Inhibitory Effects of Constituents of an Endophytic Fungus Hypoxylon investiens on Nitric Oxide and Interleukin‐6 Production in RAW264.7 Macrophages

Abstract

Three new compounds, hypoxyloamide (1), 8-methoxynaphthalene-1,7-diol (2), and hypoxylonol (3), together with seven compounds isolated from nature for the first time, investiamide (4), hypoxypropanamide (5), hypoxylonol A (6), investienol (7), 2-heptylfuran (8), (3S)-5-methyl-8-O-methylmellein (9), (4R)-O-methylsclerone (10), along with 19 known compounds, 11-29, were isolated from the culture broth of Hypoxylon investiens BCRC 10F0115, a fungal endophyte residing in the stems of an endemic Formosan plant Litsea akoensis var. chitouchiaoensis. The structures of the new compounds were established by spectroscopic methods, including UV, IR, HR-ESI-MS, and extensive 1D- and 2D-NMR techniques. Of these isolates, 2, 8-methoxynaphthalen-1-ol (15), and 1,8-dimethoxynaphthalene (16) showed nitric oxide (NO) inhibitory activity with IC50 values of 11.8±0.9, 17.8±1.1, and 13.3±0.5 μM, respectively, stronger than the positive control quercetin (IC50 36.8±1.3 μM). Compounds 2, 15, and 16 also showed interleukin-6 (IL-6) inhibitory activity with IC50 values of 9.2±1.7, 18.0±0.6, and 2.0±0.1 μM, stronger than the positive control quercetin (IC50 31.3±1.6 μM). To the best of our knowledge, this is the first report on guaiane sesquiterpene metabolites, 3, 6, and 7, from the genus Hypoxylon.

Napthrene Compounds from Mycelial Fermentation Products of Marasmius berteroi

“…The twelve known compounds ( 4 – 15 ) was determined to be daldinone C ( 4 ) [ 16 ], 1,8-dimethoxynaphthalene ( 5 ) [ 17 ], 8-methoxy-1-naphthol ( 6 ) [ 18 ], 8-methoxynaphthalen e-1,7 -diol ( 7 ) [ 19 ], 5-methoxy-1,4-naphthoquinone ( 8 ) [ 20 ], isosclerone ( 9 ) [ 21 ], 5- O -methylsclerone ( 10 ) [ 22 ] 4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2 H )-one(6-hydroxy-isosclerone) ( 11 ) [ 23 ], trans -3,4-dihydro-3,4,8-trihydroxynaphthalene-1-(2 H )-one( 12 ) [ 24 ], scytalone ( 13 ) [ 25 ], xylarenone ( 14 ) [ 26 ] and cis -4-hydroxyscytalone ( 15 ) [ 27 ] by comparison of its spectroscopic data with those of literature.…”

Chemical Constituents from Endophytic Fungus Annulohypoxylon cf. stygium in Leaves of Anoectochilus roxburghii

“…[47] Compound 15, a naphthalene derivative, was reported to be found in other genera like Coniothyrium palmarum, [48] Edenia gomezpompae, [49] Edenia sp., [50] Anteaglonium sp., [51] Rhytidhysteron rufulum. [52] Compound 16, a dihydrocoumarin compound, was reported to be found in other genera like Septoria nodorum, [53] Aspergillus melleus, [54] Brosimum acutifolium, [55] Apiospora montagnei, [56] Nodulisporium sp., [57] Xylaria sp., [58] Campylotropis hirtella., [59] Hypoxylon investiens., [60] Penicillium sp., [61] Botryosphaeria sp., [62] Sarcosomataceae sp., [63] Pyronema sp. [64] and Pestalotiopsis sp.…”

Volatiles from the hypoxylaceous fungi Hypoxylon griseobrunneum and Hypoxylon macrocarpum

“…1,8-Dimethoxynaphthalene ( 27 ) was also found and has been reported previously from other Hypoxylon spp. [19,37]. The corresponding compound 1,8-dihydroxynaphthalene is a known precursor of fungal melanin pigments [38].…”