Harvest time on the content and chemical composition of essential oil from leaves of guava

Abstract

The essential oil plants contents can be affected by several factors. For example, in certain plants, collection time has been observed to affect the content and chemical composition of the essential oil obtained from the plant. The objective of this study was to evaluate the effect of collection time on the . Leaves collected at 7:00 AM had higher essential oil production, with a content of 0.38% (d.b.), whereas leaves collected at 7:00 PM had lower essential oil production, 0. 24% (d.b.) 4%, 63.8-61.7%, and 15.9-13.2%, respectively (2,(2)(3)(4)4%),(1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)1%),(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)4%), aromadendreno (7,(6)(7)(8)(9)(10)(11)(12)2%),(3)(4)(5)(6)(7)(8)(9)(10)(11)3%), óxido de cariofileno (3,3%) epóxido de humuleno II (4,(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)1%) (63,8-61,7% e 15,9-13,2%, respectivamente). RESUMO Existem fatores que podem afetar o conteúdo de óleo essencial das plantas, sendo o horário de coleta um deles. Assim, observa-se que o teor e a composição química de óleo essencial podem variar em certas plantas de acordo com horário de coleta. O objetivo deste trabalho foi avaliar o efeito do horário de coleta sobre o conteúdo e a composição química do óleo essencial das folhas de goiabeira (Psidium guajava). Folhas de Psidium guajava foram coletadas em diferentes horários do dia para determinar teor e composição química de seu óleo essencial. O óleo essencial não apresentou variação qualitativa da composição química em relação ao horário de coleta das folhas de Psidium guajava, mas alterou a concentração das substâncias, entre elas o α-humuleno e o trans-cariofileno. Os constituintes principais do óleo essencial das folhas de Psidium guajava são o limoneno Palavras-chave: Psidium guajava L., plantas medicinais, metabólitosespeciais, α-humuleno, trans-cariofileno, goiaba.

Chemical Composition, Antibacterial, Antioxidant and Enzyme Inhibitory Activities of the Essential Oil from Leaves of Psidium guajava L.

“…The results of these studies are roughly comparable, but there are cases where the content of the same ingredients varies for distinct reasons. Such differences may be due to the variations in plant growth stage, region, altitude, climate, and other factors at the time of sampling, as well as in the extraction process parameters and drying methods [30] …”

“…Such differences may be due to the variations in plant growth stage, region, altitude, climate, and other factors at the time of sampling, as well as in the extraction process parameters and drying methods. [30] Antioxidant Properties of GLEO The antioxidant activity of GLEO was evaluated by DPPH free radical, ABTS free radical scavenging test, and β-carotene bleaching test. For the experimental results, Figures 1(A) and 1(B) demonstrate that the scavenging ability of GLEO to DPPH free radical and ABTS free radical gradually increases with the increase in its concentration, showing a dose-dependent relationship that is consistent with the findings of [a] RI, the retention indices on the HP-5MS benzyl siloxane capillary column.…”

Essential Oil Composition Analysis, Antimicrobial Activities, and Biosystematic Studies on Six Species of Salvia

“…Plant samples were collected from the locations indicated in Table 1 . All plants were collected during the flowering period and in the morning hours [ 32 ]. For essential oil studies, approximately 200 g of plant samples were dried in a place out of the sun.…”

Essential oil composition and stable isotope profile of cultivated Lippia alba (Verbenaceae) from Ecuador

“…The authors of this latter study attributed their results to fluctuations in temperature and light intensity throughout the day. Furthermore, investigations encompassing distinct species have exhibited a similar tendency concerning essential oil yield, in which an increase or decrease is observed contingent upon the harvest time [23][24][25][26].…”