Simultaneous densitometric determination of shikonin, acetylshikonin, and β‐acetoxyisovaleryl‐shikonin in ultrasonic‐assisted extracts of four Arnebia species using reversed‐phase thin layer chromatography

Abstract

A simple, precise, and rapid high-performance thin-layer chromatographic (HPTLC) method for the simultaneous quantification of pharmacologically important naphthoquinone shikonin (1) together with its derivatives acetylshikonin (2), and beta-acetoxyisovalerylshikonin (3) in four species of genus Arnebia (A. euchroma, A. guttata, A. benthamii, and A. hispidissima) from the Indian subcontinent has been developed. In addition, the effect of solvents with varying polarity (hexane, chloroform, ethyl acetate, and methanol) for the extraction of these compounds was studied. HPTLC was performed on precoated RP-18 F(254S )TLC plates. For achieving good separation, mobile phase consisting of ACN/methanol/5% formic acid in water (40:02:08 v/v/v) was used. The densitometric determination of shikonin derivatives was carried out at 520 nm in reflection/absorption mode. The method was validated in terms of linearity, accuracy, precision, robustness, and specificity. The calibration curves were linear in the range of 100-600 ng for shikonin and acetylshikonin, and 100-1800 ng for beta-acetoxyisovalerylshikonin. Lower LOD obtained for compounds 1-3 were 18, 15, and 12 ng, respectively, while the LOQ obtained were 60, 45, and 40 ng, respectively.

Biological efficacy and radical scavenging potential of shikonin in Arnebia benthamii (Wall ex. G Don) Johnston

“…Five solvents with diverse polarity such as hexane, chloroform, ethanol, ethyl acetate, and methanol had been selected based on prior studies (Papageorgiou et al, 1999;Bozana et al, 1999;Hu, 2004;Sharma et al, 2009). Further, it has been reported from previous studies that shikonin was first isolated as acetate from roots of Lithospermum erythrorhizon by Japanese chemists (Majima and Kuroda, 1922).…”

Antibacterial and COX-1 Inhibitory Effect of Medicinal Plants from the Pamir Mountains, Afghanistan

“…The antibacterial activity of Arnebia species is due to alkannin and derivatives thereof [ 5 ]. A. guttata had a strong red color, indicating the presence of alkannin-derivatives, and previously several of such compounds have been shown to be present in the species [ 6 , 7 ].…”

Discrimination of Zicao Samples Based on DNA Barcoding and HPTLC Fingerprints, and Identification of (22E)-Ergosta-4,6,8(14),22-tetraen-3-one As a Marker Compound

“…To determine the best HPTLC conditions, eleven solvent systems were selected based on literature and in-house data, and tested using samples 1 – 12 and different isolated shikonins as reference compounds: ACN/MeOH/5% formic acid in water 40 : 2 : 8 29 , MeOH/acetic acid 20 : 1 30 , n -hexane/EtOAc/formic acid 100 : 15 : 1 31 , chloroform/light petroleum/MeOH/formic acid 3 : 4 : 0.5 : 0.1 32 , EtOAc/MeOH/formic acid 6 : 2 : 0.1 32 , EtOAc/MeOH/water 100 : 13.5 : 10 (SS1), toluene/EtOAc/formic acid 55 : 5 : 1 (SS2) 33 , toluene/ethyl formate/formic acid 70 : 50 : 10, 70 : 60 : 10, and 70 : 20 : 2, and EtOAc/MeOH/water/formic acid 100 : 20 : 10 : 1 (data not all shown). SS1 and SS2 turned out to be most useful.…”