Biologically Active Metabolites from Fungi 7¹); Aposphaerin A and B Two New Chroman-4-ones fromAposphaeriasp

Chromone Derivatives from a Sponge-Derived Strain of the Fungus Corynespora cassiicola

“…fungus cultured from a birch tree growing in a forest in Lower Saxony, Germany. 6 The only difference between 1 and aposphaerin B was the substituent at C-2. The COSY cross-peaks of H-1′/H-2′/H-3′, together with the HMBC correlations from H-3′ to C-1′ and C-2′, suggested the presence of a 2-hydroxypropyl [−CH 2 CH(OH)CH 2 ] moiety (Figure 1).…”

“…Corynechromone J (10) was obtained as a white, amorphous powder possessing a molecular formula of C 18 H 20 O 6 with nine degrees of unsaturation, one more degree of unsaturation than aposphaerin B. 6 The NMR data (Tables 2 and 3) showed that the differences between 10 and aposphaerin B are the appearance of an olefinic bond between C-2 and C-3 in 10 and the replacement of the methylene at C-4′ in aposphaerin B with an oxymethine in 10. The complete assignments for all protons and carbons were achieved by its COSY, HMQC, and HMBC spectra (Figure 1).…”

A Facile Enantioselective Alkynylation of Chromones

“…Chromanones constitute an important core that is shared by many biologically active natural products . Diverse bioactivities include antitumor, antimicrobial, and antibacterial activities, among others. This core has also been incorporated into synthetic analogues such as Krische's chromanone‐based bryostatin analogues .…”

Chemical constituents isolated from the fungus Monascus sp.

“…The carbon signals of 1 were assigned, from 13 C NMR, DEPT, and HSQC experiments, as two methyls at G 23.5 (Me-13) and 24.2 (Me-12), two methylenes at G 36.1 (C-3) and 64.4 (C-2), four aromatic olefinic carbons at G 109.3 (C-8), 122.4 (C-6), 125.0 (C-5), and 128.5 (C-7), and four quaternary carbons at G 70.2 (C-4), 84.8 (C-11), 135.2 (C-10), and 142.2 (C-9). The above data also point to a chroman derivative skeleton [14][15][16][17][18].…”

“…[14,15]. The presence of an amidocarbonyl (-CONH 2 ) group was revealed by IR absorption, along with a resonance signal in the 13 Hz, H eq -2), and two methyl moieties attached to a 1-hydroxy-1-methyl-ethyl group observed at G 1.04, 1.31 (each 3H, s, H-12, 13), indicating that 1 was probably a chroman derivative possessing a conjugated carbonyl group [14][15][16][17][18].…”