title: In vitro antibacterial activity of sphaeropsidins and chemical derivatives toward Xanthomonas oryzae pv. oryzae, the causal agent of rice bacterial blight.
abstract: Sphaeropsidin A, the main phytotoxin produced by Diplodia cupressi, as well as the two natural analogues sphaeropsidins B and C and 14 derivatives obtained by chemical modifications were assayed for antibacterial activity against Xanthomonas oryzae pv. oryzae, Pseudomonas fuscovaginae, and Burkholderia glumae, the causal agents of severe bacterial rice diseases. The results showed a strong and specific activity of sphaeropsidin A against X. oryzae pv. oryzae, while no activity was observed against the other two pathogens. The results of structure-activity relationship studies showed that structural features important to impart this antibacterial activity are the presence of the C-7 carbonyl group and the hemiketalic lactone functionality. The C-13 vinyl group, the double bond of ring C, and/or the tertiary C-9 hydroxy group, as well as the pimarane arrangement of the tricylic carbon skeleton, were also important for the antibacterial activity. These findings may be useful in designing novel compounds for practical applications in agriculture.
authors: Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy. evidente@unina.it
authors: Antonio
authors: A
authors: Evidente
authors: Vittorio
authors: V
authors: Venturi
authors: Marco
authors: M
authors: Masi
authors: Giuliano
authors: G
authors: Degrassi
authors: Alessio
authors: A
authors: Cimmino
authors: Lucia
authors: L
authors: Maddau
authors: Anna
authors: A
authors: Andolfi
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D019117:Burkholderia / Q000187:drug effects; D004224:Diterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009426:Netherlands; D012275:Oryza / Q000378:metabolism* / Q000382:microbiology; D010935:Plant Diseases / Q000209:etiology / Q000235:genetics / Q000382:microbiology*; D011549:Pseudomonas / Q000187:drug effects; D013329:Structure-Activity Relationship; D014974:Xanthomonas / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D004224:Diterpenes; C570422:sphaeropsidin A