Proximate nutritive values, antioxidant capacity, antimicrobial properties and profiling the chemical content of opuntia stricta cladodes and fruit peel by HPLC-DAD-ESI/MS analyses.

The study characterises the phenolic compounds in ethanol, butanol, and ethyl acetate extracts from the fruit peels and cladodes of Opuntia stricta (syn. Opuntia dillenii (Ker-Gawl) Haw), from Morocco using UHPLC/DAD/ESI-MS. Additionally, the study evaluates the antimicrobial and antioxidant activities of these extracts. Thirteen phenolic compounds were found in Opuntia stricta extracts, such as flavonoids (kaempferol 3-O-arabinoside, isorhamnetin rhamnosyl-rutinoside, quercetin 3-O-rutinoside, isorhamnetin-3-O-rutinoside, and isorhamnetin) and phenolic acid. The fruit peels were found to contain the highest phenolic content, protein, and total sugars. The antibacterial effect was investigated in vivo. The most active extract was the ethyl acetate extract of fruit peels and cladodes against Staphylococcus aureus and P. aeruginosa, with inhibition zone diameters of 16.2 and 15 mm, respectively, followed by dichloromethane extract, with zone diameters of 13.8 and 14 mm, respectively. Our results revealed higher antioxidant activity for the ethyl acetate and butanol extracts from fruit peels than cladodes.

Chemical Composition, Antioxidant and Antibacterial Activities and Acute Toxicity of Cedrus atlantica, Chenopodium ambrosioides and Eucalyptus camaldulensis Essential Oils.

The essential oils yield of Cedrus atlantica, Chenopodium ambrosioides and Eucalyptus camaldulensis was different. C. ambrosioides gave a relatively higher yield (2.1 ± 0.1%), while that of C. atlantica was low (1.0 ± 0.1%) and that of E. camaldulensis was lower (0.75 ± 0.1% of dry matter). The active ingredients of the essential oils and some of their biological effects were also determined. The characterization of their chemical compositions showed that the three essences have different chemical profiles: C. atlantica was richer in sesquiterpenes (ß-Himachalene (54.21%) and γ -Himachalene (15.54%)), C. ambrosioides was very rich in monoterpene peroxides and monoterpenes (α-Terpinene (53.4%), ascaridole (17.7%) and ρ-Cymene (12.1%)) and E. camaldulensis was very rich in monoterpene compounds and monoterpenols (p-cymene (35.11%), γ-Eudesmol (11.9%), L-linalool (11.51%) and piperitone (10.28%)). The in vitro measurement of antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) reduction assay showed a significant performance of the eucalyptus oil and average performance of the other two (C. atlantica and C. ambrosioides). The in vitro bio-test for their antimicrobial effects showed that the antibacterial activity differed depending on the essential oil and the concentration used, and that their bactericidal efficacy was similar or superior to that of synthetic antibiotics. The toxicity test on rats revealed that the LD50 of the three essential oils was 500 mg/kg body weight, which classifies them as category four cytotoxic natural products at high doses.