Growth inhibition ofMusca domestica L. andCulex quinquefasciatus (say) by (−)-3-epicaryoptin isolated from leaves ofClerodendron inerme (Gaertn) (Verbenaceae)

The petroleum ether extract ofClerodendron inerme leaves afforded a compound that matched the clerodane compound (–)-3-epicaryoptin in physical and spectral characteristics. The test compound inhibited the development ofMusca domestica andCulex quinquefasciatus larvae. First- and third-instar fly larvae reared on 3-epicaryoptin-treated diet pupariated later and earlier than their respective controls and adult emergence from puparia was inhibited. Apart from larval mortality, exposure of fourth-instar mosquito larvae to 3-epicaryoptin resulted in death at larval-pupal molt and pupaladult eclosion, indicating inhibition of the molting process.     

Rheological studies on Streptomyces fradiae ScF-5 in submerged fermentation

Studies on the rheology of Streptomyces fradiae ScF-5 in a 10-dm³ submerged fermenter for the production of intracellular glucose isomerase revealed that the apparent viscosity of the broth increased with increase in cell density up to 24 h and then declined while the density of the broth remained constant. The plot of shear stress versus shear rate at various fermentation periods showed the applicability of the Casson model. The yield stress and consistency index were found to increase gradually then decrease subsequently. In contrast, the flow behaviour index was less than unity and remained constant throughout the fermentation. The results contrast with the findings of other workers on the Newtonian and non-Newtonian character of fermentation broths and the applicability of the power law model to such systems.     

Length scale dependent deformation in natural rubber

Strong length scale dependent deformation has been previously observed in the elastomer polydimethylsiloxane by indentation type experiments at micro‐ to nanometer length scales with a sharp conical tip. To examine if other nonsilicone based elastomers exhibit similar length scale dependent deformation behavior, natural rubber has been chosen in this study. Performing indentation type tests with a nanoindentation system, the universal hardness and the elastic modulus are determined at different probing depths ranging from about 90 to 5 μm to characterize length scale dependent deformation behavior in natural rubber. The testing with a Berkovich tip resulted in an amazing increase in the universal hardness with decreasing probing depth indicating that the deformation mechanisms at the micrometer length scales are significantly different as compared to those at the macroscopic length scales. The observed length scale dependent deformation is associated with an increase in rotation gradients with decreasing probing depth. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42683.     

Short chain xylooligosaccharides: a potential prebiotic used to improve batter fermentation and its effect on the quality attributes of idli,a cereal–legume‐based Indian traditional food

Xylooligosaccharides (XOS), a potential prebiotic exhibits important technological characteristics and interesting nutritional properties. The major fraction in XOS produced enzymatically from corncob was characterised as β‐d ‐xylopyranosyl‐(1,4)‐d ‐xylanopyranose (xylobiose) using ¹³C and 2D‐HSQC NMR. The use of this XOS as a prebiotic in idli, a cereal/legume‐based fermented cake, and its effect on texture, fermentation and sensory characteristics was investigated. Idli batter was fermented with different concentrations of XOS (0, 0.2, 0.4 and 0.6% w/v) for 4–18 h conventionally. The addition of XOS markedly increased lactic acid bacteria number (9.88 ± 0.08 log cfu g^?1) which resulted in rapid reduction in pH (4.61 ± 0.03) and specific gravity after 6 h of fermentation when compared to conventional batter fermentation for 18 h without XOS (9.46 ± 0.06 log cfu g^?1). Instrumental (colour and texture) and sensory evaluation indicated that the optimum conditions were 0.4% XOS and 6 h fermentation. Idlis with XOS had higher moisture content and a softer texture. Addition of XOS benefits both fermentation and idli quality.     

Value addition to spent osmotic sugar solution (SOS) by enzymatic conversion to fructooligosaccharides (FOS), a low calorie prebiotic

Value addition of spent osmotic sugar solution (SOS) obtained after the osmotic dehydration of carrot cubes using 60 °Bx sucrose solution has been studied. Two sets of experiments, one with the use of fresh carrots in every cycle of osmotic dehydration (3 h) and in the other set, carrots of previous cycle were reused in successive cycles, were carried out. The SOS obtained in each cycle was concentrated to 60 °Bx and used in successive cycles. FOS was produced from SOS (with or without concentration) by transfructosylation reaction of fructosyl transferase enzyme produced by Aspergillus oryzae MTCC 5154 under submerged fermentation condition. An FOS yield of 50.63 ± 0.94 to 57.86 ± 0.18% was obtained in both cases, which is comparable with the literature reports. FOS produced from SOS gets enriched with leached out bioactive components of fruits and vegetables used. The β-carotene concentration was in the range of 1300.9 ± 25.1 to 2800 ± 68.3 µg/100 ml of FOS. The colour of the FOS produced was golden brown and was much more appealing than FOS produced from sucrose.Industrial relevanceThe implementation of osmotic treatment of fruits and vegetables using concentrated sugar solution presents a critical factor due to the management of spent osmotic solutions. Disposal of spent osmotic solution has severe economical, environmental and technological implications. The possibilities of reuse of SOS have been suggested. The present investigation offers a better alternative for the use of SOS for developing a technologically viable process for the production of FOS. The resulting FOS is a highly valued low calorie, non-cariogenic prebiotic with high market demand in neutraceutical food sector.     

Xylooligosaccharides (XOS) as an Emerging Prebiotic: Microbial Synthesis,Utilization, Structural Characterization,Bioactive Properties,and Applications

Abstract: Xylooligosaccharides (XOS) have great prebiotic potential and can be incorporated into many food products. XOS seem to exert their nutritional benefits in various animal species, which by definition have an intestinal tract populated by a complex, bacterial intestinal ecosystem. The production of XOS on an industrial scale is carried out from lignocellulosic materials (LCMs) rich in xylan by chemical and enzymatic methods and the latter is preferred in the food industry because of the lack of undesirable side reactions and products. The information available does not provide an exact explanation about the bioactive effects of XOS. Their fermentation results in the acidification of the colonic contents and the formation of short chain fatty acids that serve as fuels in different tissues and may play a role in the regulation of cellular processes. Only data from small trials are currently available to support use of XOS in the treatment of different clinical scenarios. Numerous questions about the molecular mechanisms of action or clinical indications of XOS and other prebiotics remain unanswered. This article presents XOS as an emerging prebiotic with more emphasis on its microbial production, structural characterization, and bioactive properties.     

Effect of Additives on Quality of Spray-Dried Fructooligosaccharide Powder

Fructooligosaccharide (FOS) finds its applications as an alternative sweetener in powder form. The effect of different process parameters (feed concentration, feed flow rate, inlet air temperature), different additives (maltodextrin, gums, starch), and anticaking agents (in different combinations and concentrations) during spray drying were investigated. FOS solution with 2% magnesium oxide as an additive gave a maximum powder yield (43% w/w), and the spray-dried powder size was fine and the texture was like talcum powder. Flow properties and microbial analysis were found to be satisfactory. The addition of anticaking agents did not have a significant effect either on the color of the powder or on FOS content, indicating good quality of the powder with respect to flowability, microbial load, and texture.     

Synthesis, structure, and antiproliferative activity of selenophenfurin, an inosine 5'-monophosphate dehydrogenase inhibitor analogue of selenazofurin

The synthesis and biological activity of selenophenfurin (5-beta-D-ribofuranosylselenophene-3-carboxamide, 1), the selenophene analogue of selenazofurin, are described. Glycosylation of ethyl selenophene-3-carboxylate (6) under stannic chloride-catalyzed conditions gave 2- and 5-glycosylated regioisomers, as a mixture of alpha- and beta-anomers, and the beta-2,5-diglycosylated derivative. Deprotected ethyl 5-beta-D-ribofuranosylselenophene-3-carboxylate (12 beta) was converted into selenophenfurin by ammonolysis. The structure of 12 beta was determined by 1H- and 13C-NMR, crystallographic, and computational studies. Selenophenfurin proved to be antiproliferative against a number of leukemia, lymphoma, and solid tumor cell lines at concentrations similar to those of selenazofurin but was more potent than the thiophene and thiazole analogues thiophenfurin and tiazofurin. Incubation of K562 cells with selenophenfurin resulted in inhibition of IMP dehydrogenase (IMPDH) (76%) and an increase in IMP pools (14.5-fold) with a concurrent decrease in GTP levels (58%). The results obtained confirm the hypothesis that the presence of heteroatoms such as S or Se in the heterocycle in position 2 with respect to the glycosidic bond is essential for both cytotoxicity and IMP dehydrogenase inhibitory activity in this type of C-nucleosides.     

Enzymatic synthesis of ethyl hexanoate by transesterification

Summary Enzymatic synthesis of ethyl hexanoate by means of an acyl transfer reaction has been studied by using an immobilized Rhizomucor miehei lipase (RML). The effect of reaction parameters on ester synthesis has been investigated. Rhizomucor miehei lipase showed more specificity than other lipases when ethyl hexanoate was synthesized in n‐hexane. Maximum ester synthesis was obtained by using a 0.5 m substrate concentration (equimolar ratio). Temperatures in the range of 45–55 °C were found to be optimum and at higher temperatures (>60 °C) deactivation of enzyme was observed. Higher molar concentrations of hexanoic acid inhibited RML, but no inhibitory effect of ethyl caprate, even at higher molar concentrations, was observed. Apparent kinetic parameters have been determined. The values are as follows: K_M (ester), 0.0135 m ; K_M (acid), 0.08466; K_i (ester), 3.07 m ; K_i (acid), 0.550 m ; V_max, 1.861 µmol min^?1 mg^?1 enzyme.