Oil in Inajá Pulp ( Maximiliana maripa ) : Fatty Acid Profile and Anti-acetylcholinesterase Activity

The inajá (Maximiliana maripa) is a palm from Arecaceae family. The inajá distribution occurs from Amazon to the west-central of South America. The inajá has edible parts: the palm heart and oils obtained from pulp and seed. The aims of this study were to verify the fatty acid profile from pulp oil by GCFID and analyzing acetylcholinesterase inhibition by inajá pulp oil. Chromatographic analysis provided eleven fatty acids. The major unsaturated fatty acids are oleic (22.32%), linoleic (4.72%) and linolenic acids (3.95%). The major saturated fatty acids are palmitic (20.76%), myristic (20.48%) and lauric acids (17.42%). The acetylcholinesterase inhibition by inajá oil pulp was over 63.76%.


INTRODUCTION
The inajá palm (Maximiliana maripa) is from Arecaceae family.It is considered a large plant (can reach up to 20 meters in height) and its distribution occurs in flooded areas [1].This palm is very hardy, regenerates quickly in the environments where it is burned [2,3].
Geographically, the inajá palm is widely distributed throughout the Amazon to west-central South America.It is easily in the central and northern regions of Brazil [3].In the state of Roraima, Brazil, which borders the north of Venezuela, there is a significant population of this palm in these areas of savannah.
Oil is extracted from M. maripa seed and pulp for human consumption [3 ,4].The inajá fruit is rich in fatty acids and minerals (phosphorus and magnesium) [5], and has interest as biofuel in the process of obtaining biodiesel [6].
The aims of this study is to verify the fatty acid profile in inajá pulp collected in Roraima state, Brazil, as well as analyzing their acetylcholinesterase enzyme inhibition.

Obtaining Fruit and Extracting Oil from Inajá Pulp
The fruits were obtained in Mucajaí (Roraima, Brazil), in Tantinho region, at 451 miles on the BR 174 highway (2º27'44" N, 60º55'10" W).Samples were taken to the Laboratory of Environmental Chemistry in the Center for Research and Post-Graduate in Science and Technology (NPPGCT) of the Federal University of Roraima, Boa Vista city, Roraima.
The pulp was removed, washed and dried for 24 hours at 50 °C in an oven with air circulation.Pulp was grounded and sieved on a 20 to 40 mesh fabric to obtain a homogeneous granulation.Lipid extraction gave Soxhlet apparatus with hexane solvent, any procedure effected in triplicate [7].

Inajá Oil Analysis by GC-FID
Were dissolved in 2.0 mL cryogenic tube approximately 12 mg of the oil sample in 100 µL of a solution of ethanol (95%) / potassium hydroxide mol L -1 (5%).After vortexing for 10 s, oil was hydrolyzed in a domestic microwave oven (Panasonic Piccolo), at a power of 80W for 5 minutes.After cooling, 400 µL of hydrochloric acid 20% was added a spatula tip of NaCl (about 20 mg) and 600 µL of ethyl acetate.After vortexing for 10 s rest for 5 minutes.An aliquot of 300 µL of the organic layer was removed, placed into micro centrifuge tubes, dried by evaporation, thus obtaining free fatty acids [8].Subsequently, the free fatty acids were methylated with 100 µL of BF3 / methanol (14%), by heating for 10 minutes in water bath at 60 °C.These samples were diluted in 400 µL of methanol and analyzed by gas chromatography.

Fatty Acids Determination in Inajá Pulp
The GC-FID analysis provided 11 fatty acids (94.01%), as shown below in the chromatogram of Figure 1 and in Table 1.

Full Paper
Orbital: Electron.J. Chem.8 ( 2): 80-83, 2016 82 Note that the unsaturated fatty acids, UFA, predominate in the inajá pulp oil studies of Roraima are oleic, linoleic and linolenic acids (Table 1).The oleic acid which is found in greater proportion in the studied sample (22.32%).This acid is with values close to the inajá and other fruits of the Amazon region, as shown in Table 1.To saturated fatty acids, SFA (62.78%), the most abundant in this oil are palmitic (20.76%), myristic (20.48%) and lauric acids (17.42%).There is a difference of lauric and myristic sample studies compared with inajá of literature, but the values are close to as palmitic acid, even to other oleaginous species.The same applies to the unsaturated, UFA (22.56%), note the ω-9 and ω-6 sample and literature, while the ω-3 there is a slight difference.The amount of polyunsaturated fatty acids, PUFAs, differs from inajá of literature, but it is close to other species in Table 1.According to Crowley and Fröhlich (1998) [14] differences may occur due biotic and abiotic factors that influence the composition and concentration of fatty acids.
Fatty acids when in equilibrium in the diet have benefits for human health by preventing heart disease, inflammation and even neurodegenerative diseases.Some fatty acids such as linoleic and linolenic acids, mammals do not synthesize and can only be obtained through diet [18,19].

Inhibition of Acetylcholinesterase
The test results for acetylcholinesterase enzyme inhibition by inajá pulp oil is considered potent, as Table 3.This classification is given by Vinutha et al. (2007) [20] in which higher than 50% inhibitions are potent and inhibition values between 30-50% are moderate and below 30% are weak inhibitors.This enzyme has biochemical importance in humans, but its sudden increase may develop neurodegenerative diseases, one of them is Alzheimer disease [20,21].

CONCLUSION
The oil from the inajá pulp has a fatty acid profile similar to other oils or fats, so its lipid content can bring many benefits to human health.Thus, we can see a potent inhibition of acetylcholinesterase, almost 64%.The good results obtained of the fatty acid profile from inajá suggests future studies of chemical and biological prospecting for this plant species with the intention of developing bio products for human health.

Table 2 .
Profile main fatty acids in edible oils and fat.

Table 3 .
Percentage inhibition of acetylcholinesterase and its classification.