Biosynthesis of penitrems and roquefortine by Penicillium crustosum

Abstract

Roquefortine and the penitrems were biosynthesised concurrently at an approximately equimolar rate by Penicillium crustosum after growth and sporulation. [14C]mevalonic acid was incorporated (15% efficiency) into the isoprenoid regions of the penitrem and roquefortine molecules to an extent consistent with their 6:1 molar ratio of isoprenoid components. [14C]penitrem A (specific activity, 3.4 X 10(2) mu Ci mmol-1) and 14C-penitrems B, C, and E readministered to young cultures were metabolically interconverted, indicating considerable metabolic flux, though generally directed towards penitrem A as the end product and suggesting a metabolic grid for the penitrem metabolites. Addition of bromide to the medium preferentially favored the production of bromo-analogs rather than the usual chloropenitrems.

Influence of Environmental Factors on the Production of Penitrems A–F by Penicillium crustosum

“…Mycotoxin production depends on the fungal strain, the substrate and the environmental conditions. To determine the optimal growth conditions for the production of penitrems A–F, several abiotic factors were screened using P. crustosum , which is considered the main producer of penitrems [ 5 , 30 ]. Initially, for monitoring positive or negative effects of abiotic factors on the penitrem production, only the penitrem A concentration, expressed as mg per g of dry biomass, was determined by means of an HPLC-DAD method ( Figure 2 ).…”

“…In most cases, P. crustosum is cultivated on Czapek–Dox broth supplemented with yeast extract followed by extraction of the mycelium with organic solvents. Subsequent separation and purification of penitrems is achieved via column chromatography and preparative HPLC [ 5 , 10 , 15 , 30 , 31 ].…”

Bioactive Secondary Metabolites Produced by the Fungal Endophytes of Conifers

“…The Taxus brevifolia-associated Penicillium sp. that produced oxaline (64) also yielded the alkaloid roquefortine C, which was isolated based on its brine shrimp lethality (65) [18], which was first isolated as a neurotoxic component of P. roqueforti [100] and P. crustosum [101]. Steyn and Vleggaar proved that roquefortine was an intermediate in oxaline biosynthesis and were able to induce production of radiolabeled oxaline in P. oxalicum by adding radiolabeled roquefortine to the fungal medium [102].…”

Bioguided discovery and pharmacophore modeling of the mycotoxic indole diterpene alkaloids penitrems as breast cancer proliferation, migration, and invasion inhibitors

“…To determine whether the fungal biosynthetic machinery can produce other halogenated compounds, KBr and KF were separately added to 3 days old cultures at 1 and 2 mM nal concentrations. Accordingly, the new 6-bromoprenitrem B ( 8) and the known 6-bromopenitrem E (9) 22 were identied with the aid of LC-MS which showed the characteristic mass pattern (M and M + 2 at 1 : 1 isotopic peak intensity) for monobrominated compounds. No uoride derivative was identied, which was consistent with literature reports indicating the predominance of chlorination, followed by bromination, and the scarcity of iodination and uorination in nature.…”

“…IPP: isopentenyl diphosphate; FPP: farnesyl diphosphate; GGPP: geranylgeranyl diphosphate. 22 The ESIMS spectrum showed a molecular ion peak at m/z 676.2 [M À H] À and an isotopic peak at 678.2 [M À H + 2] À with a 1 : 1 relative abundance, indicating a single bromo substitution. Thus, the molecular formula of 9 was determined to be C 37 H 44 BrNO 6 .…”