アコニチン 化学特性,用途語,生産方法
外観
白色～ほとんど白色, 結晶性粉末～粉末
溶解性
水, 石油エーテルに殆ど不溶。エタノール, アセトンに可溶。エーテルに微溶。エタノール及びアセトンに溶け、水にほとんど溶けない。
解説
アコニチン．キンポウゲ科トリカブト属Aconitumに含まれるジテルペンアルカロイド．アコニットアルカロイド中の代表的なエステル型のアルカロイド．猛毒性で，はげしい神経麻ひ作用を示し，植物毒のうちでもっとも強力なものに属する．直接心臓に作用し，呼吸器を麻ひする．柱状晶．融点204 ℃．[α]D＋17.3°(クロロホルム)．クロロホルム，ベンゼンに可溶，エーテル，乾燥エタノールに微溶，水，石油エーテルにほとんど不溶．比較的不安定で，アルカリと加熱するとすみやかに加水分解して脱アセチル化，および脱ベンゾイル化を起こし，無毒のアコニン(C25H41NO9，融点132 ℃)を与える．LD50 0.4 mg/kg(ネコ，皮下)．きわめて猛毒で，直接心臓に作用し，呼吸麻痺を起させる。かつて矢毒として使用された。
用途
生薬成分定量用標準品。
効能
再結 OH-H2O
説明
Aconitum plants (Wu Tou, Ranunculaceae family) have been widely used to treat
various diseases, such as rheumatism, knee pain, herpes zoster, scabies, and other
disorders in China for thousands of years. It was first described in Shen Nong’s
Herbal Classic (the earliest classical work of Chinese herbs). Aconitine is the main
active component in Aconitum plants.
化学的特性
Off-White Solid
物理的性質
Appearance: solid. Solubility: barely soluble in water and soluble in organic solvents such as chloroform or diethyl ether. Its solubility in water and ethanol are
0.3?mg/mL and 35?mg/mL, respectively. Melting point: 203–204?°C (397–399?°F;
476–477?K). Optical rotation:D+17.3°
来歴
Preparations of Aconitum roots are employed in Chinese medicine for analgesic,
antirheumatic, and neurological indications. In the Ming Dynasty, Chinese people
had extracted the aconitine from the Aconitum plants. Aconitine is synthesized by
the Aconitum plants via the terpenoid biosynthesis pathway (MEP chloroplast
pathway)
使用
Neurotoxin. Activates tetrodotoxin-sensitive Na+ channels, inducing presynaptic depolarization, thus blocking the nerve action potential which, in turn, blocks the release of neurotransmitters and dec
reases the end plate potential at the neuromuscular junction. Aconitine also blocks norepinephrine reuptake. In the heart, aconitine induces ventricular tachycardia after intracoronary injection. In c
ultured ventricular myocytes, aconitine increases the duration of the action potential and induces the appearance of early after depolarization.
Used in producing heart arrhythmia in experimental anim
als.
定義
ChEBI: A diterpenoid that is 20-ethyl-3alpha,13,15alpha-trihydroxy-1alpha,6alpha,16beta-trimethoxy-4-(methoxymethyl)aconitane-8,14alpha-diol having acetate and b
nzoate groups at the 8- and 14-positions respectively.
適応症
Aconitine was previously used as an antipyretic and analgesic. However, the clinical
application of aconitine is limited by its high toxicity. Its lethal dose 50% (LD50) for
mice is 1.8?mg/kg (orally) and 0.308?mg/kg (intraperitoneally).
健康ハザード
Aconitine is among the most toxic alkaloidsknown. Toxic doses are close to therapeuticdoses, and in humans as little as 2 mgmay cause death (Ferry and Vigneau 1983).An oral lethal dose of 28 mg/kg has alsobeen recorded (NIOSH 1986). The toxicsymptoms at low doses may be excitement,drowsiness, and hypermotility. The first signof poisoning from ingestion is a tingling,burning feeling on the lips, mouth, gums,and throat (Hodgson et al. 1988). This isfollowed by nervous disorders, anesthesia,loss of coordination, vertigo, hypersalivation,nausea, vomiting, and diarrhea. Toxic actionsof aconitine are very rapid. The crystallineform of this compound is much more toxicthan the amorphous aconitine. At a lethaldose, death may result from cardiorespiratoryfailure. Procaine may be an effective antidoteagainst aconitine poisoning.
薬理学
Aconitum was found to have neurotoxin. It could activate tetrodotoxin-sensitive Na+
channels, inducing presynaptic depolarization and blocking the nerve action potential and, in turn, blocking the release of neurotransmitters and decreasing the end
plate potential at the neuromuscular junction. Aconitine was also found to block
norepinephrine reuptake
In the heart, aconitine could induce ventricular tachycardia. In cultured ventricular myocytes, aconitine could induce the appearance of early after depolarization by
increasing the duration of the action potential.
Research with mouse nerve-hemidiaphragm muscle preparation found that aconitine at low concentrations (<0.1?μM) could increase the electrically evoked acetylcholine release causing an induced muscle tension. Action potentials were
generated more often at this concentration. While at higher concentrations
(0.3–3?μM), aconitine could decrease the electrically evoked acetylcholine release,
resulting in a decrease in muscle tension. Under the circumstance with high
concentration (0.3–3?μM) of aconitine, the sodium-ion channels were constantly
activated, and transmission of action potentials was suppressed, leading to the formation of non-excitable target cells or paralysis.
臨床応用
In clinic, it can be used for treating and alleviating the symptoms caused by arthritis,
lumbocrural pain, and herpes zoster; however, it is utilized infrequently in clinical
practice due to its obvious side effects
According to a review of different reports of aconite poisoning in human beings,
the following clinical features such as neurological, cardiovascular, and gastrointestinal features were observed. The first symptom of aconitine poisoning appeared
approximately 20?min–2?h after oral intake, and they were paresthesia, sweating,
and nausea, which led to severe vomiting, colicky diarrhea, intense pain, and then
paralysis of the skeletal muscles. Following the onset of life-threatening arrhythmia,
including ventricular tachycardia and ventricular fibrillation, death finally occurred
as a result of respiratory paralysis or cardiac arrest.
純化方法
Crystallise it from EtOH, CHCl3 or toluene. [Beilstein 21/6 V 310.]
参考文献
H. Mayer, L. Marion, Can. J. Chem., 37, 856 (1959), DOI: 10.1139/v59-116.
アコニチン 上流と下流の製品情報
原材料
準備製品