Flavonolignans from Aspergillus iizukae, a fungal endophyte of milk thistle (Silybum marianum).
Silybin A (1), silybin B (2), and isosilybin A (3), three of the seven flavonolignans that constitute silymarin, an extract of the fruits of milk thistle (Silybum marianum), were detected for the first time from a fungal endophyte, Aspergillus iizukae, isolated from the surface-sterilized leaves of S. marianum. The flavonolignans were identified using a UPLC-PDA-HRMS-MS/MS method by matching retention times, HRMS, and MS/MS data with authentic reference compounds. Attenuation of flavonolignan production was observed following successive subculturing of the original flavonolignan-producing culture, as is often the case with endophytes that produce plant-based secondary metabolites. However, production of 1 and 2 resumed when attenuated spores were harvested from cultures grown on a medium to which autoclaved leaves of S. marianum were added. The cycle of attenuation followed by resumed biosynthesis of these flavonolignans was replicated in triplicate.
Department of Chemistry and Biochemistry, University of North Carolina at Greensboro , Greensboro, North Carolina 27402, United States.
Tamam
T
El-Elimat
Huzefa A
HA
Raja
Tyler N
TN
Graf
Stanley H
SH
Faeth
Nadja B
NB
Cech
Nicholas H
NH
Oberlies
D001230:Aspergillus / Q000737:chemistry*; D044947:Flavonolignans / Q000737:chemistry / Q000302:isolation & purification*; D005638:Fruit / Q000737:chemistry; D020944:Silybum marianum / Q000382:microbiology*; D015394:Molecular Structure; D000077385:Silybin; D012838:Silymarin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification
D044947:Flavonolignans; D012838:Silymarin; D000077385:Silybin; C523198:isosilybin A