Extraction of Alkaloids Using Ultrasound from Pulp and By-Products of Soursop Fruit (Annona muricata L.)

Abstract

The main goal of this work was to measure the total alkaloid content (TALC) from pulp, peel, seed, and columella of soursop fruit (Annona muricata L.) by ultrasound-assisted extraction (UAE) and to obtain the best conditions of the UAE with the response surface methodology (RSM). We evaluated the effect of amplitude (40%, 70%, and 100%), time (5, 10, and 15 min) and pulse-cycles (0.4, 0.7, and 1 s) and compared the best UAE conditions of alkaloids with a conventional extraction (maceration). The structural characterization of the raw material with the highest TALC was developed using nuclear magnetic resonance (NMR) techniques [1H, 13C, heteronuclear single quantum correlation (HSQC), heteronuclear multiple bond correlation (HMBC), and homonuclear correlation spectroscopy (COSY)]. According to the RSM, the best conditions in the UAE for extracting alkaloids varied depending on the type of plant tissue. It took 5 min with an amplitude of 70% and pulse-cycles of 1, 0.4, and 1 s, respectively, to extract the highest TALC in peel, seed, and columella while the optimal conditions for extracting the largest amount of alkaloids from the pulp were obtained at 5 min in UAE with pulse-cycles of 0.55 s and 100% amplitude. The TALC was highest in the peel (7.48 mg/g), which was followed by the seed (2.31 mg/g), the pulp (1.20 mg/g), and the columella (0.79 mg/g) and was positively correlated (R2 = 0.98–0.88) with the predicted values. In addition, the extraction alkaloids from the peel, pulp, seed, and columella using the UAE was 56.31, 5.45, 3.06, and 2.96 times higher, respectively, than the extraction by maceration. The alkaloids identified in the peel have not been reported and were nornuciferin, assimilobin, anonaine, and isolaureline. This study showed that the soursop fruit peel can be a source of alkaloids and that UAE has an important potential for extracting these compounds.

Ultrasonic-Assisted Extraction and Natural Deep Eutectic Solvents Combination: A Green Strategy to Improve the Recovery of Phenolic Compounds from Lavandula pedunculata subsp. lusitanica (Chaytor) Franco

“…UAE was more efficient (TPC from 22.90–56.00 mg GAE g dw ) than maceration (18.22–50.05 mg GAE /g dw ) for all solvents, excepting Glu:CA, in which maceration extracted a larger amount of phenolics (14.07 ± 1.24 vs. 9.64 ± 1.36 mg GAE /g dw ). Similar results were obtained by other authors [ 36 , 37 ]. In addition, Jeong et al [ 38 ] and Nam et al [ 39 ] compared four extraction methods (stirring, heating, heating with stirring, and UAE) using DES to extract monoterpenes and phenolic compounds from Mentha piperita L. and flavonoids from Flos sophorae , respectively, and obtained a greater extraction efficiency with UAE.…”

Current Situation and Perspectives of Fruit Annonaceae in Mexico: Biological and Agronomic Importance and Bioactive Properties

“…Alkaloids that have been qualitatively identified in different plant parts of the Annona species are the isoquinoleic alkaloids. The most frequently found include aporphine, protoberberines, benzyloquinoleins, and the bis-benzylisoquinolein dimers [83]. In the leaves, seeds, stem bark, root, and peel from A. muricata, A. cherimola, A. squamosa, and A. diversifolia, anomurine, anomuricine, atherosperminine, coreximine, coclaurine, corytenchine, isocoreximine asimilobine, annonaine, corypalmine, liriodenine, nornuciferine, reticuline have been reported, among many others [109,115,119].…”

“…Table 2 and Table 3 show some phytochemicals (quantitative or qualitative) identified in pulp, leaf, peel, seeds, roots, and stem bark of fruit Annona species: A. muricata, A. cherimola, A. squamosa, A. reticulata, and A. macroprophyllata [ 83 , 84 , 85 , 86 , 87 , 88 , 89 ]. These compounds include phenolic compounds, alkaloids, fatty acids, cyclopeptides, alkaloids, and acetogenins.…”

“…The phenolic compounds are the most abundant metabolites in Annona fruits, and they are considered the principal exogenous antioxidants. Their basic structure contains an aromatic ring with one or more hydroxyl substituents [ 83 ]. However, there are some Annona species that have not been completely characterized, and one of them is A. macroprophyllata ( Table 2 ).…”

“…The presence of flavonoids, for example, derivates of quercetin, gallocatechin, and kaempferol, give significant biological value to fruits as well as leaf extracts [ 84 ]. Moreover, the presence of phenolic compounds and flavonoids has been qualitatively reported in the edible part, leaf, and seed of A. squamosa [ 83 , 84 , 85 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 ]. Chlorogenic acid, ferulic acid, p -hydroxybenzoic acid, caffeic acid, gallic acid, and epicatechin are the most abundant phenolic compounds in this specie [ 86 ].…”