Herein, we report the synthesis of different novel sets of coumarin-6-sulfonamide derivatives bearing different functionalities (4a, b, 8a–d, 11a–d, 13a, b, and 15a–c), and in vitro evaluation of their growth inhibitory activity towards the proliferation of three cancer cell lines; HepG2 (hepatocellular carcinoma), MCF-7 (breast cancer), and Caco-2 (colon cancer). HepG2 cells were the most sensitive cells to the influence of the target coumarins. Compounds 13a and 15a emerged as the most active members against HepG2 cells (IC50 = 3.48 ± 0.28 and 5.03 ± 0.39 µM, respectively). Compounds 13a and 15a were able to induce apoptosis in HepG2 cells, as assured by the upregulation of the Bax and downregulation of the Bcl-2, besides boosting caspase-3 levels. Besides, compound 13a induced a significant increase in the percentage of cells at Pre-G1 by 6.4-folds, with concurrent significant arrest in the G2-M phase by 5.4-folds compared to control. Also, 13a displayed significant increase in the percentage of annexin V-FITC positive apoptotic cells from 1.75–13.76%. Moreover, QSAR models were established to explore the structural requirements controlling the anti-proliferative activities.

Plants belonging to Euphorbia L. genus are considered very interesting from a medicinal point of view due to their diverse metabolites and bioactivities. The essential oil (EO) of Euphorbia mauritanica L. is not studied up to date. Therefore, the present study aimed to explore the chemical profile of this EO and evaluate its antioxidant, cytotoxic, and allelopathic potentialities. The EO was extracted from the whole plant via hydrodistillation and then, analyzed by gas chromatography/mass spectrometry (GC/MS). The correlation of E. mauritanica with the other Euphorbia plants was established using chemometric analysis. The antioxidant activity was determined based on scavenging of the free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The anti-proliferation of the EO on the Hep G2 and MCF-7 cells was evaluated. Finally the allelopathic activity of the EO was assessed against the two noxious weeds, Dactyloctenium aegyptium and Urospermum picroides. Forty-one compounds were identified using GC/MS analysis, with an abundance of terpenoids (91.54 %) that were categorized into mono-(30.75 %), sesqui-(15.23 %), and diterpenes (45.56 %). Interestingly, the results revealed the preponderance of diterpenoid constituents although they are rarely found in the EOs of the plant kingdom. The major compounds were (3E)-cembrene A (18.66 %), verticiol (17.05 %), limonene (7.91 %), eucalyptol (7.26 %), α-pinene (5.61 %), neo-cembrene A (3.52 %), kaur-16-ene (3.24 %), and cembrene (3.09 %). The EO showed moderate antioxidant activity where it attained IC 50 values of 83.34 and 64.21 μg mL À 1 for DPPH and ABTS compared to 23.01 and 19.23 μg mL À 1 for ascorbic acid as standard, respectively. The EO exhibited very weak cytotoxic effect on MCF-7 and Hep G2 cells. The EO showed significant allelopathic activities against the weeds D. aegyptium and U. picroides in a concentration-dependent manner. EO was found more effective against U. picroides than D. aegyptium with IC 50 values of 0.79, 0.45, and 0.67 mg mL À 1 and 1.17, 0.55, and 1.08 mg mL À 1 for germination, root, and shoot growth, respectively. Due to the high content of diterpenes in E. mauritanica, further study is recommended for more characterization of pure forms of the identified diterpenes as well as evaluating their bioactivity either solely or synergistically.

Objectives: This study focused on the identification and characterization of secondary metabolites tentatively from aqueous ethanolic leaf extract of Livistona chinensis by HPLC-PDA-ESI-MS/MS and evaluation of its cytotoxic activity. Methods: The aqueous ethanolic extract was analyzed by high performance liquid chromatography (HPLC) coupled to photodiode array detection of mass spectroscopy (PDA-MS/MS), to detect the secondary metabolites in L. chinensis leaves extract. It was also estimated for its cytotoxicity against human prostate carcinoma (PC3) and hepatocellular liver carcinoma (HepG2) cancer cell lines using SRB (3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay. Results: Fortytwo secondary metabolites were tentatively identified; the most major compounds were C-glycoside derivatives of apigenin, luteolin and tricin together with phenolic acids. The 70% alcoholic extract of L. chinensis leaves exhibit more antitumor activity against PC3 than against HepG2. Conclusion: L. chinensis is a privileged source of C-flavonoids that revealed the efficiency of HPLC-MS metabolomics in natural products drug discovery.

Three complex 7-oxygenated-8-prenylflavones, (-)-semiglabrin and (-)-pseudosemiglabrin, which are diastereoisomers, and lanceolatin A have been isolated from the root of Tephrosia apollinea (Del.) Link (Leguminosae) growing in Southern Egypt, together with two phytosterols, stigmasterol and sitosterol. The structures of the isolated compounds have been elucidated by means of physical and several spectroscopic methods including UV, IR, 1 H, 13 C NMR, DEPT, 2D 1 H-1 H COSY, HSQC, HMBC experiments, and high resolution mass spectrometry (HR-MS), as well as some chemical transformations. The stereochemistry of the structures of (-)-semiglabrin and lanceolatin A have been confirmed by X-ray crystal structure analysis. The anticarcinogenic properties of the isolated compounds showed no inhibitory mechanisms concerning the initiation, promotion, and progression stage of carcinogenesis. Moreover, the in vitro antimicrobial activities of the root ethanolic extract are discussed.

No abstract