Enantiomeric Composition, Antioxidant Capacity and Anticholinesterase Activity of Essential Oil from Leaves of Chirimoya (Annona cherimola Mill.)

Abstract

Annona cherimola Mill. is a native species of Ecuador cultivated worldwide for the flavor and properties of its fruit. In this study, hydrodistillation was used to isolate essential oil (EO) of fresh Annona cherimola leaves collected in Ecuadorian Sierra. The EO chemical composition was determined using a non-polar and a polar chromatographic column and enantiomeric distribution with an enantioselective column. The qualitative analysis was carried out by gas chromatography coupled to a mass spectrometer and quantitative analysis using gas chromatography equipped with a flame ionization detector. The antibacterial potency was assessed against seven Gram-negative bacteria and one Gram-positive bacterium. ABTS and DPPH assays were used to evaluate the radical scavenging properties of the EO. Spectrophotometric method was used to measure acetylcholinesterase inhibitory activity. GC-MS analysis allowed us to identify more than 99% of the EO chemical composition. Out of the fifty-three compounds identified, the main were germacrene D (28.77 ± 3.80%), sabinene (3, 9.05 ± 1.69%), β-pinene (4, 7.93 ± 0.685), (E)-caryophyllene (10.52 ± 1.64%) and bicyclogermacrene (11.12 ± 1.39%). Enantioselective analysis showed the existence of four pairs of enantiomers, the (−)-β-Pinene (1S, 5S) was found pure (100%). Chirimoya essential oil exhibited a strong antioxidant activity and a very strong anticholinesterase potential with an IC50 value of 41.51 ± 1.02 µg/mL. Additionally, EO presented a moderate activity against Campylobacter jejuni and Klebsiella pneumoniae with a MIC value of 500 μg/mL.

Study of the Chemical Composition and Biological Activity of the Essential Oil from Congona (Peperomia inaequalifolia Ruiz and Pav.)

“…Regarding anticholinesterase activity, this is the first report for the EO of P. inaequalifolia with an IC 50 of 43.93 ± 1.05 µg/mL, which could be considered moderate potency according to the classification of anti-AChE proposed by Santos et al in 2018 who proposed three categories: high potency IC 50 < 20 µg/mL; moderate potency 20 < IC 50 < 200 µg/mL; and low potency 200 < IC 50 < 1000 [ 31 ]. The value is quite similar to that reported for A. cherimola EO with an IC 50 of 41.51 µg/mL [ 32 ]. The results of anticholinesterase activity are relevant in researching treatments for Alzheimer disease, and Benny and Tomas in 2019 reported the neuroprotective effect of EO and the pure compounds [ 33 ].…”

Acetylcholinesterase Inhibitory Activities of Essential Oils from Vietnamese Traditional Medicinal Plants

“…Some of the essential oils in this study, although characterized by absolute predominance of sesquiterpenoids, exhibited good and potent AChE inhibitory activity (see above). Similarly, the leaf essential oil of Annona cherimola , characterized by 73.87% of sesquiterpenoids including germacrene D (28.77%), bicyclogermacrene (11.12%), E -β-caryophyllene (10.52%), sabinene (9.05%), and β-pinene (7.93%), showed strong AChE inhibition with an IC 50 value of 41.51 ± 1.02 µg/mL [ 40 ]. The essential oil of Eugenia riedeliana was characterized by an absolute predominance of sesquiterpenoids (94.2%), but also exhibited strong inhibition with an IC 50 value of 67.3 μg/mL [ 41 ].…”

Chemical and Biological Activity Profiling of Hedyosmum strigosum Todzia Essential Oil, an Aromatic Native Shrub from Southern Ecuador

“…The method followed was previously described for our research group. The culture of Campylobacter jejuni , was activated by adding horse serum at 5% in Tioglycolate medium and incubated at anaerobic conditions provided by a Campygen sachet (Thermo, scientific) at 37 °C for 48 h. The broth microdilution test was performed in MH II supplemented with 5% horse serum (Thermo) at the same conditions previously described as oil sample dilution and bacterial inoculum, and anaerobic conditions as described fully by our research group [ 31 ].…”

“…The procedure was adapted from the methodology suggested by Thaipong et al [ 32 ] and fully developed for our research group in previous reported jobs [ 31 ]. Briefly, a stable solution of DPPH in MeOH was prepared at a concentration of 625 µM.…”