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This work was the first investigation of the essential oil composition of Goniothalamus tortilipetalus M.R.Hend. The aim of this study is to investigate the essential oil composition extracted from different parts of Goniothalamus tortilipetalus M.R.Hend., including flowers, leaves, and twigs, and to evaluate their antioxidant and antibacterial activities. The Clevenger apparatus was used for hydrodistillation to prepare the essential oils. The essential oils were investigated using gas chromatography–mass spectrometry (GC-MS). The three major compounds of the flowers were bicyclogermacrene (15.81%), selin-11-en-4-α-ol (14.68%), and E-caryophyllene (7.02%), whereas the leaves were p-cymene (39.57%), ascaridole (9.39%), and α-copaene (9.12%). In the case of the twigs, α-copaene (10.34%), selin-11-en-4-α-ol (8.85%), and p-cymene (7.76%) were the major compounds. The flower essential oil showed antioxidant activities with IC50 values of 725.21 µg/mL and 123.06 µg/mL for DPPH and ABTS assays, respectively. The flower essential oil also displayed antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Micrococcus luteus, Salmonella typhimurium, and Shigella flexneri, with the same MIC value of 640 µg/mL. [ABSTRACT FROM AUTHOR]

The first phytochemical investigation of the twig extract of Uvaria leptopoda resulted in the isolation and identification of three new tetrahydroxanthene-1,3(2 H )-diones, uvarialeptones A-C, two new oxidized hexadiene derivatives, uvarialeptols A and B, together with ten known compounds. Their structures were elucidated by spectroscopic techniques and mass spectrometry. Uvarialeptones A and B were unprecedented tetrahydroxanthene-1,3(2 H )-dione dimers which exhibited a cyclobutane ring via [2 + 2] cycloaddition from uvarialeptone C and 9a- O -methyloxymitrone, respectively. The structure of uvarialeptone A was confirmed by X-ray diffraction analysis using Mo Kα radiation. Compound 3 inhibited NO production at an IC 50 value of 6.7 ± 0.1 μM.