Diketopiperazine Alkaloids from a Deep Ocean Sediment Derived Fungus Penicillium sp.

Abstract

Five new diketopiperazine alkaloids, brevicompanines D-H (3-7), together with two known analogs, allobrevicompanine B (1) and fructigenine B (2), were isolated from a deep ocean sediment derived fungus Penicillium sp. Their structures were established by spectroscopic methods including 2D NMR and chiral HPLC analysis. Compounds 4 and 7 inhibited lipopolysaccharide (LPS)-induced nitric oxide production in BV2 microglial cells.

Structure, Bioactivity and Synthesis of Natural Products with Hexahydropyrrolo[2,3‐b]indole

“…Leptosins D-F (12)(13)(14), [23] gliocladines C-E (15-17), [24] gliocladins A-C, [25] plectosphaeroic acids A-C (18,19), [26] (+)-asperazine (20), [27] and naseseazines A and B [28] have an analogous DKP unit containing an extra indole, bound between C 3 and C 3a (except for in the case of (+)-asperazine and the naseseazines, in which the indole binds via C 7 and C 6 , respectively). Brevicompanines A-H (21: A, 22: B), allo-brevicompanine B and fructigenine B [29][30][31] are also alkylated at C 3a ; as is ardeemin, isolated from a strain of Aspergillus fischeri; [32] roquefortines C, D (23), F and G; [33][34][35][36] and aszonalenin (24). [37] Brevianamide E (25), [38] the sporidesmins [39][40][41][42] and notoamide D [43] are all hydroxylated at C 3a (Scheme 1).…”

Prenylated Indole Diketopiperazines from the Marine-Derived Fungus Aspergillus versicolor

“…Their structures, including the absolute configuration of the known enamide (9), 15 were elucidated on the basis of chemical and spectroscopic evidence, single-crystal X-ray diffraction analysis, and comparison between the experimental ECD and TDDFT calculated spectra. Compounds 1−6 are characterized by a 6/ 6/5/8/6/5 hexacyclic ring system containing a hydrogenated azocine moiety, and versicamide G (7) contains a novel 6/6/ 11/6/5 pentacyclic ring system, whereas versicamide H (8) has an unprecedented skeleton featuring a 2,5-dihydro-1H-azepino- [4,3-b]quinoline system.…”

New Deoxyisoaustamide Derivative from the Marine-derived Fungus Penicillium sp. JF-72

“…Penicillium species are known to produce numerous alkaloids, in which some diketopiperazine-type alkaloids have been reported so far. [1][2][3][4][5] In the course of our on-going research on the secondary metabolites of marinederived fungi, we have investigated the chemistry of the methylethylketone extract of the Penicillium sp. JF-72, and the study resulted in the isolation of three indole-containing diketopiperazine alkaloids (1)(2)(3), including a new natural compound (2) and a new metabolite (3).…”

“…The absolute configuration of compound 2 was determined based on the biogenetic considerations of diketopiperazine alkaloids isolated from the fungal genus Penecillium, [1][2][3][4][5] and NOESY correlation between H-11 and H-17. In addition, comparison of its optical rotation value, + 140 (c 0.04, CHCl 3 ) with the reported compound was in good agreement with this assignment.…”

“…As all the diketopiperazine alkaloids isolated from the fungi Penecillium showed the configuration at C-11 to be S, therefore the orientation of proton at C-11 of 3 could be assumed as α based on the biogenetic considerations. [1][2][3][4][5] In the NOESY spectrum, an NOE correlation observed between H-11 and H-16 indicated that the hydroxyl group at C-16 is β-oriented (Figure 2). Furthermore, H-11 and H-16 did not give any NOE correlation with the methoxy group, suggesting that the orientation of the methoxy group at C-17 is β, which is opposite to that of the methoxy group of verpacamide D. 8 The observation of unusual upfield-shifted proton chemical shift of the methoxy group could be rationalized by the presence of coplanar C-18 carbonyl group.…”