Diversity Analysis and Associated Antimicrobial Activity of Essential Oil inPyrrosia petiolosa

Abstract

The continued development of folk medicine to potentially treat infectious diseases has resulted in an increase in natural sources of antimicrobial agents, particularly the use of plant essential oils containing volatile products from secondary metabolism. The objectives of this investigation were to (i) analyze the chemical components of essential oils using GC/MS and (ii) to examine their in vitro antimicrobial activities against four strains of bacteria (Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Shigella flexneri) and one fungus (Candida albicans) by determining minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) in liquid and solid media, respectively, from different Pyrrosia petiolosa locations. Eightyeight evaporable compounds were confirmed in their essential oils; the major components in the oils were 2,4pentadienal (12.5 %), phytol (10.5 %) and nonanal (8.6 %). Based on hierarchical cluster analysis, Pyrrosia samples were categorized into four groups, indicating significant essential oil diversity from different Pyrrosia locations. Results also indicated that essential oils had a broad spectrum of antibacterial activities, particularly against Shigella flexneri and Staphylococcus aureus with MICs of 5 μL/mL. Results from this investigation are the first to record the chemical component and antimicrobial potential of essential oils from different P. Petiolosa locations.

Assessment of Contact Toxicity and Repellent Effects of Essential Oils from Piper Plants Piper yunnanense and Piper boehmeriifolium against Three Stored‐Product Insects

“…Novel amide alkaloids isolated from P. boehmeriifolium , were proved to have antidepressant [48] or inhibitory effects [15] . P. boehmeriifolium leaf oils also performed outstanding antioxidant potential in ABTS assays with an IC 50 value of 7.36 μg/mL [18] . To our knowledge, no reports have been made on insecticidal effects of P. yunnanense and P. boehmeriifolium essential oils against three stored product insects.…”

“…Our oil was dominated by methyl 4,7,10,13,16,19‐docosahexaenoate (17.90 %), bicyclogermacrene (13.58 %) and δ‐cadinene (13.03 %). Nevertheless, the main compounds in EOs harvested from Guizhou province of China were β‐caryophyllene (7.9 %), caryophyllene oxide (6.9 %) and β‐elemene (6.4 %), [18] but α‐copaene (28.3 %), α‐pinene (7.4 %) and 1,8‐cineole (5.7 %) were identified in Vietnam's specimens [35] . The discrepancy in quantity and quality may be attributed to several factors such as harvest time, climatic condition and soil composition, [36] finally leading to various chemotypes.…”

“…[15] P. boehmeriifolium leaf oils also performed outstanding antioxidant potential in ABTS assays with an IC 50 value of 7.36 μg/ mL. [18] To our knowledge, no reports have been made on insecticidal effects of P. yunnanense and P. boehmeriifolium essential oils against three stored product insects. EOs of P. boehmeriifolium leaves were observed with moderate toxicity against three species of storage pests (52.42 μg/adult for T. castaneum; 15.76 μg/adult for L. serricorne; 18.72 μg/cm 2 for L. bostrychophila) in this work.…”

“…Recent papers concluded that EOs from piper species possessed bioactivities such as larvicidal, antioxidant, antibacterial properties, [17][18][19] closely related to their diverse chemical compositions. Despite the chemical profiles of P. boehmeriifolium EOs have been investigated previously, their insecticidal efficacy against stored product insects remains underexplored.…”

Seasonal Variation in the Essential Oil Yield and Composition of Cinnamomum parthenoxylon (Jack) Meisner

“…The synthesis, accumulation, and change of various chemical components in leaf essential oil were the comprehensive results from many physiological and biochemical reactions in plants, such as polymerization, oxidation, dehydrogenation, dehydration, esterification, cyclization, and so on. The diversity of plant components resulted from the joint action of climatic conditions, microorganisms, and soil components [25–27] . Also, certain rhythmic changes occurred in different growth seasons.…”