Six flavonoids present in Pulicaria jaubertii, i.e., 7,3′-di-O-methyltaxifolin (1), 3′-O-methyltaxifolin (2), 7-O-methyltaxifolin (3), taxifolin (4), 3-O-methylquercetin (5), and quercetin (6), were tested for their anticancer activities. The methylated flavonoids, compounds 1–3 and 5, were evaluated for their anticancer activities in comparison to the non-methylated parent flavonoids taxifolin (4) and quercetin (6). The structures of the known compounds were reconfirmed by spectral analyses using 1H and 13C NMR data comparisons and HRMS spectrometry. The anticancer activity of these compounds was evaluated in colon cancer, HCT-116, and noncancerous, HEK-293, cell lines using the MTT antiproliferative assays. The caspase-3 and caspase-9 expressions and DAPI (4′, 6-diamidino-2-phenylindole) staining assays were used to evaluate the apoptotic activity. All the compounds exhibited antiproliferative activity against the HCT-116 cell line with IC50 values at 33 ± 1.25, 36 ± 2.25, 34 ± 2.15, 32 ± 2.35, 34 ± 2.65, and 36 ± 1.95 μg/mL for compounds 1 to 6, respectively. All the compounds produced a significant reduction in HCT-116 cell line proliferation, except compounds 2 and 6. The viability of the HEK-293 normal cells was found to be significantly higher than the viability of the cancerous cells at all of the tested concentrations, thus suggesting that all the compounds have better inhibitory activity on the cancer cell line. Apoptotic features such as chromatin condensation and nuclear shrinkage were also induced by the compounds. The expression of caspase-3 and caspase-9 genes increased in HCT-116 cell lines after 48 h of treatment, suggesting cell death by the apoptotic pathways. The molecular docking studies showed favorable binding affinity against different pro- and antiapoptotic proteins by these compounds. The docking scores were minimum as compared to the caspase-9, caspase-3, Bcl-xl, and JAK2.

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Pulicaria jaubertii is a medicinal herb that alleviates inflammations and fever. Chromatographic separation, phytochemical characterization, and in vitro biological activities of the plant n-hexane extract were conducted for the first time in this study. Six compounds were isolated for the first time from the n-hexane fraction of Pulicaria jaubertii aerial parts and were identified on the bases of NMR and MS analyses as pseudo-taraxaterol (1), pseudo-taraxasterol acetate (2), 3β-acetoxytaraxaster-20-en-30-aldehyde (3), calenduladiol-3-O-palmitate (4), stigmasterol (5), and α-tocospiro B (6). Compound (6) was a rare tocopherol-related compound and was isolated for the first time from family Asteraceae, while compound (3) was isolated for the first time from genus Pulicaria. The total alcoholic extract and n-hexane fraction were tested for their anti-inflammatory, antidiabetic, and cytotoxic activities. The n-hexane fraction has dose dependent red blood cells (RBCs) membrane stabilization and inhibition of histamine release activities with IC50: 60.8 and 72.9 µg/mL, respectively. As antidiabetic activity, the alcoholic extract exerted the most inhibition on the activity of yeast α-glucosidase, with an IC50: 76.8 µg/mL. The n-hexane fraction showed cytotoxic activity against hepatocarcinoma (HepG-2), breast carcinoma (MCF-7), and prostate carcinoma (PC-3) cell lines with IC50: 51.8, 90.8 and 62.2 µg/mL, respectively. In conclusion, the anti-inflammatory effect of Pulicaria jaubertii might be attributed to the triterpenoid constituents of the n-hexane extract of the plant.

Phytochemical investigation of Calliandra hematocephala (L` Her) Benth leaves (Leguminosae) resulted in isolation of β-sitosterol (1), Lupeol (2) and dodecanoic acid (3). The compounds were identified by chromatographic (TLC, PC) and spectroscopic analysis (1 H NMR and 13 C NMR). This is the first report for isolation of compounds 2 and 3 from Calliandra hematocephala. All compounds (1-3) showed antifungal activity against Aspergillus fumigates, Penicillium italium and Geotricum candidum .They also showed antimicrobial activity against Staphylococcus aureus, Bacillis subtilis and Escherichia coli.

Thevetia peruviana and Plumeria rubra (family Apocyanaceae) are shrubs cultivated in Egypt for ornamental purposes. This study was done to compare the volatile oils of T. peruviana and P. rubra which were prepared by using the hydrodistillation method from fresh flowers and leaves of each plant. Identification and quantification of the oil components were carried out by GC/MS analysis. The major components of T. peruviana flowers oil were Nonadecane (37.69 %), followed by 1-Nonylcycloheptane (18.39%), while Perilla alcohol (20.49%), β-ylangene(10.62%) and β-Elemene (7.19%) were predominant in the leaves oil. On the other hand, the major constituents of P. rubra flowers oil were Methyl dihydroepi-jasmonate (35.41%), Linalool (14.31%) and Methyl jasmonate (11.99%), while 1-Nonylcycloheptane (32.16%) and Menthol (17.89%) were of highest abundance in the leaves oil. Also, the antimicrobial activity was investigated against Staphylococcus aureus ATCC 4175, Escherichia coli ATCC 10536, Pseudomonas aeruginosa CNCM A21, and Candida albicans ATCC 60193. The minimum inhibitory concentrations (MIC) were determined and compared with those of standard antibiotics (Ofloxacin and Amphotericin B), the tested oils showed a good inhibitory effect against the investigated microbial strains with a minimum inhibitory concentration (MIC) range of 25 to 300 µg/mL except for the P. rubra leaves oil, which showed no activity against Pseudomonas aeruginosa.