Constituents of the lichen in the genus Hypogymnia. I. Oxyphysodic acid a new depsidone from Hypogymnia enteromorpha (Ach.) Nyl.

Alectosarmentin, a New Antimicrobial Dibenzofuranoid Lactol from the Lichen, Alectoria sarmentosa

“…Alectosarmentin [1],-Colorless needles, mp 291°; uv X max (MeOH) (log e) 229 sh (4.50), 235 (4.51), 260 (4.45), 295 (4.11), 305 (4.17), 329 (3.88) nm; (MeOH+HCl) 227 (4.48), 238 (4.49), 260 (4.45), 296 (4.07), 305 (4.16), 331 (3.87) nm; (MeOH+NaOH) 236 (4.53), 274 (4.31), 319 (4.13), 357 (3.90) nm; ir v max (KBr) 3400, 1740, 1695, 1620, 1590, 1465, 1425, 1335, 1285, 1205, 1165, 1145 cm"1; *H nmr (DMSO-^ 2.74 (3H, s, Me), 6.64 (1H, d,J= 1.9 Hz, H-8), 6.82 (1H, br d,J= 1.9 Hz, H-6), 6.92 (1H, dj=7.0 Hz, Ha-1), 7.11 (1H, s, H-4), 8.05 (1H, dj=7.0 Hz, OH, D20 exchangeable), 9•90 (1H, br s, OH, D20 exchangeable), 10.81 (1H, s, OH, D20 exchangeable); BC nmr (125.7 MHz, DMSO-</6) 20.7 (Me-9), 95.5 (C-6), 96.4 (C-la), 99.8 (C-4), 107.8 (C-2), 112.2 (C-9b), 112.9 (C-9a), 113.8 (C-8), 133.6 (C-9), 141.3 (C-l), 155.0(C-4a or C-3), 157.4(C-7), 157.9(C-5a), l6l.0(C-3 orC-4a), 167.1 (C=0); eims ot/z[M]+ 286(C1,H10O6)(62), 240 (26), 212 (100), 184 (22), 155 (22), 149 (21), 128 (23), 77 (24), 69(40), 44 (52).…”

“…The presence of a lactol ring accounts for two more oxygen atoms. Lactol rings are relatively rare among lichen products but are not without precedent in depsidones (18,21,22). The dibenzofuran ring system contains the remaining oxygen and was assigned originally based on the lack of correspondence of the spectra to the more common classes of lichen substances and was encouraged by the close correspondence of the nmr spectra of alectosarmentin with those of other dibenzofurans, most particularly with the closely related strepsilin [5] and its methyl ether (23,24).…”

Stictic Acid Derivatives from the Lichen Usnea articulata and Their Antioxidant Activities

“…Our present study led to the isolation or identification of nine compounds belonging to the stictic acid chemosyndrome: two new depsidones ( 1 , 2 ) in addition to stictic acid ( 3 ), norstictic acid ( 4 ), peristictic acid, cryptostictic acid, menegazziaic acid, constictic acid, 3- O -methylconsalazinic acid, fumarprotocetraric acid ( 5 ), barbatic acid, atranorin, methyl β-orcinolcarboxylate, usnic acid, and ergosterol peroxide . Antiradical activities using the DPPH and superoxide scavenging assays were reported for some of the compounds isolated.…”

“…Three known depsidones, stictic acid ( 3 ), norstictic acid ( 4 ), and fumarprotocetraric acid ( 5 ), the depside barbatic acid, the dibenzofuran derivative usnic acid, and a terpenoid, ergosterol peroxide, were isolated and identified by comparison of the observed spectroscopic data with literature values. ,,, The known compounds were identified by direct comparison with authentic samples purchased from Sigma or provided by J. Elix, using HPLC−DAD and TLC techniques in appropriate solvent systems. ,,, …”

“…3,4,12,15 The known compounds were identified by direct comparison with authentic samples purchased from Sigma or provided by J. Elix, using HPLC-DAD and TLC techniques in appropriate solvent systems. 5,11,13,14 Although lichens have long been known to contain bioactive compounds, few attempts have been made to screen them. Most publications describe the antioxidant activities of crude lichen extracts, [19][20][21][22][23][24] but those using pure compounds reported better lipid peroxidation protection activity for depsidones rather than for depsides.…”