seems to originate from the same isoprenoid pool as used for the synthesis of cholesterol in the cat. The sulphur in the felinine molecule appears to originate from cysteine, although some contradictory evidence exists. The site of synthesis and the method of transportation in the blood remain largely unknown. The biological significance of felinine to the animal is still a matter for speculation, but its function as a precursor to a pheromone seems likely. Recently, an accurate chemical assay for felinine has been developed that will allow investigation of felinine in different tissues and excretions and from a wider range of mammals.

An evaluation of repellents to suppress browsing by possums.

The efficacy in feeding suppression trials with possums (Trichosorus vulpecula Kerr) of six synthetic odorous chemicals uniquely associated with various of the Mustelidae species and of the red fox (Vulpes vulpes) has been evaluated with respect to several proprietary repellents. The predator odors, two proprietary repellents, and two other repellent formulations (olive oil in petroleum jelly and a synthetic fermented egg odor cocktail) were applied as 5% w/v solutions in paraffin to the foliage ofPinus radiata seedlings and the extent of browse compared with that on seedlings treated with Treepel, an effective egg-based repellent already available commercially. All four of the mustelid predator odors [(∓)-2-n-propylthietane, (∓)-3-n-propyl-1,2-dithiolane, 2,2-dimethylthietane, and 3,3-dimethyl-1,2-dithiolane] and the volatile compound from fox urine (Δ(3)-isopentenyl methyl sulfide) were shown to be more or at least equally effective compared to Treepel. This was true also of one commercial repellent Gori, which contained bitrex and the synthetic fermented egg formulation. The most effective compounds will be evaluated when administered with adhesives and surfactants in the further development of possum repellents with longer field lives.

Analysis of secretions from scent-producing glands of brushtail possum (Trichosorus vulpecula Kerr).

A characterization at a molecular level of the chemical composition of the secretions of the two pairs of paracloacal glands and of the sternal sebum of the brushtail possum (Trichosorus vulpecula Kerr) has been undertaken with a view to evaluating the potential of volatile "pheromone" components as species-specific attractants for use in novel baiting systems. Particular attention has been given to the respective fatty acid fractions produced by chemical hydrolysis, since these are believed to be the products of postemission microbial degradation (fermentation) of the secretions. In all instances, the highly complex distribution of the constituents present in these organic components of the secretions were shown to be virtually identical in adult males and females. A unique suite of low-molecular-weight branched-chain carboxylic acids has been shown to be produced by chemical degradation of the holocrine (oil-secreting) gland secretion. This odor signature is suggested to function as a unique "scenting-the-habitat" pheromone that might act as an attractant to all members of the species.