Alterporriol-Type Dimers from the Mangrove Endophytic Fungus, Alternaria sp. (SK11), and Their MptpB Inhibitions

Abstract

A new alterporriol-type anthranoid dimer, alterporriol S (1), along with seven known anthraquinone derivatives, (+)-aS-alterporriol C (2), hydroxybostrycin (3), halorosellinia A (4), tetrahydrobostrycin (5), 9α-hydroxydihydrodesoxybostrycin (6), austrocortinin (7) and 6-methylquinizarin (8), were isolated from the culture broth of the mangrove fungus, Alternaria sp. (SK11), from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods, including 1D and 2D NMR spectra. The absolute configurations of 1 and the axial configuration of 2 were defined by experimental and theoretical ECD spectroscopy. 1 was identified as the first member of alterporriols consisting of a unique C-10−C-2′ linkage. Atropisomer 2 exhibited strong inhibitory activity against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB) with an IC50 value 8.70 μM.

Anthraquinones and Derivatives from Marine-Derived Fungi: Structural Diversity and Selected Biological Activities

“…The mangrove endophytic strain Alternaria sp. SK11, from the root of Excoecaria agallocha collected in the South China Sea, produces alterporriol S, (+)-aS-alterporriol C, 6-methylquinizarin along with the known austrocortinin [ 47 ]. Alternaria sp.…”

Elucidation of cladofulvin biosynthesis reveals a cytochrome P450 monooxygenase required for anthraquinone dimerization

“…Anthraquinones and xanthones contain an aromatic core that serves as a scaffold for the attachment of diverse functional groups, resulting in a wide variety of molecules with distinct biological and biochemical characteristics. This diversity is further increased by their assembly into homo-and heterodimers (3,5), with activities that are distinct from those exhibited by their respective monomeric components (6). Despite the large number of identified anthraquinones and xanthones and their potential applications, very few of their biosynthetic pathways are known.…”

Synergistic antibacterial activity between penicillenols and antibiotics against methicillin-resistant Staphylococcus aureus

“…Its absolute configuration was confirmed as (11R)-by a modified Mosher method δ(δ S −δ R ) value distribution pattern [29]. The structures of compounds penicillenol A1 (3), penicillenol A2 (4), penicillenol B1 (5), penicillenol B2 (6), penicillenol C2 (7) [30], demethyllincisterol A2 (8) [31], janthinone (9) [32], 3,8-dihydroxy-6-methyl-9-oxo-9H-xanthene-1-carboxylic acid methyl ester (10) [33], coniochaetone B (11) [34], citreorosein (12) [35], 6-methylquirizarin (13) [36] and decarboxydihydrocitrinone ( 14) [37] were confirmed through matching spectral data with those of known compounds. Penicillenols 3-7 were first isolated from Penicillium sp.…”