title: Antifungal activity of tetrasulfanes against Botrytis cinerea.
abstract: Various natural polysulfanes (RS(x)R', x > or = 3, R (double dagger) H), such as diallyltrisulfide and diallyltetrasulfide from garlic, are mostly harmless to humans, higher animals and plants, yet highly active against diverse microbes, including several fungi. Such natural organic sulfur compounds (OSCs) possess considerable practical potential against a wide range of agricultural pests. Unfortunately, their use is often hampered due to the inherently offensive smell, chemical instability and low water solubility. However, since the biological activity of polysulfanes is primarily based on their unique sulfur-sulfur motif, it is possible to preserve this motif and to modify the side-chain(s). Ultimately, such changes result in synthetic polysulfanes which retain or even exceed the activity of their natural analogues, and also show improved physico-chemical properties. The resulting acid-, ether- and ester-based tetrasulfanes synthesized as part of this study are odorless and highly active against the grey mold fungus Botrytis cinerea. Some, but not all, of the synthetic polysulfanes are recognized by an active fungal efflux mechanism mediated by the ABC transporter AtrB. Remarkably, some of them even induce transcription of the AtrB-encoding gene, mediated by transcription factor Mrr1. Taken together, the activity of synthetic polysulfanes against B. cinerea, combined with a likely low ecotoxicity of such sulfur compounds, bodes well for possible future applications against this and eventually other agronomically important plant pathogens.
authors.affiliation: Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B 2.1, D-66123 Saarbruecken, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Czepukojc
authors.affiliation: Department of Biology, University of Kaiserslautern, PO Box 3049, D-67653 Kaiserslautern, Germany.
authors.forename: Michaela
authors.initials: M
authors.lastname: Leroch
authors.affiliation: Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B 2.1, D-66123 Saarbruecken, Germany.
authors.forename: Franz
authors.initials: F
authors.lastname: Salm
authors.affiliation: Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B 2.1, D-66123 Saarbruecken, Germany.
authors.forename: Uma M
authors.initials: UM
authors.lastname: Viswanathan
authors.affiliation: Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B 2.1, D-66123 Saarbruecken, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Burkholz
authors.affiliation: Department of Biology, University of Kaiserslautern, PO Box 3049, D-67653 Kaiserslautern, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Hahn
authors.affiliation: Division of Bioorganic Chemistry, School of Pharmacy, Saarland University, Campus B 2.1, D-66123 Saarbruecken, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Jacob
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology; D020171:Botrytis / Q000187:drug effects* / Q000235:genetics; D005659:Fungicides, Industrial / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D013440:Sulfides / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D005659:Fungicides, Industrial; D013440:Sulfides