RESUMEN
Essential oil (EO) from Origanum majorana L. (Lamiaceae) shoots, extracted by hydrodistillation from plant cultivated under control and salt conditions. Essential oil composition was determined by GCMS. Plant material was harvest at three vegetative stages; early (EVS), late (LVS) and early flowering (P.F.S). Essential oil yield were 0.11% and 0.071 for E.V.S, 0.19% to 0.37% for L.V.S 0.23% and 0.47% for P.F.S, at the control and in the presence of 75 mM NaCl, respectively. Salt stress and development of vegetative stage affected the formation of the major compounds: cis-sabinene hydrate and terpinene-4-ol. Leaves were observed with scanning electron microscope (SEM), to determined trichomes number, size and distribution. Results showed that globular trichome density decrease with leaf maturity but increased with salinity.
O óleo essencial (OE) de Origanum majorana L. (Lamiaceae) foi extraído, através de hidrodestilação, de plantas cultivadas sob condições controladas e salinas. A composição do óleo essencial foi determinada por GC-MS. O material vegetal foi coletado em três estádios vegetativos: precoce (EVS), tardio (L.V.S) e floração precoce (PFS). O rendimento do óleo essencial foi de 0,11% e 0,071% para S.V.S, 0,19% e 0,37% para L.V.S, 0.23% e 0,47% para P.F.S, para o controle e na presença de NaCl 75 mM, respectivamente. O estresse salino e desenvolvimento vegetativo de rendimento afetou a formação dos principais compostos: cis-sabineno hidratado terpineno- 4-ol. As folhas foram observadas em microscópio eletrônico de varredura (MEV), para determinar o número de tricomas. Os resultados mostraram que a densidade globular do tricoma diminui com a maturidade da folha mas aumenta com a salinidade.
Asunto(s)
Aceites Volátiles , Origanum , Salinidad , TricomasRESUMEN
Essential oils of marjoram were extracted from plants, growing under non-saline and saline condition (75mM NaCl). Their antioxidant and antibaterial activity against six bacteria (Enterococcus faecalis, Escherichia coli, Salmonella enteritidis, Listeria ivanovii, Listeria inocula, and Listeria monocytogenes) were assessed. Result showed that, (i) independently of salt treatment, marjoram essential oils inhibited the growth of most of the bacteria but in degrees. The least susceptible one was Enterococcus faecalis. (ii) Gram negative bacteria seemed more sensitive to treated essential oils than Gram positive ones. (iii) Compared to synthetic antibiotics, marjoram essential oils were more effective against E. coli, L. innocua and S. enteridis. This activity was due to their high antioxidant activity. Thus, essential oils of marjoram may be an alternative source of natural antibacterial and antioxidant agents.
