| the application of mass spectrometry to the study of evolutionary trends in amphibians. | the glandular secretions of the skin of litoria rubella specimens collected from five locations on the eastern seaboard of queensland (australia) contain the three tryptophyllin peptides phe pro trp leu (nh2), phe pro trp pro (nh2) and phe pro phe pro trp leu (nh2). the relative proportions of these peptides in the glandular secretion are associated with geographic location, i.e. phe pro trp pro (nh2) is a minor component of the peptide mixture in frogs from southern queensland, but becomes sign ... | 1996 | 8563019 |
| mosquito repellents in frog skin. | the search for novel insect repellents has been driven by health concerns over established synthetic compounds such as diethyl-m-toluamide (deet). given the diversity of compounds known from frog skin and records of mosquito bite and ectoparasite infestation, the presence of mosquito repellents in frogs seemed plausible. we investigated frog skin secretions to confirm the existence of mosquito repellent properties. litoria caerulea secretions were assessed for mosquito repellency by topical appl ... | 2006 | 17148373 |
| skin peptides from anurans of the litoria rubella group: sequence determination using electrospray mass spectrometry. opioid activity of two major peptides. | many species of frogs of the genus litoria secrete bioactive peptides from their skin glands. these peptides are normally host-defence compounds and may have one, or more of the following activities; smooth muscle contraction, analgesic, antimicrobial, antiviral, lymphocyte proliferator (immunomodulator) and neuronal nitric oxide synthase (nnos) inactivation. two frog species of the litoria rubella group that have been studied before, namely, litoria electrica and litoria rubella, are different ... | 2009 | 19291693 |
| diversity and community composition of vertebrates in desert river habitats. | animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. this tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. in this study, we first test the hypothesis that productive riparian sites in arid australia support higher vertebrate diversity than other desert habitats, and then elucidate the ... | 2015 | 26637127 |
| an unusual kynurenine-containing opioid tetrapeptide from the skin gland secretion of the australian red tree frog litoria rubella. sequence determination by electrospray mass spectrometry. | the kyn-containing peptide fp-kyn-l(nh(2)) is an unusual minor component of the skin peptide profile of the australian red tree frog litoria rubella collected from an area within a 20 kilometre radius of alice springs in central australia. the structure was determined by electrospray mass spectrometry and synthesis. the major component of the skin secretion is the analogous tryptophyllin peptide fpwl(nh(2)). both peptides show opioid activity at 10(-7) m, and are likely to act via the μ opioid r ... | 2011 | 21598333 |
| comparative analysis of cutaneous evaporative water loss in frogs demonstrates correlation with ecological habits. | most frog species show little resistance to evaporative water loss (ewl), but some arboreal species are known to have very high resistances. we measured ewl and cutaneous resistance to evaporation (rc) in 25 species of frogs from northern australia, including 17 species in the family hylidae, six species in the myobatrachidae, and one each in the bufonidae and the microhylidae. these species display a variety of ecological habits, including aquatic, terrestrial, and arboreal specialisations, wit ... | 2008 | 16052451 |
| a comparison of the positive- and negative-ion mass spectra of bio-active peptides from the dorsal secretion of the australian red tree frog, litoria rubella. | the collision-induced tandem mass spectral data for mh+ and [m-h]- ions from six bio-active peptides from litoria rubella are compared. backbone cleavages of [m-h]- ions provide sequencing information for five of the peptides [e.g. phe pro trp leu (nh2) and pglu phe pro trp leu (nh2)] and in these cases, the negative-ion spectra are as informative as the positive-ion spectra. side-chain cleavages are also noted in these spectra. for example, (i) when trp is present, the loss of c9h7n (129 u) com ... | 1996 | 8759334 |