Shagufta Kamal

Starch based polyurethanes: A critical review updating recent literature.

Recent advancements in material science and technology made it obvious that use of renewable feed stock is the need of hour. Polymer industry steadily moved to get rid of its dependence on non-renewable resources. Starch, the second largest occurring biomass (renewable) on this planet provides a cheap and eco-friendly way to form huge variety of materials on blending with other biodegradable polymers. Specific structural versatility design for individual application and tailor-made properties have established the polyurethane (PU) as an important and popular class of synthetic biodegradable polymers. Blending of starch with polyurethane is relatively a developing area in PU chemistry but with lot of attraction for researchers. Herein, various starch based polyurethane materials including blends, grafts, copolymers, composites and nano-composites, as well as the prospects and latest developments are discussed. Additionally, an overview of starch based polymeric materials, including their potential applications are presented.

Chemical Composition and in-Vitro Evaluation of the Antimicrobial and Antioxidant Activities of Essential Oils Extracted from Seven Eucalyptus Species

Eucalyptus is well reputed for its use as medicinal plant around the globe. The present study was planned to evaluate chemical composition, antimicrobial and antioxidant activity of the essential oils (EOs) extracted from seven Eucalyptus species frequently found in South East Asia (Pakistan). EOs from Eucalyptus citriodora, Eucalyptus melanophloia, Eucalyptus crebra, Eucalyptus tereticornis, Eucalyptus globulus, Eucalyptus camaldulensis and Eucalyptus microtheca were extracted from leaves through hydrodistillation. The chemical composition of the EOs was determined through GC-MS-FID analysis. The study revealed presence of 31 compounds in E. citriodora and E. melanophloia, 27 compounds in E. crebra, 24 compounds in E. tereticornis, 10 compounds in E. globulus, 13 compounds in E. camaldulensis and 12 compounds in E. microtheca. 1,8-Cineole (56.5%), α-pinene (31.4%), citrinyl acetate (13.3%), eugenol (11.8%) and terpenene-4-ol (10.2%) were the highest principal components in these EOs. E. citriodora exhibited the highest antimicrobial activity against the five microbial species tested (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Aspergillus niger and Rhizopus solani). Gram positive bacteria were found more sensitive than Gram negative bacteria to all EOs. The diphenyl-1-picrylhydazyl (DPPH) radical scavenging activity and percentage inhibition of linoleic acid oxidation were highest in E. citriodora (82.1% and 83.8%, respectively) followed by E. camaldulensis (81.9% and 83.3%, respectively). The great variation in chemical composition of EOs from Eucalyptus, highlight its potential for medicinal and nutraceutical applications.

Role of Interleukin-6 in Development of Insulin Resistance and Type 2 Diabetes Mellitus

Interleukin-6 (IL-6) is a proinflammatory cytokine that decisively induces the development of insulin resistance and pathogenesis of type 2 diabetes mellitus (T2DM) through the generation of inflammation by controlling differentiation, migration, proliferation, and cell apoptosis. The presence of IL-6 in tissues is a normal consequence, but its irregular production and long-term exposure leads to the development of inflammation, which induces insulin resistance and overt T2DM. There is a mechanistic relationship between the stimulation of IL-6 and insulin resistance. IL-6 causes insulin resistance by impairing the phosphorylation of insulin receptor and insulin receptor substrate-1 by inducing the expression of SOCS-3, a potential inhibitor of insulin signaling. In this article, we have briefly described how IL-6 induces the insulin resistance and pathogenesis of T2DM. The prevention of inflammatory disorders by blocking IL-6 and IL-6 signaling may be an effective strategy for the treatment of insulin resistance and T2DM.

Cu nanoparticles synthesis using biological molecule of P. granatum seeds extract as reducing and capping agent: Growth mechanism and photo-catalytic activity

In view of extended applications of nanoparticles, the nanoparticles synthesis is an extensive research field and green synthesis is one of the co-friendly methodologies. Plant extract mediated synthesis of nanoparticles has gained much attention in current decade. In current investigation, copper nanoparticles (CuNPs) were prepared using P. granatum seeds extract (biological molecules) from copper(II) chloride salt. The synthesized CuNPs were characterized by UV-vis spectroscopy, X-ray diffraction measurements (XRD), scanning electron microscopy (SEM), Energy Dispersive X- Ray Spectroscopy (EDX), Fourier transform infra-red spectroscopy (FTIR) and atomic force microscopy techniques. The CuNPs formation occurred through reduction of metal ions followed by nucleation. The size of the CuNPs was in the range of 40-80nm (average particle size was 43.9nm) with semi spherical shape and uniformly distribution. Photocatalytic activity was evaluated by degrading methylene blue dye (150mg/L) at various CuNPs doses (10mg/L-100mg/L). The synthesized CuNPs showed excellent PCA for the degradation of methylene blue (MB) under solar light irradiation and up to 87.11% degradation was achieved. The oxidative degradation mechanism for MB was proposed. In view of efficient PCA, the use of biological molecules of P. granatum seeds extracts for the synthesis of CuNPs.

Nickel nanoparticle synthesis using Camellia Sinensis as reducing and capping agent: Growth mechanism and photo-catalytic activity evaluation

Recently, the biosynthesis of nanoparticle attracted the attention of scientific community due to its simplicity, ease and eco-friendly nature. In the present study, Camellia Sinensis (C. Sinensis) leaves extract was employed for the synthesis of nickel nanoparticles (NiNPs). The fabricated NiNPs were characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) and X-ray diffraction techniques. The photocatalytic activity (PCA) was evaluated by degrading crystal violet (CV) dye. The NiNPs size was in the range of 43.87-48.76nm, spherical in shape and uniformly distributed with magnetization saturation of 0.073 emu/g. The NiNPs showed promising PCA under solar light irradiation. At optimized conditions, up to 99.5% CV dye degradation was achieved. Results revealed that biosynthesis can be adopted for the synthesis of NiNPs in nano-size range since it is simple, cost effective and eco-friendly in nature versus physico-chemical methods.

Extraction and quantification of phenolic compounds from Prunus armeniaca seed and their role in biotransformation of xenobiotic compounds

The current research project has been devoted to isolating new low cost and eco-friendly phenolic compounds from fruit seeds, peels and vegetables to reduce the atmospheric pollution. Natural phenolic compounds were extracted from different fruit seeds and agriculture waste: P. armeniaca, P. persica, P. domestica and Triticum aesativum. The total phenolic content was quantified, and the maximum value (1 mL extract having 1,933 μg) was found in P. armeniaca seed extract. Phytochemical screening showed that P. armeniaca seeds contain higher amount of alkaloid, tannins, saponins and flavonoid. P. armeniaca seeds enhanced the biotransformation of reactive yellow dye up to 69.89% with maximum laccase (322.45 IU/mL) production. Biodegradation of reactive yellow was only 23.34% without natural redox mediator at sixth day of incubation. Use of P. armeniaca seed stimulators resulted in maximum laccase activity (894.4 IU/mL) with 99.5% rate of removal. UV-Vis, HPLC & FTIR analysis confirmed the transformation of parent dye into various new products. Phytotoxicity study indicated 0% germination index of Avena sativa seeds with reactive yellow, whereas 83% germination index having 100% seed germination while 83% root elongation with treated sample. Thus, the study revealed that the natural phenolic compounds could serve as high potential redox mediators for enhanced laccase-mediated decolorization of reactive yellow dye.

Protein engineering: Regulatory perspectives of stearoyl CoA desaturase

Stearoyl Co A desaturase (SCD) is a rate-limiting lipogenic enzyme that plays an integral role in catalyzing the synthesis of monounsaturated fatty acids, chiefly oleate and palmitoleate. Both contribute a major part of the biological membrane. Numerous SCD isoforms exist in mouse and humans, i.e., SCD-1 to SCD-4 and SCD-1 and SCD-5, respectively. From the biological viewpoint, hyperexpression of SCD1 cause many metabolic disorders including obesity, insulin resistance, hypertension, and hypertriglyceridemia, etc. Herein, an effort has been made to highlight the value of protein engineering in controlling the SCD-1 expression with the involvement of different inhibitors as therapeutic agents. The first part of the review describes Stearoyl CoA desaturase index and different SCD isoforms. Various regulatory aspects of SCD are reviewed in four subsections, i.e., (1) hormonal regulation, (2) regulation by dietary carbohydrates, (3) regulation by green tea, and (4) regulation via polyunsaturated fatty acids (PUFAs). Moreover, the regulation of Stearoyl CoA desaturase expression in the metabolism of fats and carbohydrates is discussed. The third part mainly focuses on natural and synthetic inhibitors. Towards the end, information is also given on potential future considerations of SCD-1 inhibitors as metabolic syndrome therapeutics, yet additional work is required.

Biochemical investigation of gender-specific association between insulin resistance and inflammatory biomarkers in types 2 diabetic patients

Inflammatory mediators play a key role in the pathogenesis of type 2 diabetes mellitus (T2DM) and development of insulin resistance (IR). The purpose of the present study was to investigate the gender-specific association between serum levels of inflammatory biomarkers and development of IR in type 2 diabetic patients. We recruited 90 study participants and collected their blood samples to measure the serum level of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), insulin and glucose. We found that the serum levels of IL-6 (< 0.0001), TNF-α (< 0.0001) and CRP (< 0.0001) in type 2 diabetic patients were significantly high as compared to control participants. Moreover, we also found that in female diabetic patients, a significant association was observed between the elevated levels of IL-6 (r = 0.8819, R2 = 0.7778), TNF-α (r = 0.9833, R2 = 0.9669) and CRP (r = 0.9529, R2 = 0.9080) and increased risk of developing IR when compared with that of the serum levels of IL-6 (r = 0.7977, R2 = 0.6364), TNF-α (r = 0.9445, R2 = 0.8920) and CRP (r = 0.9051, R2 = 0.8192) of male diabetic patients. Additionally, we also found that the Body mass index (BMI) of female diabetic patients was strongly correlated (r = 0.9694, R2 = 0.9398) with the increased incidence of IR as compared to that of the BMI (r = 0.9188, R2 = 0.8442) of male diabetic patients. The key findings of present study exhibit that gender differences significantly influence the association of inflammatory biomarkers with the development of IR in T2DM.

Blends of Algae With Natural Polymers

Abstract Due to developing environmental and ecological consciousness, various end-use applications have driven the attentions of scientists to develop new innovative materials. In the recent years, natural polymers and their blends strove a considerable interest. This chapter is intended to provide a brief outline of work that covers the area of blends; major class of algal polymers, their extraction methods from algae, their blending techniques with natural polymers, as well as their properties are also emphasized. Several methods of blending are amalgamated for the enhancement of mechanical properties of the blends. Moreover, economical impact and future direction of these blends are also critically reviewed. This chapter concludes that the blends form one of the emergent areas in polymer science that gained attention for practice in numerous bids ranging from building industries to the automobile.

Algae-Based Biologically Active Compounds

Abstract Algae belong to a much-diversified group of autotrophic organisms ranging from simple unicellular to complex multicellular forms. Till date at least 37,000 species of “true” algae and 4000 cyanobacteria are well recognized. They have proved to be the chief source of vitamins, minerals, proteins, and amino acids. Marine algae are used mainly as food and medicine in many parts of the world since ancient times. In addition to their nutraceutical values, they serve as a major constituent in value-added products of dairy and cosmetics. Edible algae are considered as complete and perfect diets which provide precise balance of proteins, carbohydrates, vitamins, and minerals. Various compounds with diverse pharmacological activities such as anticoagulants, antioxidants, antiproliferative, antitumoral, anticomplementary, and antibiotic activities are isolated and characterized from alga. Moreover, natural molecules from algal origin displayed remarkable antiinflammatory, antibacterial, antifungal, antiviral, antihelminthic, antiprotozoal, antipeptic, hypolipidemic, antiadhesive, and antifouling activities.