Bioactive Natural Products from Plants and Biotechnological Approaches for their Production

Bioactive natural products are economically important as drugs, fragrances, pigments, food additives and pesticides. The biotechnological tools are important to select, multiply, improve and analyze medicinal plants for production of such products. The utilization of medicinal plant cells for the production of natural or recombinant compounds of commercial interest has gained increasing attention over the past decades. Plant tissue culture systems are possible source of valuable medicinal compounds, fragrances and colorants, which cannot be produced by microbial cells or chemical synthesis. In vitro production of bioactive natural products in plant cell suspension culture has been reported from various medicinal plants and bioreactors are the key step towards commercial production. Genetic transformation is a powerful tool for enhancing the productivity of novel products; especially by Agrobacterium tumefacians. Combinatorial biosynthesis is another approach in the generation of novel natural products and for the production of rare and expensive natural products. Recent advances in the molecular biology, enzymology and bioreactor technology of plant cell culture suggest that these systems may become a viable source of important secondary metabolites. Genetic fingerprinting could be a powerful tool in the field of medicinal plants to be used for correct germplasm identification. In addition, when linked to emerging tools such as metabolomics and proteomics, providing fingerprints of the plant's metabolites or protein composition, it gives data on phenotypic variation, caused by growth conditions or environmental factors, and also yield data on the genes involved in the biosynthesis. DNA profiling techniques like DNA microarrays serve as suitable high throughput tools for the simultaneous analysis of multiple genes and analysis of gene expression that becomes necessary for providing clues about regulatory mechanisms, biochemical pathways and broader cellular functions. New and powerful tools in functional genomics can be used in combination with metabolomics to elucidate biosynthetic pathways of natural products

Synthesis of enantiomerically enriched benzimidazole-triazoles: Application as organocatalyst for asymmertric Diels-Alder reaction

93-1014-(Benzimidazolylmethyl)-1,2,3-triazole derivatives 8a-g and 9a-g have been developed using click chemistry protocol in regioselective manner and in high yields. These compounds have geometry to behave as chiral tweezers due to the presence of flexibly bound pi-rich hetero-aryl rings in addition to a chiral center. The synthesized chiral benzimidazole-triazoles have been found to be useful as organocatalysts for the enantioselective Diels-Alder (DA) reaction between anthrone 10 and maleimide detivatives 11a-g. Enantioselectivity levels have been found to be dependent on several factors including nature of substituents in benzimidazole-triazoles 8a-g and 9a-g

Diversity of halophilic bacteria and actinobacteria from India and their biotechnological applications

1575-1587This review summarizes the current diversity of halophilic bacteria and actinobacteria from Indian coastal region, salt lakes and their use in various biotechnological applications, including industrial, pharmaceutical, agricultural and environmental aspects. Culture dependent as well as culture independent methods for isolation of halophiles should go hand in hand to provide the insight mechanism of halophilic adaptation and their future applications

A convenient route to benzimidazole fused chiral heterocyclic bases

707-712<span style="font-size:11.0pt;font-family: " times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">An efficient synthetic protocol has been developed to obtain new chiral heterocyclic bases pyrrolo-benzimidazoles (DHP-Bz) and thiazolo-benzimidazoles (DHT-Bz). Notable characteristic of both series of the fused heterocycles is the presence of a chiral center. Chiral HPLC separations of the fused heterocycles have been achieved. These molecules possess structural features well-suited to function as chiral organocatalysts after resolution, apart from potential biological activities.</span

Cell Suspension Culture and In Vitro Screening for Drought Tolerance in Soybean Using Poly-Ethylene Glycol

Soybean (Glycine max (L) Merrill) is used in India mostly as a substantial fund of protein and oil, which makes the crop significantly important. Somaclonal variation has been researched as a base of additional variability for drought in soybean. In the present experiment calli/cell clumps/embryoids rose from immature and mature embryonic axis and cotyledons explants were exposed to different concentrations of polyethylene glycol (PEG6000). A discontinuous method proved to be superior as it permitted the calli/embryoids/cell clumps to regain their regeneration competence. A total of 64 (12.21%) plantlets of genotype JS335 and 78 (13.13%) of genotype JS93-05 were regenerated after four consequent subcultures on the selection medium with an effective lethal concentration of 20% PEG6000, and proliferated calli/embryoids/cell clumps were further subcultured on Murashige and Skoog regeneration medium supplemented with 0.5 mgL−1 each of α-napthalene acetic acid (NAA), 6-benzyladenine (BA) and Kinetin (Kn), 20.0 gL−1 sucrose and 7.5 gL−1 agar. Putative drought-tolerant plantlets were acquired from genotype JS93-05 (38) in more numbers compared to genotype JS335 (26). Random decamer primers confirmed the presence of variability between mother plants and regenerated plants from both the genotypes. Since these plantlets recovered from tolerant calli/embryoids/cell clumps selected from the medium supplemented with PEG6000, the possibility exists that these plants may prove to be tolerant against drought stress

Screening and Selection of Drought-Tolerant High-Yielding Chickpea Genotypes Based on Physio-Biochemical Selection Indices and Yield Trials

Chickpea production is seriously hampered by drought stress, which could be a great threat in the future for food security in developing countries. The present investigation aimed to screen the drought-tolerant response of forty desi chickpea genotypes against drought stress through various physio-biochemical selection indices and yield-attributing traits. Principle component-based biplot analysis recognized PG205, JG2016-44, JG63, and JG24 as tolerant genotypes based on physiological selection indices. These genotypes retained higher relative water content, stomatal conductance, internal CO2 concentration, and photosynthetic rate. ICC4958, JG11, JAKI9218, JG16, JG63, and PG205 were selected as tolerant genotypes based on biochemical selection indices. These genotypes sustained higher chlorophyll, sugar and proline content with enhanced antioxidant enzyme activities. With respect to yield trials, JAKI9218, JG11, JG16, and ICC4958 had higher seed yield per plant, numbers of pods, and biological yield per plant. Finally, JG11, JAKI9218, ICC4958, JG16, JG63, and PG205 were selected as tolerant genotypes based on cumulative physio-biochemical selection indices and yield response. These identified drought-tolerant genotypes may be further employed in climate-smart chickpea breeding programs for sustainable production under a changing climate scenario

Optimization of Different Factors for Initiation of Somatic Embryogenesis in Suspension Cultures in Sandalwood (Santalum album L.)

Santalum album (L.) is a prized tropical tree species of high therapeutic and industrial importance. The wood of these naturally grown plants is extensively harvested to acquire therapeutically important metabolite santalol and be used for additional functions such as in wood statuette industries. Due to high demand, it is crucial to maintain a sufficient plant population. An easy protocol for establishing cell suspension culture initiated from the loose embryogenic callus mass of sandalwood was realized by shifting 6–8-week-old morphogenic calli acquired from the mature embryonic axis and cotyledon explant cultures in fluid media. The asynchronous embryogenic cultures were sloughed with clumps of flourishing cell clumps and embryos of various progressive phases along with diffident non-embryogenic tissues. The frequency of embryo proliferation was evidenced to determinethe expansion pace of embryogenic masses under diverse conditions. The intonation of initiation and creation of cell suspension was under the directive of the influence of exogenous plant growth regulators amended in the nutrient medium at different concentrations and combinations. Maximum relative growth rate (386%) and clumps/embryoids in elevated integers (321.44) were accomplished on MS nutrient medium fortified with 2.0 mg L−1 2,4-D in association with 0.5 mg L−1 BA and 30.0 g L−1 sucrose raised from mature embryonic axis-derived calli. Plantlet regeneration in higher frequency (84.43%) was evidenced on MS medium amended with 1.0 mg L−1 each of TDZ and GA3 in conjunction with 0.5 mg L−1 NAA and 20.0 g L−1 sucrose. Mature embryonic axis-derived calli were found to be constantly better than mature cotyledon-derived calli for raising profitable and reproducible cell suspension cultures. Regenerants displayed normal growth and morphology and were founded successfully in the external environment after hardening

Prioritization of Physio-Biochemical Selection Indices and Yield-Attributing Traits toward the Acquisition of Drought Tolerance in Chickpea (<i>Cicer arietinum</i> L.)

Chickpea is widely grown in rainfed areas of developing countries because of its nutritional abundance and adaptability. To overcome the environmental effect of drought on yield, a characteristic-linked selection strategy is proved as well-thought-out and advantageous for the development of drought-tolerant cultivars. To precisely understand the contribution of various physio-biochemical and yield-attributing traits toward drought tolerance in chickpea (Cicer arietinum L.), forty chickpea genotypes were evaluated in the years 2020–2021 and 2021–2022 under normal irrigated as well as drought-stressed conditions. Among the studied genotypes, genotype ICC4958 retained the highest chl content (0.55 mg g−1 FW), minimal electrolyte leakage, and superoxide dismutase (1.48 U/mg FW) and peroxidase (2.21 µmol/min/g FW) activities while cultivar JG11 maintained the maximum relative water content and proline accumulation. The principal-component-based biplots prioritized the physio-biochemical and yield-accrediting characteristics based on their association significance and contribution to terminal drought tolerance. Under drought stress, grain yield per plant was depicted to have a strongly positive association with canopy temperature depression, catalase, superoxide dismutase, and peroxidase activities as well as total soluble sugar, proline, and chlorophyll content, along with the numbers of pods and biological yield per plant. These identified physio-biochemical and yield-attributing traits can be further deployed to select drought-tolerant chickpea genotypes for the breeding of climate-smart chickpea genotypes