517-89-5

History

Kuroda and Majima firstly identified acetyl shikonin from L. erythrorhizon in 1922 , followed by the discovery of other shikonin derivatives, including shikonin. The chemical structure of shikonin was not precisely identified till 1936 for its high physicochemical similarity with naphthazarin . There have been about 500 publications on shikonin up to now. Great attention has also been paid on the biosynthesis of shikonin and its derivatives, and an increasing number of shikonin derivatives have been designed and synthesized for exploring their antitumor effect. There are two types of derivatives: one is modifications of 1′-OH with parent nucleus naphthazarin remained and the other is modifications of both 1′-OH and parent nucleus naphthazarin, as shown in Fig. 3c, d .

Pharmacology

Shikonin possesses anti-inflammatory, antioxidant, antiviral, cardiovascular protective,and antitumor activities. Shikonin reduces inflammation by inhibiting the biosynthesis of leukotrienes and 5-hydroxyeicosatetraenoic acid and thus reduces synthesis of inflammation-related active molecules, which selectively block chemokine binding to CC chemokine receptor 1 . Shikonin shows free radical scavenging and antioxidant (especially toward superoxide anion and DPPH) activities. It significantly inhibits autoxidation caused by β-carotene and linoleic acid . Its anti-HCV effects have been reported recently with an EC50 at 25 ng/mL, which is lower than that of ribavirin (2.6 μg/mL) . Recent studies also reveal shikonin possesses cardiovascular protective effects. Shikonin inhibits the activity of TNF-α promoter, revealing its transcriptional antagonism to pro-inflammatory cytokine . Shikonin also shows antitumor potentials by inducing apoptosis and/or necrosis, inhibiting DNA topoisomerase activity and angiogenesis, and regulating proliferative signaling pathways (including MAPK, VEGF, and PTKs ). In addition, shikonin circumvents cancer drug resistance by induction of necroptotic cell death .

Physical properties

Appearance: purple lamellae or crystalline powder. Melting point: 147 °C. Specific optical rotation: +138°(benzene). Solubility: soluble in ethanol, vegetable oils, and other organic solvents.

General Description

This substance is a primary reference substance with assigned absolute purity (considering chromatographic purity, water, residual solvents, inorganic impurities). The exact value can be found on the certificate. Produced by PhytoLab GmbH & Co. KG