# _Sponias mombin_ Seed Oil Compounds Identification by Raman Spectroscopy and NMR
## 1 Introduction  
Vegetable oils constitute a major source of nutritional lipids, and supply a great amount of fats and oils consumed worldwide. Several oils have shown to be relevant for medical treatments due to their composition, containing monounsaturated fatty acids and antioxidants which can be used to prevent cardiovascular diseases, osteoporosis and cancer [1, 2].  
_Sponias mombin_ L. is a tropical fruit that has been widely used for its medicinal and nutritional values. The pulp and leaves of _Sponias mombin_ L. are important in food and biomedical industries, and their use in traditional medicine has been reported for the treatment of stomach infection and inflammation [3, 4]. In addition, other studies have revealed antibacterial activity against various strains such as _Bacillus cereus_, _Streptococcus pyogenes_ and _Mycobacterium fortuitum_. Likewise, it has demonstrated sedative, antipsychotic, diuretic, gastroprotective and antioxidant activity in mammals [4, 5, 6]. The essential oils composition of _Sponias mombin_ L. shows more than 54 compounds [7]. Particularly, the content of the seed oil is remarkable, as it is present in 31.5% _w/w_ yield [8].  
Some molecules contained in oils, such as triacylglycerolglycerol (TAG) and unsaturated fatty acids, indicate the quality of the sample and its potential for pharmaceutical applications.  
Several methods have been developed for the determination of TAG profiles in oils. Here, we use the proton and carbon nuclear magnetic resonance technique (1H-NMR and 13C-NMR, respectively) as an analytical method to determine the structural analysis and quantification of fatty acids and their derivatives. The analysis focuses on characterizing several specific signals such as those of the olefinic, allylic and bis-allylic, methylene and the terminal methyl group protons [9,10].  
Raman spectroscopy (RS) is an analytical method that provides many advantages compared to traditional analysis methods, as it is precise and easy to use while not requiring sample preprocessing. It has been used in chemical, medical, biological, environmental and food applications, sometimes in combination with chemometric methods [11, 12, 13, 14, 15]. This method has been used to provide an accurate identification of compounds present in oils and is therefore useful to identify purity or possible adulterations [16, 17, 18, 19, 20]. RS has been used for the identification of carotenoid compounds of different vegetable oils such as goji berries, buriti and passionflower, as well as the petals of some flowers [21, 22, 23]. Furthermore, in samples of fruit and vegetable juices such as tomatoes, carrots, oranges, spinach and black grapes, they have been analyzed to identify main carotenoids such as lycopene, lutein, \(\beta\)-carotene, \(\alpha\)-carotene, \(\beta\)-cryptoxanthin and zeaxanthin [24].  
This work is intended to contribute to the development of feasible and accurate methods to characterize natural product composition, and relate them with biological activities and biocompatibility. We performed RS and NMR (\({}^{1}\)H- and \({}^{13}\)C-) as noninvasive and non-destructive analytical techniques to identify molecule profiles through the characterization of molecular vibrations and resonant frequencies associated with the carotenoids and fatty acid profile of _Spondias monthi_ L. seed oil.