Penidioxolanes A and B, 1,3-Dioxolane Containing Azaphilone Derivatives from Marine-derivedPenicilliumsp. KCB12C078

Abstract

-Two new azaphilone derivatives containing 1,3-dioxolane moiety, penidioxolanes A (1) and B (2), were isolated from marine-derived fungus Penicillium sp. KCB12C078, together with four known compounds (3-6) by chemical investigation. Compounds 1 -6 were isolated by combination of silica gel, ODS column chromatography and preparative HPLC. Their structures were determined by analysis of spectroscopic data including 1D-, 2D-NMR, and MS techniques. The isolates were evaluated against cancer cell growth inhibition effects and antimicrobial activity.

New Azaphilones from the Marine-Derived Fungus Penicillium sclerotiorum E23Y-1A with Their Anti-Inflammatory and Antitumor Activities

“…However, the side chain of compound 4 included the additional consecutive 1 H- 1 H COSY correlations of H-21/H-22/H 2 -23 (H 3 -25)/H 3 -24 excepting H-9/H-10 and H-12/H-13/H-14 (H 3 -18)/H 3 -15 were identical to compound 1 . This observation was further confirmed by the HMBC correlations from H-24 to C-23, from H-23 to C-22, from H-21 to C-22, and from H-25 to C-21, no long range HMBC correlations from H-21 to C-11 and C-12 were found, and the connection position with the azaphilone unit was deduced by downfield chemical shifts of C-11 and C-12 [ 28 ] ( Figure 2 ). All arrangements of 1D and 2D NMR data allowed the construction of the planar structure of compound 4 .…”

Azaphilones from the Fungus Penicillium multicolor LZUC‐S2 and Their Antibacterial Activity

“…For the 1,3‐dioxolane part, the strong NOE correlations of H‐1′/H‐12 and H‐13/H 3 ‐16 implied that H‐1′ and H‐12 were located on the same side while H 3 ‐16 was located on the opposite side ( Figure 3). [19] The absolute configurations of C‐7, C‐8, and C‐8a in 1 were all assigned to be R on the basis of its ECD spectrum which was similar with that of hypocrellone A (positive Cotton effects at 218 nm and 258 nm; negative Cotton effects at 234 nm, 284 nm, and 371 nm) ( Figure 4). [22] Moreover, considering compounds 1 and 3 – 8 were cometabolites, the 13 S in 1 was proposed based on the known S configuration of C‐13 in 3 – 8 .…”

“…The relative configuration of 1 was elucidated by the 1 H‐NMR coupling constants and the NOE experiments. The coupling constants of 3 J 8,8a =10.2, 3 J 8a,1 α =13.8, and 3 J 8a,1 β =4.8 showed that H‐8 and H‐8a had α ‐axial and β ‐axial orientations, respectively [19,22] . The NOE correlation observed between H‐8 and H 3 ‐18 indicated that H 3 ‐18 was in the α orientation ( Figure 3).…”

“…Considering the characteristic resonance of C-1' at δ 99.2, a 1,3-dioxolane moiety was constructed through C-11 and C-12 of the azaphilone unit and C-1' of the 3-oxobutyl unit, although no direct HMBC cross-peak was evident (Table 1). [18,19] Thus, the planar structure of 1 was deduced as shown (Figure 1).…”

“…To the best of our knowledge, only three azaphilones, penidioxolane A, penidioxolane B, and penicilazaphilone A, containing such unit have been found in nature. [18,19] Herein, we present the details of the isolation, structural elucidation, and antibacterial activity evaluation of all the azaphilones obtained.…”