Sains Malaysiana 44(1)(2015): 127–137

Mass Spectrometry (LC-MS-MS) as a Tool in the Maillard Reaction Optimisation and Characterisation of New 6-methoxy-tetrahydro-β-carboline Derivatives

(Spektometri Jisim (LC-MS-MS) Sebagai Alat dalam Pengoptimuman Tindak Balas Maillard

dan Pencirian Terbitan Baru 6-metoksi-tetrahidro-β-karbolina)

T.B. GOH*, M.N. MORDI & S.M. MANSOR

Centre for Drug Research, Universiti Sains Malaysia, 11800 Penang, Malaysia

Diserahkan: 18 Januari 2014/Diterima: 6 Jun 2014

ABSTRACT

Four new 6-methoxy-tetrahydro-β-carboline derivatives (1-6- methoxy-1-phenyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole,2-6-methoxy-1-(4-methoxyphenyl)-2,3,4,9-tetrahydro-1H-pyrido[3,4-]indole, 3-6-methoxy-1-methyl-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indole and 4-2-methoxy-4-(6-methoxy-2,3,4,9-tetrahydro-1H-pyrido[3,4-b]indol-1-yl)phenol) were prepared via the Maillard reaction using 5-methoxytryptamine and various aldehydes in water. The synthesis reaction conditions were optimised in catalyst loading, temperature and time using LC-MS for optimum yields. Surface response methodology and contour plot was selected as an approach for optimisation. The optimum yield could be achieved below 50^oC within 5 h at 7 mole % catalyst loading at yields > 70%. The β-carboline compounds produced were characterised using electrospray ionization mass spectrometry (ESI-MS) and electrospray tandem mass (ESI-MS/MS). The mass fragmentation patterns of this group of heterocyclic tetrahydro-ß-carboline compounds are described herein.

Keywords: Catalyst loading; heterocyclic; optimization; 5-methoxytryptamine; 6-methoxy-tetrahydro-β-carboline

ABSTRAK

Empat terbitan baru 6-metoksi-tetrahidro-β-karbolina (1-6- methoksi-1-fenil-2,3,4,9-tetrahidro-1H-pirido[3,4-b]indol,2-6-metoksi-1-(4-metoksifenil)-2,3,4,9-tetrahidro-1H-pirido[3,4-b]indol,3-6-metoksi-1-metil-2,3,4,9-tetrahidro-1H-pirido[3,4-b]indol dan 4-2-metoksi-4-(6-metoksi-2,3,4,9-tetrahidro-1H-pirido[3,4-b]indol-1-yl)fenol ) telah disediakan melalui tindak balas Maillard dengan menggunakan 5-metoksitriptamin dan pelbagai aldehid dalam air. Keadaan tindak balas sintesis telah dioptimumkan daripada segi muatan mangkin, suhu dan masa dengan menggunakan LC-MS untuk hasil yang optimum. Kaedah gerak balas permukaan dengan plot kontur telah dipilih sebagai satu pendekatan untuk pengoptimuman. Hasil yang optimum telah dicapai pada suhu bawah 50ºC dalam masa 5 jam pada muatan mangkin 7% mol dengan hasil pemerolehan > 70%. Sebatian β-karbolina yang dihasilkan telah dicirikan dengan menggunakan spektrometri jisim pengionan semburan elektron (ESI-MS) dan jisim seiring semburan elektron (ESI-MS/MS). Corak fragmentasi kumpulan sebatian heterosiklik tetrahidro-β-karbolina telah diterangkan di sini.

Kata kunci: Heterosiklik; muatan mangkin; pengoptimuman; 5-metoksitriptamin; 6-metoksi-tetrahidro-β-karbolina

RUJUKAN

Antônio, E.M.C., Paul, J.G., João, L.C.L. & Norberto, P.L. 2010. Electrospray MS-based characterization of β-carbolines-mutagenic constituents of thermally processes meat. Mol. Nutr. Food Res. 54: 433-439.

Arisseto, A.P., Figueiredo, M.C.T., Govaert, Y., Van Loco, J., Fraselle, S. & Degroodt, J.L. 2008. A modified sample preparation for acrylamide determination in cocoa and coffee products food anal. Methods 1: 49-55.

Benjamin, L., Jayasree, S. & Abdul Majeed, S. 2006. Catalytic asymmetric Pictet-Spengler reaction. J. of American Chemical Society 128: 1086-1087.

Erica, O.B., G Alessandro, C.M., Luciana, E., Marcus, V.K., Rafael, S., Osvaldo, P.J., Jesui, V.V. & Vitor, C.A. 2013. Optimisation of antioxidant compounds extraction from flesh of new developed apple cultivar using response surface methodology. Food Anal. Methods 6(5): 1407-1415.

Farah, D.M.H., Zaibunnisa, A.H. & Misnawi, J. 2012. Optimization of cocoa beans roasting process using response surface methodology based on concentration of pyrazine and acrylamide. Int. food Res. J. 19(4): 1355-1359.

Herraiz, T., Galisteo, J. & Chamorro, C. 2003. L-Tryptophan reacts with naturally occurring and food-occurring phenolic aldehydes to give phenolic tetrahydro-β-carboline alkaloids: Activity as antioxidants and free radical scavengers. J. of Agri. and Food Chem. 51: 2168-2173.

Herraiz, T. & Galisteo, J. 2004. Endogenous and dietary indoles: A class of antioxidants and radical scavengers in the ABTS assay. Free Radic Res. 38: 323-331.

Jintao, Z., Eric, W.K., Nancy, J., Prabir, S., Ze-Qi, X. & Michael, T.F. 2000. Automated process research. An example of accelerated optimization of the friedel−crafts acylation reaction, a key step for the synthesis of anti-HIV (+)-CalanolideOrg. Process Res. and Dev. 4: 577-580.

Larghi, E.L., Amongero, M., Bracca, A.B.J. & Kaufman, T.S. 2005. The intermolecular Pictet-Spengler condensation with chiral carbonyl derivatives in the stereoselective synthesesof optically-active isoquinoline and indole alkaloids. Arkivoc. 12: 98-153.

Maurício, R.M., Maria, A.M., Cláudio, F.T., Bibiana, M.S., Lílian, M.M.C., Roberto, R. & Mario, S.P. 2005. Structure determination of a tetrahydro-β-carboline of arthropod origin: A novel alkaloid-toxin subclass from the web of spider Nephila clavipes. Chemistry and Biodiversity 2(4): 525-534.

Pari, K., Sundari, C.S., Chandani, S. & Balasubramaniam, D. 2000. Β-carbolines that accumulate in human tissues may serve a protective role against oxidative stress. J. of Biological Chem. 275(4): 2455-2462.

Saha, B., Sharma, S., Sawant, D. & Kundu, B. 2007. Water as an efficient medium for the synthesis of tetrahydro-β- carbolines via Pictet–Spengler reactions. Tetrahedron Lett. 48: 1379-1383.

Teik Beng, G., Nizam Mordi, M. & Sharif Mahsufi, M. 2013. Demethylation of mitragynine picrate with BBr3 and C12H25-SH/NaOMe: A new entry for ester derivatives preparation based on position carbon 9. Asian J. Res. Chem 6(9): 863-867.

Teik Beng, G., Ming Tze, L. & Azhar, M.E. 2009. Using soy protein isolate/glucose edible films to protect fish oil from lipid oxidation. Asean Journal of Food and Agro-Industry 2(03): 342-350.

Teik Beng, G., Poh Bee, C. & Azhar, M.E. 2003. Enhancement of soy protein isolate films properties by using the Maillard reactions and curing treatments. ASEAN Food Journal 12(3): 149-158.

*Pengarang untuk surat-menyurat; email: gohteikbeng@yahoo.com