Lupinus montanus: chemical characterization of organs

Abstract

Introduction Lupinus montanus is a herbaceous perennial plant found in pine and oak forests between 2500 and 4100 meters above sea level and flowers blooms between May and September. It is widely diffused in all Mexico and populations were found between the south of United States of America until Guatemala. It is well known that L. montanus produce quinolizidine alkaloids as part of a defence strategy against herbivores. However, very few is know about the presence of other compounds. Aim of present work was to obtain a chemical profile of L. montanus with special focus on flavonoids, alkaloids and proteins. Methods Plants and seeds of L. montanus were collected in the Iztaccihuatl volcano slope (N 19\ub0 04\u2019 58,7\u201d ; W 0,98\ub0 39\u2019 35,7\u201d) at 3581 m above sea level. Biological material was air-dried at 50\ua0\ub0C. For proximal analysis, seeds were manually separated and milled. The flour was analysed for fat, ash and crude protein using the AOAC (1990) methods. For the analysis of flavonoid, leaf, thallus, root and flower sample was extracted with methanol and analysed by HPLC and NMR. Alkaloids were extracted following the classical protocol of Wink (1995).Results and discussion/conclusions The proximal analysis showed that seeds present 15,5% fat, 40,7 % protein, 2,5 % of ashes. Methanol extract of leaf, thallus, root and flower was analyzed by HPLC and NMR, showing that flavonoids are found in every part of the plant, but specially in leaves, where acacetine, apigenine (and their glycosides), orientine, luteoline (and their glycosides, vitexine, 3\u2019 hidroxyvitexine and some other unidentified flavonoids were found. Alkaloid extracts of leaf, thallus, root and flower were analyzed by GC-MS. Leaf is the organ where got the higher diversity of alkaloids and seeds is the part with the highest concentration. Classical profile was found, with quinolizidine alkaloids like sparteine, isosparteine, lupanine, dehydrolupanine and two new compounds undescribed for L.montanus,hexa (methoxymethyl) melamine and sophocarpine. Financial Support: SIP-IPN (20110739), Erasmus-Mundus Program and CONACyT (100808)