Ali Movafeghi

Phytoremediation potential of duckweed (Lemna minor L.) in degradation of C.I. Acid Blue 92: Artificial neural network modeling

In present study, the potential of duckweed (Lemna minor L.) for degradation of an azo dye C.I. Acid Blue 92 (AB92) has been investigated. The effect of operational parameters such as initial dye concentration, pH, temperature and amount of plant on the efficiency of biological decolorization process was determined. The reusability of Lemna minor L. in long term repetitive operations was also examined. Growth and some biochemical parameters (photosynthetic pigments content, superoxide dismutase, catalase and peroxidase activity) were used to detect the toxic effects of AB92 on duckweed plant. The biological degradation compounds formed in the present process were analyzed by GC-MS technique. In addition, an artificial neural network (ANN) model was expanded to predict the biological decolorization efficiency. The obtained data indicated that ANN provide realistic predictive performance (R(2)=0.954).

Bioprocess engineering of Echium italicum L.: induction of shikonin and alkannin derivatives by two-liquid-phase suspension cultures

An in vitro cell suspension culture of Echium italicum was established and assayed for the production of shikonin and alkannin derivatives. Callus tissues were induced from cotyledon explants of the plant incubated onto the solidified B5 medium. A two-liquid-phase system suspension culture was then established to elicit pigments of shikonin and alkannin derivatives using liquid paraffin. The presence of liquid paraffin efficiently induced production of pigments in cultured cells. The production and/or accumulation of these compounds in the E. italicum cells was examined using fluorescence microscopy as the naphthoquinone molecules display autofluorescent properties. Phytochemical analysis of the n-hexane extract of the medium was also carried out using preparative HPLC. The chemical structure of shikonin and alkannin derivatives were characterized by UV, 1H-NMR, and 13C-NMR techniques. Based on our findings, this bioprocess engineering approach resulted in induction of shikonin and alkannin derivatives, whereupon it may be recruited for production of these important secondary metabolites.

Cycloartane-type glycosides from the roots of Astragalus caspicus Bieb.

Two new cycloartane-type glycosides, caspicuside I and caspicuside II, were isolated along with two known saponins, cycloastragenol and astragaloside IV, from the roots of Astragalus caspicus. As the aglycon group, caspicuside I possesses 3β,6α,16β,(24S),25-pentahydroxycycloartane (cyclocanthagenol), while caspicuside II owns (20R, 24S)-epoxy-3β, 6α,16β, 25-tetrahydroxycycloartane (cycloastragenol). The chemical structures of these new cycloartane-type glycosides were established as 3-O-α-L-rhamnopyranosyl-16-O-β-D-xylopyranosyl-cyclocanthogenol and 3-O-[β-D-xylopyranosyl(1 → 3)-β-D-glucopyranosyl]-6-O-β-xylopyranosyl-cycloastragenol, respectively. These findings add to a growing body of literature demonstrating the high variation of cycloartane-type triterpene glycosides in different species of Astragalus.

Floral ontogeny in Astragalus compactus (Leguminosae: Papilionoideae: Galegeae): variable occurrence of bracteoles and variable patterns of sepal initiation

Comparative studies of floral ontogeny represent a growing field that promise to provide new insights on floral evolution. Floral ontogenetic information has been used successfully in Leguminosae for re-examining phylogenetic relationships at different levels. Using epi-illumination light microscopy, we present original ontogenetic data in Astragalus compactus, which was chosen because of its unusual arrangement of inflorescence and variable occurrence of bracteoles on flowers. Based on our results, uncommon ontogeny of the inflorescence led to the arrangement of flowers in four different positions. Variation was observed not only in the presence of bracteoles, but also in the order of sepal initiation in flowers of the same inflorescence. Surprisingly, besides the widely stated unidirectional pattern, bidirectional, sequential and an atypical unreported order were observed. High degree of overlapping between whorls and formation of two types of common primordia also were found. The variable occurrence of bracteoles suggests that the species is in an intermediate state towards fully lacking of bracteoles. We propose that the variability of the sequence of sepal initiation is possibly a consequence of the function of mechanical forces generated by surrounding leaves. Relationships between mechanical force and auxin signalling are discussed.

Determination of floral initiation in Malus domestica: a novel morphogenetic approach

Floral initiation in apple (Malus domestica Borkh) was studied by a novel morphogenetic approach. Developmental stages of apices were evaluated based on the morphology of shoot apical meristem (SAM) from various collection dates. Besides, the frequency of each stage was calculated within apices populations after full blooming (DAFB). Prior to doming of apex, three marked phases were found based on SAM morphology: 1) narrow appearance (vegetative phase), 2) broadened form (transition phase), and 3) prominent shape (commitment phase). A furrow region was formed at the base of leaf primordium during the bract initiation, while significant broadening of SAM was observed. Cell division patterns manifested in modification of anisotropic clusters from isotropic cellular packets, as a result of which profound morphological changes of apices occurred. Based on these findings, we propose that the structural alterations prior to doming may be taken into account for determination of the initial development and reproduction signs in apple trees.

Identification of volatile organic compounds in leaves, roots and gum of Astragalus compactus Lam. using solid phase microextraction followed by GC-MS analysis

A solid phase microextraction sampling method using pencil-lead fibre coupled with gas chromatography-mass spectrometry was used to monitor the organic volatile compounds of the roots, leaves and gum of Astragalus compactus. Under optimised conditions, a range of volatile compounds were recognised in different parts of A. compactus. Based on the results obtained, the nature and level of the volatiles vary in distinct parts of the plant. In comparison with other Astragalus species investigated, only one volatile organochlorine compound, tetradecane,1-chloro, was identified in roots. Intriguingly, the toxic chlorinated component was not detectable in the gum samples. These findings highlight the higher quality of the gum of A. compactus compared to the gums of some other Astragalus species, which are reported to be contaminated with chlorinated components.

Biotechnological Production of Plant Secondary Metabolites

Description: Modern techniques have been developed to overcome problems associated with the extraction of natural products from plants. These techniques include production of secondary metabolites by biotechnological methods such as plant tissue culture and microbial biotransformation of natural substances. Such methods have led to an increased yield of secondary metabolite amount, the discovery of new biochemical derivatives and agricultural development. For instance, use of these techniques in agricultural area have led to some beneficial traits such as formation of new varieties of known plant species, better crop quality, higher yield, better nutritive properties, more resistant species to insects and pests. Microbial biotransformation is beneficial in plant secondary metabolite production and derivatization (chemical modification of any compound made by a microorganism) and is chiefly applicable to several varieties of terpenes and steroids. This E-book demonstrates recent developments in this field. It will be of particular interest to the professionals in pharmaceutical and biotechnological industries, as well as natural product chemists, medicinal chemists, plant biochemists, and molecular biologists.

Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks

The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC–MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L−1) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes.

Potential of Hydrocotyle vulgaris for phytoremediation of a textile dye: Inducing antioxidant response in roots and leaves

The potential of Hydrocotyle vulgaris as an aquatic plant species was evaluated for phytoremediation of C.I. Basic Red 46 (BR46) from nutrient solution. Under the optimized experimental conditions, BR46 was removed up to 95% from incubation medium by H. vulgaris. The ability of the plant in consecutive removal under long term repetitive experiments confirmed the biodegradation process. Accordingly, a number of produced intermediate compounds were identified. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. A predictive performance (R(2)=0.974) was obtained based on the network results. Interestingly, dye stress enhanced the activity of antioxidant enzymes including superoxide dismutase, peroxidase and catalase in H. vulgaris roots and leaves. Enzymatic responses found to be highly depended on the plant organ and dye concentration in the liquid medium. Overall, the increase in the activity of antioxidant enzymes was much higher in the roots than in the leaves. Nevertheless, no significant increase in the malondialdehyde (MDA) content was detected in both roots and leaves which reflects the high efficiency of antioxidant system in the elimination of reactive oxygen species.

Callus culture of Echium italicum L. towards production of a shikonin derivative.

Callus induction and proliferation of Echium italicum L. (Boraginaceae) were investigated using cotyledon, hypocotyl and root explants. Calli were initiated and established using B5, LS, 1/2LS and White media supplemented with different auxins, including 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA) and 1-naphthaleneacetic acid (NAA) in combination with kinetin. The maximum pigmented callus induction (100%) was observed in the White medium. The n-hexane extract of proliferated callus tissues were analysed by TLC and HPLC. The major secondary metabolite was separated by preparative HPLC and its structure was elucidated by UV, 1H and 13C-NMR spectroscopy. As a result, shikonin acetate was identified by various spectroscopic methods from callus culture of E. italicum. These findings highlight the shikonin production potential of the E. italicum callus, which may be considered as a new source for the production of shikonin and its derivatives for industrial use.