Chemical profile and biological activities of Peltigera horizontalis (Hudson) Baumg. thallus and apothecia extracts.

The aim of this study was to determine, for the first time, the chemical composition of Peltigera horizontalis thallus and apothecia extracts (ether, ethyl acetate, dichloromethane and acetone) by HPLC-UV and GC-MS, and evaluate activity of genotoxic, anticholinesterase, antioxidant and antibacterial potential of acetone extracts. Major constituents of thallus extracts were gyrophoric acid, and methyl gyrophorate while dominant component of apothecia extracts was tenuiorin. The predominant volatile compounds in extracts were methyl orsellinate, dodecyl acrylate, orcinol and orcinol monomethyl ether. The thallus acetone extract at concentration of 2.0 µg mL-1 gave the greatest decrease in the micronuclei frequency (22.4%) of all tested extracts. Apothecia extract showed stronger antioxidant activity as compared to thallus extract. Tested extracts at concentration of 10 mg mL-1 exhibited inhibitory effect (16.5% for thallus and 12.8% for apothecia) on pooled human serum cholinesterase. P. horizontalis acetone extracts had no activity against the tested five bacteria strains.

Hypogymnia tubulosa extracts: chemical profile and biological activities.

This study reports for the first time in the chemical composition of acetone, ether, ethyl acetate and dichloromethane extracts of Hypogymnia tubulosa determined by HPLC-UV, GC-FID and GC-MS as well as effect of H. tubulosa acetone extract on micronucleus distribution on human lymphocytes and on cholinesterase activity. Additionally, antioxidant (estimated via DPPH, ABTS, TRP, CUPRAC and TPC assays) and antibacterial activity against two Gram-positive and three Gram-negative bacteria were also determined. The HPLC-UV analysis revealed the presence of depsidones, 3-hydroxyphysodic, 4-O-methyl physodic acid, physodic and physodalic acid together with two depsides, atranorin and chloroatranorin. GC-FID and GC-MS analyses enabled the identification of atranol, chloroatranol, atraric acid, olivetol, olivetonide and 3-hydroxyolivetonide as the main components. The results of present study show that H. tubulosa acetone extract is a promising candidate for in vivo experiments considering antioxidant activity.

Ramalina capitata (Ach.) Nyl. acetone extract: HPLC analysis, genotoxicity, cholinesterase, antioxidant and antibacterial activity.

In the present investigation, effects of Ramalina capitata acetone extract on micronucleus distribution on human lymphocytes, on cholinesterase activity and antioxidant activity (by the CUPRAC method) were examined, for the first time as well as its HPLC profile. Additionally, total phenolic compounds (TPC), antioxidant properties (estimated via DPPH, ABTS and TRP assays) and antibacterial activity were determined. The predominant phenolic compounds in this extract were evernic, everninic and obtusatic acids. Acetone extract of R. capitata at concentration of 2 µg mL-1 decreased a frequency of micronuclei (MN) for 14.8 %. The extract reduces the concentration of DPPH and ABTS radicals for 21.2 and 36.1 % (respectively). Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.4624 ± 0.1064 µg ascorbic acid equivalents (AAE) per mg of dry extract, and 6.1176 ± 0.2964 µg Trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 670.6376 ± 66.554 µg galic acid equivalents (GAE) per mg of dry extract. Tested extract at concentration of 2 mg mL-1 exhibited inhibition effect (5.2 %) on pooled human serum cholinesterase. The antimicrobial assay showed that acetone extract had inhibition effect towards Gram-positive strains. The results of manifested antioxidant activity, reducing the number of micronuclei in human lymphocytes, and antibacterial activity recommends R. capitata extract for further in vivo studies.

Constituents of Ramalina capitata (Ach.) Nyl. extracts.

The aim of this work was to determine the chemical composition of the ether, ethyl acetate and dichloromethane extracts of Ramalina capitata by GC-FID and GC-MS for the first time. The main identified components in the ether, ethyl acetate and dichloromethane extracts were everninic acid (24.7, 33.7 and 22.2%), orcinol (25.8, 16.7 and 11.9%), orcinol monomethyl ether (11.6, 7.6 and 4.8%), 3-methylorsellinic acid (10.2, 7.1 and 9.0%) and usnic acid (4.4, 8.2 and 25.8%), respectively. Considerable amount (10.4%) of 2-hydroxy-4-methoxy-3,5,6-trimethylbenzoic acid was detected in ethyl acetate extract. Additionally, palmitic acid, linoleic acid, oleic acid and stearic acid and their esters were observed in the dichloromethane and ethyl acetate extracts in the range of 4.1-0.1%, while their amount was below 0.05% in the ether extract. According to the results reported here R. capitata predominantly biosynthesises derivatives of orcinol and, in much lesser extent, derivatives of ß-orcinol.