(+)-usnic acid | 7562-61-0

• 物质功能分类: 天然产物 - 酚类
• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: (+)-usnic acid
• 英文别名: (S)-(-)-usnic acid；2,6-diacetyl-7,9-dihydroxy-8,9b-dimethyl-1,3(2H,9bH)-dibenzofurandione；(9bS)-2,6-diacetyl-3,7,9-trihydroxy-8,9b-dimethyldibenzofuran-1-one
• CAS: 7562-61-0；6159-66-6
• 化学式: C₁₈H₁₆O₇
• 分子量: 344.321
• InChiKey: WEYVVCKOOFYHRW-GOSISDBHSA-N

物化性质

• 熔点：
  201-203 °C(lit.)
• 比旋光度：
  488 º (c=0.4, CHCl3)
• 沸点：
  399.43°C (rough estimate)
• 密度：
  1.2869 (rough estimate)
• 溶解度：
  在氯仿中几乎透明
• LogP：
  1.270 (est)

计算性质

• 辛醇/水分配系数(LogP)：
  2.1
• 重原子数：
  25
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.28
• 拓扑面积：
  121
• 氢给体数：
  3
• 氢受体数：
  7

ADMET

毒理性

• 肝毒性

商业膳食补充剂中含有辛酸，已有多起明显的急性肝损伤案例归因于这类补充剂。 “LipoKinetix”就是这样一种被宣传为减肥和健身的补充剂。每片含有辛酸钠（100毫克）、诺乙非君（25毫克）、二碘甲状腺原氨酸（100毫克）、育亨宾（3毫克）和咖啡因（100毫克）。该产品与多起急性肝损伤有关。发病时间为2到12周，临床表现类似于急性病毒性肝炎，起初出现疲劳和恶心，随后出现黄疸。血清酶升高的模式为肝细胞型，血清ALT显著升高，碱性磷酸酶水平略有增加。肝活检显示急性肝细胞坏死和炎症。免疫过敏特征（发热、皮疹和嗜酸性粒细胞增多）并不常见，自身抗体通常不存在。停止服用膳食补充剂后恢复迅速，但有些情况严重，导致急性肝衰竭，需要紧急肝移植或死亡。其他含有辛酸的多成分膳食补充剂也报告了急性肝炎的病例，但比LipoKinetix要少见得多，LipoKinetix在FDA发出警告信后已从市场撤回。基于地衣的Kombucha茶也报告了罕见的肝毒性实例，但没有显示这些是否是由于辛酸或茶中的其他污染物所致。 可能性评分（辛酸）：B（很可能是明显临床肝损伤的原因）。 可能性评分（Kombucha茶）：C（可能是明显临床肝损伤的原因）。

Several cases of clinically apparent acute liver injury have been attributed to commercial dietary supplements that contain usnic acid. “LipoKinetix” was one such supplement advertised as a weight loss and body building supplement. Each tablet contained sodium usniate (100 mg), norephedrine (25 mg), diiodothyronine (100 mg), yohimbine (3 mg) and caffeine (100 mg). The product has been linked to multiple instances of acute liver injury. The time to onset was 2 to 12 weeks and the clinical presentation resembled acute viral hepatitis with onset of fatigue and nausea, followed by jaundice. The pattern of serum enzyme elevations was hepatocellular, with marked elevations in serum ALT and minimal increases in alkaline phosphatase levels. Liver biopsy demonstrated acute hepatocellular necrosis and inflammation. Immunoallergic features (fever, rash and eosinophilia) were not common and autoantibodies were usually not present. Recovery was rapid with stopping the dietary supplement, but some cases were severe and led to acute liver failure and either death or need for emergency liver transplantation. Instances of acute hepatitis have also been reported with other multi-ingredient dietary supplements that contain usnic acid, but much more rarely than with LipoKinetix which was withdrawn from distribution after a FDA warning letter. Rare instances of hepatotoxicity have also been reported with use of lichen based teas known as Kombucha tea, but whether these were due to usnic acid or another contaminant of the tea was not shown. Likelihood score (usnic acid): B (highly likely cause of clinically apparent liver injury). Likelihood score (Kombucha tea): C (probable cause of clinically apparent liver injury).

来源:LiverTox

安全信息

• 危险等级：
  IRRITANT
• 危险品标志：
  Xn
• 安全说明：
  S36
• 危险类别码：
  R22
• WGK Germany：
  3
• 海关编码：
  2917399090
• RTECS号：
  HP5295050
• 危险性防范说明：
  P261,P305+P351+P338
• 危险性描述：
  H302,H315,H319,H335

制备方法与用途

提取与制备

称取剪碎的长松萝5.0 g，置于500 mL烧瓶中，用乙酸乙酯75 mL回流提取2次，每次4小时，合并提取液。抽滤后浓缩至原体积的1/6~1/8，自然冷却析出结晶，滤去母液并在80℃烘干，即得松萝酸粗品。

向粗品中加入30倍量的苯-乙醇（体积比1∶1）混合溶剂，回流2小时后趁热过滤。将滤液浓缩至原体积的1/5，冷却析出结晶。于80℃烘干并用乙酸乙酯重结晶2次，所得较纯的淡黄色针晶即为松萝酸精品。

生物活性

（+）Usniacin (D-Usnic Acid) 是在一些地衣中发现的一种天然存在的二苯并呋喃类衍生物。

靶点

| mTORC1 | | mTORC2 |

化学性质

松萝酸是一种黄色结晶粉末，可溶于甲醇、乙醇、DMSO等有机溶剂。它来源于松萝Usnea diffracta Vain。

用途

松萝酸具有抗菌、消炎和增强人体免疫力的作用。