Fig. 1

Morphological and molecular identification of the most potent CPT-producing endophytic fungal isolate inhabiting Catharanthus roseus. A Morphological view of C. roseus. B Plate culture and conidial ontogeny of Alternaria brassicicola as the potent CPT-producing fungal isolate. C PCR amplicons of the ITS region of A. brassicicola, normalized to the DNA ladder (1 kb Nex-gene Ladder, Puregene, Cat.# PG010-55DI). D Molecular phylogenetic analysis of A. brassicicola ITS sequence by the Maximum Likelihood method with MEGA X software package. The cultures of A. brassicicola was incubated, CPT was extracted and fractionated by the TLC (E). The CPT were purified from putative spots on TLC, based on their mobility and color, compared to the authentic CPT. F, HPLC chromatogram of the extracted CPT from A. brassicicola, compared to the authentic CPT. The sample has the same retention time 5.5 min of authentic one