Dr. S. N. Moorthy - Research - Dr. S. N. Moorthy

A Convenient Route to Medium-ring Trisubstituted cis-Olefins from Allenes

The selective introduction of a trisusbstituted carbon-carbon double bond with a specific configuration is still an interesting problem to organic chemists, although several methods have been documented in the literature1-4. The sodium/ammonia reduction of allenes, in combination with an elegant synthesis of allenes has proven to be useful in synthesizing a homologue of an olefin or a diene in good yield 5-11. In this communication, we report a further extension of this general method to provide a new and a convenient procedure to synthesize medium-ring (9 and 10 membered) tri-alkyl-substituted cis-olefins

The Effect of Low Levels of Antioxidants on the Swelling and Solubility of Cassava Starch

The addition of low levels of sodium sulphite had a dramatic effect on the structure of cassava (Manihot esculenta Crantz) starch pasted at 95oC. Inclusion of 100 ppm sulphite promoted granule disintegration resulting in a reduction in measured swelling volume to nearly 10% of its value in the absence of sulphite and release of almost all the carbohydrates from the starch granukle. It is suggested that sulphite addition promotes oxidative reductive depolymerization (ORD) of the polysaccharides since its effect on the granules is prevented when lower levels (around 20 ppm) of the polar antioxidant propyl gallate are added. Possible practical applications of the results and implications for the understanding of starch granule structure are discussed

Stereoselective Partial Hydrogenation of Allenes by Diimide in situ

Both cyclic and acyclic allenes have been hydrogenated by diimide formed in situ by oxidation of hydrazine by hydrogen peroxide as well as oxygen gas, to olefins in which the double bounds are found to have cis geometry. Terminal allenes give 2-alkenes. Both observations have been explained by the approach of diimide from the least hindered side of allenic bond. It is also noted that allenic bond is more reactive towards diimide than the olefinic double bond is. The efficiency of reduction increases as the degree of allenic substitution and the ring size of the cyclic allene decrease

Variability in starch extracted from taro

Starch was extracted from ten cultivars of taro and various physiochemical properties were determined. The granule size was found to vary considerably among the different accessions, C-9 starch having the largest average granule size (5.19 µm) while the lowest was recorded for C-46 (2.96 µm). the total amylose content varied between 14 and 19% C-9 starch having the highest value. Soluble amylose content ranged from 4 to 11%. Although there was not much difference between varieties in the 2% viscosity determined using a Redwood viscometer, the Brabender viscosity patterns showed considerable variation, and C-9 starch had the highest peak viscosity, almost twice as much as the others. The swelling volumes ranged from 25.0 to 60.0 ml g-1 with C-266 starch having the highest swelling volume

Stereochemistry & Mechanism of Birch Reduction of Cyclic Allenes

The sodium-ammonia reductions of 1,2-cyclononadiene, 1,2-cyclodecadiene, 1,2-cyclodecadiene, 1,2-cyclodecadiene , 1,2-cyclodecadiene, 1,2-cyclodecadiene , 1-methyl-1,2-cyclodecadiene, 1-methyl-1,2-cyclodecadiene and 1-methyl-1,2-cyclodecadiene have been described. All the cyclic allenes get reduced smoothly t o give good yields of olefinic product(s). Analysis of the products after partial reduction, use of lithium instead of sodium and the relative rates of reduction of cyclic allenes and acetylenes rule out the possibility of the rearrangement of cyclic allenes to acetylenes before reduction. From the ratios of cis to trans olefins obtained in the presence and absence of a proton donor, potential routes for the formation of isometric olefins have been proposed. The synthetic utility of this reduction procedure is borne out in the reduction of some trisubstituted cyclic allenes which offers a convenient stereoselective synthesis of C9?, C10?and C13? trisubstituted cyclic olefins

Functional Properties of the Starchy Flour Extracted from Cassava on Fermentation with a Mixed Culture Inoculum

The fundamental properties of the starchy flour extracted from six varieties of cassava subjected to fermentation by a mixed culture inoculum comprised of lactobacilli, streptococci, corynebacteria and yeast cells are examined. Apparent reduction in total and soluble amylose contents is observed. Differential scanning calorimetry of the samples indicated that the enthalpy of gelatinisation was reduced, while gelatinisation temperature was enhanced. A marked reduction in Brabender viscosity values of starch from fermented tuber was observed, but the X-ray diffraction pattern was unaffected. All these changes were attributed to the presence of fibrous material and consequent reduction of starch in unit volume rather than any change un the starch granule structure.

Effect of Pretreatment of Fresh Amorphophallus paeoniifolius on Physicocochemical Properties of Scratch

Fresh roots of Amorphophallus paeoniifolius were separately pretreated with sodium hexametaphosphate (SHMP), potassium metabisulphite (KMS), sodium chloride (NaCL), and ammonium hydroxide (NH4OH) within a range of 1-5% (w/v) concentration and glyceryl monosterate (GMS) at 0.025-0.125% concentration. The quality of starch extracted from pretreated roots was compared with that obtained from fresh roots by direct aqueous extraction. The starch samples prepared from chemically pretreated roots showed characteristic changes in properties of water soluble amylase content, swelling and solubility and Î¬-amylase susceptibility. X-ray diffraction of starch samples from chemically pretreated roots although resembled that of control, there was noticeable shift with respect to their’d’ spacing and Io/Imax values

Cassava Fermentation and Associated Changes in Physicochemical and Functional Properties

Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variation in the artisanal processes followed in the preparation of these products. It also stresses the need for systematic study of not only the quoted products, but also a number of other fermented cassava products and have not been well documented.

Variation in Properties of Starch in Cassava Varieties in Relation to Age of the Crop

Cassava starch extracted from six varieties at different period of growth was examined for various physicochemical properties. The granule size increased in all the six varieties upto 6th month from time of tuber initiation and thereafter remained almost constant. The amylase content and reducing values did not vary much at different stages of growth. The swelling volume and swelling power of starch showed large variations particularly after 10th month. Such changes of four varieties were not noticed in other varieties. Associative binding forces of starch molecules largely determine the stability characteristics of starch under varied environmental conditions