Biotechnology
M. Yahyazadeh; N. Hadi; Z. Shirazi; K. Jaimand; Kh. Karimzadeh Asl; M. Makizadeh Tafti; S. Fekri Qomi; M. Rahimifard; M. Gorji; F. Askari; Z. Behrad; D. Selmar
Abstract
Plants are the main sources of secondary metabolites with high medical value. The most important member of these valuable compounds are alkaloids with the different drug purposes. Concerning the limited production of some of these metabolites in the plants, these medicinal compounds can be produced naturally ...
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Plants are the main sources of secondary metabolites with high medical value. The most important member of these valuable compounds are alkaloids with the different drug purposes. Concerning the limited production of some of these metabolites in the plants, these medicinal compounds can be produced naturally and commercially with the identification and transfer of alkaloids-producing enzymes corresponding plant genes to the microorganisms as an alternative method. In this way, the characterization of the corresponding genes is the first step. Among the different enzymes involved in the alkaloid biosynthesis, the cytochrome P450 enzymes play an important role. Due to the endoplasmic reticulum (ER) localization of these enzymes and their glycoprotein characters, they cannot be expressed functionally in the standard bacterial systems. Consequently, the heterologous expression aimed to verify the enzymatic activity can favorably be performed using the eukaryotic systems, like yeast or insect cells. Herein, in this study, with employing a phylogenic comparison of cheilanthifoline synthase sequence of Eschscholzia californica Cham. and comparing the sequence with the homolog amino acid sequences of Chelidonium majus L. achieved from bioinformatics databases, six cytochrome P450 enzymes responsible for cheilanthifoline synthase in Ch. majus were identified. To prove the efficacy of these enzymes practically, their genes were cloned into the pPIC3.5 vector. Then, these recombinant vectors were transferred to the yeast cell (Pichia pastoris) and the scoulerine alkaloid was given to its media. Finally, the cheilanthifoline alkaloid microbial production by P. pastoris containing the recombinant plasmids was evaluated by LC-MS. The results of the present study indicated that among the enzymes genes cloned and introduced to the yeast host, only the Contig8931 enzyme had the cheilanthifoline synthase activity.
M. Mahboubi; M.M. Feizabadi; Gh. Haghi; H. Hosseini
Volume 24, Issue 1 , May 2008, , Pages 56-65
Abstract
Oliveria decumbens Vent. (Umbelliferae) is a shrub commonly found in the South East of Iran. Its aerial part is extensively used in herbal medicine. In this study, the antimicrobial activity of O. decumbens essential oil extracted from aerial parts of plant against a panel of microorganisms including ...
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Oliveria decumbens Vent. (Umbelliferae) is a shrub commonly found in the South East of Iran. Its aerial part is extensively used in herbal medicine. In this study, the antimicrobial activity of O. decumbens essential oil extracted from aerial parts of plant against a panel of microorganisms including gram positive, gram negative bacteria, yeast and fungi were assessed by disc diffusion method and micro broth dilution assay. The chemical constitutes of this oil was analyzed by GC. The main components of essential oil are thymol (26.9%), carvacrol (0.25%), p-cymene (13.3%) and γ-terpinene (11%). This oil exhibited strong antifungal activity against filamentous fungi and yeast with average of inhibition zone (AIZ) 34.86 and MIC≤0.25µl ml -1. The effect of 2 µl of essential oil (IZ≥27.3 mm) is larger than Amphotricin B (IZ≤17) against fungi. The gram positive bacteria are more sensitive than gram-negative bacteria (21.9 Vs 18.4). Spore forming bacteria (Bacillus sp.) are resistant to essential oil and the effect of oil against Bacillus sp. had inhibitory effect (MIC>2 µl ml-1). Pseudomonas aeruginosa were more resistant than others (IZO. decumbens oil, i.e. bacteria are more resistant than fungi and gram negative bacteria are more resistant than gram positive bacteria. These effects are more concerned to phenol components especially thymol. Therefore, further studies are required to evaluate in vivo efficacy.
