Isolation and Characterization of Methylated Flavones from Artemisia kermanensis

Isolation of potent antileishmanial agents from Artemisia kermanensis Podlech using bioguided fractionation

Leishmaniasis is a major health problem worldwide with different clinical forms that depend on the parasite, the host's immune system, and immune-inflammatory responses. This study aimed to evaluate the secondary metabolites from Artemisia kermanensis Podlech by bioguided fractionation against Leishmania major. The chemical structures of the isolated compounds were determined based on analysis of mass and nuclear magnetic resonance spectra. Antileishmanial activity were determined on promastigotes and amastigotes. Chemical structures of the isolated compound were as 1-Acetoxy-3,7-dimethyl-7-hydroxy-octa-2E,5E-dien-4-one for compound 1 and 5,7-dihydroxy-3',4',6-trimethoxyflavone (Eupatilin) for compound 2, and 5,7,3'-Trihydroxy-6,4',5'-trimethoxyflavone for compound 3. Compound 2 were confirmed by significant activity with IC50 of less than 50 μg/ml for 24 and 48 h in clinical form (amastigotes). Compound 3 demonstrated high susceptibility with an IC50 of less than 30 μg/ml for promastigotes for 24 h. The bioguided fractionation of A. kermanensis resulted the isolation of potent antileishmanial agents with a low toxicity effect on macrophages. These plant metabolites can be a candidate as a drug for treating cutaneous leishmaniasis.

Isolation and biological evaluation 7-hydroxy flavone from Avicennia officinalis L: insights from extensive in vitro, DFT, molecular docking and molecular dynamics simulation studies

The flavonoid based 7-hydroxy flavone (PubChem CID: 5281894; molecular formula: C₁₅H₁₀O₃) molecule has been isolated for the first time from the methanolic extract from the leaves of Avicennia officinalis L. in the tropical mangrove ecosystem of Andaman and Nicobar Islands (ANI), India. The molecular structure of bioactive compound was characterized by spectroscopic analysis, including FT-IR, ¹H, ¹³C NMR spectroscopy and ESI-HRMS and elucidated as 7-hydroxy flavone. An anticancer activity of isolated 7-hydroxy flavone was evaluated by in vitro study against two different human cancer cell lines namely, HeLa (cervical cells) and MDA-MB231 (breast cells) and they exhibited promising anticancer activity with IC₅₀ values are 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL, respectively. The antioxidant property of 7-hydroxy flavone at a standard concentration of 50 µg, was found to be (IC₅₀) 5.5486 ± 0.81 µg/mL. In summary, this investigation provides evidence that 7-hydroxy flavone exhibits both anticancer and antioxidant properties. Meanwhile, the antimicrobial activity ability of 7-hydroxy flavone were also evaluated using three Gram positive and two Gram negative strain exhibited no antimicrobial activities. Density-functional theory (DFT) studies confirm the structure is global minima in the PES, from the optimized geometry FMO and MESP map analyzed. Further, the molecular docking and molecular dynamics simulation studies result shows that 7-hydroxy flavone has the better binding ability with anti-apoptotic Bcl-2 protein with the estimated free energy of binding of -6.3 kcal/mol. This bioactive compound may be act as drug candidate for treating various kinds of cancers. HighlightsA 7-hydroxy flavone molecule has been isolated from Avicennia officinalis.The isolated pure compound was subjected to spectral analysis such as FT-IR, ¹H NMR, ¹³C NMR spectral data and HRMS analysis for skeleton of the molecule.The anticancer activity of 7-hydroxy flavone studied against Cervical (HeLa) cancer cell lines and breast (MDA-MB231) cancer cell lines with the IC₅₀ values of 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL), respectively.The antioxidant properties of 7-hydroxy flavone were found to be (IC₅₀) 5.5486 ± 0.81 µg/mL at a standard concentration of 50 µg.DFT, molecular docking and MD simulation results explained that 7-hydroxy flavone could be the most promising candidate to inhibit the function of anti-apoptotic Bcl-2 protein in cancerous cell.Communicated by Ramaswamy H. Sarma.