A new insight in immunomodulatory impact of botanicals in treating avian coccidiosis.

Avian coccidiosis is caused by genus Eimeria (E.) i.e. E. maxima, E. necatrix, E. tenella, E. acervulina, E. brunette and E. mitis and lead to three billion US dollar per year economic loss in poultry industry and reduces the growth performance of birds. To purge undesirable foreign agents, immune system produces a variety of molecules and cells that ultimately neutralize target particles in healthy organisms. However; when this particular system compromises, infection develops and the load of pathogens along with their virulence factors overcome both; innate and adaptive immune systems. Livestock and poultry sectors are important part of agriculture industry worldwide. Due to excessive use of chemotherapeutic agents, pathogens have developed resistance against these agents leading to the great economic losses. Numerous therapeutic approaches are in routine process for the treatment and prevention of various ailments but irrational use of antibiotics/chemicals has raised alarming concerns, like the development of drug resistant strains, residual effects in ultimate users and environmental pollution. These problems have led to the development of alternatives. In this regard, anticoccidial vaccine can be used as an alternative but due to high cost of production, plant derived biological response modifiers and antioxidants compounds are considered as a promising alternative. This review summarizes the immunotherapeutic effects of different compounds particularly with reference to avian coccidiosis.

Evaluation of Sodium Alginate Stabilized Nanoparticles and Antibiotics against Drug Resistant Escherichia coli Isolated from Gut of Houbara Bustard Bird.

Alternative approaches and/or modified approaches to tackle resistance in gut microbes are need of the hour. The current study was planned to find the resistance modulation and toxicity potential of sodium alginate stabilized MgO nanoparticles and antibiotics against Escherichia coli (E. coli) isolated from the gut of Houbara bustard bird (n = 105 fecal samples). The preparations consisted of gel stabilized ampicillin (G+A), gel stabilized MgO and ampicillin (G+M+A), gel stabilized MgO and cefoxitin (G+M+C), gel stabilized tylosin (G+T), gel stabilized MgO and tylosin (G+M+T), and gel stabilized MgO (M+G). The fecal samples showed 53% (56/105) prevalence of E. coli which was found to be significantly (p < 0.05) associated with most of the assumed factors and resistant to multiple drugs. G+M+T showed the lowest (4.883 ± 0.00µg/mL) minimum inhibitory concentration (MIC) followed G+M+C, G+M+A, G+A, M+G, and G+T. Significant reduction (p < 0.05) in MIC with respect to incubation interval found at the 16th hr for G+M+A, G+A, and G+M+C that further remained nonsignificant (p > 0.05) onwards until the 24th hr of incubation. In the case of G+T and M+G, significant reduction in MIC was found at the 20th hr and 24th hr of incubation. Ecotoxicology and histopathology trials on snails showed mild changes in MICs of the preparations. The study thus concluded increasing drug resistance in E. coli of houbara bird while sodium alginate stabilized MgO nanoparticles and antibiotics were effective alternative antibacterial composites with mild toxicity.

Vaccines against chicken coccidiosis with particular reference to previous decade: progress, challenges, and opportunities.

Chicken coccidiosis is an economically significant disease of commercial chicken industry accounting for losses of more than £10.4 billion (according to 2016 prices). Additionally, the costs incurred in prophylaxis and therapeutics against chicken coccidiosis in developing countries (for instance Pakistan according to 2018 prices) reached US $45,000.00 while production losses for various categories of chicken ranges 104.74 to US $2,750,779.00. The infection has been reported from all types of commercial chickens (broiler, layer, breeder) having a range of reported prevalence of 7-90%. The concern of resistance towards major anticoccidials has provided a way forward to vaccine research and development. For prophylaxis of chicken coccidiosis, live virulent, attenuated, ionophore tolerant strains and recombinant vaccines have been extensively trialed and commercialized. Eimeria antigens and novel vaccine adjuvants have elicited the protective efficacy against coccidial challenge. The cost of production and achieving robust immune responses in birds are major challenges for commercial vaccine production. In the future, research should be focused on the development of multivalent anticoccidial vaccines for commercial poultry. Efforts should also be made on the discovery of novel antigens for incorporation into vaccine designs which might be more effective against multiple Eimeria species. This review presents a recap to the overall progress against chicken Eimeria with particular reference to previous decade. The article presents critical analysis of potential areas for future research in chicken Eimeria vaccine development.

Nanoparticles: Synthesis and Their Role as Potential Drug Candidates for the Treatment of Parasitic Diseases.

Protozoa, helminths and ectoparasites are the major groups of parasites distributed worldwide. Currently, these parasites are treated with chemotherapeutic antiprotozoal drugs, anti-helminthic and anti-ectoparasitic agents, but, with the passage of time, resistance to these drugs has developed due to overuse. In this scenario, nanoparticles are proving to be a major breakthrough in the treatment and control of parasitic diseases. In the last decade, there has been enormous development in the field of nanomedicine for parasitic control. Gold and silver nanoparticles have shown promising results in the treatments of various types of parasitic infections. These nanoparticles are synthesized through the use of various conventional and molecular technologies and have shown great efficacy. They work in different ways, that include damaging the parasite membrane, DNA (Deoxyribonucleic acid) disruption, protein synthesis inhibition and free-radical formation. These agents are effective against intracellular parasites as well. Other nanoparticles, such as iron, nickel, zinc and platinum, have also shown good results in the treatment and control of parasitic infections. It is hoped that this research subject will become the future of modern drug development. This review summarizes the methods that are used to synthesize nanoparticles and their possible mechanisms of action against parasites.

Assessment of Avermectins-Induced Toxicity in Animals.

Macrocyclic lactones, particularly the avermectins, have completely revolutionized the approaches aimed at control of parasites. These avermectins are the most widely used anti-parasitic drugs in veterinary field with sales exceeding one billion US dollars annually. However, before clinical usage, their safety evaluation in the animals is a major critical factor that must be considered. Many studies have reported the negative effects of avermectins like ivermectin, abamectin, doramectin, and eprinomectin on the host animals. These harmful effects arise from avermectins targeting GABA and glutamate-gated chloride channels present both in the parasites and the host animals. In this review, various modes of avermectins action along with the negative effects on the host like nephrotoxicity, hepatotoxicity, neurotoxicity, reproductive toxicity, and endocrine disruption were discussed in detail. Furthermore, other important issues like ecotoxicity, drug resistance, and drug residues in milk associated with avermectins usage were also discussed, which need special attention.

Avian influenza (H5N1) virus, epidemiology and its effects on backyard poultry in Indonesia: a review.

Avian influenza (AI) is a zoonotic viral endemic disease that affects poultry, swine, and mammals, including humans. Highly pathogenic avian influenza (HPAI) is caused by influenza type A virus subtypes H5, and H7 which are naturally carried by a wild bird and often affect domestic poultry. Avian influenza (AI) is a major problem worldwide that causes significant economic losses in the poultry sector. Since 2003, the widespread H5N1 HPAI in poultry has led to high mortalities resulting in huge economic losses in the poultry sector in Indonesia. Domestic poultry is a key source of income that contributes to economic growth, both directly and indirectly, by reducing poverty among the people living in rural communities. Furthermore, in many developing countries, including Indonesia, rural people meet a portion of their food needs through backyard poultry. Nevertheless, this sector is strongly affected by biosecurity hazards, particularly in Indonesia by HPAI infections. Avian influenza (AI), subtype H5N1 has zoonotic significance, posing major risks to public health and poultry. Due to close interaction between wild migratory birds and ducks, the domestic poultry sector in Indonesia is directly affected by this virus. This virus continues to be ubiquitous in Indonesia as a result of the unpredictable mutations produced by antigenic drift and shift, which can persist from a few days to several years. In this review, the epidemiology and impact, of highly pathogenic avian influenza H5N1 subtype virus infection on backyard poultry in Indonesia were discussed.

Helminth protection against type-1 diabetes: an insight into immunomodulatory effect of helminth-induced infection.

Helminths are the old dirty friends of humans from decades and may live undetected by the immune system for years in the tissues. They have evolved as good experts at subverting the immune system. Despite of their pathogenicity, they provide protection to their host against certain inflammatory diseases such as diabetes by modulating the immune mechanisms. These parasites are extra-cellular and induce Th2 response which triggers the adaptive immune cells as well as innate immune cells to work synergistically allowing Tregs to work in a toll-like receptor-dependent manure. T-helper cells type-2 also secrete certain anti-inflammatory cytokines including IL-4, IL-10, IL-13 and TGF-ß which also provide protection against type-1 diabetes. Several helminths such as T. crassiceps, S. venezuelensis, filarial worms, Schistosoma spp. and T. spiralis have been reported to prevent diabetes in mouse models as well as in some clinical trials. Immunomodulatory talent of helminths is receiving greater attention to prevent diabetes. Herein, an attempt has been made to review and highlight the possible immuno-modulatory mechanisms by which helminths provide protection against diabetes. Moreover, this review also emphasizes on the use of helminth-derived molecules or synthetic derivatives of helminth-antigens in clinical trials to overcome rapidly growing autoimmune disorders including diabetes.

Therapeutic potential of medicinal plants against Leishmaniasis: a public healh concern / Potencial terapeútico de plantas medicinales contra la Leishmaniasis: un problema de salud pública

Leishmaniasis is an important disease affecting global public health which is spread by sand fly having different species. Various chemical drugs are used to treat and control Leishmaniasis including pentavalent antimonials, antimicrobial and antibiotics. Due to emergence of drug resistance, these therapeutic options are losing effectiveness in attaining success. Furthermore, these drugs are expensive and have toxic effects on liver and kidneys. There has been an emerging interest and excellent response by using plant based drugs and extracts to control Leishmaniasis. Different medicinal plants including Glycyrrhiza glabra, Allium sativum, Peganum harmala and Nigella sativa have shown excellent anti-leishmanial activity. Therefore, medicinal plants can help in effective drug development against Leishmaniasis diseases in both animals and humans which will be safer and health protective.

La Leishmaniasis es una enfermedad importante que afecta la salud pública mundial y que es transmitida por las moscas de la arena, que tienen diferentes especies. Se utilizan varios medicamentos químicos para tratar y controlar la Leishmaniasis, incluidos los antimoniales pentavalentes, antimicrobianos y antibióticos. Debido a la aparición de resistencia a los medicamentos, estas opciones terapéuticas están perdiendo eficacia para lograr el éxito. Además, estos medicamentos son costosos y tienen efectos tóxicos en hígado y riñones. Ha habido un interés emergente y una excelente respuesta mediante el uso de extractos y medicamentos a base de plantas para controlar la Leishmaniasis. Diferentes plantas medicinales como Glycyrrhiza glabra, Allium sativum, Peganum harmalay Nigella sativahan mostrado una excelente actividad anti-leishmanial. Por lo tanto, las plantas medicinales pueden ayudar en el desarrollo de fármacos eficaces contra las enfermedades de la leishmaniasis tanto en animales como en seres humanos, lo que será más seguro y proteja la salud.

Repellent and acaricidal activity of essential oils and their components against Rhipicephalus ticks in cattle.

Ticks, particularly the Rhipicephalus which are the most prevalent and invasive affect 80 % of the cattle population worldwide. Through transmission of pathogens, tick worry and physical damage to the hides, ticks cause economic loss of billions of dollars each year with 1 billion US dollars loss per annum reported only in Latin-America. These losses can be minimized only by successful management of Rhipicephalus ticks. Various strategies like chemical control, vaccination and biological control are aimed at control of Rhipicephalus ticks. There are some serious limitations associated with them like tick resistance, drug toxicity, antigenic variations etc. In contrast to these issues related with chemical tick control, the botanicals particularly the essential oils obtained from aromatic plants of medicinal importance are eco-friendly and non-toxic to most host. In recent years, essential oils-based control of cattle ticks has gained considerable attraction of scientists all over the world as depicted from this review. A comprehensive effort has been made to critically analyze the role of essential oils in controlling Rhipicephalus ticks with particular emphasis on the mode of action of bioactive compounds both as repellents and acaricides. Furthermore, we have pointed out the most important challenges which need to be addressed for development and commercialization of an essential oil based anti-tick product.

Influence on the reactivity properties of the substitution by different halogens on the conjugated backbone of the 1,3,5-triaryl-2-pyrazoline skeleton in relation to the increasing alkyloxy chain length: a conceptual density functional theory study.

A series of non-substituted 1,3,5-triaryl-2-pyrazolines and pyrazolines substituted with Fluoro (-F), Chloro (-Cl) and Bromo (-Br) groups at the 3-aryl position were studied. All calculations were done using the conceptual framework of density functional theory. The geometries and reactivity properties were analyzed according to an increase from one to twelve alkyl units in the 5-aryl of 2-pyrazoline ring. In order to be able to apply the particular methodology named KID procedure (for Koopmans in DFT), the KID descriptors were calculated and the results showed that the use of this approximation (Koopmans' theorem in DFT studies) is feasible. The results for the geometries determined that the increase of the chain with alkyl units does not affect the geometry of the systems. However, the solvation energy also calculated is affected by this increase in the allyl chain length. Due to this, as the chains increases, the solubility of the molecular systems diminishes. The chemical reactivity properties were determined by calculating the descriptors that arise from conceptual DFT and it could be demonstrated that they are not affected by the chain growth. Slight differences were found due to the different halogen substitutions. Finally, it could be observed that all the pyrazolines present an important electrophilic behavior. Graphical Abstract Properties changes in relation to the increasing alkyloxy chain length and halogens presence.

An Insight Into COVID-19: A 21st Century Disaster and Its Relation to Immunocompetence and Food Antioxidants.

Coronavirus Disease 2019 (COVID-19) ranks third in terms of fatal coronavirus diseases threatening public health, coming after SARS-CoV (severe acute respiratory syndrome coronavirus), and MERS-CoV (Middle East respiratory syndrome coronavirus). SARS-CoV-2 (severe acute respiratory syndrome coronavirus type 2) causes COVID-19. On January 30, 2020, the World Health Organization (WHO) announced that the current outbreak of COVID-19 is the sixth global health emergency. As of December 3, 2020, 64 million people worldwide have been affected by this malaise, and the global economy has experienced a loss of more than $1 trillion. SARS-CoV-2 is a positive-sense single-stranded RNA virus belonging to the Betacoronavirus genus. The high nucleotide sequence identity of SARS-CoV-2 with the BatCoV RaTG13 genome has indicated that bats could be the possible host of SARS-CoV-2. SARS-CoV-2 penetrates the host cell via binding its spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor, which is similar to the mechanisms of SARS-CoV and MERS-CoV. COVID-19 can spread from person to person via respiratory droplets and airborne and contaminated fomites. Moreover, it poses a significant risk to smokers, the elderly, immunocompromised people, and those with preexisting comorbidities. Two main approaches are used to control viral infections, namely, vaccination, and biosecurity. Studies to analyze the antigenicity and immunogenicity of SARS-CoV-2 vaccine candidates are underway, and few vaccines may be available in the near future. In the current situation, the Human Biosecurity Emergency (HBE) may be the only way to cope effectively with the novel SARS-CoV-2 strain. Here, we summarize current knowledge on the origin of COVID-19 as well as its epidemiological relationship with humans and animals, genomic resemblance, immunopathogenesis, clinical-laboratory signs, diagnosis, control and prevention, and treatment. Moreover, we discuss the interventional effects of various nutrients on COVID-19 in detail. However, multiple possibilities are explored to fight COVID-19, and the greatest efforts targeted toward finding an effective vaccine in the near future. Furthermore, antioxidants, polyphenols, and flavonoids, both synthetic and natural, could play a crucial role in the fight against COVID-19.

Potential of botanical driven essential oils against Haemonchus contortus in small ruminants / Potencial de aceites esenciales botánicos contra Haemonchus contortus en pequeños rumiantes

The livestock sector is continuously facing problems in controlling parasitic diseases especially Haemonchosis due to emergence of anthelminthic resistance and failure in vaccination control programmes. Therefore, to increase milk and meat production and emerging demand of meat free from drug residues development of new alternative approaches are appealing for prevention and control of Haemonchosis in small ruminants. Among alternatives, plants driven essentials oils have shown promising results in control of Haemonchus contortus infection at various concentrations by different assays including egg hatch assay, larval development assay, larval exsheathment assay and adult motility assay. Essential oils are complex mixtures of various impulsive or volatile compounds which have potential to control Haemonchosis. The current study reviews the therapeutic effects of essential oils of plants against Haemonchus contortus and to be used them against Haemonchus contortus for future perspectives.

El sector ganadero enfrenta continuamente problemas para controlar las enfermedades parasitarias, especialmente la hemoncosis, debido a la aparición de resistencia antihelmíntica y al fracaso en los programas de control de vacunación. Por lo tanto, para aumentar la producción de leche y carne, y la demanda emergente de carne libre de residuos de medicamentos, el desarrollo de nuevos enfoques alternativos es atractivo para la prevención y el control de la hemoncosis en pequeños rumiantes. Entre las alternativas, los aceites esenciales producidos por las plantas han mostrado resultados prometedores en el control de la infección por Haemonchus contortus a diversas concentraciones mediante diferentes ensayos, incluido el análisis de eclosión de huevos, el desarrollo de larvas, el análisis de vaciado de larvas y el ensayo de motilidad en adultos. Los aceites esenciales son mezclas complejas de varios compuestos impulsivos o volátiles que tienen potencial para controlar la hemonchosis. Este estudio revisa los efectos terapéuticos de los aceites esenciales de las plantas contra Haemonchus contortus y evalúa sus perspectivas futuras como agentes para combatir las enfermedades causadas por este parásito.

Acaricidal and insecticidal effects of essential oils against ectoparasites of veterinary importance / Efectos acaricidas e insecticidas de los aceites esenciales contra los ectoparásitos de importancia veterinaria

Ectoparasitism in animals has become an issue of great concern that needs to be resolved to prevent huge economic losses occurring to livestock industry all over the world. Synthetic adrugs have been playing a major role in controlling ectoparasites, but their frequent and irrational use has resulted in drug resistance to routinely used chemicals and their residual effects on food and environment. Therefore, this approach of using chemical acaricides and insecticides is losing its popularity and effectiveness in controlling ectoparasites. So, the development of alternative approaches in ectoparasite management is currently required. Among alternative protocols, plants and their essential oils have played remarkable role in controlling different ectoparasites (ticks, flies, mites, lice) of veterinary importance. Essential oils have been proved to be cheaper, more effective and safer therapeautic agents against different ectoparasites of livestock importance.

En los animales el ectoparasitismo se ha convertido en un tema de gran preocupación que debe resolverse para evitar que se produzcan grandes pérdidas económicas para la industria ganadera en todo el mundo. Los aditivos sintéticos han desempeñado un papel importante en el control de los ectoparásitos, pero su uso frecuente e irracional ha dado como resultado la resistencia a los fármacos utilizados habitualmente y efectos residuales sobre los alimentos y el medio ambiente. Por lo tanto, el enfoque basado en el uso de acaricidas e insecticidas químicos está perdiendo popularidad y efectividad en el control de los ectoparásitos. Por lo tanto, actualmente se requiere el desarrollo de enfoques alternativos en el manejo de ectoparásitos. Entre los protocolos alternativos, las plantas y sus aceites esenciales han jugado un papel notable en el control de diferentes ectoparásitos (garrapatas, moscas, ácaros, piojos) de importancia veterinaria. Se ha demostrado que los aceites esenciales son agentes terapéuticos más baratos, más efectivos y más seguros contra diferentes ectoparásitos de importancia ganadera.

In vivo anticoccidial effects of Beta vulgaris (sugar beet) in broiler chickens.

Recently, use of botanicals as an alternative to anticoccidial drugs has been appealing approach for controlling avian coccidiosis. Therefore, this study was conducted to evaluate the anticoccidial activity of aqueous methanolic extract (100, 200 and 300 mg/kg of body weight) of Beta vulgaris (roots) in broiler chicks. A total of 315 day old broiler chicks were divided into seven equal groups (A, B, C, D, E, F and G). At 14th day of age, all groups except group G, which served as non infected non medicated control, were infected orally with 60,000 sporulated oocysts of mixed Eimeria species. At the same day, groups A, B and C were treated with graded oral doses of B. vulgaris aqueous methanolic extract (100, 200 and 300 mg/kg of body weight, respectively). Group D was treated with Vitamin-E, group E served as infected medicated control group (Baycox® treated) and group F served as infected non medicated control group (PBS treated). Treatment with extract, reference drug Baycox®, Vitamin E and PBS was continued for three consecutive days (14-16 days of age). Though, not at par with reference drug (Baycox®), B. vulgaris demonstrated good anticoccidial activity adjudged based on considered criteria, i.e., feed conversion ratio, lesion score, oocyst score and oocysts per gram of feces. Results of serum profile of infected chicks revealed no adverse effects of aqueous methanolic extract of B. vulgaris on the experimental chicks.

Prevalence and associated risk factors of haemoparasites, and their effects on hematological profile in domesticated chickens in District Layyah, Punjab, Pakistan.

Several haemoparasites commonly infect avian species, including chicken that significantly decline productivity and ultimately lead to high mortality rate. The current study was designed to assess the prevalence and associated risk factors of haemoparasites in domesticated chickens in and around District Layyah, Punjab Province, Pakistan. For this purpose, blood samples from a total of 384 backyard chickens were collected from wing vein using sterile insulin syringe. The parasites were identified from Giemsa stained thin blood smears based on morphological features using standard keys. Results demonstrated that a total of 265 backyard chickens (69%) were infected with haemoparasites in District Layyah. According to genus-wise distribution, 31.5%, 24.4% and 13% prevalence of genera Plasmodium/Haemoproteus, Leucocytozoon and mixed species were recorded, respectively. Among associated risk factors, the prevalence was relatively higher in females, chicks, naked neck breeds, scavengers feeding patterns and chickens reared at fully open coops type. The information given in the study could be of much importance in planning of an effective haemoparasites control program at District and Provincial level.

In-vitro anticoccidial potential of Saccharum officinarum extract against Eimeria oocysts / Potencial in vitro anti coccidial de un extracto de Saccharum officinarum contra oocistos de Eimeria

Present study was conducted to evaluate the effect of aqueous methanolic extract from Saccharum officinarum on the sporulation and morphology of oocysts of four Eimeria species (Eimeria tenella, E. necatrix, E. mitis, E. brunetti) of poultry. Sporulation inhibition bioassay was used to evaluate the activity of Saccharum officinarum extract (SOE) on the sporulation of coccidian oocysts. In this assay, unsporulated oocysts were exposed to six concentrations of S. officinarum in 10 percent dimethyl sulfoxide solution (w/v; 10, 5, 2.5, 1.25, 0.625 and 0.31 percent) while DMSO and potassium dichromate solution (K2Cr2O7) served as control groups. The Petri dishes were partially covered to allow the passage of oxygen and incubated at 25-29° C for 48 h, providing 60-80 percent humidity. The sporulation of the oocyst was confirmed by examining sporocysts under inverted microscope at 40x. Results showed anticoccidial activity of SOE against all Eimeria species as proved by its ability to inhibit the sporulation of the oocysts under laboratory conditions. Inhibition of sporulation was observed in dose dependent manner. S. officinarum extract at higher dose also damaged the normal morphology and shape of oocysts of Eimeria species.

El presente estudio se llevó a cabo para evaluar el efecto del extracto metanólico acuoso a partir de Saccharum officinarum en la esporulación de los ooquistes y la morfología de cuatro especies de Eimeria tenella (Eimeria, E. necatrix, E. mitis, E. brunetti) de aves de corral. Bioensayos de la inhibición de la esporulación se utilizaron para evaluar la actividad de extracto de Saccharum officinarum (SOE) en la esporulación de ooquistes de coccidios. En este ensayo, los ooquistes no esporulados se expusieron a seis concentraciones de S. officinarum en solución de dimetil sulfóxido 10 por ciento (w / v; 10, 5, 2,5, 1,25, 0,625 y 0,31 por ciento), mientras DMSO y una solución de dicromato de potasio (K2Cr2O7) sirvió como grupos de control. Las placas de Petri se cubren parcialmente para permitir el paso de oxígeno y se incubaron a 25-29° C durante 48 h, proporcionando el 60-80 por ciento de humedad. La esporulación de los ooquistes fue confirmado mediante el examen de esporoquistes bajo microscopio invertido a 40x. Los resultados mostraron actividad anticoccidial de SOE contra todas las especies de Eimeria como se ha demostrado por su capacidad para inhibir la esporulación de los ooquistes en condiciones de laboratorio. Se observó una inhibición de la esporulación de manera dependiente de la dosis. Extracto de S. officinarum en dosis más alta también dañó la morfología normal y la forma de ooquistes de las especies de Eimeria.

Synthesis and spectral characterization of new homologous 1,3,5-triaryl-2-pyrazolines: Influence of alkyloxy chain length on fluorescence.

Twelve new homologous 1,3,5-triaryl-2-pyrazolines (1c-12c) have been synthesized and characterized on the basis of their spectral (IR, (1)H and (13)C NMR and MS) data and microanalysis. The influence of alkyloxy chain length on absorption and fluorescence properties of 1c-12c was studied by UV-Vis and emission spectroscopy. For all the compounds, fluorescence was observed in the blue region of the visible spectrum. Furthermore, a strong influence of alkyloxy chain length was found on the emission intensity of 1,3,5-triaryl-2-pyrazolines, without causing any major blue- or red-shift in the emission wavelength (λmax(em)). The absorption and emission maxima (λmax(abs) and λmax(em)) for all the compounds were observed in the range of 408-416nm and 471-476nm, respectively. The effect of chloro-substituent present on the conjugated backbone of 1,3,5-triaryl-2-pyrazoline moiety is also discussed.

Synthesis and spectral characterization of new 1,3,5-triaryl-2-pyrazolines highlighting effect of alkyloxy chain length on fluorescence.

A series of new 1,3,5-triaryl-2-pyrazolines (1b-12b) having one to twelve carbon alkyloxy side chains were synthesized and characterized on the basis of their spectral (IR, (1)H &(13)C NMR and GC-MS) and microanalytical data. The UV-Vis and emission spectroscopy was used to study the effect of alkyloxy chain length on absorption and fluorescence properties of 1b-12b. All the compounds showed fluorescence in the blue region of the visible spectrum. Interestingly, the alkyloxy chain length strongly affects the emission intensity of 1,3,5-triaryl-2-pyrazoline framework without causing any major blue- or red-shift in the emission wavelength (λmax(em)). The absorption and emission maxima (λmax(abs) &λmax(em)) for compounds (1b-12b) were observed in the range of 337-364nm and 454-464nm, respectively. Furthermore, the effect of fluorine substituent on aryl ring present at 3-position of pyrazoline moiety on fluorescence properties is also discussed.