OBJECTIVETo study the metabolites of marine fungus Alternalia sp.

METHODCompounds were separated by column chromatography and their structures were elucidated by means of chemical and spectral analysis.

RESULTSix compounds were isolated from the ethyl acetate and n-butanol extracts of the fermentation of marine fungus Alternalia sp. Their structures were elucidated as p-benzyloxy-phenol ( I ), p-hydroxy phenyl ethylamine( II ), 3-hydroxymethyl-8-hydroxyl-pyrrolopiperazine-2, 5-dione ( III ), 3-isobutyl-6-secbutyl-piperazine-2, 5-dione (IV), 5alpha, 8alpha-epidioxy-ergosta-6, 22-diene-3beta-ol (V), 3beta-hydroxxy-cholesta-5-ene (VI).

CONCLUSIONCompounds I , II, III, IV have the activity of inducing morphological deformation of mycelia germinated from conidia of Pyricularia oryzae. Compounds I , II , III were isolated from the genus Alternalia for the first time.

Antifungal Agents ; isolation & purification ; pharmacology ; Ascomycota ; drug effects ; Fermentation ; Fungi ; chemistry ; Molecular Structure ; Phenethylamines ; chemistry ; isolation & purification ; pharmacology ; Phenols ; chemistry ; isolation & purification ; pharmacology

In this work, a novel conjugate of ractopamine and bovine serum albumin (RAC-BSA) has been developed via the Mannich reaction, with a mole coupling ratio for RAC-BSA of 9:1. The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays. RAC-BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed. For sample preparation, RAC was spiked in swine feed purchased from the local markets in Thailand, and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer. The procedures for sample preparation were completed within 25 min. Under optimal conditions, the limit of detection (LOD), assessed by the naked eye within 5 min, was found to be 1 ng/g. A semi-quantitative analysis was also conducted using a smart phone and computer software, with a linearity of 0.075-0.750 ng/g, calculated LOD of 0.10 ng/g, calculated limit of quantitation of 0.33 ng/g, and good correlation of 0.992. The recoveries were found in the range of 96.4%-103.7% with a relative standard deviation of 2.5%-3.6% for intra- and inter-assays. Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy. Furthermore, this strip test exhibited highly specific RAC detection without cross reactivity with related compounds. Therefore, the RAC-BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.
Animal Feed/analysis* ; Animals ; Cross Reactions ; Enzyme-Linked Immunosorbent Assay/methods* ; Limit of Detection ; Phenethylamines/chemistry* ; Reagent Strips ; Serum Albumin, Bovine/chemistry* ; Swine