New Triquinane-Type Sesquiterpenoids from Macrocystidia cucumis (Basidiomycetes)

Abstract

Arthrosporone (1) and eight new triquinane-type sesquiter-The absolute configuration of cucumin F (8) was assigned by 1 H-NMR analysis of the corresponding Mosher esters. Two penoids have been isolated from mycelial cultures of the agaric Macrocystidia cucumis. The cucumins AϪD (2, 4Ϫ6) are further metabolites were identified as cyclo(phenylalanylprolyl) (12) and cyclo(leucylprolyl) (13). Cucumin A (2) exhibits highly unsaturated hirsutane derivatives, whereas the cucumins EϪG (7Ϫ9) represent a new type of linear triquinanes. antibacterial and cytotoxic activities. Cucumin H (10) is a new member of the ceratopicane group. cystidia cucumis (Pers. ex Fr.) Heim (German: Gurkenschnitzling) have previously been shown to exhibit antimicrobial activity and strong cytotoxic effects [1] . We now report on the isolation of the active principles, which were identified as a series of biosynthetically related triquinanetype sesquiterpenoids. Fermentation of the Fungus and Isolation of the MetabolitesFor production of the cucumins, fermentations of Macrocystidia cucumis were carried out in 100 l of YMG medium. When the antifungal activity had reached its maximum, the mycelia were separated from the culture fluid by filtration and discarded. The antibiotics were adsorbed onto HP 21 resin, washed with methanol, and eluted with acetone. The qualitative and quantitative composition of the culture filtrate varied with the fermentation time. The metabolites were isolated from the crude fermentation extract by flash chromatography on silica gel followed by HPLC on RP-18 material (Figure 1 and Experimental Section). Hirsutane Derivatives 1, 2, 4؊6

Isolation and Structural Elucidation of Chondrosterins F–H from the Marine Fungus Chondrostereum sp.

“…Compound 3 , identified as arthrosporone, has been found in an unidentified arthroconidial fungus [6] and in Macrocystidia cucumis [7]. Careful analysis of our data indicated that these data are consistent with the data reported by Steglich et al [7].…”

New triquinane and gymnomitrane sesquiterpenes from fermentation of the basidiomycete Antrodiella albocinnamomea

“…The first example of triquinane-type sesquiterpene was hirsutane, which was isolated from a higher fungus Stereum hirsutum in 1947 [18]. Up to date, a series of triquinane-type sesquiterpenes were isolated from fungi [4,5,19], plants [20], as well as Streptomyces [21,22]. Those sesquiterpenes were formed via the humulane-protoilludane biosynthetic pathway.…”

Computational-guided discovery and characterization of a sesquiterpene synthase from Streptomyces clavuligerus

“…Cytochrome monooxygenases are often involved in oxidative modification reactions in terpene biosynthesis (44). For example, eight linear triquinane metabolites with cucumane, hirsutane, and ceratopicane carbon skeletons isolated from Macrocystidia cucumis were oxidized at two or more positions (45). Typically, linear triquinane metabolites described in the literature were isolated from fungi in the phylum basidiomycota and often possess antifungal, antibacterial, and/or cytotoxic activity (46).…”