Cymbopogon flexuosus is a highly valued botanical species with significant applications in
the food and food supplement industries, medicine, and cosmetics. The effects of four extraction
techniques, supercritical CO2, microwave–ultrasonic, steam distillation, and hydrodistillation techniques,
on the yield, phytochemical constituents, and antifungal activity against nine fungal species of
Cymbopogon flexuosus aromatic oil (AO) were explored in this investigation. Gas chromatography
connected with a mass spectrometry apparatus was employed for the qualitative and quantitative
analyses of the investigated plant AOs. In addition, using the broth microdilution method, minimum
inhibitory concentrations (MICs) were calculated for several fungi species. The supercritical CO2
method gave the highest yield of AO (11.62  0.03 (w/w)) followed by the microwave–ultrasonic
method (1.55  0.05% (w/w)) and the steam distillation method (1.24  0.04% (w/w)), while the
hydrodistillation methods gave the lowest yield (1.17  0.01 (w/w)). In addition, eighteen molecules
were specified in the AOs obtained with the supercritical CO2, microwave–ultrasonic, steam distillation,
and hydrodistillation techniques, which constituted 99.36, 98.6, 98.21, and 98.31% (v/v) of
the total oils, respectively. Additionally, linalyl acetate was the trending molecule in the microwave–
ultrasonic and steam distillation methods, representing 24.61 and 24.34% (v/v), respectively, while
geranial was the dominant molecule in the AOs extracted with the hydrodistillation and supercritical
CO2 extraction techniques (27.01 and 25.6% (v/v), respectively). The antifungal screening
results revealed that the tested C. flexuosus AOs have potential antifungal effects against all the
screened fungi species. The antifungal effect of the AOs extracted with the steam distillation and
microwave–ultrasonic methods was remarkable compared with that of the commercial antifungal
drug Fluconazole. However, the AOs extracted with these two methods have a more potent antifungal
effect against Candida parapsilosis than that of Fluconazole with MICs of 3.13  0.01, 3.13  0.01,
and 6.25  0.91 g/mL, respectively. The same effects were also observed against Trichophyton rubrum
with MICs of 6.25  0.91 g/mL, respectively. The results of this investigation demonstrated that
the steam distillation and microwave–ultrasonic methods are promising processes for the extraction
of C. flexuosus AO with a potent antifungal effect. This may be an advantage for the utilization of
C. flexuosus AO over some antifungal synthetic agents commonly utilized as medicines, preservatives,
food additives, cosmetics, and nutrient supplements.

Title

Molecules

Publisher

MDPI

Publisher Country

Sweden

Indexing

Thomson Reuters

Impact Factor

3.9

Publication Type

Both (Printed and Online)

Volume

28

Year

2023

Pages

1-14