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The genus Diaporthe (Diaporthaceae, Diaporthales) is a large group of fungi frequently reported as phytopathogens, with ubiquitous distribution across the globe. Diaporthe have traditionally been characterized by the morphology of their ana- and teleomorphic state, revealing a high degree of heterogeneity as soon as DNA sequencing was utilized across the different members of the group. Their relevance for biotechnology and agriculture attracts the attention of taxonomists and natural product chemists alike in context of plant protection and exploitation for their potential to produce bioactive secondary metabolites. While more than 1000 species are described to date, Africa, as a natural habitat, has so far been under-sampled. Several endophytic fungi belonging to Diaporthe were isolated from different plant hosts in Cameroon over the course of this study. Phylogenetic analyses based on DNA sequence data of the internal transcribed spacer region and intervening 5.8S nrRNA gene, and partial fragments of the calmodulin, beta-tubulin, histone and the translation elongation factor 1-α genes, demonstrated that these isolates represent four new species, i.e. D.brideliae , D.cameroonensis , D.pseudoanacardii and D.rauvolfiae . Moreover, the description of D.isoberliniae is here emended, now incorporating the morphology of beta and gamma conidia produced by two of our endophytic isolates, which had never been documented in previous records. Moreover, the paraphyletic nature of the genus is discussed and suggestions are made for future revision of the genus., Competing Interests: The authors have declared that no competing interests exist., (Christopher Lambert, Lena Schweizer, Blondelle Matio Kemkuignou, Elodie Gisèle M. Anoumedem, Simeon F. Kouam, Yasmina Marin-Felix.)

During the course of a study on the biodiversity of endophytes from Cameroon, a fungal strain was isolated. A multigene phylogenetic inference using five DNA loci revealed that this strain represents an undescribed species of Diaporthe , which is introduced here as D.breyniae . Investigation into the chemistry of this fungus led to the isolation of two previously undescribed secondary metabolites for which the trivial names fusaristatins G ( 7 ) and H ( 8 ) are proposed, together with eleven known compounds. The structures of all of the metabolites were established by using one-dimensional (1D) and two-dimensional (2D) Nuclear Magnetic Resonance (NMR) spectroscopic data in combination with High-Resolution ElectroSpray Ionization Mass Spectrometry (HR-ESIMS) data. The absolute configuration of phomopchalasin N ( 4 ), which was reported for the first time concurrently to the present publication, was determined by analysis of its Rotating frame Overhauser Effect SpectroscopY (ROESY) spectrum and by comparison of its Electronic Circular Dichroism (ECD) spectrum with that of related compounds. A selection of the isolated secondary metabolites were tested for antimicrobial and cytotoxic activities, and compounds 4 and 7 showed weak antifungal and antibacterial activity. On the other hand, compound 4 showed moderate cytotoxic activity against all tested cancer cell lines with IC 50 values in the range of 5.8-45.9 µM. The latter was found to be less toxic than the other isolated cytochalasins ( 1 - 3 ) and gave hints in regards to the structure-activity relationship (SAR) of the studied cytochalasins. Fusaristatin H ( 8 ) also exhibited weak cytotoxicity against KB3.1 cell lines with an IC 50 value of 30.3 µM.  Graphical abstract ., (Blondelle Matio Kemkuignou, Lena Schweizer, Christopher Lambert, Elodie Gisèle M. Anoumedem, Simeon F. Kouam, Marc Stadler, Yasmina Marin-Felix.)