Simultaneous determination of three canthin-6-one alkaloids in different extracts of Eurycoma longifolia and Eurycoma harmandiana using HPLC-UV

Eurycoma longifolia Jack. and Eurycoma harmandiana Pierre are well-known herbal medicine in Thailand and neighboring countries. For several decades, E. longifolia has been studied for various pharmacological properties. Several compounds have been discovered in these plants, among these canthin-6-one alkaloids have been the outstanding compounds likely to be active ingredients. However, analytical method in separation and quatification of canthin-6-one alkaloids are limited. Analytical separation and qualification were achieved using high-performance liquid chromatography (HPLC) with UV detection at 354 nm. The samples were analyzed using Lichrospher® 100 RP18 with mobile phase consists of 0.1% acetic acid: acetonitrile (65:35 v/v). Linearity was observed in the range between 0.39-50 µg/mL with correlation coefficient of 0.9996-0.9998. Limit of detections were 2.52-2.88 µg/mL, and limit of qualifications were 7.63-8.73 µg/ml. Recovery values were in an acceptable range. The result revealed high contents of total canthin-6-one alkaloids in E. harmandiana (1.72±0.06 mg/g DW) compared to E. longifolia (0.16±0.01 mg/g DW). Moreover, different extracts of Eurycoma spp., (methanol, hydro-methanol (50%), ethanol, and hydro-ethanol (50%)), were prepared and tested of canthin-6-one alkaloids (9-hydroxycanthin-6-one, canthin-6-one and 9-methoxycanthin-6-one). The maximum of canthin-6-one content was observed from 50% methanolic extract followed by 50% ethanolic, methanol and ethanol extracts, respectively. In conclusion, A HPLC procedure for determination of canthin-6-one alkaloids is developed. The HPLC method was shown to be simple, accurate and selective for separation and quantification of three known canthin-6-one alkaloids in the root extracts of both E. longifolia and E. harmandiana.

• References

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