The authors describe a method for the determination of byssochlamic acid in fruit juice. After extraction and purification, byssochlamic acid is separated by thin-layer chromatography on HF 254 silica gel. The quenching of fluorescence of byssochlamic acid is estimated quantitatively on the plate by means of the thin-layer attachment of a fluorescence spectrophotometer using reference substances. For fruit juices the recovery rate is 80%; the limit of detection lies at 0.5 p.p.m. Byssochlamic acid could not be detected in commercially-available fruit juice and neither in juices produced of fruits which had spontaneously got mouldy.
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http://dx.doi.org/10.1002/food.19760200513 | DOI Listing |
assays of enzymes involved in the biosynthesis of maleidrides from polyketides in fungi were performed. The results show that the enzymes are closely related to primary metabolism enzymes of the citric acid cycle in terms of stereochemical preferences, but with an expanded substrate selectivity. A key citrate synthase can react both saturated and unsaturated acyl CoA substrates to give solely substituted citrates.
View Article and Find Full Text PDFJ Nat Prod
November 2019
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica , Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050 , People's Republic of China.
Six new nonadride derivatives (-) and three new spirocyclic anhydride derivatives (-) were isolated from the endophytic fungus obtained from fresh leaves of the toxic medicinal plant The structures of these compounds were determined by spectroscopic analyses including 1D and 2D NMR, HRESIMS, and ECD techniques. Maleic anhydride derivatives - were evaluated for their anti-inflammatory activities. Compound showed significant inhibitory activity against NO production in LPS-induced RAW264.
View Article and Find Full Text PDFMar Drugs
December 2017
ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
A previously unreported dihydrochromone dimer, paecilin E (), was isolated, together with eleven known compounds: β-sitostenone, ergosta-4,6,8 (14), 22-tetraen-3-one, cyathisterone, byssochlamic acid, dehydromevalonic acid lactone, chevalone B, aszonalenin, dankasterone A (), helvolic acid, secalonic acid A and fellutanine A, from the culture filtrate extract of the marine sponge-associated fungus KUFA 0811. Nine previously reported metabolites, including a chromanol derivative (), (3β, 5α, 22), 3,5-dihydroxyergosta-7,22-dien-6-one (), byssochlamic acid, hopan-3β,22-diol, chevalone C, sartorypyrone B, helvolic acid, lumichrome and the alkaloid harmane were isolated from the culture of the marine-sponge associated fungus KUFC 9213. Paecilin E (), dankasterone A (), a chromanol derivative (), (3β, 5α, 22)-3,5-dihydroxyergosta-7,22-dien-6-one (), hopan-3β,22-diol (), lumichrome (), and harmane () were tested for their antibacterial activity against Gram-positive and Gram-negative reference and multidrug-resistant strains isolated from the environment.
View Article and Find Full Text PDFChem Commun (Camb)
July 2017
Institute for Organic Chemistry, and BMWZ, Leibniz University of Hannover, Schneiderberg 1B, 30167, Germany.
The biosynthesis of the herbicide cornexistin in the fungus Paecilomyces variotii was investigated by full sequencing of its genome, knockout of key genes within its biosynthetic gene cluster and isolation and identification of intermediate compounds. The general biosynthetic pathway resembles that of byssochlamic acid and other nonadrides in the early stages, but differs in requiring fewer enzymes in the key nonadride dimerisation step, and in the removal of one maleic anhydride moiety.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
June 2016
Institute for Organic Chemistry, Leibniz University of Hannover, Schneiderberg 1B, 30167, Germany.
Fungal maleidrides are an important family of bioactive secondary metabolites that consist of 7, 8, or 9-membered carbocycles with one or two fused maleic anhydride moieties. The biosynthesis of byssochlamic acid (a nonadride) and agnestadride A (a heptadride) was investigated through gene disruption and heterologous expression experiments. The results reveal that the precursors for cyclization are formed by an iterative highly reducing fungal polyketide synthase supported by a hydrolase, together with two citrate-processing enzymes.
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