Zarka, M. A.

Phytochemical biological and cytotoxic activities of calothamnus quadrifidus leaves cultivated in egypt - Vol.83(4), July-Aug - Mumbai Indian Journal of Pharmaceutical Science 2021 - 648-662p.

The hydro distilled essential oil obtained from Calothamnus quadrifidus leaves was analyzed by gas
liquid chromatography-mass spectroscopy. Quantification of the oil constituents was carried out using
the gas liquid chromatography-flame ionization detection device where 1,8-cineole was quantified as
525.62 μg/ml. The oil showed potential antioxidant activity when tested by 1,1-diphenyl-2-picrylhydrazine
radical scavenging assay where the concentration required to scavenge 1,1-diphenyl-2-picrylhydrazine
by 50 %=37.3 μg. The cytotoxic activity of the essential oil was evaluated using 3-(4,5-dimethylthiazol-
2-yl)-2,5-diphenyltetrazolium bromide assay compared with 1,8-cineole and doxorubicin. Calothamnus
quadrifidus leaves essential oil cytotoxic activity was significant against human lung cell line A-549 (2.37 μg),
human colon cell line HCT-116 (2.39 μg), human hepato-cellular cell line HepG-2 (2.55 μg) and intestinal
epithelium carcinoma Caco-2 (5.80 μg) cell lines, respectively. The oil cytotoxicity exceeded 1,8-cineole
except for intestinal epithelium carcinoma Caco-2. Additionally, the antimicrobial activity was evaluated
using agar disc diffusion and minimum inhibitory concentration where the oil exhibited the best activity
against Penicillium italicum and Geotrichum candidum with minimum inhibitory concentration=0.49 and
0.98 μg, respectively. Structure elucidation of the pure compounds isolated from Calothamnus quadrifidus
leaves was done according to their chromatographic behavior, chemical and spectroscopic data. These
compounds were isolated for the first time from Calothamnus quadrifidus leaves and identified as gallic
acid, gallic acid methyl ester, 7,4'-dimethoxy-apigenin, 6,7-dimethoxy-apigenin, (Bis[3(2-methyl propan-
1-one)-2, 6 dihydroxy-4-methoxy phenyl] methane, quercetin 3-O-beta-D-arbinopyranoside and quercetin
3-O-beta-D-4C1-xylopyranoside. In addition to the molecular docking of novel compound 3 was done in
peroxiredoxins and the binding mode was found. Conformation 2 was found to be the most stable and
may be responsible for the antioxidant effect as it showed the best free binding energy and affinity when
compared to conformations.


PHARMACEUTICS