Four new compounds, the limonoid 24-epi-melianodiol (8), the tirucallane aglaiodiol (9), and the two cyclopentatetrahydrobenzopyran derivatives pyramidaglain A (11) and B (12) were isolated from the leaves of Aglaia andamanica Hiern (Meliaceae), together with the eleven known constituents beta-sitosterol, beta-sitosterol glucoside, cycloart-23E-ene-3 beta,25-diol (1), three flavonoids 5-hydroxy-3,4',7-trimethoxyflavone (2), retusin (3) and pachypodol (4), the tirucallane 24-epi-piscidinol A (5), the lignan yangambin (6), the limonoid melianodiol (7), the bisamide pyramidatine (10) and the amino acid N-methyl-trans-4-hydroxy-L-proline (13). All structures were established by means of detailed spectroscopic analysis.

To evaluate the antibacterial activity of 12 ethanol extracts of Thai traditional herb against oral pathogens. The antibacterial activities were assessed by agar well diffusion, broth microdilution, and time-kill methods. Antibiofilm activity was investigated using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium-bromide (MTT) assay. High performance liquid chromatography (HPLC), thin layer chromatography (TLC) fingerprinting, and TLC-bioautography were used to determine the active antibacterial compounds. Piper betle showed the best antibacterial activities against all tested strains in the minimal inhibitory concentration and minimal bactericidal concentration, ranged from 1.04–5.21 mg/mL and 2.08–8.33 mg/mL, respectively. Killing ability depended on time and concentrations of the extract. P. betle extract acts as a potent antibiofilm agent with dual actions, preventing and eradicating the biofilm. The major constituent of P. betle extract was 4-chromanol, which responded for antibacteria and antibiofilm against oral pathogens. It suggests that the ethanol P. betle leaves extract may be used for preventing oral diseases.

The structure of pyramidatine [1], a new bisamide alkaloid from leaves of Aglaia pyramidata, was determined through extensive nmr studies, including homonuclear COSY, NOESY, APT, HETCOR, and selective INEPT techniques. Revision of the 13C-nmr assignment of piriferine [2], an alkaloid previously isolated from A. pirifera, was achieved by examination of several 2D nmr spectra (homonuclear COSY, NOESY, and HETCOR) and confirmed by selective INEPT nmr experiments. Evaluation of the cytotoxic potential of the two alkaloids, along with two other bisamides from Aglaia odorata, odorine [3] and 5'-epi-odorine [4], was carried out in eleven human cancer cell lines. None of these bisamides showed significant cytotoxicity. Nevertheless, piriferine [2], odorine [3], and 5'-epi-odorine [4] were found to inhibit the growth of the vinblastine-resistant KB cells by enhancing the anticancer activity of vinblastine.

The phytochemical investigation of a methanolic leaf extract of Aglaia rubiginosa furnished 15 isoprenoid constituents, eight of which represented new natural entities. Two androstane derivatives (1 and 2), previously synthesized, and also obtained by microbiological transformations; an extraordinary 17-octanor-cycloartane-ring-A-seco acid (3); four cycloartane-type triterpenes (4-7); and three unusual cholesterol derivatives (8-10) were isolated, along with two known dammaranes (11 and 12), a stigmastandiol (13), and beta-sitosterol and its beta-D-glucoside. Spectroscopic structure elucidation of the new natural products (1-3, 6, 7, 8-10) is described.

Various dermatological disorders and microbial skin infection can cause hyperpigmentation. Therefore, screenings for whitening and antimicrobial agents from Thai medicinal plants have been of research interest. Seventy-seven ethanol plant extracts were investigated for antityrosinase activity, eleven samples showed the tyrosinase inhibition more than 50 % were further preliminary screening for antimicrobial activity by agar disc diffusion and broth micro-dilution methods. Artocarpus integer (Thunb.) Merr. (Moraceae) root extract, which showed the potential of tyrosinase inhibition with 90.57 ± 2.93 % and antimicrobial activity against Staphylococcus aureus, S. epidermidis, Propionibacterium acnes and Trichophyton mentagophytes with inhibition zone as 9.10 ± 0.00, 10.67 ± 0.09, 15.25 ± 0.05 and 6.60 ± 0.17 mm, respectively was selected for phytochemical investigation. Three pure compounds were isolated as artocarpin, cudraflavone C and artocarpanone. And artocarpanone exhibited anti-tyrosinase effect; artocarpin and cudraflavone C also showed the potential of antibacterial activity against S. aureus, S. epidermidis and P. acnes with MIC at 2, 4 and 2 μg/ml, respectively and MBC at 32 μg/ml for these bacteria. So, these pure compounds are interesting for further study in order to provide possibilities of new whitening and antibacterial development. This will be the first report of phytochemical investigation of A. integer root.