Physiological Properties. Toxicity

Pb(CH3)4 is highly poisonous. Special care is necessary in handling the compound since its vapor pressure is appreciably high, and its faint smell is almost imperceptible after a short time [1]. 

Pb(CH3)4 is absorbed through the skin, the mucosa of the alimentary tract, and the alveoli. Being lipid soluble it is concentrated in the brain, body fat, and liver. Manifestations of poisoning are dominated by involvement of the central nervous system [22] see also [41, 53, 66, 95, 98, 99]. Symptoms of Pb(CH3)4 as well as of Pb(C2H5)4 intoxication include insomnia, excessive dreaming, toxic psychosis, headaches, hyperactivity, ataxia, emotional instability, erratic behavior, delusions, convulsions, and mania [66, 100]. However, there is also a case reported with a patient showing no such symptoms [50]. Hematological abnormalities are rarely observed [66]. 

Pb(CH3)4 itself does not have toxic properties, the toxic effects being due to trimethyllead compounds formed by dealkylation in the liver [58, 59]. Absorption of Pb(CH3)4 is associated with an increase in urinary 5-aminolevulinic acid levels [45]. Metabolism and toxicokinetics of Pb(CH3)4 and other alkyllead compounds are reviewed in [101]. 

First aid in case of contact, inhalation, or ingestion of Pb(CH3)4 is described in [110]. No specific therapeutic measures for treatment of patients intoxicated by Pb(CH3)4 have been reported. Chelation therapy with calcium disodium versenate is described to be justified in 

Pb(CH3)4 administered to mice by Intraperitoneal Injection Is converted Into trimethyllead species. The LD50 value In mice is given as 14.3 mg/kg [37]. In the muscle of mice, intoxicated subacutely or chronically with Pb(CH3)4, morphological anomalies concerning mostly the inner part of the blood vessels, sarcoplasmic reticulum, and mitochondria are observed [82]. The effect of microparticles from pyrolysis of Pb(CH3)4 and other antiknock compounds on lungs of mice was Investigated [62]. For studies of intoxication In mice by Pb(CH3)4, see also [8]. The toxicity of Pb(CH3)4 solutions to mice and other animals In combination with other compounds, mainly fuel additives, was studied [20, 25, 26]. 

Intoxication by Pb(C2H5)4 induces a syndrome different from that associated with inorganic lead [5]. Symptoms characteristic of poisoning with inorganic lead are not observed in poisoning with Pb(C2Hs)4 [101]. 

The latency period between acute exposure to Pb(C2H5 4 and the onset of symptoms varies from a few hours in serious cases to as much as 10 d [437]. In serious cases death has followed in 36 h or after several days [437]. However, even after acute toxic psychosis, patients are apparently completely recovered in 2 to 6 months, although minor symptoms and signs may persist. In some cases intellectual impairment and decreased working ability have remained as long-term sequelae [378, 437]. For prognosis of recovery, see [297]. For neurobehavioral effects, see [435]. 

Lead distribution in organs of men intoxicated by Pb(C2H5)4 has been determined [7]. 

Pb(C2H5 4 itself does not have toxic properties. The toxic effects are due to triethyllead compounds formed by dealkylation in the liver [163, 357, 419] see also [184]. In contrast to the rat, [Pb(C2H5)2] was determined as the main metabolite of Pb(C2H5 4 in man [258]. 

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Substances Hazardous to Health, See also Toxic chemicals, 19, 138, 140 Substitution, 133 Sulphur, 30 Sulphur dioxide first aid, 280, 306 physical properties, 306 physiological properties, 69, 71, 304, 305 precautions, 305, 306 vapour pressure, 305 Suppression, 135 Surface area effects, 50, 199 Symbols for dangerous substances, 446, 452 Synthetic lubricants, 159 Synthetic resins, 172 Systemic poisons, 19, 77... 

The myotic, toxic and other physiological properties of the dialkyl phosphorofluoridates, POF(O.R)2, have been fully described on pp. 42, 68 et seq. In 19444 we described an analogous compound of the phosphorofluoridite series, namely, diethyl phosphorofluoridite, PF(OEt)2. This could not be prepared by the action of sodium fluoride on the corresponding diethyl phosphorochloridite (the preparation of which is considered below). We obtained it, however, by the action of ethyl alcohol on phosphorus dichlorofluoride,... 

This ester, isopropyl methylphosphonofluoridate (X), is a colourless liquid. It is more toxic than D.F.P., but shows very similar physiological properties, intense myosis, respiratory collapse, powerful anticholinesterase activity, etc. The liquid passes rapidly through the skin. At the end of World War II, two plants were under construction in Germany for the production of the material on a large scale. 

We see from the above that there is a striking alternation in the physiological properties of w-fluorocarboxylic esters of the general formula of F- [CH2]w-C02.R. Thus when n is an odd number the compound is highly toxic to animals, whereas when n is even the compound is non-toxic. All the toxic compounds are powerful convulsant poisons and showed symptoms of the fluoroacetate type. 

Dicyclohexyl-18-crown-6 polyether possesses unusual physiological properties which require care in its handling. It is likely that other cyclic polyethers with similar (iomplcxing power are also toxic, and should be handled with ccpml care. 

Physiological Properties. See under Toxicity Power. See under Explosive Strength Pressure Developed on Explosion of One Kilogram in One Liter— I2498kg/cm2 for NGc vs 12048 for NG (Ref 6, p 298 Ref 19, p 132) Reaction on Explosion, See Decomposition (or Explosion) Equation... 

C. Physiological Properties 1. Toxic or Insecticidal Simple and Complex Benzofurans... 

Furocoumarins, such as xanthotoxin (20), are also strongly ichthyo-toxic.35 It is not yet possible to deduce the toxophore responsible for these physiological properties. 

In recent years, many physiological properties of melatonin have been described resulting in much attention in the development of synthetic compounds possessing indole ring [94]. These compounds have structural similarity to melatonin. However, the therapy of oxidative stress-related diseases has not found satisfactory application in clinical practice. This may be due to the insufficient efficacy of drugs available, their unsuitable pharmacokinetics, side effects, and toxicity. 

Chirality plays a major role in biological processes and enantiomers of a particular molecule can often have different physiological properties. In some cases, enantiomers may have similar pharmacological properties with different potencies for example, one enantiomer may play a positive pharmacological role, while the other can be toxic. For this reason, advancements in asymmetric synthesis, especially in the pharmaceutical industry and life sciences, has led to the need to assess the enantiomeric purity of drugs. Chromatographic chiral separation plays an important role in this domain. Today, there are a large number of chiral stationary phases on the market that facilitate the assessment of enantiomeric purity. 

C. Physiological Properties 1. Toxic or Insecticidal Simple and Complex Benzofurans Pesticidal carbamates with 2,3-dihydrobenzofuran structures carbo-furan or NIA-9242 is methyl 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-carbamate (14) NIA 10559 (15) is its 4-chloro, and NIA 10586 (16) its 4-methyl derivative. Benzofuran itself, 2,3-dibromobenzofuran and 2,3-dihydro-3-oxobenzofuran and their derivatives have very low or zero activity. ... 

Resistance to pesticides is the development of an ability in a population of a pest to tolerate doses of toxicants that would prove lethal to the majority of individuals within the same species. The term behavioristic resistance describes the development of the ability to avoid a dose that would prove lethal. Resistance is distinct from the natural tolerance shown by some species of pests. Here a biochemical or physiological property renders the pesticide ineffective against the majority of normal individuals. 

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