Comparative phytochemical study on the phenolic compounds content of Artemisia annua L. from wild populations in Republic of Moldova

Artemisia annua is a medicinal plant traditionally used as anti-parasitic and fever relieving agent. The species is well-known for artemisinin which is the lead drug in the treatment of malaria. Besides artemisinin, other chemical constituents also include essential oil, terpenes, and phenolic compounds [1]. The aim of our study is to assess the phenolic acids and flavonoids content in A. annua samples harvested from several locations from the north, centre and south regions of R. Moldova in 2014 and 2015. The powdered plant material (leaves) was extracted with chloroform, in order to isolate the sesquiterpene lactone fraction and the residual plant material was extracted with methanol to isolate the phenolic compounds. The phytochemical analysis was performed by HPLC, the identification of the compounds being done using available standards. All amounts are expressed as mg/100 g d.w. In all analysed samples the following compounds were identified: caffeic ac. in amounts of 1.70 – 4.31(2014) and 1.18 – 3.37 (2015), p-coumaric ac. 0.50 – 4.35 (2014) and 1.46 – 5.59 (2015), chlorogenic ac. 112.6 – 210.5 (2014) and 170.3 – 512.3 (2015). Cynarin was found in amounts varying from 307.1 to 617.7 (2014) and 553.6 – 1391 (2015). There are few reports of cynarin being found in A. annua [2, 3]. Isoquercitrin was found in amounts of 5.24 – 30.3 (2014) and 8.83 – 33.7 (2015), while luteolin-7-glucoside was 9.80 – 40.5 (2014) and 28.1 – 132.9 (2015). The content in phenolic compounds was higher in the samples harvested in 2015, compared with the samples from 2014. For the 48 analysed samples the content of phenolic compounds varied both depending on the collection site and region, a relatively high diversity also being observed for samples collected from the same site. All analysed samples had high amounts of phenolic compounds, thus the residual plant material resulting from the isolation of artemisinin may be considered an important source of antioxidant compounds.

Acknowledgements: The work is financed through SCOPES program of SNF, Project no. IZ73Z0_152265.

Keywords: A. annua, phenolic acids, flavonoids, HPLC.

References:

[1] Han J, Ye M, Qiao X, Xu M, Wang B, Guo D. Characterization of phenolic compounds in the Chinese herbal drug Artemisia annua by liquid chromatography coupled to electrospray ionization mass spectrometry. J Pharm Biomed Anal 2008; 47: 516 – 525

[2] Zhao YW, Ni FY, Song YL, Wang SY, Huang WZ, Wang ZZ, Xiao W. Chemical constituents from Artemisia annua. Zhongguo Zhong Yao Za Zhi 2014; 39: 4816 – 4821

[3] Zhao W, Zhang W, Chen Y, Yang F, Cao Q, Chen, Liu J, Dai K. Identification and purification of novel chlorogenic acids in Artemisia annua L. J Exp Biol Agric Sci 2015; 3: 415 – 422