title: Factors affecting the separation and bioactivity of red clover (Trifolium pratense) extracts assayed against Clostridium sticklandii, a ruminal hyper ammonia-producing bacterium.
abstract: Red clover (Trifolium pratense) is rich in phenolic compounds. Both the crude phenolic extract and biochanin A, an isoflavonoid component of the extract, suppress growth of Clostridium sticklandii, a bovine, Gram-positive, ruminal hyper-ammonia producing bacterium (HAB). The purpose of this study was to determine if other components of red clover extract contributed to its anti-HAB activity. Extracts of the Kenland cultivar of red clover, collected 0 h and 24 h after cutting, were separated by normal-phase thin-layer chromatography (TLC) in either ethyl acetate-hexanes (9:1, v/v) or ethyl acetate-methanol (4:1, v/v). Bands on TLC plates were assayed by either overlaying the plates with agar seeded with C. sticklandii, or setting the excised bands face-down onto plates of bacteria-seeded agar. Biochanin A inhibited C. sticklandii growth on TLC plates when as little as 8 nmol was present in the extract. An antimicrobial band, seen in a previous bioassay, was not found, suggesting that this second compound may be more labile than biochanin A.
authors: USDA-ARS Forage-Animal Production Research Unit, Lexington, KY 40546, USA. isabelle.kagan@ars.usda.gov
authors: Isabelle A
authors: IA
authors: Kagan
authors: Michael D
authors: MD
authors: Flythe
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D047991:Acetoanaerobium sticklandii / Q000187:drug effects* / Q000378:metabolism; D019833:Genistein / Q000302:isolation & purification / Q000494:pharmacology; D007202:Indicators and Reagents; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012417:Rumen / Q000382:microbiology; D012639:Seeds / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D029921:Trifolium / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D010636:Phenols; D010936:Plant Extracts; D000644:Quaternary Ammonium Compounds; D019833:Genistein; C004541:biochanin A