A new alkenylphenol, 2-hydroxyl-6-(14' Z -nonadecenyl)benzoic acid (1), was isolated from the ethanolic extract of Vietnamese stingless bee propolis Trigona minor (Meliponini, Apidae), together with two known compounds (2 and 3). Their chemical structures were determined by extensive NMR spectroscopic analysis. All compounds were tested for preferential cytotoxicity against the PANC-1 human pancreatic cell line under nutrition-deprived conditions (NDM). Compound 1 exhibited the strongest preferential cytotoxicity, with a PC50 value of 2.4 μM.

From the stem barks of Swintonia griffithii, six flavonoids: (–)‐naringenin (1), (–)‐eriodictyol (2), (+)‐taxifolin (3), (–)‐butin (4), (–)‐fustin (5), and 3′,4′,7‐trihydroxyflavone (6) were isolated. Their structures were determined based on the spectroscopic interpretation and compared with those of reported data. In the tyrosinase inhibitory activity test, (+)‐taxifolin (3) and 3′,4′,7‐trihydroxyflavone (6) exhibited potent effect with the IC50 values of 20.9 and 56.7 μM, respectively.

Swintonia floribunda Griff. is an evergreen tree that belongs to Anacardiaceae family, which grows at Tay Nguyen, Lam Dong, and Dong Nai Provinces in Vietnam. Swintonia floribunda showed many interesting biological activities such as antitumor effect against breast and pancreatic cancers, antioxidant, and antimicrobial activities. From the stem barks of Swintonia floribunda Griff. (Anacardiaceae) collected in Dong Nai province, three epoxylignans: pinoresinol (1), syringaresinol (2), epipinoresinol (3), together with three other compounds: n-heptacosyl trans-ferulate (4), methyl orsellinate (5), and friedelin (6) have been isolated from the EtOAc-soluble extract. The chemical structure of these compounds were determined by 1D and 2D NMR spectra and comparison with published data. These compounds were first reported in Swintonia floribunda