ABSTRACT
Eleven alkaloids (1-11) including seven new ones, 1-7, were isolated from the solid fermentation of Aspergillus fumigatus VDL36, an endophytic fungus isolated from the leaves of Vaccinium dunalianum Wight (Ericaceae), a perennial evergreen shrub distributed across the Southwest regions of China, Myanmar, and Vietnam. Their structures were elucidated on the basis of extensive spectroscopic methods. The isolates were evaluated for in vitro antifungal activities against five phytopathogenic fungi (Fusarium oxysporum, Coriolus versicolor, Fusarium solani, Botrytis cinerea, Fusarium graminearum). As a result, the new compounds fumigaclavine I (1), 13-ethoxycyclotryprostatin A (5), 13-dehydroxycyclotryprostatin A (6), and 12ß-hydroxy-13-oxofumitremorgin C (7) exhibited antifungal activities with MIC values of 7.8-62.5 µg/mL which were comparable to the two positive controls ketoconazole (MIC = 7.8-31.25 µg/mL) and carbendazim (MIC = 1.95-7.8 µg/mL). Furthermore, compounds 1 and 5 demonstrated potent protective and curative effects against the tomato gray mold in vivo. Preliminary structure-activity relationships of the tested indole diketopiperazine alkaloids indicate that the introduction of a substituent group at position C-13 enhances their biological activities.
Subject(s)
Alkaloids , Aspergillus fumigatus , Endophytes , Alkaloids/pharmacology , Alkaloids/chemistry , Aspergillus fumigatus/drug effects , Endophytes/chemistry , Molecular Structure , Fusarium/drug effects , Fungicides, Industrial/pharmacology , Fungicides, Industrial/chemistry , Plant Leaves/microbiology , Plant Leaves/chemistry , Microbial Sensitivity Tests , China , Plant Diseases/microbiologyABSTRACT
Pholidota Lindl. ex Hook. was placed in tribe Arethuseae Lindl. (Epidendroideae, Orchidaceae), while its generic relationship has been unclear. Since the plastid genome could play a key role in plant systematics, the complete chloroplast (cp) genome of P. articulata was reported in this paper. The cp genome was 160,114 bp in length with four typical quadripartite structures, which was consisted of a large single copy (LSC) region of 87,756 bp, a small single copy (SSC) region of 18,872 bp, and two inverted repeats (IR) of 26,734 bp. In addition, the cp genome encoded 132 genes in total, of which were 113 unique genes, including 79 protein-coding genes, 30 tRNAs, and 4 rRNAs. The phylogenetic analysis indicated that P. articulata was closely clustered with other two species of Pholidota and that they appeared to be related to Pleione in Arethuseae Lindl.
