Three new isoflavonoid glycosides, termisoflavones A-C (1-3), and eight isoflavonoids (4-11) were isolated from termite-associated Streptomyces sp. RB1 recovered from the cuticle of the South African termite, Macrotermes natalensis. The structures of new compounds were determined by spectroscopic methods including 1D and 2D NMR and HR-MS analysis, as well as comparison of their NMR data with those of related isoflavonoid glycoside derivatives. The absolute configurations of the sugar moieties were clarified by chemical reactions. None of the isolates (1-11) displayed antifungal or antimicrobial activities (MICs > 100 μg/mL), whereas compounds 6 and 11 ameliorated cisplatin-induced kidney cell damage to 80% of the control value at a cisplatin dose of 25 μM.

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Oryza sativa L. is consumed globally as a staple food, and its roots have been used as a Korean and Chinese medical supplement for protection of the stomach and lungs and for amelioration of vomiting and fever. In our continuing search for biologically effective metabolites from Korean natural materials, we found that an EtOH extract of O. sativa root reciprocally regulated adipocyte and osteoblast differentiation. Chemical analysis of the EtOH extract using a bioassay-guided fractionation protocol led to the isolation and determination of two novel lignans, oryzativols A and B, responsible for these regulatory activities. Using 1D and 2D nuclear magnetic resonance spectroscopic analyses, high-resolution mass spectrometry, and circular dichroism analysis, the structures of the novel compounds were elucidated. We examined their effects on the regulation of mesenchymal stem cell differentiation. Treatment with oryzativol A in the human mesenchymal cell line C3H10T1/2 suppressed gene expression of peroxisome proliferator activated receptor γ, which resulted in a reduction in adipogenesis. Oryzativol A also enhanced the expression of Runx2 and cellular differentiation into osteoblasts in the same mesenchymal stem cell line.

Euonymus alatus (Celastraceae) has been used as an anticancer agent in Korean traditional medicine. However, the potential bioactive contributors to the anticancer effects have not been thoroughly studied. Our screening test revealed that the MeOH extract of E. alatus twigs exhibited significant cytotoxicity against A549, SK-OV-3, and SK-MEL-2 cell lines. A bioassay-guided separation of the MeOH extract of E. alatus twigs resulted in the isolation and identification of 14 triterpenes as main phytochemicals. The structures of the compounds were elucidated on the basis of spectroscopic evidence as lupeol (1), betulin (2), 3β,28,30-lup-20(29)-ene triol (3), lupenone (4), betulone (5), 28,30-dihydroxy-3-oxolup-20(29)-ene (6), messagenin (7), glut-5-en-3β-ol (8), maslinic acid (9), hederagenin (10), 3-oxo-11α-methoxyolean-12-ene (11), 3β-hydroxy-1-oxo-olean-12-en-28-oic acid (12), ursolic acid (13), and 2α-hydroxy-ursolic acid (14). Of these compounds, 3, 6–8, and 10–14 were isolated for the first time from this plant. All isolated triterpenoids had consistent antiproliferative activities against A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines. Compounds 2, 5, and 7 showed significant cytotoxicity against all four cell lines tested, with IC50 values of 3.26–8.61 μM.