title: Isolation and chemical characterization of PwTx-II: a novel alkaloid toxin from the venom of the spider Parawixia bistriata (Araneidae, Araneae).
abstract: Brazil has many species of spiders belonging to Araneidae family however, very little is known about the composition, chemical structure and mechanisms of action of the main venom components of these spiders. The main objective of this work was to isolate and to perform the chemical characterization of a novel beta-carboline toxin from the venom of the spider Parawixia bistriata, a typical species of the Brazilian 'cerrado'. The toxin was purified by RP-HPLC and structurally elucidated by using a combination of different spectroscopic techniques (UV, ESI-MS/MS and 1H NMR), which permitted the assignment of the molecular structure of a novel spider venom toxin, identified as 1-4-guanidinobutoxy-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline, and referred to here as PwTx-II. This compound is toxic to insects (LD50 = 12+/-3 etag/mg honeybee), neurotoxic, convulsive and lethal to rats (LD50 = 9.75 mg/kg of male Wistar rat).
authors.affiliation: Institute of Biosciences, São Paulo State University (UNESP), Avenue 24 A, 1515-Bela vista, 13506-900 Rio Claro, SP, Brazil.
authors.forename: Lilian M M
authors.initials: LM
authors.lastname: Cesar
authors.forename: Maria A
authors.initials: MA
authors.lastname: Mendes
authors.forename: Claudio F
authors.initials: CF
authors.lastname: Tormena
authors.forename: Maurício R
authors.initials: MR
authors.lastname: Marques
authors.forename: Bibiana M
authors.initials: BM
authors.lastname: de Souza
authors.forename: Daniel Menezes
authors.initials: DM
authors.lastname: Saidemberg
authors.forename: Jackson C
authors.initials: JC
authors.lastname: Bittencourt
authors.forename: Mario S
authors.initials: MS
authors.lastname: Palma
mesh_terms: D000818:Animals; D002243:Carbolines / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity; D004305:Dose-Response Relationship, Drug; D007928:Lethal Dose 50; D008297:Male; D015394:Molecular Structure; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced; D013111:Spider Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity; D013112:Spiders / Q000737:chemistry*; D014118:Toxins, Biological / Q000737:chemistry* / Q000302:isolation & purification* / Q000633:toxicity
chemical_list: D002243:Carbolines; C507171:PwTX-II; D013111:Spider Venoms; D014118:Toxins, Biological