Rats absorb 2,6,10,14-tetramethylhexadecane (phytane) from the intestinal tract intact into the lymph. Intestinal microbes appeared to be unable to metabolize phytane in vitro. Rats metabolized phytane to (a) a tertiary alcohol tentatively identified as 2,6,10,14-tetramethylhexadecan-2-ol, and (b) a variety of short-chain acids which were excreted in the urine. These included acetic, isobutyric, and 2-methylbutyric acids. CO2 was a very minor product, even following intravenous injection of phytane. Lipoidal intermediates in the degradation of phytane could not be detected, suggesting that the initial attack on the molecule was rate-limiting. Urinary excretion products were apparent following oral but not intravenous, intraperitoneal, or subcutaneous administration of phytane. However, the tertiary alcohol was produced following both oral and intraperitoneal administration. ...
IDENTIFICATION AND USE: Phytane is a hydrocarbon found in rock specimens 2.5-3 billion years old. Know to be synthesized only by living organisms (is a derivative of chlorophyll) and to withstand heat and pressure, so helps to date the existence of life on earth (biomarker). HUMAN EXPOSURE AND TOXICITY: There are no data available. ANIMAL STUDIES: Rats absorbed phytane from the intestinal tract intact into the lymph.
/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on the left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Aliphatic hydrocarbons and related compounds/
/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool. Administer activated charcoal ... . Treat frostbite with rapid rewarming techniques ... ./Aliphatic hydrocarbons and related compounds/
/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag-valve-mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Aliphatic hydrocarbons and related compounds/
Emergency and supportive measures. 1. General. Provide basic supportive care for all symptomatic patients. Maintain an open airway and assist ventilation if necessary. Administer supplemental oxygen. Monitor arterial blood gases or oximetry, chest radiographs, and ECG and admit symptomatic patients to an intensive care setting. Use epinephrine and other beta-adrenergic medications with caution in patients with significant hydrocarbon intoxication because arrhythmias may be induced. 2. Pulmonary aspiration. Patients who remain completely asymptomatic after 4-6 hours of observation may be discharged. In contrast, if the patient is coughing on arrival, aspiration probably has occurred. Administer supplemental oxygen and treat bronchospasm and hypoxia if they occur. Do not use steroids or prophylactic antibiotics. 3. Ingestion. In the vast majority of accidental childhood ingestions, less than 5-10 mL is actually swallowed and systemic toxicity is rare. Treatment is primarily supportive. Injection. For injections into the fingertip or hand, especially those involving a high-pressure paint gun, consult with a plastic or hand surgeon immediately, as prompt wide exposure, irrigation, and debridement are often required. /Hydrocarbons/
Rats absorb 2,6,10,14-tetramethylhexadecane (phytane) from the intestinal tract intact into the lymph. Intestinal microbes appeared to be unable to metabolize phytane in vitro. Rats metabolized phytane to (a) a tertiary alcohol tentatively identified as 2,6,10,14-tetramethylhexadecan-2-ol, and (b) a variety of short-chain acids which were excreted in the urine. These included acetic, isobutyric, and 2-methylbutyric acids. CO2 was a very minor product, even following intravenous injection of phytane. Lipoidal intermediates in the degradation of phytane could not be detected, suggesting that the initial attack on the molecule was rate-limiting. Urinary excretion products were apparent following oral but not intravenous, intraperitoneal, or subcutaneous administration of phytane. However, the tertiary alcohol was produced following both oral and intraperitoneal administration. ...
This study was concluded to elucidate a pathway for formation of C19 isoprenoid hydrocarbons (isops) in petroleum from chlorophylls. C19 isops are predominantly produced when dihydrophytol is heated at 320 °C for a period ranging from 1 to 5 h under vacuum while C20 isops are predominantly produced when chlorophyll a or phytol is heated. A radical chain reaction of decomposition of dihydrophytol is proposed as plausible pathway for producing C19 isops.
这项研究旨在阐明石油中叶绿素形成 C19 异构烃（isops）的途径。在真空条件下，将双氢植物醇在 320 °C 下加热 1 至 5 小时，主要会产生 C19 异丙醇，而加热叶绿素 a 或植物醇，则主要会产生 C20 异丙醇。二氢植物醇分解的自由基链反应被认为是产生 C19 异构体的可能途径。
The formation features of C10–C20 regular petroleum isoprenanes
作者：G. N. Gordadze、M. V. Giruts、A. R. Poshibaeva、V. N. Koshelev
DOI：10.1134/s0965544116080077
日期：2016.8
To model the formation processes of C-10-C-20 petroleum isoprenanes, thermolysis of regular and irregular C-20-C-40 isoprenanes (phytane, crocetane, squalane, and lycopane) and the suggested precursors of regular petroleum isoprenanes (phytol and isophytol) has been conducted. It has been shown that the thermolysis of these compounds results in the formation of regular, irregular, and pseudoregular isoprenanes; the trends in their distribution have been revealed; and the retention indices have been determined. It has been assumed that the pristane/phytane ratio, which is used in petroleum geochemistry, should be treated with caution.
