Chemical Constituents of Rumex abyssinicus Roots and Evaluation of Its Antimicrobial Activities

Abstract

Medicinal plants are usually screened for phytochemicals that may lead to further isolation, purification, and characterization of their active principles. The roots of Rumex abyssinicus are used traditionally in Ethiopia for treating different diseases such as hepatitis, hemorrhoids, gonorrhea, typhus, and wounds. Thus, this study was conducted to investigate the phytochemicals and in vitro antimicrobial activity of the roots of R. abyssinicus extracts. The roots were collected, chopped, and airdried under shade in the laboratory. Then, the dried plant material was subjected to sequential extraction using the maceration technique by soaking 1 kg of the sample in petroleum ether, chloroform, acetone, and methanol. Meanwhile, the filtrates were concentrated under reduced pressure using a rotary evaporator. Afterward, the crude extracts were dried and screened for in vitro antimicrobial activity tests using four bacterial and two fungal strains. Based on its activity, the acetone extract was used for column chromatographic isolation. Herein, two known anthraquinones were isolated and characterized: chrysophanol and emodin. The microbial activity of both extracts and isolated compounds were evaluated against medically important strains by the agar disc diffusion method. The concentration of the extracts and isolated compounds was 100 mg/mL tested against S. aureus ATCC25903, K. pneumoniae NCTC13368, E. coli ATCC 25722, P. aeruginosa DSMZ 1117 and C. albicans and S. cerevisiae. The zone of growth inhibition of extracts and isolated compounds were compared with standard drugs like Gentamycin and Mancozeb. The results showed that the isolated compounds (1 and 2) have higher bacterial growth inhibition than the extracts. However, compound 2 was not active against S. cerevisiae strain.

A New Ceramide (Rumexamide) and Other Chemical Constituents from <i>Rumex abyssinicus</i> Jacq (Polygonaceae): Isolation, Characterization, Antibacterial Activities and Chemophenetic Significance

“…In this study, seventeen secondary metabolites (Figure 1) were isolated from Rumex abyssinicus including one new ceramide (1), one phthalate derivative (2), six anthraquinones (3)(4)(5)(6)(7)(8), four triterpenes (9-12) and five steroids (13)(14)(15)(16)(17). From all these isolated metabolites, it appears that compounds 2, 5, 8-17 are reported here for the first time from R. abyssinicus.…”

“…In conclusion, the chemical study of the whole plant of R. abyssinicus led to the isolation of one previously undescribed ceramide (1) and sixteen known (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17) compounds which enriched the chemical diversities of the plant, genus Rumex and Polygonaceae family. Compounds 10-12 may demonstrate here the relationship between F. aubertii and other species belonging to other genera herbs of Polygonaceae.…”

“…It is a medicinal plant widely distributed in the highlands of tropical Africa and distributed throughout North Africa and Ethiopia [5]. Indeed, Rumex abyssinicus is used in traditional medicine to treat several diseases like rheumatism, malaria, typhoid and hepatitis [5] [6]. Members of the genus Rumex have been reported to produce a wide range of secondary metabolites such as anthraquinones [7], flavonoids [8], stilbenoids [9] [10], tannins [11], triterpenoids [12], steroids and saponins [13].…”

“…20 (br s, H-5),6.54 (br s, H-7), 4.70 (s, -OCH 2 -); 13 C-NMR (150 MHz, CD 3OD) δ C : 191.5 (C-9), 183.4 (C-10), 169.1 (C-8), 166.7 (C-6), 163.7 (C-1), 152.9 (C-3), 136.9 (C-11), 135.0 (C-14), 122.2 (C-2), 118.4 (C-4), 115.9 (C-13), 111.1 (C-5), 109.2 (C-7), 108.5 (C-12), 64.1 (-OCH 2 -). Emodin (6)-Red powder; (C 15 H 10 O 5 ): 1 H-NMR (600 MHz, DMSO-d 6 ) δ H : 12.1 (s, 3-OH), 12.0 (s, 8-OH) 7.48 (d, 0.7Hz, H-5), 7.16 (d, 0.7Hz, H-7) 7.11 (d, 2.4 Hz, H-4) 6.59 (d, 2.4Hz, H-2), 2.41 (s, -CH 3 ); 13 C-NMR (150 MHz, DMSO-d 6 ) δ C : 190.2 (C-9), 181.9 (C-10), 166.1 (C-1), 164.9 (C-3), 161.9 (C-8), 148.7 (C-6), 135.6 (C-14), 133.3 (C-11), 124.6 (C-7), 120.9 (C-5), 113.8 (C-12), 109.4 (C-13), 109.3 (C-4), 108.4 (C-2), 21.9 (-CH 3 ).…”

The Health Benefits of Emodin, a Natural Anthraquinone Derived from Rhubarb—A Summary Update

“…Shifa et al [103] isolated two anthraquinones: emodin and chrysophanol from the roots of Rumex abyssinicus, which were used to cure various diseases, including gonorrhea, typhus and hepatitis. The two compounds were next tested for antimicrobial activity.…”