Volatile toxins

Reports on volatile toxins originate primarily from studies on plants found in more arid regions of the world. Among the genera shown to release volatiles are Artemisia, Eucalyptus, and Salvia (4). When identified, the compounds were found to be mainly mono- and sesquiterpenes. Work of Muller and associates (13) has indicated that vapors of these compounds may be absorbed by surrounding plants, and that the chemicals can be absorbed from condensate in dew, or by plant roots after the compounds reach the soil. ... 

Less Typical Cases arise in which the usual biological materials are not sufficient to answer the pertinent forensic questions. The typie of toxin suspected, the mechanism of action, and the state of e body dictate which atypical materials would be submitted. If exposure to a volatile toxin might be involved, a sample of lung tissue would be useful. If a body is decomposed or burned, hair, bone, or insects associated with it may be all that is available for analysis. Other materials, such as muscle tissue, have been studied, but these samples would not be the first choice in many cases. 

The common hemlock, Conium maculatum, contain five alkaloids. Power and Tutin found a similar mixture in fool s parsley, and a volatile alkaloid resembling coniine i.s stated to occur in certain aroids. According to Svagr, water hemlock Cicuta virosa) owes its poisonous properties to toxin and not to cicutine, a name sometimes used as a synonym for coniine. The toxic properties of hemlock juice have been known ftom very early times thus it was the chief ingredient in the poison administered to criminals by the Greeks. The leaves and the unripe fruits are the parts used in medicine. The following are the names and formulae of the alkaloids —... 

With the development of HPLC, a new dimension was added to the tools available for the study of natural products. HPLC is ideally suited to the analysis of non-volatile, sensitive compounds frequently found in biological systems. Unlike other available separation techniques such as TLC and electrophoresis, HPLC methods provide both qualitative and quantitative data and can be easily automated. The basis for the HPLC method for the PSP toxins was established in the late 1970 s when Buckley et al. (2) reported the post-column derivatization of the PSP toxins based on an alkaline oxidation reaction described by Bates and Rapoport (3). Based on this foundation, a series of investigations were conducted to develop a rapid, efficient HPLC method to detect the multiple toxins involved in PSP. Originally, a variety of silica-based, bonded stationary phases were utilized with a low-pressure post-column reaction system (PCRS) (4,5), Later, with improvements in toxin separation mechanisms and the utilization of a high efficiency PCRS, a... 

The PSP toxins represent a real challenge to the analytical chemist interested in developing a method for their detection. There are a great variety of closely related toxin structures (Figure 1) and the need exists to determine the level of each individually. They are totally non-volatile and lack any useful UV absorption. These characteristics coupled with the very low levels found in most samples (sub-ppm) eliminates most traditional chromatographic techniques such as GC and HPLC with UVA S detection. However, by the conversion of the toxins to fluorescent derivatives (J), the problem of detection of the toxins is solved. It has been found that the fluorescent technique is highly sensitive and specific for PSP toxins and many of the current analytical methods for the toxins utilize fluorescent detection. With the toxin detection problem solved, the development of a useful HPLC method was possible and somewhat straightforward. 

Gyrometrin toxin is produced by the false morel (Gyromitra esculenta), a short-stalked mushroom with a brain-like cap of dark brown color. Fruiting bodies of this mushroom appear mostly in spring and are valued as edible, even as delicacies. While many people consume the mushroom without any troubles, others become ill, some of them severely. It has been shown that the toxin content may vary with growth conditions, such as altitude and temperature. More probably, however, the variation is caused by differences in handling or cooking as the toxic components are volatile. The toxin has been detected in cooked, frozen, and dried specimens. 

Other aspects of implementing indirect volatile defenses, as recently discussed in several excellent reviews [17, 94, 95], will include the assessment of timing and synergy of volatile emissions with direct defense responses of the herbivore-damaged plant, especially if indirect defense strategies will be integrated with toxin-based pest control strategies. 

Since the PSP toxins lack native fluorescence, useful UV absorption or adequate volatility, more traditional analytical procedures such as gas chromatography or spectrometry have proven ineffective in assaying for the toxins. A number of chemical assays for the toxins have been developed though with the fluorometric method of Bates and Rapoport (3 ) proving to be the most useful to date. This assay is based on oxidation of the PSP toxins under alkaline conditions to fluorescent derivatives. The assay is highly sensitive, fairly specific for the PSP toxins and was incorporated into a detection method in the column chromatographic separation of the toxins described by Buckley et al (4 ). 

All the present evidence points to phytotoxic steam-volatile fatty acids/ particularly acetic, being a major microbiological factor responsible for the crop damage, and the conditions of ecological significance referred to earlier have been satisfied. However, the toxin is produced only in the straw tissue and its concentration declines exponentially with distance from the straw (13). A correlation of soil acetic acid content with phytotoxicity is therefore neither expected nor found. 

Whatever quantity of toxin is released generally enters the soil, where several things may happen to it. The order of the second, third, and fourth steps in Figure 1 is not necessarily the order in which the reactions actually occur. In fact, if the toxin is a volatile substance, these steps may be skipped entirely. In most cases, however, it appears that allelopathic chemicals enter the soil. 

As yet, there is no specific pattern in how induced volatiles affect the attractiveness of plants to herbivores. Obviously, the responses will be correlated with fitness consequences. Insects vulnerable to natural enemies and induced plant toxins are, therefore, expected to avoid induced plants, whereas those that are adapted to plant defenses and/or benefit from aggregating are likely to be attracted. Comparative studies could test such hypotheses. 

Such high photocatalytic reactivities of photo-formed e and h can be expected to induce various catalytic reactions to remove toxic compounds and can actually be applied for the reduction or elimination of polluted compounds in air such as NO cigarette smoke, as well as volatile compounds arising from various construction materials, oxidizing them into CO2. In water, such toxins as chloroalkenes, specifically trichloroethylene and tetrachloroethene, as well as dioxins can be completely degraded into CO2 and H2O. Such highly photocatalyti-... 

If you re going to paint your nursery, plan on having it done when you can be out of the house for a week (it all depends on the paint, but three weeks would be even better), ventilate extremely well, and be absolutely sure to use a zero-VOC paint with little to no hazardous fumes. The VOC (or volatile organic compound) content is usually listed in grams per liter, ranging from 5 to 200. Even zero-VOC paints have some amount of toxins. Currently the non-milk-based paint we re the happiest with is Safecoat (www.afmsafecoat.com). Milk-based paint is just that, and while pure, it s less durable than non-milk-based paint. For more on paint, see pg.48. 

E1 Metabolism of low molecular-weight toxins, fluorinated ether volatile... 

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