LC-MS/MS Screening, Total Phenolic, Flavonoid and Antioxidant Contents of Crude Extracts from Three Asclepiadaceae Species Growing in Jordan.

This study aimed to evaluate the antioxidant activity and total phenolic content (TPC) and total flavonoid content (TFC) of crude extracts obtained from three Asclepiadaceae species, namely, Calotropis procera L., Peruglaria tomentosa L., and Pentatropis spiralis (Forsk.) Decne. Both butanol and aq. methanol extracts of the three species showed the highest amount of phenol and flavonoid contents, which exhibited the greatest antioxidant activity in the scavenging of 2,2-diphenyl-2-picrylhydrazyl free radical (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt radical cation (ABTS), ferrous chelating effect (FIC), and hydroxyl radical (HDR) assays. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, sponins, flavonoids, terpenoids, and glycosides. LC-MS analysis was carried out to identify the major compounds from each crude extract. A total of 12 phenolic compounds in the extracts of the 3 species were identified and quantified, including 9 flavonoids, 2 hydroxybenzoic acids, and 3 hydroxycinnamic acids. The current study also revealed a good correlation between total phenolic contents and the observed antioxidant activity of the crude extracts.

DNA Barcoding of Two Thymelaeaceae Species: Daphne mucronata Royle and Thymelaea hirsuta (L.) Endl.

Daphne mucronata Royle and Thymelaea hirsuta (L.) Endl both belong to the Thymelaeaceae family. Both species are used traditionally to treat several diseases along with various daily applications by Jordanian Bedouins. Traditionally, those species are identified through personal proficiency, which could be misleading due to human errors or lack of expertise. This study aims to investigate an effective DNA barcoding method to identify and characterize Daphne mucronata Royle and Thymelaea hirsuta plant species at the molecular level. Daphne mucronata Royle and Thymelaea hirsuta were collected from the ancient city of Petra in the Southern part of Jordan. Sequences of candidate DNA barcodes were amplified (rbcL, matK, and rpoC1), sequenced, and aligned to the blastn database. Moreover, the obtained sequences were compared with available sequences of related species at the GenBank database. Our results showed that DNA barcoding successfully identifies the two plant species using any of chloroplast genes (rbcL, matK, or rpoC1). The results emphasize the ability of DNA barcoding for identifying and characterizing different plant species through the recruitment of different barcode loci in molecular identification.

New isoflavones from Gynandriris sisyrinchium and their antioxidant and cytotoxic activities.

Chemical investigation of Gynandriris sisyrinchium (L.) Parl growing in Jordan resulted in the isolation and characterization of a total of twelve compounds two of which are reported here for the first time in nature. These new compounds included the isoflavones; 3'-methyl tenuifone (2) and gynandrinone (5). In addition, ten known compounds including; ß-sitosterol (1), 7,3'-dimethoxy-5,6,4'-trihydroxyisoflavone (3), iristectorigenin (4), hispidulin (6), galangustin (7), 6-hydroxybiochanin A (8), ursolic acid (9), ladanetin (10), 4'-O-methylgenistein (11) and ß-sitosterol glucoside (12) are also reported here for the first time from G. sisyrinchium. The isolated compounds were characterized by different spectroscopic methods including NMR (1D and 2D), UV, IR and MS (HRESIMS and EIMS). The antioxidant and cytotoxic activities of isoflavones 2, 3 and 5 were investigated. Compound 3 showed the highest antioxidant activity (IC50=17.3µg/mL), as compared to compounds 5 and 2 (IC50=26.7 and 51.7µg/mL, respectively). The cytotoxic activity against the human promyelocytic leukemia HL-60 cells revealed that compound 2 was the most active (40µM). The results indicate that the cytotoxicity of compound 2 is mediated by apoptosis.