Phytochemical investigation of Pistacia lentiscus L. var. Chia leaves: A byproduct with antimicrobial potential.

Pistacia lentiscus L. var. Chia belongs to the Anacardiaceae family, and it is cultivated only in the south part of Chios island, in Greece. Even though it is renowned for its unique resin, Chios mastic gum (CMG), the tree leaves have also been used in traditional medicine, while the annual pruning generates a large biomass of unused by-products. Thus, the aim of the present study was the detailed phytochemical investigation of P. lentiscus var. Chia leaves towards the search of antimicrobial agents. UPLC-HRMS & HRMS/MS based dereplication methods led to the detailed characterization of the aqueous leaf extract. In addition, twelve compounds were isolated and purified from the methanol extract and were identified using spectroscopic and spectrometric methods (NMR, HRMS) belonging to phenolic acids, tannins, flavonoids and terpenes, with the most interesting being 2-hydroxy-1,8-cineole ß-D-glucopyranoside which was isolated for the first time in the Anacardiaceae family. Remarkably, based on NMR data, methanol and aqueous extracts were found to be particularly rich in shikimic acid, a valuable building block for the pharmaceutical industry, for instance in the synthesis of the active ingredient of Tamiflu®, oseltamivir. Finally, extracts (EtOAc, MeOH, H2O) and major compounds i.e., shikimic acid, 2-hydroxy-1,8-cineole ß-D-glucopyranoside and myricitrin were evaluated for their antimicrobial properties. MeOH and H2O mastic leaf extracts as well as myricitrin and, particularly, 2-hydroxy-1,8-cineole ß-D-glucopyranoside showed significant selective activity against pathogenic Mucorales, but not against Aspergilli (Aspergillus nidulans, Aspergillus fumigatus), Candida albicans or bacteria (Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis).

Convergent evolution and orphan genes in the Fur4p-like family and characterization of a general nucleoside transporter in Aspergillus nidulans.

The function of seven paralogues phylogenetically related to the Saccharomyces cerevisiae Fur4p together with a number of functionally related transporters present in Aspergillus nidulans has been investigated. After deletion of the cognate genes we checked the incorporation of radiolabelled substrates, utilization of nitrogen sources, resistance to toxic analogues and supplementation of auxotrophies. FurA and FurD encode allantoin and uracil transporters respectively. No function was found for FurB, FurC, FurE, FurF and FurG. As we failed to identify Fur-related transporters for uridine, pyridoxine or thiamine, we deleted other possible candidates for these functions. A FCY2-like gene carrying in its 5' UTR a putative thiamine pyrophosphate riboswitch, and which encodes a protein similar to the pyridoxine transporter of yeast (Tpn1p), does not encode either a major thiamine or a pyridoxine transporter. CntA, a member of the concentrative nucleoside transporter family, is a general nucleoside permease, while no function was found for PnpA, a member of the equilibrative transporter family. Phylogenetic analysis shows that within the ascomycetes, the same transport activity could be catalysed by totally unrelated proteins and that within the Fur subfamily convergent evolution towards uracil and allantoin transport activity has occurred at least three and two independent times respectively.