In this study, biologically active compounds were isolated from Protaetia brevitarsis larva (PBL) by dichloromethane extraction. The dichloromethane extract from PBL was highly cytotoxic to various cancer cells. From a silica gel column chromatograpy of this extract, we obtained four fractions (F-2, F-4, F-5 and F-7) having apoptosis-inducing activity. These fractions induced DNA ladder and caspase-3 activation during apoptosis in colon 26 tumor cells. In 1H and 13C NMR and mass spectral analysis of the fraction F-2 showing the highest apoptosis-inducing activity, we found that the fraction was composed of three free fatty acids such as palmitic acid, (Z)-9-octadecenoic acid and octadecenoic acid. These results indicate that the dichloromethane extract of PBL includes anticancer components composed of at least three fatty acids, and apoptosis-inducing activity of the extract was mediated by caspase-3 activation in tumor cells.

Hot water extract prepared from the mycelial culture of mushroom Phellinus linteus stimulated polyclonal antibody production in an in vitro culture system. The active fraction PLP was purified from the extract ca. 1030-fold by ethanol precipitation followed by DEAE-cellulose and gel permeation chromatography. PLP contained 13.2% (w/w) peptide and 82.5% (w/w) carbohydrate. About 6.8% (w/w) of the total carbohydrate was uronic acid. The molecular weight distribution of PLP was found to be nearly homogeneous (153 kDa) in gel permeation HPLC analysis. Neutral sugar composition analysis revealed Ara (7.5%), Xyl (3.7%), Glc (21.1%), Gal (24.1%) and Man (44.2%). Uronic acid was identified as a glucuronic acid by gas chromatography. Ten amino acids were detected and Asp and Glu were the major components. In our assay system, the half-maximal concentration of PLP for B-lymphocyte stimulation was ca. 3 micrograms/ml. Partial acid hydrolysis as well as sodium periodate treatment of PLP decreased the activity significantly, suggesting that both the full molecular size and the sugar moiety were essential. However, proteinase K treatment for up to 48 h did not affect the activity.

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Phytochemical study on the EtOAc-soluble fraction of the stem bark of Populus davidiana resulted in the isolation of 10 phenolic glycosides (1-10), which were identified on the basis of physicochemical and spectroscopic analyses. Among these, three new compounds, populosides A-C (1-3), were determined to be 2-coumaroylmethyl-4-hydroxyphenyl-beta-D-glucopyranoside, 2-coumaroylmethylphenyl-beta-D-glucopyranoside, and 2-feruoylmethylphenyl-beta-D-glucopyranoside, respectively. Compounds 1-10 were tested for their radical scavenging activity against an azo radical, ABTS*+. Of these, populosides A-C (1-3), populoside (4), grandidentatin (8), salireposide (9), and coumaroyl-beta-D-glucoside (10) exhibited antioxidant activity in this assay.