Nonacosane

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.3X10+8(SRC), determined from a structure estimation method(2), indicates that nonacosane is expected to be immobile in soil. Volatilization of nonacosane from moist soil surfaces is expected given an estimated Henry's Law constant of 1150 atm-cu m/mole(SRC), using a fragment constant estimation method(2). However, adsorption to soil is expected to attenuate volatilization(SRC). Nonacosane is not expected to volatilize from dry soil surfaces(SRC) based upon an extrapolated vapor pressure of 4.30X10-10 mm Hg at 25 °C(3). Biodegradation oxygen consumption values of 8.2 and 7.8 ug/mL for analogous tetracosane (C24) and dotriacontane (C32), respectively, using a soil suspension(4) indicate that biodegradation of nonacosane may be a slow environmental fate process in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.3X10+8(SRC), determined from a structure estimation method(2), indicates that nonacosane is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 1150 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 6 hours and 8 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column(SRC). The estimated volatilization half-life from a model pond is more than 2 years if adsorption is considered(4). According to a classification scheme(5), an estimated BCF of 3(SRC), from an estimated log Kow of 14.58(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Biodegradation oxygen consumption values of 8.2 and 7.8 ug/mL for analogous tetracosane (C24) and dotriacontane (C32), respectively, using a soil suspension(6) indicate that biodegradation of nonacosane may be a slow environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), nonacosane, which has an extrapolated vapor pressure of 4.30X10-10 mm Hg at 25 °C(2), will exist in solely particulate phases in the ambient atmosphere. Particulate-phase nonacosane may be removed from the air by wet and dry deposition(SRC). Nonacosane does not contain chromophores that absorb at wavelengths >290 nm(3) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Nonacosane is a higher n-alkane containing 29 carbon atoms (C29). HUMAN EXPOSURE AND TOXICITY: A case report described human disorder characterized by the accumulation of plant long-chain n-alkanes in viscera of a human patient. Diffuse visceral granuloma containing lipophilic crystallized material showed the presence of long-chain n-alkanes including n-nonacosane. Study of n-alkane distribution in patient tissues showed a major accumulation in lumbo-aortic lymph nodes, adrenal glands, lung and liver; significantly lower amounts were detected in myocardium and kidney, whereas no detectable level was found in brain. ANIMAL STUDIES: Nonacosane can contribute to the "paraffin liver" in cows. The very large quantities of the abnormal substance in the cow livers indicate low toxicity, and evidently accumulation over long periods of time.

Nonacosane detections in plants used in food and medicinal applications(1). /Nonacosane/

n-Nonacosane detections in plants used in food and medicinal applications(1).

Using a structure estimation method based on molecular connectivity indices(1), the Koc of nonacosane can be estimated to be 1.3X10+8(SRC). According to a classification scheme(2), this estimated Koc value suggests that nonacosane is expected to be immobile in soil.

URBAN/SUBURBAN: Nonacosane was detected in particulate air samples from Georgia Tech campus, GA at mean concentrations of 3.20 and 2.30 ng/cu m for summer 2005 and winter 2006, respectively(1). A mean nonacosane concentration of approximately 20 ng/cu m was reported in the particulate phase of air samples collected in an urban and industrialized area in Prato, Italy during 2002(2). Nonacosane concentration was 15.4 and 10.1 ng/cu m in particulate phase in the summer and winter, respectively; the concentration was 1.2 and 0.9 ng/cu m in the vapor phase in summer and winter, respectively; samples were collected in an urban area in Nagoya, Japan in 1991(3).

RURAL/REMOTE: Nonacosane was detected in particulate air samples from a rural area of Yorkville, GA at mean concentrations of 0.54 and 1.61 ng/cu m for summer and winter, respectively(1).

SOURCE DOMINATED: Nonacosane was detected in the gas and particle phase of tailpipe emissions from non-catalyst equipped gasoline powered motor vehicles at concentrations of 2.8 and 95 ug/km, respectively(1). Nonacosane was detected at 140-1660 pg/cu m with a mean of 620 pg/cu m in particulate air samples collected near a highway in Raleigh, NC; concentrations in samples collected 275 meters from the highway contained 230-2740 pg/cu m with a mean of 710 pg/cu m(2). Nonacosane was detected in particulate air samples from an interstate highway in Georgia at a mean concentration of 5.96 and 3.16 ng/cu m for summer and winter, respectively(3).

/CASE REPORTS/ We report a case of n-nonacosane storage disease, which went undiagnosed until the death of a 55-year-old farmer. Clinical, histological, and biochemical features are discussed. n-Nonacosane storage was identified by gas chromatographic-mass spectrometric analysis of different tissue extracts, n-nonacosane concentration reaching 1.2 mg/g of lung tissue and 0.32 mg/g of liver tissue. It was possible to rule out a work-induced intoxication, and n-nonacosane storage appeared to be accounted for by a lifelong, heavy consumption of unpeeled apples and Brussels sprouts.

/CASE REPORTS/ This report deals with a new human disorder characterized by the accumulation of plant long-chain n-alkanes in viscera of a human patient. Lipid analysis of tissues from an adult male after sudden death (affected with diffuse visceral granuloma containing lipophilic crystallized material) showed the presence of abnormal compounds identified as long-chain n-alkanes with 29 (n-nonacosane), 31 (n-hentriacontane) and 33 carbons (n-tritriacontane). Study of n-alkane distribution in patient tissues showed a major accumulation in lumbo-aortic lymph nodes, adrenal glands, lung (the highest levels were found in lung granulomas) and liver; significantly lower amounts were detected in myocardium and kidney, whereas no detectable level was found in brain. On the basis of the structural composition and of the tissue distribution of the accumulated n-alkanes, their dietary (plant) origin and the pathophysiological mechanism of the storage are discussed.

Catfish samples collected from seven locations in the Arabian Gulf had concentrations of C29 alkanes (possibly nonacosane) ranging from not detected to 2.2 ng/g wet weight(1). Mean nonacosane concentrations of 265.9, 132.4, and 207.7 ng/g dry weight were reported in intertidal limpet (Patella ulyssiponensis) from 3 sampling stations in the Canary Islands during 1991-1993(2). Mean nonacosane concentrations of 505.3, 333, and 493 ng/g dry weight were reported in intertidal limpet (Patella crenata) collected during May 1991-December 1993 at 3 sampling stations in the Canary Islands (3).

AEROBIC: Oxygen consumption of 8.2 and 7.8 ug/mL over 10 days was reported for straight chain alkanes tetracosane (C24) and dotriacontane (C32), respectively, using a soil suspension of Hudson-Collamer silt loam soil incubated in the dark at 25 °C(1). By analogy, these test results suggest that biodegradation rates are slow for long chain alkanes such as nonacosane (C29) under these conditions(SRC).

PURE CULTURE: Using 5 different marine bacterial strains and 4 different nitrogen sources, biodegradation of petroleum oil was examined under aerobic conditions at 26 °C for 10 days. Data reported for similar long chain alkanes, hexacosane (C26), octacosane (C28), and triacontane (C30), which were present as components of the petroleum oil, indicate that these compounds were degraded by 4 of 5 bacterial strains with certain nitrogen sources, and consumption ranged from 5 to 96%(1). Other long chain alkanes such as nonacosane (C29) may behave similarly(SRC).