A new lanostane-type terpenoid, lucidenic acid SP1 (1), was isolated from a CHCl(3)-soluble fraction of Ganoderma lucidum spores together with four other known compounds (2 - 5). The structure of lucidenic acid SP1 was determined to be 3 beta,7 beta-dihydroxy-4,4,14 alpha-trimethyl-11,15-dioxo-5 alpha-chol-8-en-24-oic acid by spectroscopic means including 2D-NMR. Twelve triterpenes (1-12) isolated from G. lucidum spores were investigated in vitro for their anticomplementary activity. Compounds 1 - 5 were inactive, whereas ganoderiol F (8), ganodermanondiol (9) and ganodermanontriol (10) showed a strong anticomplement activity against the classical pathway (CP) of the complement system with IC(50) values of 4.8, 41.7, and 17.2 microM, respectively. The potency of these triterpene alcohols (8-10) in inhibiting CP activity was improved when the number of hydroxymethyl groups on the side chain moiety is increased. On the other hand, the ganoderic acids 1-7, which contain a carboxyl group in the side chain, and lucidumols A and B (11, 12) had little activity on this system.

Two neolignan compounds, magnolol (5,5'-diallyl-2,2'-dihydroxybiphenyl, 1) and honokiol (5,5'-diallyl-2,4'-dihydroxybiphenyl, 2), were isolated from the stem bark of Magnolia obovata and evaluated for antifungal activity against various human pathogenic fungi. Compound 1 and 2 showed significant inhibitory activities against Trichophyton mentagrophytes, Microsporium gypseum, Epidermophyton floccosum, Aspergillus niger, Cryptococcus neoformans, and Candida albicans with minimum inhibitory concentrations (MIC) in a range of 25-100 microg/ml. Therefore, compound 1 and 2 could be used as lead compounds for the development of novel antifungal agents.

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The aim of this work was to study the structure-activity relationships of the antioxidant activity of natural coumarins isolated from four Korean medicinal plants (1-17) and four purchased coumarins (18-21). The free radical scavenging and lipid peroxidation assays revealed that five phenolic coumarins, scopoletin (1), aesculetin (2), fraxetin (3), umbelliferone (18) and daphnetin (19), possessed considerable antioxidant activities. The coumarins having a catechol group, 2, 3 and 19, showed significant free radical scavenging activity and inhibitory effects on lipid peroxidation, indicating that the catechol group significantly contributed to the antioxidant activities of coumarins. In contrast, the sugar moiety markedly reduced the activities of coumarin glycosides. The results also demonstrate that the alpha-pyrone ring of coumarins significantly enhanced the capacity of inhibiting oxidative reactions of coumarins.

Arginase II has recently reported as a novel therapeutic target for the treatment of cardiovascular diseases such as atherosclerosis. In the course of screening plants used in natural medicines as arginase II inhibitory activity, a methanol extract of Scutellaria indica showed significant inhibitory effect. Further fractionation and repeated column chromatography led to the isolation of a new flavan-type (1), and seven known compounds (2–8). The chemical structures of isolated compounds were elucidated based on extensive 1D and 2D NMR spectroscopic data. The isolates 1–8 were investigated in vitro for their arginase II inhibitory activity using enzyme solution prepared from kidney of anesthetized C57BL/6 mice. Compounds 3 and 5 significantly inhibited arginase II activity with IC50 values of 25.1 and 11.6 μM, respectively, whereas the other compounds were apparently inactive.