Headspace volatile oxylipins of Eastern Himalayan moss Cyathophorella adiantum extracted by sample enrichment probe.

Cyathophorella adiantum (Griff.) M. Fleisch.

Lizard epidermal gland secretions. II. Chemical characterization of the generation gland secretion of the sungazer, Cordylus giganteus.

In lizards, the epidermal glands of the femoral and precloacal regions are involved in the production of semiochemicals. In addition to its femoral glands, the giant girdled lizard, or sungazer, Cordylus giganteus, which is endemic to South Africa, has generation glands as an additional potential source of semiochemicals. These epidermal glands are described as glandular scales that overlay the femoral glands and are included in the normal epidermal profile located in the femoral (thigh) and anterior antebrachial (fore-leg) regions of the male sungazer.

Butenolides from plant-derived smoke: natural plant-growth regulators with antagonistic actions on seed germination.

Smoke plays an intriguing role in promoting the germination of seeds of many species following a fire. Recently, a bicyclic compound containing a condensed butenolide moiety, 3-methyl-2H-furo[2,3-c]pyran-2-one (1), was reported as a potent germination promoter from plant-derived smoke. In this study, a related butenolide, 3,4,5-trimethylfuran-2(5H)-one (2), which inhibits germination and significantly reduces the effect of 1 when applied simultaneously, was also isolated from plant-derived smoke.

Lizard epidermal gland secretions I: Chemical characterization of the femoral gland secretion of the sungazer, Cordylus giganteus.

The giant girdled lizard or sungazer, Cordylus giganteus, is endemic to South Africa. It has been suggested that in this species, as in other lizard species, epidermal glands in the femoral, pre-cloacal regions, and cloacal glands are the main sources of semiochemicals and that these secretions could play an important role at different levels of the social biology of the animals. To gain a better understanding of the nature of the femoral gland secretions of the sungazer, characterization of the constituents of the secretions was carried out.

The analysis of estrone and 17beta-estradiol by stir bar sorptive extraction-thermal desorption-gas chromatography/mass spectrometry: application to urine samples after oral administration of conjugated equine estrogens.

The development of a sensitive and solvent-free method for the measurement of estrone (E(1)) and 17beta-estradiol (17beta-E(2)) in human urine samples is described. The deconjugated estrogens were derivatized in situ with acetic acid anhydride and the derivatives were extracted directly from the aqueous samples using stir bar sorptive extraction (SBSE). The compounds containing a secondary alcohol function are further derivatized by headspace acylation prior to thermal desorption and gas chromatography/mass spectrometry (GC/MS).

Simplified analysis of organic compounds in headspace and aqueous samples by high-capacity sample enrichment probe.

A sample enrichment probe (SEP) consisting of a thin rod of an inert material and provided at one end with a short sleeve of polydimethylsilicone rubber was used for the high-capacity sample enrichment of analytes from gaseous and aqueous samples for analysis by gas chromatography (GC) and its hyphenated techniques. The silicone rubber was exposed to the analytical sample, after which the end of the rod carrying the silicone rubber was introduced into the injector and the analytes thermally desorbed and analysed by GC. This technique is similar to, but differs from, solid-phase microextraction (SPME) in that a much larger volume of the sorptive phase is employed, the sorptive phase is not introduced into the inlet of the GC via a needle and the injector is opened to the atmosphere for the introduction and removal of the SEP.

Elemental sulfur identified in urine of cheetah, Acinonyx jubatus.

The urine of the cheetah, Acinonyx jubatus, is almost odorless, and probably for this reason, it has not attracted much attention from scientists. Using gas chromatography-mass spectrometry, we identified 27 and 37 constituents in the headspace vapor of the urine of male and female cheetah, respectively. These constituents, composed of hydrocarbons, short-chain ethers, aldehydes, saturated and unsaturated cyclic and acyclic ketones, 2-acetylfuran, dimethyl disulfide, dimethyl sulfone, phenol, myristic acid (tetradecanoic acid), urea, and elemental sulfur, are all present in the headspace vapor in very small quantities; dimethyl disulfide is present in such a low concentration that it cannot be detected by the human nose.

Characterization of dog repellent factor from cuticular secretion of female yellow dog tick, Haemaphysalis leachi.

During its natural life cycle, the yellow dog tick, Haemaphysalis leachi, has three hosts, and it has to spend enough time on each of them to complete a blood meal. When irritated, the females of this tick species produce a cuticular secretion that contains a dog-repelling allomone. This improves the tick's chances of survival by deterring the dog from biting the tick off its body.

Urinalysis of 4-hydroxynonenal, a marker of oxidative stress, using stir bar sorptive extraction-thermal desorption-gas chromatography/mass spectrometry.

A simple and fast method for the measurement of 4-hydroxynonenal (4HNE), a highly toxic end-product of lipid peroxidation, in urine samples is described. The method combines stir bar sorptive extraction (SBSE) with two derivatization steps, followed by thermal desorption and GC/MS. 4HNE is derivatized in situ with O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine and the oxime is extracted from the aqueous phase with SBSE.

Radiosynthesis and evaluation of two novel 123I-labeled 2-methyl-4-nitroimidazole derivatives as potential infection imaging agents.

Introduction: The inflammation- and infection-seeking properties of (131)I-labeled ornidazole, a 5-nitroimidazole derivative, have recently been reported. Whole-body images in rabbits showed a more rapid uptake in inflamed areas compared to (67)Ga. In the present study, two novel (123)I-labeled 2-methyl-4-nitroimidazole derivatives were synthesized and their infection-seeking properties compared with those of (67)Ga and (123)I-labeled ornidazole.