薄荷醇

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薄荷醇,有機化合物,無色針狀結晶或粒狀。為薄荷和歐薄荷精油中的主要成分,以遊離和酯的狀態存在薄荷醇有 8種異構體,它們的呈香性質各不相同左旋薄荷醇具有薄荷香氣並有清涼的作用,消旋薄荷醇也有清涼作用,其他的異構體無清涼作用。可用作牙膏香水飲料糖果等的賦香劑。在醫藥上用作刺激葯,作用於皮膚粘膜,有清涼止癢作用;內服可作為驅風葯,用於頭痛及鼻;咽;喉炎症等。

薄荷醇介紹

  一種萜,又稱薄荷腦分子式C10H20O,左旋薄荷醇為無色透明

薄荷醇

針狀晶體;熔點44℃ ,沸點 216.4℃,比旋光度 -48° ;微溶於水 ,溶於乙醇乙醚丙酮氯仿。 消旋薄荷醇為無色透明針狀晶體;熔點 38℃, 沸點216℃; 溶於乙醇、乙醚、丙酮、苯。薄荷醇氫化生成對烷;用鉻酸氧化催化脫氫得薄荷酮;消旋薄荷醇可通過苯甲酸酯化法拆分。薄荷醇可從薄荷油分離得到,也可由香茅醛或百里酚製造。薄荷醇是一種重要香料。左旋薄荷醇由於其清涼效果,大量用於香煙化妝品、牙膏、口香糖、甜食和藥物、塗擦劑[發揮局部止癢、止痛、清涼(機理:刺激皮膚上的冷感受器但不導致實際溫度變化)及輕微局麻等作用,也起促滲透劑作用]中。合成薄荷醇是各種異構體的混合物,價值不大。   薄荷醇是在葉片里製造的,也就是薄荷油的主要成分,是環類單萜的一種。是植物所產生的高揮發性精油,其成份多為半萜、單萜及倍半萜,尤其在氣候溫暖時產量更高。某些重要的植物色素是類萜或含類萜基的化合物。

植物來源

  唇形科植物薄荷Mentho haplocalyx Bing)全草,金錢草Glechoma longituba(Nakai)Kupr.全草,尖紫蘇Perilla frutescens (L.)Britt.var .Acuto(Thunb.)Kudo葉.

分子式及分子量

  C10H20O,156.27 [CAS NO.]:89-78-1   [物理性質]白色晶體

藥理作用

  有止癢、止痛、防腐、刺激、麻醉、清涼和抗炎作用,可治頭痛、神經痛瘙癢及呼

薄荷醇

吸道炎症、萎縮性鼻炎聲啞等.   [Herb source]: Mentho haplocalyx Bing   [Molecular Formula]: C10H20O,   [Molecular Weight]: 156.27   [Physics Properties]:white crystal   [Pharmacology function]: itching, pain relieving and anti-corrosion and stimulating, narcotic, cool and anti-inflammatory effects, to cure a headache, neuralgia, itching and respiratory inflammation, atrophic rhinitis, signs, etc.

檢驗

  取本品葉粉末少許,經微量升華得油狀物,迅速加硫酸2滴及香草醛結晶少量,顯黃色至橙黃色,再加水1滴,即變紫紅色。(示薄荷醇)

貯藏

  :密閉、避免高溫及強氧化劑。   薄荷醇;薄荷腦;[1R-(1α,2β,5α)]-5-甲基-2-(1-甲基乙基)環己醇;薄荷冰;萜醇-[3];對烷-3-醇;[1R-(1A,2B,5A)]-5-甲基-2-(1-甲基乙基);2-異丙基-5-甲基環己醇;l-menthol;(-)-menthol;(-)-menthyl alcohol;(1r,3r,4s)-(-)-menthol;(1r-(1-alpha,2-beta,5-alpha))-5-methyl-2-(1-methyl

薄荷醇氣相色譜

ethyl)cyclohexanol;(l)-menthol;(r)-(-)-menthol   資料: CAS:2216-51-5   分子式: C10H20O   分子質量: 156.26   沸點: 212℃   熔點: 41-43℃   中文名稱: 薄荷醇;薄荷腦;[1R-(1α,2β,5α)]-5-甲基-2-(1-甲基乙基)環己醇;薄荷冰;萜醇-[3];對烷-3-醇;[1R-(1A,2B,5A)]-5-甲基-2-(1-甲基乙基);2-異丙基-5-甲基環己醇   英文名稱: l-menthol;(-)-menthol;(-)-menthyl alcohol;(1r,3r,4s)-(-)-menthol;(1r-(1-alpha,2-beta,5-alpha))-5-methyl-2-(1-methylethyl)cyclohexanol;(l)-menthol;(r)-(-)-menthol

性質

  無色針狀結晶或粒狀。熔點41-43℃(42-45℃),沸點216.5℃,相對密度0.890(15/15℃),折光率1.458。易溶於醇;氯仿;醚;冰醋酸;液狀石蠟石油醚,微溶於水。薄荷醇含有三個不對稱碳原子,已知四個空間順式和反式異構體,它們每個都有右旋型;左旋型以及消旋型。左旋薄荷醇具有特徵有薄荷香氣並有清涼的作用。消旋薄荷醇([89-78-1])也有清涼作用,其它的異構體無清涼作用。

生產

  薄荷醇可由天然薄荷原油提純也可用合成法制取。唇形科植物薄荷的地上部分(莖;枝;葉和花序)經水蒸氣蒸餾所得的精油稱薄荷原油,得油率為0.5-0.6。合成薄合腦的方法有多種。1.從香茅醛中製造 利用香茅醛易環化成異胡薄荷醇的性質,將右旋香茅醛用酸催化劑(如硅膠)環化成左旋異胡薄荷醇,分出左旋異胡薄荷醇,氫化生成左旋薄荷。其立體導師構體經熱裂解可部分地遭到轉變成右旋香茅醛,再循環使用。2.從百里酚中製造 在間甲酚鋁存在,對間甲酚進行烷基反應生成百里酚。經催化加氫得所有四對薄荷醇立體異構體(即消旋薄荷醇;消旋新薄荷醇;消旋異薄荷醇和消旋新異薄荷醇)。將其進行蒸餾,取消旋薄荷醇餾分,製造酯后反覆重結晶,進行異構體的分離和光學拆分。分離出來的左旋薄荷醇酯,經皂化后得薄荷腦。   薄荷醇是一種重要的香料,有多種生產方法:   ①從薄荷油製造:將薄荷油冷凍后析出結晶,離心所得結晶用低沸溶劑重結晶得純左旋薄荷醇。除去結晶后的母液仍含薄荷醇40%~50%,還含較大量的薄荷酮,經氫化轉變為左旋薄荷醇和右旋新薄荷醇的混合物。將酯的部分皂化,經結晶、蒸餾或製成其硼酸酯後分去薄荷油中的其他部分,可得到更多的左旋薄荷醇。   ②從香茅醛製造:利用香茅醛易環化成異胡薄荷醇的性質,將右旋香茅醛用酸催化劑(如硅膠)環化成左旋異胡薄荷醇,分出左旋異胡薄荷醇,氫化生成左旋薄荷醇。其立體異構體經熱裂解可部分再轉變成右旋香茅醛,再循環使用。   ③從百里酚製造:百里酚氫化得所有四對薄荷醇立體異構體

應用

  薄荷腦和消旋薄荷腦均可用作牙膏;香水;飲料和糖果等的賦香劑。在醫藥上用作刺激葯,作用於皮膚或粘膜,有清涼止癢作用;內服可作為驅風葯,用於頭痛及鼻;咽;喉炎症等。其酯用於香料和藥物。在世界上,我國和巴西是主要的天然薄荷生產國,薄荷油的年產量均達到2000-3000t。

注意

  由於本品對皮膚以及眼睛有刺激作用以及一定的毒性,大量使用時必須戴好手套以及安全眼鏡   [中毒急救措施]   1、吸入:將中毒著轉移通風處,採取一般急救措施。   2、誤入眼睛:按一般步驟沖洗眼睛,有必要著請咨詢醫師。   3、皮膚接觸:用清水和肥皂清洗。   4、其他:咨詢醫師。   消旋薄荷醇可用蒸餾法與其他三對異構體分開,剩下的異構體混合物在百里酚氫化條件下可平衡成消旋薄荷醇、消旋新薄荷醇、消旋異薄荷醇,比例為 6:3:1,新異薄荷醇含量很少,可不計。從以上混合物可再分出消旋薄荷醇。消旋薄荷醇經苯甲酸酯飽和溶液或其超冷混合物以左旋酯接種結晶,分開后皂化,得純左旋薄荷醇;不要的右旋薄荷醇及其他異構體,可再按氫化條件平衡轉變為消旋薄荷醇。

相關外文文獻

  下列為食品夥伴網上的關於薄荷醇(menthol)的英語資料。   Menthol is a terpenoid, found in the essential oils of the mint family (Mentha spp), such as peppermint, spearmint and others. Menthol (C10H20O) is solid at room temperature, forming long crystals that have a fatty touch. Several isomers of menthol exist, some with a menthol smell, others without. Normally occurring menthol, with the strongest smell, is (-)-menthol (lower left in figure below).   Structure of menthol and isomers   Menthol is not or poorly soluble in water, but readily soluble in alcohol or oils.   Besides the use as an aroma in many different food products (especially dental products, such as chewing gum, cough drops and confectionary, such as mints), menthol is contained in non-prescription products for short-term relief of minor sore throat and minor mouth or throat irritation, for example in lip balms and cough medicines. It is classed as an antipruritic, which reduces itching. Menthol is also contained in combination products used for relief of muscle aches, sprains, and similar conditions, as well as in decongestants. In addition, it is used as an additive in certain cigarette brands, both for flavour and to reduce the throat and sinus irritation caused by smoking. Menthol also is a common ingredient in mouthwash.   Menthol   From Wikipedia, the free encyclopedia   Jump to: navigation, search   Not to be confused with methanol.   Menthol   General   Systematic name 2-(2-Propyl)-5-   methylcyclohexanol   Stereochemical   configuration (2S,5R,1R)   Other names 3-p-Menthanol,   Hexahydrothymol,   Menthomenthol,   peppermint camphor   Molecular formula C10H20O   SMILES CC1CCC(C(C1)O)C(C)C   Molar mass 156.27 g·mol−1   Appearance White or colorless   crystalline solid   CAS number [89-78-1], racemic   [2216-51-5], (−)-isomer   Properties   Density and phase 0.890 g·cm−3, solid   (racemic or (−)-isomer)   Solubility in water Slightly soluble, (−)-isomer   In ethanol, diethyl ether,   acetone, chloroform   acetic acid, hexane Soluble   Melting point 36-38 °C (311 K), racemic   42-45 °C (318 K), (−)-form (α)   35-33-31 °C, (−)-isomer   Boiling point 212 °C (485 K)   Chiral rotation [α]D -50° at 18 °C, 10% in EtOH   Hazards   MSDS External MSDS   Main hazards Irritant, flammable   NFPA 704 210   Flash point 93 °C   R/S statement R37/38, R41 S26, S36   RTECS number OT0350000, racemic   OT0700000, (−)-enantiomer   Supplementary data page   Structure & properties n, εr, etc.   Thermodynamic data Phase behavior   Solid, liquid, gas   Spectral data UV, IR, NMR, MS   Related compounds   Related alcohols Cyclohexanol, Pulegol,   Dihydrocarveol, Piperitol   Related compounds Menthone, Menthene,   Thymol, p-Cymene,   Citronellal   Except where noted otherwise, data are given for   materials in their standard state (at 25 °C, 100 kPa)   Infobox disclaimer and references   Menthol is a covalent organic compound made synthetically or obtained from peppermint or other mint oils. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is (-)-menthol, which is assigned the (1R,2S,5R) configuration. Menthol has local anesthetic and counterirritant qualities, and it is widely used to relieve minor throat irritation.   Contents [hide]   1 History and occurrence   2 Structure   3 Applications   4 Synthesis   5 Natural menthol   6 Chemical properties   7 Biological properties   8 Notes   9 References   History and occurrence   There is evidence[1] that menthol has been known in Japan for more than 2000 years, but in the West it was not isolated until 1771, by Gambius.[2] (-)-Menthol (also called l-menthol or (1R,2S,5R)-menthol) occurs naturally in peppermint oil (along with a little menthone, the ester menthyl acetate and other compounds), obtained from mentha x piperita. Japanese menthol also contains a small percentage of the 1-epimer, (+)-neomenthol.   Structure   Natural menthol exists as one pure enantiomer, nearly always the (1R,2S,5R) form (bottom left of diagram below).   In the natural compound, the isopropyl group is oriented trans- orientation to both the methyl and alcohol groups.   In the ground state all three bulky groups in the chair are equatorial, making (-)-menthol and its enantiomer the most stable two isomers out of the eight.   There are two crystal forms for racemic menthol; these have melting points of 28 °C and 38 °C. Pure (-)-menthol has four crystal forms, of which the most stable is the α form, the familiar broad needles.   Applications   Menthol is included in many products for a variety of reasons. These include:   In non-prescription products for short-term relief of minor sore throat and minor mouth or throat irritation   Examples: lip balms and cough medicines   As an antipruritic to reduce itching   As a topical analgesic to relieve minor aches and pains such as muscle cramps, sprains, headaches and similar conditions, alone or combined with products like Camphor or Capsaicin. In Europe it tends to appear as a gel or a cream, while in the US patches and body sleeves are very frequently used   Examples: Tiger Balm IcyHot patches or knee/elbow sleeves   In decongestants for chest and sinuses (cream, patch or nose inhaler)   Examples: Vicks Vaporub   In certain medications used to treat sunburns, as it provides a cooling sensation (then often associated with Aloe)   As an additive in certain cigarette brands, for flavor, to reduce the throat and sinus irritation caused by smoking and arguably to reduce the bad-breath smokers experience and possibly improve the smell of second-hand smoke.   Commonly used in oral hygiene products and bad-breath remedies like mouthwash, toothpaste, mouth and tongue-spray, and more generally as a food flavor agent e.g. in chewing-gum, candy   In a soda as well as in a syrup to be mixed with water to obtain a very low alcohol drink or (brand Riclès in France). The syrup is/was also used to alleviate nausea, in particular motion sickness, by pouring a few drops on a lump of sugar.   As a pesticide against tracheal mites of honeybees   In perfumery, menthol is used to prepare menthyl esters to emphasise floral notes (especially rose)   In first aid products such as "mineral ice" to produce a cooling effect as a substitute for real ice in the absence of water or electricity (Pouch, Body patch/sleeve or cream)   In various patches ranging from fever-reducing patches applied to children's foreheads to "foot patches" to relieve numerous ailments (the latter being much more frequent and elaborate in Asia, esp. Japan: some variety use `functional protrusion' i.e. small bumps to massage ones feet as well as soothing them and cooling them down)   In some beauty products such as hair-conditioners, based on natural ingredients (ex: St Ives)   Some supporters of the homeopathic theory of pharmacology believe that menthol interferes with the effects of homeopathic remedies. Its use is strongly discouraged for those seeking homeopathic cures, to the point of prohibiting the use of mint-flavored toothpaste. Currently no other reported nutrient or herb interactions involve menthol. It is used in Eastern medicine to treat indigestion, nausea, sore throat, diarrhea, colds, and headaches. (-)-Menthol has low toxicity: Oral (rat) LD50: 3300 mg·kg−1; Skin (rabbit) LD50: 15800 mg·kg−1).   In organic chemistry, menthol is used as a chiral auxiliary in asymmetric synthesis. For example, sulfinate esters made from sulfinyl chlorides and menthol can be used to make enantiomerically pure sulfoxides by reaction with organolithium reagents or Grignard reagents. Menthol is also used for classical resolution of chiral carboxylic acids, via the menthyl esters.   Synthesis   As with many widely-used natural products, the demand for menthol greatly exceeds the supply from natural sources. Menthol is manufactured as a single enantiomer (94% ee) by Takasago International Co. on a scale of 400 000 tonnes per year. The process involves an asymmetric synthesis developed by a team led by Ryoji Noyori.   The process begins by forming an allylic amine from myrcene, which undergoes asymmetric isomerisation in the presence of a BINAP rhodium complex to give (after hydrolysis) enantiomerically pure R-citronellal. This is cyclised by a carbonyl-ene-reaction initiated by zinc bromide to isopulegol which is then hydrogenated to give pure (1R,2S,5R)-menthol.   Racemic menthol can be prepared simply by hydrogenation of thymol, and menthol is also formed by hydrogenation of pulegone. For preparation of other isomers such as neomenthol, see ref. 1.   Natural menthol   Mentha arvensis is the primary species of mint used to make natural menthol crystals and natural menthol flakes. This species is primarily grown in the Uttar Pradesh region in India.   Chemical properties   Menthol reacts in many ways like a normal secondary alcohol. It is oxidised to menthone by oxidising agents such as chromic acid, though under some conditions the oxidation can go further and break open the ring. Menthol is easily dehydrated to give mainly 3-menthene, by the action of 2% sulfuric acid. PCl5 gives menthyl chloride.   Biological properties   Menthol's ability to chemically trigger cold-sensitive receptors in the skin is responsible for the well known cooling sensation that it provokes when inhaled, eaten, or applied to the skin. Menthol does not cause an actual drop in temperature.[3] In this sense it is similar to capsaicin, the chemical responsible for the spiciness of hot peppers (which stimulates heat sensors, also without causing actual temperature rise).   Notes   ^ J. L. Simonsen, The Terpenes Volume I (2nd edition), Cambridge University Press, 1947, p230-249.   ^ Adversoriorum varii argumentii, Liber unus, Leiden, 1771, p99.   ^ R. Eccles, Menthol and Related Cooling Compounds, Journal of Pharm. Pharmacol. 1994 46: 618-630   References   E. E. Turner, M. M. Harris, Organic Chemistry, Longmans, Green & Co., London, 1952.   Handbook of Chemistry and Physics, 71st edition, CRC Press, Ann Arbor, Michigan, 1990.   The Merck Index, 7th edition, Merck & Co, Rahway, New Jersey, USA, 1960.

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