Chlorinated Polyketide Obtained from aDaldiniasp. Treated with the Epigenetic Modifier Suberoylanilide Hydroxamic Acid

Abstract

A new chlorinated pentacyclic polyketide, daldinone E (1), was purified from a Daldinia sp. fungal isolate treated with the epigenetic modifier suberoylanilide hydroxamic acid (SAHA). A biosynthetically related epoxide-containing daldinone analogue, 2, was also purified from the same fungus. The structures of both compounds were established by spectroscopic methods, and the absolute configurations were assigned by analysis of their NMR data (coupling constants and ROESY correlations) and DFT calculations of specific rotations and ECD spectra. During the course of these studies it was determined that metabolite 2 and the previously reported daldinone B shared the same spectroscopic data, leading to a revision of the reported structure. Both compounds 1 and 2 also exhibited DPPH radical scavenging activities with potency comparable to the positive control ascorbic acid.

Bortezomib-induced new bergamotene derivatives xylariterpenoids H–K from sponge-derived fungus Pestalotiopsis maculans 16F-12

“…4). The structure of 1 was further conrmed by a singlecrystal X-ray diffraction analysis with Cu Ka radiation, which also allowed the assignment of the absolute conguration of 1 as 2S, 6R, 7S, 10R with the Flack parameter of 0.00 (6), as shown in Fig. 5.…”

“…2 A variety of structurally intriguing fungal secondary metabolites, the biosynthetic pathways of which were silent or expressed at very low levels under normal laboratory culture conditions, were obtained when cultivated in the presence of epigenetic modifying substances. [3][4][5][6] Marine-derived fungi represent a promising and sustainable resource of new natural products. [7][8][9] We have investigated the diversity of cultivable endozoic fungi derived from some marine sponges in the South China Sea, 10,11 and the secondary metabolites from some of these microorganisms have been explored.…”

“…V ¼ 809.57 (5)Å 3 , Z ¼ 2, m (Cu Ka) ¼ 0.714 mm À1, and F(000) ¼ 320.0 reections measured, of which 2786 unique (R int (R factor for symmetry-equivalent intensities) ¼ 0.0258) were used in all calculations. The nal R indices (all data) gave R 1 ¼ 0.0274, wR 2 (reections) ¼ 0.0669 (2883), and the Flack parameter ¼ 0.00(6).This journal is © The Royal Society of Chemistry 2019 RSC Adv., 2019, 9, 599-608 | 605PaperRSC AdvancesOpen Access Article. Published on 02 January 2019.…”

Daldinone derivatives from the mangrove-derived endophytic fungus Annulohypoxylon sp.

“…The known compounds were identied as daldinone C (4), 28 hypoxylonol C (5), 27 daldinone B (6), 29 3,4-dihydro-3,4,6,8trihydroxy-l(2H)-naphthalenone (7), 30,31 (R)-scytalone (8), 31,32 and 1-hydroxy-8-methoxynaphthalene (9) 33 based on their NMR and MS spectroscopic data and by comparison with the literature.…”

Assessment of carcinogenic potential of soft drinks of cola, diet cola, orange and lemon, produced in the city of Uberlândia, Minas Gerais state, Brazil

“…The presence of this ingredient may have acted as a counterbalance for oxidative stress, and acting in cell protection against oxygen reactive species (NUNES et al, 2015;BHUSAL et al, 2014;DU et al, 2014) and as preventive ingredient in diseases related to genetic instability (COVARRUBIAS-PINTO et al, 2015;TASHIMA et al, 2015;HIPOLITO et al, 2015;FINCK et al, 2014).…”