Phytochemical composition and antitumor activity of a new arctic lichen Anamylopsora pakistanica.

For the first-time, chemical composition and in vitro antitumor activity was investigated of a newly described lichen Anamylopsora pakistanica Usman & Khalid from the second highest plateau of the world (Deosai Plains, Pakistan). HPLC-UV method was used for identification of secondary metabolites and the acetone extract had higher values of TPC (41.90 mg GA/g) and TFC (75.37 mg RE/g) as compared to methanol extract. As chemical constituents 5,7-dihydroxy-6-methylphthalide, haematommic acid and alectorialic acid, were identified as major compounds. Atranol, alectorialin, gyrophoric acid and usnic acid were detected as minor substances. Acetone and methanol extracts induced a dose-dependent and time-dependent decrease in the viability of three types of tumour cells HeLa, HCT116 and MDA-MB-231. This lichen extract can induce S phase arrest in HeLa as compared to the untreated cells. Extract of this unique lichen, A. pakistanica, can be used safely as a significant source of biologically active compounds.

The largest European forest carbon sinks are in the Dinaric Alps old-growth forests: comparison of direct measurements and standardised approaches.

BACKGROUND: Carbon (C) sink and stock are among the most important ecosystem services provided by forests in climate change mitigation policies. In this context, old-growth forests constitute an essential reference point for the development of close-to-nature silviculture, including C management techniques. Despite their small extent in Europe, temperate old-growth forests are assumed to be among the most prominent in terms of biomass and C stored. However, monitoring and reporting of C stocks is still poorly understood. To better understand the C stock amount and distribution in temperate old-growth forests, we estimated the C stock of two old-growth stands in the Dinaric Alps applying different assessment methods, including direct and indirect approaches (e.g., field measurements and allometric equations vs. IPCC standard methods). This paper presents the quantification and the distribution of C across the five main forest C pools (i.e., aboveground, belowground, deadwood, litter and soil) in the study areas and the differences between the applied methods. RESULTS: We report a very prominent C stock in both study areas (507 Mg C ha- 1), concentrated in a few large trees (36% of C in 5% of trees). Moreover, we found significant differences in C stock estimation between direct and indirect methods. Indeed, the latter tended to underestimate or overestimate depending on the pool considered. CONCLUSIONS: Comparison of our results with previous studies and data collected in European forests highlights the prominence of temperate forests, among which the Dinaric Alps old-growth forests are the largest. These findings provide an important benchmark for the development of future approaches to the management of the European temperate forests. However, further and deeper research on C stock and fluxes in old-growth stands is of prime importance to understand the potential and limits of the climate mitigation role of forests.