title: Matrix effect and optimization of LC-MSn determination of trachylobane-360 in mice blood.
abstract: Xylopia langsdorffiana A. St.-Hil. & Tul. (Annonaceae) is popularly known as "pimenteira-da-terra". Various constituents have been isolated from this species, including diterpenes, such as 8(17), 12E, 14-labdatrien-18-oic acid, ent-atisan-7α, 16α-diol (xylodiol), ent-7α-hydroxytrachyloban-18-oic acid (trachylobane-318) and ent-7α-acetoxytrachyloban-18-oic acid, a crystalline solid with a molecular weight of 360 and molecular formula of C22H32O4 (trachylobane-360). When administered intraperitoneally to mice, trachylobane-360 (T-360) significantly inhibits growth of the solid tumor sarcoma 180 transplanted in mice, without causing alterations in biochemical, hematological and histopathological parameters that are frequently associated with the clinical use of antineoplastic. Furthermore, this diterpene blocks voltage-dependent calcium channels (Cav), showing spasmolytic activity. The present study shows that variables such as extraction solvent (methanol, acetonitrile and chloroform), centrifugation force (1000, 7000 and 14,000×g), and centrifugation time (5, 15 and 25min), are important in the liquid-liquid extraction of T-360 from male Swiss mice blood in HPLC-MSn studies. The study confirms matrix influence on recovery and detection of T-360. The recovery for T-360 was 37.02% using chloroform as better extractor solvent, while centrifuged at 14,000×g for 15min demonstrated the importance of the parameters chosen for the extraction/recovery process of analyte. The effect of mice blood matrix for T-360 was -51.23%. This method was optimized by repeating the extraction procedure and acidification of samples. These conditions were essential in increasing recovery (49.47%) by decreasing the matrix effect (-37.60%). The efficiency of the process, after optimization with two extractions and acidification, increased by 14.19% when compared to the initial method, from 18.05% to 32.24%. According to Marchi et al. (2010), the matrix effect does not necessarily need to be reduced or eliminated, but it does need to be identified and quantified. Therefore, these findings are essential for the subsequent evaluation of the pharmacokinetic parameters of this promising natural product.
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: joaocpita@yahoo.com.br.
authors.forename: João Carlos Lima Rodrigues
authors.initials: JCLR
authors.lastname: Pita
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: isisfarmacia@hotmail.com.
authors.forename: Isis Fernandes
authors.initials: IF
authors.lastname: Gomes
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: socratesgolzio@gmail.com.
authors.forename: Socrates Golzio
authors.initials: SG
authors.lastname: Dos Santos
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: josean@ltf.ufpb.br.
authors.forename: Josean Fechine
authors.initials: JF
authors.lastname: Tavares
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: marcelosobral.ufpb@gmail.com.
authors.forename: Marcelo Sobral
authors.initials: MS
authors.lastname: da Silva
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: margareth@ccs.ufpb.br.
authors.forename: Margareth de Fátima Formiga Melo
authors.initials: MFFM
authors.lastname: Diniz
authors.affiliation: Programa de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, Centro de Ciências da Saúde, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB, Brazil. Electronic address: mariannavbs@gmail.com.
authors.forename: Marianna Vieira
authors.initials: MV
authors.lastname: Sobral
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000097:blood*; D002121:Calcium Channel Blockers / Q000097:blood*; D002138:Calibration; D002498:Centrifugation; D002725:Chloroform / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000592:standards; D004224:Diterpenes / Q000097:blood*; D006863:Hydrogen-Ion Concentration; D059625:Liquid-Liquid Extraction; D008297:Male; D051379:Mice; D008517:Phytotherapy; D010946:Plants, Medicinal; D012015:Reference Standards; D012997:Solvents / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods* / Q000592:standards; D013997:Time Factors; D054336:Xylopia
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002121:Calcium Channel Blockers; D004224:Diterpenes; D012997:Solvents; C572780:ent-7alpha-acetoxytrachyloban-18-oic acid; D002725:Chloroform
keywords: HPLC–MSn; Matrix effect; Method development; Trachylobane-360