Physicochemical properties of starch obtained from Curcuma karnatakensis - A new botanical source for high amylose content.

Curcuma karnatakensis, a member of Zingiberaceae, is endemic to the state of Karnataka, India. The structure and physicochemical properties of starch isolated from rhizomatous rootstocks of two samples - A and B were analyzed for the first time. Sample A contains 76.4 ± 0.3% of starch, of which 86.6 ± 0.4% is amylose, while sample B has 75.0 ± 0.4% of starch containing 84.6 ± 0.4% of amylose according to UV-Vis spectrophotometric analysis. The shape of the starch granules in both the samples is polygonal and cuboidal with a smooth surface, as revealed by SEM studies. The X-ray diffractogram indicated A type of polymorphs in contrast to other Curcuma species, where B types are reported. Since its high amylose content leads to an increased tendency to retrogradation and the formation of resistant starch, this taxon could become one of the major dietary sources of starch in the future. In addition, a source rich in amylose specifies its prospective application in the pharmaceutical and biodegradable film industry.

Gas Chromatographic Method for the Quantitative Determination of a Hydrolytic Degradation Impurity in Busulfan Injectable Products.

An efficient and stability-indicating method has been developed and validated for the quantitative determination of tetrahydrofuran (THF), a hydrolytic degradation impurity, in Busulfan injectable pharmaceutical products by using gas chromatograph equipped with a liquid autosampler and a flame ionization detector. The chromatographic separation was performed on a fused silica capillary (Stabilwax; 60 m length × 0.32 mm i.d., 0.5 µm film thickness) column. The methodology was validated in accordance with regulatory guidelines. The proposed method was found to be specific, stable, precise, linear, accurate, robust, and rugged in the concentration range from 4 to 1,080 ppm for THF. The developed method was successfully applied to determine the THF content in Busulfan injectable pharmaceutical products.

Effect of biotic elicitors on the accumulation of bilobalide and ginkgolides in Ginkgo biloba cell cultures.

The effect of biotic elicitors on the production of bilobalide and ginkgolides in Ginkgo biloba cell suspension cultures was studied. The treatment of cell cultures with Candida albicans and Staphylococcus aureus as elicitors increased the amounts of bilobalide (BB), ginkgolide A (GA) and ginkgolide B (GB), with slight growth inhibition. The native bacterial elicitor was more effective for secondary metabolite accumulations both in cells and culture medium than autoclaved. However, exposure times of the cells to the elicitors strongly influenced the production of BB, GA and GB. This study suggests that biotic elicitors can regulate the production of BB, GA and GB either directly or indirectly. These results also describe the establishment of optimum conditions that determine the effects of biotic elicitors on secondary metabolism of bilobalides.

Biotransformation and impact of ferulic acid on phenylpropanoid and capsaicin levels in Capsicum annuum L. cv. P1482 cell suspension cultures.

Cell suspension cultures of Capsicum annuum L. cv. P1482 were fed with exogenous ferulic acid to monitor their biotransformation abilities. A portion of the ferulic acid was biotransformed into vanillin, a major natural flavor, and capsaicin, a principle secondary metabolite characteristic of Capsicum species. The cellular vanillin concentrations were relatively higher than capsaicin levels and were maximal (2 mg/g DW) 4 days after 0.6 mM ferulic acid feeding. Maximal vanillin levels in the culture medium were 10 mg/L at 4 and 3 days after feeding with 1.25 and 2.5 mM ferulic acid, respectively. With regard to capsaicin levels, the cellular levels were slightly decreased by ferulic acid feeding, whereas the levels in the culture medium were increased. Ferulic acid feeding not only enhanced vanillin and capsaicin production but also increased the concentrations of other phenylpropanoid metabolites.

Rapid in vitro adventitious shoot propagation of Scopolia parviflora through rhizome cultures for enhanced production of tropane alkaloids.

A rapid micropropagation system for Scopolia parviflora Nakai (Solanaceae), a rare medicinal plant native to Korea, was established using rhizome cultures. Shoots that originated from adventitious shoots of the rhizome were multiplied when the rhizomes were cultured on half-strength B5 liquid medium supplemented with various growth regulators. Optimum shoot multiplication was observed in half-strength B5 medium containing 3% (w/v) sucrose and 5.77 microM gibberellic acid (GA(3)). Each rhizome gave rise to an average of 12 shoots. Shoot elongation and root induction from multiple shoots occurred on growth regulator-free half-strength B5 solid medium. Healthy plantlets were transferred to a peat moss:vermiculite mixture for acclimatization, which was successful. The concentrations of tropane alkaloids, hyoscyamine and scopolamine were determined in different tissues of native growing plants, in vitro-propagated plants and acclimatized plants by high-performance liquid chromatography. The analysis revealed that the levels of hyoscyamine and scopolamine were higher in in vitro-propagated plants than in the native growing plants. When the rhizome was cut into segments and transferred to optimal culture conditions for multiple shoot propagation, only 12 weeks were required to produce a mature plant. We conclude that in vitro propagation techniques through rhizome cultures provide an efficient and rapid method for shoot propagation of S. parviflora.

Metabolism of dimethylterephthalate by Aspergillus niger.

Aspergillus niger (AG-1) metabolized dimethylterephthalate through monomethylterephthalate, terephthalate and protocatechuate. Degradation of dimethylterephthalate was followed by extraction of residual dimethylterephthalate from the spent medium. The quantitative UV analysis showed that 58% of the dimethylterephthalate supplement was taken up in 144 h. The metabolites were isolated from resting cell cultures. Thin layer chromatography analysis of the extract revealed the presence of two intermediates, monomethylterephthalate and terephthalate. Use of an inhibitor in resting cell culture experiment demonstrated the accumulation of protocatechuate. The time course of protocatechuate accumulation was also studied. Metabolites were identified by employing various physicochemical methods. Enzyme studies using cell-free extracts exhibited dimethylterephthalate esterase and protocatechuate dioxygenase activities. Protocatechuate was oxidized by the meta cleavage pathway. A tentative pathway for the degradation of DMTP has been proposed in A. niger.

Metabolic pathway of homophthalic acid in Pseudomonas alcaligenes.

A microorganism capable of degrading homophthalic acid as a sole carbon source was isolated from garden soil. The strain was identified as Pseudomonas alcaligenes. The organism degraded homophthalate by a pathway which involved phenylacetate and p-hydroxyphenylacetate as intermediates. The intermediates have been identified by physico-chemical methods. A tentative pathway for the degradation of homophthalate is proposed based on isolation of intermediates, oxygen uptake studies and presence of enzymes involved in the degradation.

Degradation of homophthalic acid byAspergillus niger.

The fungusAspergillus niger degraded homophthalic acid through the involvement ofo-hydroxyphenylacetic acid and homogentisic acid as the metabolic intermediates. Isolation of intermediates was carried out by extracting the spent medium and by using inhibitor in replacement culture techniques. Metabolites were characterized by various physicochemical methods. Oxygen uptake studies and enzyme investigations also confirmed that the degradation of homophthalic acid follows through these intermediates in the fungus.

Metabolism of benzalphthalide by Pseudomonas sp.

A Pseudomonas sp. degraded benzalphthalide to o-phthalate and benzoate. A tentative pathway for the metabolism of benzalphthalide in this Pseudomonas sp. is proposed on the basis of isolated metabolites, oxygraphic assay and enzymatic studies.