The crude methanol extracts and fractions of the root and stem barks of Dillenia serrata Thunb. showed 64% to 73% inhibition on the production of prostaglandin E2 (PGE2) in lipopolysaccharide-induced human whole blood using a radioimmunoassay technique. Three triterpenoids isolated from the root bark of the plant, koetjapic (1), 3-oxoolean-12-en-30-oic (2), and betulinic (3) acids, exhibited significant concentration-dependent inhibitory effects on PGE2 production with IC50 values of 1.05, 1.54, and 2.59 μM, respectively, as compared with the positive control, indomethacin (IC50 = 0.45 μM). Quantification of compounds 1 and 3 in the methanol extracts and fractions were carried out by using a validated reversed-phase high performance liquid chromatography (RP-HPLC) method. The ethyl acetate fraction of the stem bark showed the highest content of both compound 1 (15.1%) and compound 3 (52.8%). The strong inhibition of the extracts and fractions on cyclooxygenase-2 (COX-2) enzymatic activity was due to the presence of their major constituents, especially koetjapic and betulinic acids.

The leaf, bark and wood oils of Cinnamomum rhyncophyllum Miq. were investigated by gas chromatography on two columns of different polarity, retention indices and GC-MS. The oils were composed mainly of phenylpropanoids and benzylic compounds. The leaf oil may be a potential natural source of benzyl benzoate, since it constituted up to 77% of the oil. Other compounds present in appreciable amounts in the oil were β-phellandrene (6.3%) and methyl (E)-cinnamate (4.2%). The bark and wood oils were found to possess compositional similarities with little variation in the levels of each component. Safrole (43.3-51.0%) and methyl (E)-cinnamate (40.5-43.1%) were the major constituents in these oils. However, the bark oil could be distinguished from the wood oil by containing a higher concentration of benzyl benzoate.

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The chemical composition of the leaf oil of Cinnamomum pubescens Kochummen was examined by GC with authentic samples on two columns of different polarity, GC/MS and retention indices. Oils hydrodistilled from samples collected from two different sites at different periods were found to possess minor compositional differences but considerable variation in the levels of some components. The oils were rich in benzyl benzoate (46.1-47.1%) and β-phellandrene (14.9-16.4%). The samples could be differentiated from each other in which one sample contained a significantly higher concentration of benzyl salicylate and relatively lower concentrations of pinenes and (E)-methyl cinnamate.