Phytochemical, Antibacterial and Antioxidant Activity Evaluation of Rhodiola crenulata

Abstract

The chemical components, as well as the antibacterial and antioxidant activities of the essential oil (EO) and crude extracts prepared from Rhodiola crenulata were investigated. The essential oil was separated by hydrodistillation, and gas chromatography-mass spectrometry (GC-MS) was used to identify its constituents. A total of twenty-seven compounds was identified from the EO, and its major components were 1-octanol (42.217%), geraniol (19.914%), and 6-methyl-5-hepten-2-ol (13.151%). Solvent extraction and fractionation were applied for preparing the ethanol extract (crude extract, CE), petroleum ether extract (PE), ethyl acetate extract (EE), n-butanol extract (BE), and water extract (WE). The CE, EE and BE were abundant in phenols and flavonoids, and EE had the highest total phenol and total flavonoid contents. Gallic acid, ethyl gallate, rosavin and herbacetin were identified in the EE. The antibacterial activity results showed that the EO exhibited moderate inhibitory activity to the typical clinic bacteria, and EE exhibited the strongest antibacterial activity among the five extracts. For the compounds, ethyl gallate showed the strongest inhibitory activity to the test bacteria, and its minimum inhibitory concentration (MIC) value and minimum bactericidal concentration (MBC) value for all the tested bacteria was 0.24 mg/mL and 0.48 mg/mL, respectively. The results of antioxidant activity showed that both CE and EE exhibited strong antioxidant activities in the DPPH radical scavenging and Fe2+ reducing power tests, however, EO showed relatively weaker antioxidant ability. Ethyl gallate and rosavin exhibited excellent activity in the DPPH radical scavenging assay, and their IC50 value was 5.3 µg/mL and 5.9 µg/mL, respectively. Rosavin showed better reduction power activity than the other three compounds. These results could provide more evidence for the traditional use of R. crenulata, and would be helpful for improving its application further.

Biotransformation of Flavonoids Improves Antimicrobial and Anti-Breast Cancer Activities In Vitro

“…Antimicrobial biological activities of the tested compounds were evaluated as Zhong et al, with some modifications [20]. Gram-positive and -negative bacteria and fungi (S. aureus ATCC6538, E. coli ATCC25922, and C. albicans SC5314) were selected for evaluation in the present study.…”

Extraction, Radical Scavenging Activities, and Chemical Composition Identification of Flavonoids from Sunflower (Helianthus annuus L.) Receptacles

“…According to the previously described protocol with some modifications [ 18 , 19 , 20 ], the whole sunflower receptacles were ground into fine powder (1.5 kg) and extracted with the optimal extraction conditions. All filtrates were collected and dried to obtain crude extracts of 186 g. One hundred and fifty of gram of the crude extracts were suspended into water, three solvents (petroleum ether, ethyl acetate, n-butanol) with increasing polarities were successively used to partition plant extracts, the partitioning of each solvent was operated three times, the extract liquor were collected and concentrated by vacuum distillation at 60 °C, 0.8 MPa for 3–4 h. The remaining water was removed by using freeze dryer (Alpha 1-2 LD plus, Christ, Germany) with −52 °C, 0.052 mbar for 72 h. The dry fractions were obtained and recorded as petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butanol fraction (nBUF) and water fraction (WAF).…”

Promising Herbs as Alternatives for Women with Symptoms of Menopause: A Review

“…This potent herb aids the body in combating stress's harmful effects. 110 Because of its benefits on levels of cortisol; it is also considered one of the finest antiaging herbs. Many neuropsychological symptoms encountered by menopausal women can be improved by Rhodiola rosea, according to animal and human research, including tiredness, nervousness, stress, neurological problems, loss of memory, decreased executive functioning, and stress intolerance.…”