Meliquercifolins A (1), and B (2), two new coumarins are bearing an acetophenone derivative were isolated from the leaves of Melicope quercifolia along with three known compounds, melicodenines E (3), F (4) and I (5). Structures of two new compounds were identified based on spectroscopic analyses (UV, HR-ESI-MS, 1 D and 2 D NMR). Cytotoxic activities of compounds (1–5) towards three human cancer cells (HeLa, MCF-7, P-388), compounds 1, 4 and 5 showed very potent activity against Hela cells with IC₅₀ values 2.6; 0.8; 1.1 μM, respectively. Graphical Abstract

Two new isoprenylated benzofuran 3-ones, airlanggin A (1) and B (2) along with two known xanthones, ananixanthone (3) and trapezifolixanthone (4) were isolated from the stem bark of Calophyllum soulattri. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1–4 were evaluated for their cytotoxicity against P-388 cells, showing that compound 3 was the most active with IC₅₀ 0.68 μg/mL and compound 1 showed moderate activity with IC₅₀ 5.80 μg/mL.

The aim of this study was to assess the antimalarial and antioxidant effects of the n-hexane and ethyl acetate extracts together with three isolated isoprenylated coumarins, mammea A/BA(1),mammea A/ AA cyclo D (2) and mesuol (3) from the stem bark of M. borneensis L. The n-hexane and ethyl acetate extracts, as well as compounds 1-3 were evaluated for their antimalarial activity against Plasmodium falciparum strain 3D7 (chloroquine-sensitive) and their antioxidant activity against DPPH radical scavenging. Compound 2 exhibited slightly more active than chloroquine. Compounds 1 and 3 showed very high activity against DPPH radical.

A new isoprenylated 4-phenylcoumarin derivative, mesucalophylloidin (1) along with three known compounds, mammea A/BA cyclo F (2), calolongic acid (3) and isocalolongic acid (4) were isolated from the stem bark of Mesua calophylloides (Ridl.) Kosterm. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1–4 were evaluated for their cytotoxicity against P-388 cells, showing that compound 1 gave moderate activity with IC₅₀ 6.26 μg/mL.

Three new pyranoxanthones, calotetrapterins A-C (1-3) were isolated from the stem bark of Calophyllum tetrapterum Miq along with three known xanthones, α-mangostin (4), garciniafuran (5), and pyranojacareubin (6). All structures were elucidated based on their IR, UV, HRESIMS, 1 D (¹H, ¹³C) and 2 D (HMBC, HMQC) NMR spectral data. Compounds 1-6 were tested to P-388 cells for cytotoxic activity, compound 2 exhibited high activity with IC₅₀ value 1.0 μM. Graphical Abstract