Bioconversion of eugenol into food flavouring agent vanillin

Microorganisms have the ability to chemically modify a wide variety of organic compounds by a process referred to as biological or microbial transformation, or in general, bioconversion. The microbial cells and their catalytic machinery (enzymes) accept a wide array of complex molecules as substrates, yielding products with unparallel chiral (enantio-), positional (region-) and chemical (chemo-) selectivity through various biochemical reactions. The present study was formulated on the objective of the conversion of abundantly available phytomolecules eugenol into vanillin, a compound of industrial importance, using microorganisms Aspergillus flavus, Aspergillus niger and Pseudomonas aeruginosa. These microbes were found to be capable of converting eugenol to industrially important cost-effective products, vanillin (used as flavouring agent). The results were analyzed using thin layer and gas chromatographic techniques. Our results demonstrated that A. flavus, A. niger and P. aerouginosa were able to transform eugenol to vanillin. Our findings may provide a novel approach for the production of cost-effective vanillin using microorganisms

Positive correlation between menthol content and in vitro menthol tolerance in Mentha arvensis L. cultivars

Menthol is a highly valued monoterpene produced by Japanese mint (Mentha arvensis) as a natural product with wide applications in cosmetics, confectionery, flavours, beverages and therapeutics. Selection of high menthol yielding genotypes is therefore the ultimate objective of all genetic improvement programmes in Mentha arvensis. A positive correlation was observed in the present study between menthol content in oils of evaluated genotypes and the level of tolerance to externally supplied menthol of explants of these genotypes in culture medium. The easy use of this relationship as a selectable biochemical marker opens the practical applicability of largescalein vitro screening of the germplasm, clones and breeders' material for selection of elite genotypes

Biotransformation of artemisinin mediated through fungal strains for obtaining derivatives with novel activities

Artemisinin, a sesquiterpene lactone, is the active antimalarial constituent of Artemisia annua. Several fungal strains Saccharomyces cerevisiae, Aspergillus flavus, Aspergillus niger and Picchia pastoris were used to biotransform artemisinin. Among these strains, A. flavus was the only microorganism capable of transforming artemisinin to deoxyartemisinin in higher yields than the previous reports. The structure of deoxyartemisinin was elucidated by spectroscopy. Deoxyartemisinin showed antibacterial activity against Staphylococcus aureus, S. epidermidis and S. mutans at a minimum inhibitory concentration (MIC) of 1 mg/mL compared to artemisinin whose MIC was >2 mg/mL

Isolation of poly (A⁺)<i> </i>mRNA for downstream reactions from some medicinal and aromatic plants^†

197-201In the present protocol for extraction of RNA, hexadecyltrimethylammoniumbromide (CTAB) and insoluble polyvinylpyrrolidone were used followed by LiCl precipitation, CsCl ultracentrifugation and finally poly (A+) mRNA was isolated with the help of oligo(dT)-cellulose columns. The isolated poly (A+) mRNA was found to be suitable for cDNA-AFLP and suppression subtractive hybridization applications. It is a modified and consolidated protocol based on previously described methods for isolated steps and works better for medicinal and aromatic plants. High yield of poly (A+) mRNA coupled with its amenability for downstream reactions like RT-PCR. northern blotting and cDNA synthesis for library construction is a key feature of the present protocol

Low levels of genetic diversity detected by RAPD analysis in geographically distinct accessions of Bacopa monnieri

Brahmi (Bacopa monnieri) is a traditional Indian medicinal plant known for its natural nootropic action of saponins present in large amount in its shoots. A collection of 24 B. monnieri accessions from different agro-climatic zones of India and an introduction from Malaysia maintained in the field genebank at CIMAP was analysed for RAPD variation. Among the 40 random primers tested, 29 primers generated one or more polymorphic bands. The number of polymorphic bands generated was primer dependent, ranging from 2 to maximum of 8. Similarity matrices were generated from the RAPD data on the basis of Nei's estimates of similarity indices and dendrograms were constructed based on UPGMA clustering. All the accessions were found to be in the range of 0.8-1.0 of similarity, which is indicative of a narrow genetic base among the various accessions with a medium level of polymorphism. It was possible to differentiate individual accessions, showing differences in morphological and growth properties at DNA level. The observed low levels of genetic variation were attributed to interplay of sexual and vegetative modes of reproduction and similarity of local environments in habitats of B. monnieri

Rapid isolation of DNA from dry and fresh samples of plants producing large amounts of secondary metabolites and essential oils

The presence of certain metabolites has been observed to interfere with DNA isolation procedures and downstream reactions such as DNA restriction, amplification and cloning. The chemotypic heterogeneity among species may not permit optimal DNA yields with a single protocol, and thus, even closely related species may require different isolation protocols. Here we describe the essential steps of a rapid DNA isolation protocol that can be used for diverse medicinal and aromatic plants, which produce essential oils and secondary metabolites such as alkaloids, flavanoids, phenols, gummy polysaccharides, terpenes and quinones. The procedure is applicable to dry as well as fresh plant tissues. This protocol, in our experiments, permitted isolation of DNA from tissues of diverse plant species and produced fairly good yields. The isolated DNA proved amenable to PCR amplification and restriction digestion

Antioxidant potential of the root of Vetiveria zizanioides (L.) Nash

122-125Vetiveria zizanioides, an aromatic plant commonly known as vetiver has been used for various ailments. The essential oil of vetiver root has been shown to possess antioxidant activity. However, antioxidant potential of spent root extract has not been reported. Hence, in the present study, ferric reducing, free radical scavenging and antioxidant activity of two genotypes namely KS1 and gulabi of V. zizanioides L. Nash root were investigated using in vitro assays — the ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), total phenolic content (TPC), total antioxidant capacity (TAC) and reducing power (RP). KS1 genotype showed higher FRAP values, DPPH inhibition, TPC and RP potential compared to gulabi and the antioxidant activity increased with the concentration of the extract (10-1000 µg/mL). A significant protective effect of cv KS1 (100 µg/mL) extract was also observed in reduced glutathione (GSH) and malondialdehyde (MDA) concentrations of erythrocytes subjected to oxidative stress by tert-butyl hydroperoxide (t-BHP) and hydrogen peroxide (H₂O₂). The cv KS1 showed better antioxidant activity, compared to cv gulabi indicating the possibility of exploring the presence of different phytoconstituents in the two varieties

Menthol tolerant clones of Mentha arvensis: approach for in vitro selection of menthol rich genotypes

In vitro raised shoots of Mentha arvensis L. were screened for menthol tolerance level by growing them in media containing 0-100 μg ml<SUP>−1</SUP> menthol. A total of 2850 regenerated shoots were step wise screened for menthol tolerance at the concentrations of 50 μg ml<SUP>−1</SUP> followed by 60 and 70 μg ml<SUP>−1</SUP>. In this screening, only 30 individual regenerated shoots were able to survive. The clones from the primary screen were inoculated into rooting medium and, after rooting, transferred to pots in the greenhouse. Ultimately, these 30 menthol tolerant clones were multiplied and grown in the field in replicated plots of 2.5×2.5 m sizes. Twigs of 30 clones from the replicated trials were rechecked for tolerant phenotypes at a concentration of 70 μg ml<SUP>−1</SUP> menthol wherein, these survived even after 7 days (secondary screening). These clones were checked for oil and menthol content and were found to be better than the control plants. Out of these 30 plants, five tolerated 80 μg ml<SUP>−1</SUP> menthol (tertiary level screening) and were found to contain the highest amount of menthol per g leaf biomass. Molecular analysis through RAPD showed distinct variation in the profiles of these five plants, in comparison to the control. Using this method the relationship between the primer OPT 04, menthol tolerance and high menthol content character of the genotype was established. Further, a cultivar 'Saksham' was released from the selections by CIMAP for superior performance

Expression of tropane alkaloids in the hairy root culture of Atropa acuminata substantiated by DART mass spectrometric technique

ABSTRACT: Agrobacterium rhizogenes-mediated &apos;hairy root&apos; cultures were established in Atropa acuminata. The chemical profiling of the hairy roots was carried out by a new mass spectrometric technique, direct analysis in real time (DART). The intact hairy roots were directly analyzed by holding them in the gap between the DART ion source and mass spectrometer. Two alkaloids, atropine and scopolamine, were characterized. The structural confirmation of the two alkaloids was made through their accurate molecular formula determinations. This is the first report of establishing hairy roots in A. acuminata as well as application of the DART technique for the chemical profiling of its hairy roots

An alpha-1 antitrypsin genetic variant from India

176-178The highly polymorphic human alpha-1 antitrypsin (AAT) gene codes for the most abundant circulating plasma serine protease inhibitor. Previously, genetic variants of the AAT gene were reported from different regions of the world. In the present study, the AAT gene was characterized in an Indian sample. The AAT gene was isolated and cloned from a liver biopsy sample through RT-PCR and the full-length gene was sequenced. Nucleotide sequence comparison with the human genome and the AAT sequences available in the GenBank (NCBI) demonstrated four unique variations—(i) an A to G variation at position 286 (Thr96Ala), (ii) an A to G variation at position 839 (Asp280Gly), (iii) a T to C variation at position 1182 that did not result in any change in the protein sequence (TTT to TTC both code for Phe) and (iv) an A to C variation at position 1200 (Glu400Asp) that resulted in replacement by an amino acid of similar nature. Other variations found were T to C at position 710 (Val237Ala) and T to A at position 863 (Val288Glu), which were also reported earlier. In conclusion, this study reports the entire 1257 bp nucleotide sequence of protein coding region of the human AAT gene from an Indian sample. This preliminary finding is significant, as it reports for the first time the AAT gene sequence in the Indian sample