Sociedade Brasileira de Espectrometria de Massas – BrMASS
Natural Products - NAT
Screening for Annonaceous acetogenins in crude fractions from
the leaves of Annona rugulosa by Liquid Chromatography-Mass
Spectrometry
Francinete Ramos Campos1,*, Luiz Eduardo da Silva1, Vanessa Cristina G.
Jasinski1, Roberto Pontarolo1, Andersson Barison², Mayara E. Vendramin²
*[email protected]
1
Center of Studies in Biopharmacy, Department of Pharmacy, Federal
University of Paraná, Curitiba, PR, Brazil.
2
Department of Chemistry, Federal University of Paraná, Curitiba, PR, Brazil.
The Annonaceae acetogenins are a singular class of secondary metabolites
found in plants[1]. Over the last thirty years, many studies were conducted in isolation
and identification of this class of natural products, especially by their broad range of
biological properties such as cytotoxic, antitumoral and pesticidal activities[2]. Annona
rugulosa is a tree up to 12 m high and 40 cm diameter, found in South and Southeast
of Brazil in “Mata Atlântica”. It is popularly known as “araticum” and “anona”. In folk
medicine the tea from leaves is used against kidney infection and sore throat[3].
In view of its relevance, the isolation and identification of acetogenins become
essential since there are no studies of these compounds in A. rugulosa reported in
literature so far. For this purpose, ESI-MSn and LC-MS/MS analysis were performed in
crude alkaloid and neutral fractions from the leaves of A. rugulosa.
Initially, purified alkaloid fraction was dissolved in methanol/water (50:50 v/v)
with 0.1% formic acid solution. The samples were directly infused into the ESI(+)-MS
resulting in identification of three known adjacent bis-THF acetogenins
(dihydroxylated): isodesacetyluvaricin, desacetyluvaricin and membranacin. Besides,
the structures were confirmed by 13C NMR. These compounds were also identified in
crude alkaloid fraction by LC-MS/MS, detected by their successive losses of water,
showing a common fragmentation pattern for this group. On the other hand,
monitoring the specific transition from m/z 645 to 533 under the SIM mode in LC-MS
analysis of the crude neutral fraction the following adjacent bis-THF acetogenins
(trihydroxylated / with OH at C4) were identified: bullatacin, asimicin and trilobacin.
For this second group, an ion pathway leading to the loss of 112 Da was recognized,
as previously described in literature[4].
All the acetogenins elucidated are being reported for the first time in A.
rugulosa and their fragmentation patterns are supporting the recognition of new
acetogenins readily in complex fractions, reducing time and costs in future analyzes.
[1] Aminimoghadamfarouj, N.; Nematollahi, A.; Wiart, C. J. Asian Nat. Prod. Res., 2011, 13,
465.
[2] Bermejo, A.; Figadère B.; Zafra-Polo, M.; Barrachina, I.; Estornell, E.; Cortes, D. Nat. Prod.
Rep., 2005, 22, 269.
[3] Vendramin, M.E.; Costa, E.V.; Santos, E.P. dos; Pinheiro, M.L.B.; Barison, A.; Campos, F.R.
Biochem.Sys. Ecol., 2013, 49, 152.
[4] Gu, Z.; Zhou, D.; Wu, J.; Shi, G.; Zeng, L.; McLaughlin, J.L. J. Nat. Prod., 1997, 60, 242.
5º Congresso BrMass – 7 a 11 de Dezembro de 2013