The chlorinated natural products, rubrolides B, I, K, L, M and O and analogues were synthesized in only five steps employing a robust and divergent synthetic strategy. The synthesis is performed without using protecting groups starting from a key intermediate, which can be synthesized from commercially available tetronic acid in only two steps. Selective halogenation and vinylogous aldol condensation enable the efficient synthesis of highly halogenated natural occurring rubrolides as well as synthetic analogues to build up a compound library for antiviral and antibiofilm testing. All synthesized compounds were then tested for their activity against the two influenza A virus strains pH1N1 and H3N2 as well as for their antibiofilm activity. Naturally occurring as well as synthetic analogues showed promising antiviral and antibiofilm activities.

Combating Stenotrophomonas maltophilia biofilms in clinical and industrial settings has proven to be challenging. S. maltophilia is multidrug resistant, and occurrence of resistance to commonly used drugs as well as to antibiotic combinations, such as trimethoprim-sulfamethoxazole, is now frequently reported. It is therefore now necessary to look beyond conventional and already existing antimicrobial drugs when battling S. maltophilia biofilms.

The price of different truffle types varies according to their culinary value, sometimes by more than a factor of ten. Non-professionals can hardly distinguish the species within the white or black truffles by eye, which makes the possibility of food fraud very easy. Therefore, the identification of different truffle species (Tuber spp.) is an analytical task that could be solved in this study. The polar extract from a total of 80 truffle samples were analyzed by 1H NMR spectroscopy in combination with chemometric methods covering five commercially relevant species. All classification models were validated with nested cross-validation. The two very similar looking and closely related black representatives Tuber melanosporum and Tuber indicum could be classified 100% correctly in direct comparison. The most expensive truffle Tuber magnatum could be distinguished 100% from the other relevant white truffle Tuber borchii. Furthermore, signals for a potential Tuber borchii, and a potential Tuber melanosporum marker for targeted approaches could be detected and the corresponding molecules were identified as betaine and ribonate. A model covering all five truffle species Tuber aestivum, Tuber borchii, Tuber indicum, Tuber magnatum and Tuber melanosporum was able to correctly discriminate between all species.