The terpenoids constitute the largest class of natural products and many interesting products are extensively applied in the industrial sector as flavors, fragrances, spices and are also used in perfumery and cosmetics. Many terpenoids have biological activities and also used for medical purposes. In higher plants, the conventional acetate-mevalonic acid pathway operates mainly in the cytosol and mitochondria and synthesizes sterols, sesquiterpenes and ubiquinones mainly. In the plastid, the non-mevalonic acid pathway takes place and synthesizes hemi-, mono-, sesqui-, and diterpenes along with carotenoids and phytol tail of chlorophyll. In this review paper, recent developments in the biosynthesis of terpenoids, indepth description of terpene synthases and their phylogenetic analysis, regulation of terpene biosynthesis as well as updates of terpenes which have entered in the clinical studies are reviewed thoroughly.
The secreted proteomes of a three week old culture of an Indian (190/96) and a German (DAYA) Aspergillus fumigatus isolate were investigated for reactivity with IgG and/or IgE antibodies derived from pooled allergic broncho-pulmonary aspergillosis (ABPA) patients' sera. Two dimensional Western blotting followed by mass spectrometric analysis of the reactive protein spots revealed 35 proteins from the two A. fumigatus strains. There were seven known A. fumigatus allergens among them (Asp f1-4, Asp f9, Asp f10, and Asp f13/15), whereas three proteins displaying significant sequence similarity to known fungal allergens have been assigned as predicted allergens (Dipeptidyl-peptidase-V precursor, Nuclear transport factor 2, and Malate dehydrogenase, NAD-dependent). Eight IgG and IgE reactive proteins were common in both strains; however, 12 proteins specifically reacted in 190/96 and 15 in DAYA. Further testing with sera of 5 individual ABPA patients demonstrated that 12 out of 20 immunoreactive proteins of 190/96 strain of A. fumigatus had consistent reactivity with IgE. Seven of these proteins reacted with IgG also. The 25 of 35 identified proteins are novel with respect to immuno-reactivity with ABPA patients' sera and could form a panel of molecules to improve the currently existing less-sensitive diagnostic methods. Through expressing recombinantly, these proteins may also serve as a tool in desensibilization strategies.
Aspergillus fumigatus is the common cause of allergic broncho-pulmonary aspergillosis (ABPA) and most of the allergens have been described from its secreted fraction. In the present investigation, germinating conidial cytosolic proteins of A. fumigatus were extracted from a 16 h culture. The proteome from this fraction was developed, and immuno-blots were generated using pooled ABPA patients' sera. Well separated Immunoglobulin-E (IgE) and Immunoglobulin-G (IgG) reactive spots were picked from corresponding 2DE gels and subjected to mass spectrometric analysis. As a result, 66 immuno-reactive proteins were identified from two geographically different strains (190/96 and DAYA) of A. fumigatus. Only 3 out of 66 proteins reacted with IgG, and the remaining 63 proteins were found to be IgE reactive. These 63 IgE-reactive cytosolic proteins from germinating conidia included 2 already known (Asp f12 and Asp f22) and 4 predicted allergens (Hsp88, Hsp70, malate dehydrogenase, and alcohol dehydrogenase) based on their homology with other known fungal allergens. In view of this, the panel of presently identified IgE-reactive novel proteins holds the potential of providing a basis for the wider diagnostic application in assay for allergic aspergillosis. We could demonstrate that recombinantly expressed proteins from this panel showed consistent reactivity with IgE of individual sera of ABPA patients. The recombinantly expressed proteins may also be useful in desensitization therapy of allergic disorders including ABPA.
Histopathological studies of the hepatic tissues of Wistar rats treated with diethylnitrosamine (DEN) (200 mg/kg b wt, i.p.) once a week for 2 weeks, followed by treatment with DDT, a tumor promoter (0.05% in diet) for 2 weeks and kept under observation for another 18 weeks, demonstrated the development of malignancy. Pretreatment of Wistar rats with the aqueous extract of the roots of Asparagus racemosus prevented the incidence of hepatocarcinogenesis. Immunohistochemical staining of the hepatic tissues of rats treated with DEN showed the presence of p53+ foci (clusters of cells expressing the mutated p53 protein), whereas an absence of p53+ foci was observed in Wistar rats pretreated with the aqueous extract of the roots of Asparagus racemosus. The microsections of the hepatic tissue of rats treated with DEN followed by treatment with the aqueous extract of Asparagus racemosus showed an absence of p53+ foci. The results of the biochemical determinations also show that pretreatment of Wistar rats with the aqueous extract of Asparagus racemosus leads to the amelioration of oxidative stress and hepatotoxicity brought about by treatment with DEN. These results prove that the aqueous extract of the roots of Asparagus racemosus has the potential to act as an effective formulation to prevent hepatocarcinogenesis induced by treatment with DEN.
A synthetic coumarin, N,N,N-triethyl-11-(4-methyl-2-oxo-2H-chromen-7-yloxy)-11-oxoundecan-1-aminium bromide (SCD-1), having potent activity against pathogenic Aspergilli (MIC90 15.62 μg/mL), was investigated to identify its molecular targets in the pathogen. The proteome of Aspergillus fumigatus was developed after treatment with sublethal doses of compound and analyzed. The results demonstrated 143 differentially expressed proteins on treatment with SCD-1. The expression of four proteins, namely cell division control protein, ubiquitin-like activating enzyme, vacuolar ATP synthase catalytic subunit A, and UTP-glucose-1-phosphate uridylyltransferase of A. fumigatus, was completely inhibited, whereas there were 13 newly expressed and 96 overexpressed proteins, mainly belonging to stress pathway. The treatment of A. fumigatus with SCD-1 also led to attenuation of proteins involved in cell replication and other important biosynthetic processes, including riboflavin biosynthesis, which has been pathogen-specific. In addition to key enzymatic players and antioxidants, nine hypothetical proteins were also identified, seven of which have been novel, being described for the first time. As no cellular functions have yet been described for these hypothetical proteins, their alteration in response to SCD-1 provides significant information about their putative roles in pathogen defense.
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