植醇

植醇（Phytol）是一种链状的二萜醇，分子式C 20H 40O，用于维生素E和维生素K1的合成前体。植醇是叶绿素分子侧链结构的组成部分。反芻動物的消化道中，叶绿素分解的游离植醇被动物吸收，转化为植烷酸储存在脂肪中。植醇在鲨鱼肝臟中轉化为姥鮫烷。 有一种名为雷弗素姆病（英语：Refsum disease）的常染色体隐性遗传病，患者体内植烷酸大量积累，导致多发性周围神经病变、小脑共济失调（英语：cerebellar ataxia）、視網膜色素變性、嗅觉缺失（英语：anosmia）和耳聋。尽管人体不能通过降解叶绿素获取植醇，但能将游离植醇转化为植烷酸。因此，雷弗素姆病患者必须严格控制植烷酸及游离植醇的摄取量。有研究系统测定了各种食材中植醇和植烷酸含量，发现食物中游离植醇含量一般不及该病患者需要控制饮食的浓度；植物及植物油中不含植烷酸，而反刍类动物和鱼类的脂肪含有一定比例的植烷酸。 有研究称漆树跳甲（英语：Blepharida rhois）等昆虫使用叶绿醇及其代谢产物（例如植烷酸）作为防止自己被捕食的化学威慑剂。这些化合物摄取自它的宿主植物。 间接的证据已经证明大型类人猿在植物的后肠发酵过程中可获得数量可观的植烷酸，这点与人类不同。 植醇可能是生物圈中最丰富的链状萜类。植醇及其代谢产物可用作水生环境的生化示踪剂。 日化行业中，植醇用于化妆品、洗发水、厕所肥皂、家用清洁剂和洗涤剂。世界年消耗量约0.1–1.0吨。 Netscher, Thomas. Synthesis of Vitamin E. Litwack, Gerald (编). Vitamin E. Vitamins & Hormones 76. 2007: 155–202. ISBN 978-0-12-373592-8. doi:10.1016/S0083-6729(07)76007-7.  Daines, Alison; Payne, Richard; Humphries, Mark; Abell, Andrew. The Synthesis of Naturally Occurring Vitamin K and Vitamin K Analogues. Current Organic Chemistry. 2003, 7 (16): 1625–34. doi:10.2174/1385272033486279.  Van Den Brink, D. M.; Wanders, R. J. A. Phytanic acid: Production from phytol, its breakdown and role in human disease. Cellular and Molecular Life Sciences. 2006, 63 (15): 1752–65. PMID 16799769. doi:10.1007/s00018-005-5463-y.  Wierzbicki, A.S. Peroxisomal disorders affecting phytanic acid α-oxidation: A review. Biochemical Society Transactions. 2007, 35 (5): 881–6. PMID 17956237. doi:10.1042/BST0350881.  Komen, J.C.; Wanders, R.J.A. Peroxisomes, Refsum's disease and the α- and ω-oxidation of phytanic acid. Biochemical Society Transactions. 2007, 35 (5): 865–9. PMID 17956234. doi:10.1042/BST0350865.  Brown, P. June; Mei, Guam; Gibberd, F. B.; Burston, D.; Mayne, P. D.; McClinchy, Jane E.; Sidey, Margaret. Diet and Refsum's disease. The determination of phytanic acid and phytol in certain foods and the application of this knowledge to the choice of suitable convenience foods for patients with Refsum's disease. Journal of Human Nutrition and Dietetics. 1993, 6 (4): 295–305. doi:10.1111/j.1365-277X.1993.tb00375.x.  Vencl, Fredric V.; Morton, Timothy C. The shield defense of the sumac flea beetle, Blepharida rhois (Chrysomelidae: Alticinae). Chemoecology. 1998, 8 (1): 25–32. doi:10.1007/PL00001800.  Watkins, Paul A; Moser, Ann B; Toomer, Cicely B; Steinberg, Steven J; Moser, Hugo W; Karaman, Mazen W; Ramaswamy, Krishna; Siegmund, Kimberly D; Lee, D Rick; Ely, John J; Ryder, Oliver A; Hacia, Joseph G. Identification of differences in human and great ape phytanic acid metabolism that could influence gene expression profiles and physiological functions. BMC Physiology. 2010, 10: 19. PMC 2964658 . PMID 20932325. doi:10.1186/1472-6793-10-19.  Moser, Ann B; Hey, Jody; Dranchak, Patricia K; Karaman, Mazen W; Zhao, Junsong; Cox, Laura A; Ryder, Oliver A; Hacia, Joseph G. Diverse captive non-human primates with phytanic acid-deficient diets rich in plant products have substantial phytanic acid levels in their red blood cells. Lipids in Health and Disease. 2013, 12: 10. PMC 3571895 . PMID 23379307. doi:10.1186/1476-511X-12-10.  Rontani, Jean-François; Volkman, John K. Phytol degradation products as biogeochemical tracers in aquatic environments. Organic Geochemistry. 2003, 34 (1): 1–35. doi:10.1016/S0146-6380(02)00185-7.  McGinty, D.; Letizia, C.S.; Api, A.M. Fragrance material review on phytol. Food and Chemical Toxicology. 2010, 48: S59–63. PMID 20141879. doi:10.1016/j.fct.2009.11.012.  IFRA (International Fragrance Association（英语：International Fragrance Association）), 2004. Use Level Survey, August 2004.