Antioxidant activity of Piper caninum and Cyclooxygenase-2 inhibition by methoxylated flavones.

Background: This study investigated on antioxidant activity of Piper caninum and cyclooxygenase-2 inhibition by methoxylated flavones.Materials and methods: The present study was carried out to quantify the total phenolic content and free radical scavenging activities of the crude extracts by Folin-Ciocalteu and 1,1-diphenyl-2-picrylhydrazyl free radical scavenging assay respectively.Results: Methanolic extracts of Piper caninum exhibited the highest total phenolic content and free radical scavenging activities. All the pure compounds possessed significant cyclooxygenase-2 inhibition at physiological concentrations.Conclusion: Based on in vitro and molecular docking, we therefore suggest that Piper caninum methoxylated flavones are potent inhibitors of cyclooxygenase-2 at physiological concentrationsKey words: Piper caninum; antioxidant; cyclooxygenase-2.List of abbreviations: COX-2, cyclooxygenase-2; DPPH, 2,2-diphenyl- 1-picrylhydrazyl; PGE2, prostaglandin E2

Application of Box-Behnken Design for Ultrasound- Assisted Extraction and Recycling Preparative HPLC for Isolation of Anthraquinones from Cassia singueana

Introduction – Cassia singueana Del. (Fabaceae) is a rare medicinal plant used in the traditional medicine preparations to treat various ailments. The root of C. singueana is a rich source of anthraquinones that possess anticancer, antibacterial and antifungal properties. Objective – The objective of this study was to develop ultrasound-assisted extraction (UAE) method for achieving a high extraction yield of anthraquinones using the response surface methodology (RSM), Box-Behnken Design (BBD), and a recycling preparative HPLC protocol for isolation of anthraquinones from C. singueana. Methodology – Optimisation of UAE was performed using the Box-Behnken experimental design. Recycling preparative HPLC was employed to isolate anthraquinones from the root extract of C. singueana. Results - The BBD was well-described by a quadratic polynomial model (R2 = 0.9751). The predicted optimal UAE conditions for a high extraction yield were obtained at: extraction time 25.00 min, temperature 50C and solvent-sample ratio of 10 mL/g. Under the predicted conditions, the experimental value (1.65 ± 0.07%) closely agreed to the predicted yield (1.64%). The obtained crude extract of C. singueana root was subsequently purified to afford eight anthraquinones. Conclusion - The extraction protocol described here is suitable for large-scale extraction of anthraquinones from plant extracts

A new xanthone and a new benzophenone from the roots of Garcinia hombroniana

In this study, the roots of Garcinia hombroniana were chemically investigated, in which novel derivatives of xanthone and benzophenone, known as garcihomxanthone (1) and garcihombrianone (2), respectively, together with garceduxanthone (3), cheffouxanthone (4), norathyriol (5), and 2,3′,4,5′-tetrahydroxy-6-methoxybenzophenone (6) were isolated.. The structures of these compounds were elucidated by extensive spectroscopic techniques and evaluated based on references with previous literature data

Chemical compositions of the rhizome oils of two Alpinia species of Malaysia

The essential oils obtained by hydrodistillation of the rhizomes of Alpinia aquatica Rosc. syn. Alpinia melanocarpa and Alpinia malaccensis Roscoe were analysed by capillary gas chromatography and gas chromatography-mass spectrometry. Eighteen compounds, representing 98.4% of the essential oil were identified in A. aquatica rhizome oil, with ß-sesquiphellandrene in 36.5% being the major constituent, while 20 compounds representing 99.7% of the rhizome oil of A. malaccensis were identified, among which methyl (E)-cinnamate (78.2%) was the major constituent