**Preface to "Selected Papers from XVI MaNaPro and XI ECMNP"**

The International Symposium on Marine Natural Products (MaNaPro) and the European Conference on Marine Natural Products (ECMNP) are two of the top three most prestigious conferences on marine natural products. MaNaPro started in 1975 and ECMNP began in 1997, and they are conducted in triennial and biennial frequencies, respectively. Both conferences focus on studies related to marine chemistry. The MaNaPro symposia are the world's most noteworthy events in marine natural products. The ECMNP mission is to promote the participation of younger researchers in high-quality scientific meetings in this field and encourage collaborations worldwide.

In 2019, the 2nd joint XVI MaNaPro and XI ECMNP meeting (http://wmnp2019.ipleiria.pt/) was held in Peniche, Portugal, from the 1st to the 5th of September. A Special Issue dedicated to this symposium entitled "Selected Papers from the XVI MaNaPro and XI ECMNP" was developed to maximize the impact of this conference in the marine natural products community. The conference Special Issue resulted in 1 conference report and 12 articles published in *Marine Drugs* (https://www. mdpi.com/journal/marinedrugs/special issues/MaNaPro-ECMNP-2019).

The 12 articles are included in this volume and provide a good representation of the richness of the joint XVI MaNaPro and XI ECMNP conference topics: (1) the development of an advanced floating chirality distance geometry approach that uses anisotropic NMR parameters to support the determination of the relative configuration of natural products; (2) the use of a phenotarget approach for identifying an alkaloid that interacts with the tuberculosis protein; (3) the discovery of anti-inflammatory cembranoids from the soft coral *Sarcophyton cherbonnieri*; (4) the finding of anticancer metabolites from the marine sediment-derived fungus *Aspergillus flocculosus*; (5) the discovery of dolabellanes and secosteroids that potentiate proteasome inhibition from the soft coral *Clavularia flava*; (6) the investigation of avarone, avarol, and the novel semisynthetic thiazinoquinone analog thiazoavarone as antiparasitic agents; (7) the assessment of napyradiomycins from the marine-derived actinomycetes *Streptomyces aculeolatus* as antifouling agents; (8) the evaluation of amentadione from the alga *Cystoseira usneoides* as an osteoarthritis protective agent; (9) the study of the antifouling properties of saponin-containing crude extracts from sea cucumbers; (10) the discovery of new benthic cyanobacteria from Guadeloupe Mangroves as producers of antimicrobials; (11) the uncovering of the core microbiome and distribution of palmerolide in *Synoicum adareanum* across the Anvers Island, Antarctica; and (12) the light-mediated toxicity of porphyrin-like pigments from a marine polychaeta.

This collection of selected scientific publications provides a comprehensive overview of the wide diversity of marine bioresources, the relentless search for new tools for advancing structure elucidation and configuration assignment and for the rapid discovery of bioactive natural products, and the interdisciplinary nature of the research of marine natural products and their extensive medical and biotechnological potential.

### **Susana P. Gaudˆencio, Rui Pedrosa, Vitor Vasconcelos**

*Article*
