Shaping the future of antiviral Treatment: Spotlight on Nucleobase-Containing drugs and their revolutionary impact

Nucleobases serve as essential molecular frameworks present in both natural and synthetic compounds that exhibit notable antiviral activity. Through molecular modifications, novel nucleobase-containing drugs (NCDs) have been developed, exhibiting enhanced antiviral activity against a wide range of viruses, including the recently emerged SARS‑CoV‑2. This article provides a detailed examination of the significant advancements in NCDs from 2015 till current, encompassing various aspects concerning their mechanisms of action, pharmacology and antiviral properties. Additionally, the article discusses antiviral prodrugs relevant to the scope of this review. It fills in the knowledge gap by examining the structure-activity relationship and trend of NCDs as therapeutics against a diverse range of viral diseases, either as approved drugs, clinical candidates or as early-stage development prospects. Moreover, the article highlights on the status of this field of study and addresses the prevailing limitations encountered.

Signal transduction of the insulin secretion induced by the chalcone analogue, (E)-3-(phenyl)-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one, and its role in glucose and lipid metabolism

A chalcone analogue, (E)-3-(phenyl)-1-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (DMU 101), was synthesized using classic base catalysis and Claisen-Schmidt condensation, and then screened for its antidiabetic properties. The compound's effects on glucose and lipid metabolism were assayed in rats that were treated acutely and for a short time to elucidate its mechanism of action, evaluating glucose tolerance and lactate dehydrogenase activity in response to chalcone analogue administration. The chalcone's in vitro and ex vivo effects on glycogen, glucose, lipid and lipolysis were also investigated, as well as the mechanism by which it induces 45Ca2+ influx-mediated insulin secretion. The analogue (10 mg/kg) diminished glycemia, without inducing acute cell damage, increased glycogen content in the skeletal muscle and reduced serum triacylglycerol and total cholesterol, but did not alter high-density lipoprotein or low-density lipoprotein. Chalcone (10 μM) stimulated glucose uptake in the soleus muscle and did not modulate in vitro or ex vivo lipolysis. This analogue also increased insulin secretion by triggering calcium influx and blocking ATP-sensitive K+ channels and voltage-dependent calcium channels. However, it also modulated stored calcium via sarco/endoplasmic reticulum calcium ATPase (SERCA) and ryanodine receptor (RYR) activity. These findings indicate that this chalcone may induce cellular repolarization via a mechanism mediated by calcium-dependent potassium channels.

One-pot synthesis of heteroaryl diketoalkynyl C-glycoside and dialkynyl di-C-glycoside analogues by three-component successive coupling reaction

The synthesis of heteroaryl diketoalkynyl C-glycoside and dialkynyl di-C-glycoside analogues has been accomplished by successive coupling of heteroaromatics, oxalyl chloride and terminal sugar alkynes in one pot. The three-component coupling reaction catalyzed by CuI gives heteroaryl diketoalkynyl C-glycosides. The same three-component coupling in the presence of n-BuLi produces dialkynyl di-C-glycosides, and the 1:1 of molar ratio of heteroaromatics to terminal sugar alkynes affords the corresponding esters of dialkynyl di-C-glycosides. The desired products have been obtained in good to excellent yields. This sequential one-pot method is mild and efficient, suitable for different heteroaromatics and terminal sugar alkynes. The sugar alkynes include furanosides, pyranosides, and acyclic sugars. Twenty-seven examples have been given. The mechanism for the formation of the desired products has been elucidated.

Contaminant release, mixing and microbial fluctuations initiated by infiltrating water within a replica field-scale legacy radioactive waste trench

Numerous legacy near-surface radioactive waste sites dating from the mid 20th century have yet to be remediated and present a global contamination concern. Typically, there is insufficient understanding of contaminant release and redistribution, with invasive investigations often impractical due to the risk of disturbing the often significantly radiotoxic contaminants. Consequently, a replica waste trench (~5.4 m³), constructed adjacent to a legacy radioactive waste site (Little Forest Legacy Site, LFLS), was used to assist our understanding of the release and mixing processes of neodymium (Nd) - a chemical analogue for plutonium(III) and americium(III), two significant radionuclides in many contaminated environments. In order to clarify the behaviour of contaminants released from buried objects such as waste containers, a steel drum, representative of the hundreds of buried drums within the LFLS, was placed within the trench. Dissolved neodymium nitrate was introduced as a point-source contaminant to the base of the trench, outside the steel drum. Hydrologic conditions were manipulated to simulate natural rainfall intensities with dissolved lithium bromide added as a tracer. Neodymium was primarily retained both at its point of release at the bottom of the trench (>97 %) as well as at a steel container corrosion point, simulated through the emplacement of steel wool. However, over the 8-month field experiment, advective mixing initiated by surface water intrusions rapidly redistributed a small proportion of Nd to shallower waters (~1.5-1.7 %), as well as throughout the buried steel drum. Suspended particulate forms of Nd (>0.2 μm) were measured at all depths in the suboxic trench and were persistent across the entire study. Analyses of the microbial communities showed that their relative abundances and metabolic functions were strongly influenced by the prevailing geochemical conditions as a result of fluctuating water depths associated with rainfall events. The site representing steel corrosion exhibited divergent biogeochemical results with anomalous changes (sharp decrease) observed in both dissolved contaminant concentration as well as microbial diversity and functionality. This research demonstrates that experimental trenches provide a safe and unique method for simulating the behaviour of subsurface radioactive contaminants with results demonstrating the initial retention, partial shallow water redistribution, and stability of particulate form(s) of this radioactive analogue. These results have relevance for appropriate management and remediation strategies for the adjacent legacy site as well as for similar sites across the globe.

Amylin as a Future Obesity Treatment

Obesity is defined as abnormal or excessive fat accumulation that contributes to detrimental health impacts. One-third of the population suffers from obesity, and it is important to consider obesity as a chronic disease requiring chronic treatment. Amylin is co-secreted with insulin from β pancreatic cells upon nutrient delivery to the small intestine as a satiety signal, acts upon sub-cortical homeostatic and hedonic brain regions, slows gastric emptying, and suppresses post-prandial glucagon responses to meals. Therefore, new pharmacological amylin analogues can be used as potential anti-obesity medications in individuals who are overweight or obese. In this narrative review, we analyse the efficacy, potency, and safety of amylin analogues. The synthetic amylin analogue pramlintide is an approved treatment for diabetes mellitus which promotes better glycaemic control and small but significant weight loss. AM833 (cagrilintide), an investigational novel long-acting acylated amylin analogue, acts as a non-selective amylin receptor. This calcitonin G protein-coupled receptor agonist can serve as an attractive novel treatment for obesity, resulting in reduction of food intake and significant weight loss in a dose-dependent manner.

Performance of forensic facial comparison by morphological analysis across optimal and suboptimal CCTV settings

Facial comparison is an important yet understudied discipline in forensics. The recommended method for facial comparison in a forensic setting involves morphological analysis (MA) with the use of a facial feature list. The performance of this approach has not been tested across various closed-circuit television (CCTV) conditions. This is of particular concern as video and image data available to law enforcement is often varied and of subpar conditions. The present study aimed at testing MA across two types of CCTV data, representing ideal and less than ideal settings, also assessing which particular shortcomings arose from less-than-ideal settings. The study was conducted on a subset of the Wits Face Database arranged in a total of 225 face pools. Each face pool consisted of a target image obtained from either a high-definition digital CCTV camera or a low-definition analogue CCTV camera in monochrome, contrasted to 10 possible matches. The face pools were analysed and scored using MA and confusion matrices were used to analyse the outcomes. A notably high chance corrected accuracy (CCA) (97.3%) and reliability (0.969) was identified across the digital CCTV sample, while in the analogue CCTV sample MA appeared to underperform both in accuracy (CCA: 33.1%) and reliability (0.529). The majority of the errors in scoring resulted in false negatives in the analogue sample (75.2%), while across both CCTV conditions false positives were low (digital: 0.3%; analogue: 1.2%). Even though hit rates appeared deceptively high in the analogue sample, the various measures of performance used and particularly the chance corrected accuracy highlighted its shortfalls. Overall, CCTV recording quality appears closely associated to MA performance, despite the favourable error rates when using the Facial Identification Scientific Working Group feature list.

Comparative study on the intestinal absorption of three gastrodin analogues via the glucose transport pathway

Gastrodin is the main active constituent of Tianma, a famous traditional Chinese herbal medicine. Our previous research has found that gastrodin is absorbed rapidly in the intestine by the sodium-dependent glucose transporter 1 (SGLT1). In the current report, gastrodin is the best glycoside compound absorbed via the glucose transport pathway. This study aimed to investigate the effect of the slight difference in chemical structure on the drug intestinal absorption via the glucose transport pathway. Traditional biopharmaceutical and computer-aided molecular docking methods were used to evaluate the intestinal absorption characteristics of three gastrodin analogues, namely, salicin, arbutin and 4-methoxyphenyl-β-D-glucoside (4-MG). The oil-water partition coefficient (logP) experiments showed that the logP values of the gastrodin analogues followed the order: 4-MG > salicin > arbutin. In vitro Caco-2 cell transport experiments demonstrated that the apparent permeability coefficient (P_app) value of arbutin was higher than those of salicin and 4-MG. In situ single-pass intestinal perfusion experiments showed that the absorption of arbutin and 4-MG was better than that of salicin and that the absorption of the three compounds in the colon was lower than that in the small intestine. Quantitative real-time polymerase chain reaction results confirmed that the SGLT1 mRNA expression in the small intestine of rats was obviously higher than that in the colon of rats. In vivo pharmacokinetic experiments demonstrated that the oral bioavailability of salicin was lower than those of arbutin and 4-MG. In vitro and in vivo experiments showed that glucose or phlorizin (SGLT1 inhibitor) could decrease the intestinal absorption of the three compounds. Contrary to the above biopharmaceutical experiments, the computer-aided molecular docking test showed that the affinity of salicin to the vSGLT receptor was stronger than those of arbutin and 4-MG. In conclusion, the SGLT1 can facilitate the intestinal absorption of salicin, arbutin and 4-MG, and the slight difference in chemical structure can affect absorption.

Characterization of sedimentary and volcanic rocks in Armintza outcrop (Biscay, Spain) and its implication for Oxia Planum (Mars) exploration

The landing site of the next planetary mission lead by ESA (ExoMars 2022) will be Oxia Planum. This location has been chosen due to different reasons, among them, the existence of sedimentary rocks that could host remains of organic matter. The fact that this type of rocks coexists with volcanic ones makes of high importance the study of the processes and the possible interactions that could happen among them. Therefore, in this research work the Armintza outcrop (Biscay, North of Spain) is proposed as an Oxia Planum analogue since it has the dichotomy of volcanic and sedimentary rock layers that is expected on the landing site of the ExoMars 2022 mission. As Raman and visible near infrared spectroscopies will be in the payload of the rover of that mission, they have been used to characterize the samples collected in the Armintza outcrop. With the help of these techniques, feldspars (albite mainly) and phyllosilicates (kaolinite and dickite, together with micas and chlorite minerals) have been identified as the major products on the samples, together with some weathering products (carbonates, sulphates, oxides) and apatite. Moreover, remains of kerogen have been detected in the sedimentary layers in contact with the interlayered lava flows, confirming the capability of similar sedimentary-volcanic layers to trap and store organic remains for millions of years. After establishing which compounds have volcanic or sedimentary origin, and which must be considered alteration phases, we can consider Armintza as a good Oxia Planum analogue.

Vitamin D analogues exhibit antineoplastic activity in breast cancer patient-derived xenograft cells

Despite advances in breast cancer (BC) treatment, its mortality remains high due to intrinsic or acquired resistance to therapy. Several ongoing efforts are being made to develop novel drugs to treat this pathology with the aim to overcome resistance, prolong patient survival and improve their quality of life. We have previously shown that the non-hypercalcemic vitamin D analogues EM1 and UVB1 display antitumor effects in preclinical studies employing conventional cell lines and animal models developed from these cells. In this work, we explored the antitumor effects of EM1 and UVB1 employing BC cells derived from patient-derived xenografts (PDXs), which are a powerful preclinical tool for testing new drugs. We demonstrated that the analogues reduced the viability of HER2-positive and Triple Negative BC-PDXs. Moreover, using an in vitro model of acquired resistance to Trastuzumab-emtansine, UVB1 displayed anti-proliferative actions under 2D and 3D culture conditions. It inhibited both formation and growth of established organoids. In addition, a direct correlation between UVB1 antitumor effects and VDR expression in PDXs was found. In conclusion, all the results reinforce the potential use of these vitamin D analogues as antitumor agents to treat HER2-positive and Triple Negative BC.

Quantification of vitamin D3 and 25-hydroxyvitamin D3 in food - The impact of eluent additives and labelled internal standards on matrix effects in LC-MS/MS analysis

Deuterated vitamin D standards are used commonly as internal standards in LC-MS/MS analysis of vitamin D3 and 25-hydroxyvitamin D3 in food. However, the use of various eluent additives, such as methylamine, formic acid and ammonium formate, also contributes to matrix effects and the performance of analysis by affecting accuracy and robustness. For the first time, continuous post-column infusion experiments of isotopically labelled vitamin D3-[d6] were performed to evaluate ion-suppression in a wide variety of food (salmon, cheese, pork fat, pork meat, and egg yolk). Furthermore, results collected using five analytical methods, employing DAD/UV and MS/MS-detectors, were evaluated with in-house and standardised reference materials. The matrix effect was significant when analysing vitamin D3 in most food matrices using the deuterium labelled internal standard. Even though the use of the 13C5-labelled internal standard reduced matrix effects, a standardised method is needed to agree on the true value of vitamin D in food.

CT2-3, a novel magnolol analogue suppresses NSCLC cells through triggering cell cycle arrest and apoptosis

Magnolol, a major bioactive component found in Magnolia officinalis with anti-inflammation and anti-oxidation activities as well as minimized cytotoxic effects. Although magnolol has a wide range of clinical applications, the anti-tumor activity of magnolol is not efficient. Herein, we reported the synthesis and anti-cancer activities of three novel magnolol analogues CT2-1, CT2-2, CT2-3, among which CT2-3 revealed more efficient anti-non-small cell lung cancer (NSCLC) activity than magnolol. Our data showed that CT2-3 could significantly inhibit the proliferation of human NSCLC cells in a dose-dependent manner. In addition, we revealed CT2-3 could induce cell cycle arrest through down-regulating mRNA expression of CDK4, CDK6 and cyclin D1. Moreover, we verified that CT2-3 could cause ROS generation, leading to apoptosis of human NSCLC cells. Further more, we also provided strong evidences that CT2-3 down-regulates the expression of c-Myc and topoisomerases, and contributes to the apoptosis of human NSCLC cells. Taken together, the current study is the first to report a promising new chemotherapeutic drug candidate CT2-3 that can efficiently eliminate human NSCLC cells through triggering cell cycle arrest as well as ROS-mediated and c-Myc/topoisomerases-mediated apoptosis.

KEA-1010, a ketamine ester analogue, retains analgesic and sedative potency but is devoid of Psychomimetic effects

Background

Ketamine, a widely used anaesthetic and analgesic agent, is known to improve the analgesic efficacy of opioids and to attenuate central sensitisation and opioid-induced hyperalgesia. Clinical use is, however, curtailed by unwanted psychomimetic effects thought to be mediated by N-methyl-D-aspartate (NMDA) receptor antagonism. KEA-1010, a ketamine ester-analogue designed for rapid offset of hypnosis through hydrolysis mediated break-down, has been shown to result in short duration sedation yet prolonged attenuation of nociceptive responses in animal models. Here we report on behavioural effects following KEA-1010 administration to rodents.

Methods

KEA-1010 was compared with racemic ketamine in its ability to produce loss of righting reflex following intravenous injection in rats. Analgesic activity was assessed in thermal tail flick latency (TFL) and paw incision models when injected acutely and when co-administered with fentanyl. Tail flick analgesic assessment was further undertaken in morphine tolerant rats. Behavioural aberration was assessed following intravenous injection in rats undergoing TFL assessment and in auditory pre-pulse inhibition models.

Results

KEA-1010 demonstrated an ED₅₀ similar to ketamine for loss of righting reflex following bolus intravenous injection (KEA-1010 11.4 mg/kg [95% CI 10.6 to 12.3]; ketamine (racemic) 9.6 mg/kg [95% CI 8.5–10.9]). Duration of hypnosis was four-fold shorter in KEA-1010 treated animals. KEA-1010 prolonged thermal tail flick responses comparably with ketamine when administered de novo, and augmented morphine-induced prolongation of tail flick when administered acutely. The analgesic effect of KEA-1010 on thermal tail flick was preserved in opioid tolerant rats. KEA-1010 resulted in increased paw-withdrawal thresholds in a rat paw incision model, similar in magnitude yet more persistent than that seen with fentanyl injection, and additive when co-administered with fentanyl. In contrast to ketamine, behavioural aberration following KEA-1010 injection was largely absent and no pre-pulse inhibition to acoustic startle was observed following KEA-1010 administration in rats.

Conclusions

KEA-1010 provides antinociceptive efficacy in acute thermal and mechanical pain models that augments standard opioid analgesia and is preserved in opioid tolerant rodents. The NMDA channel affinity and psychomimetic signature of the parent compound ketamine is largely absent for KEA-1010.

Developments in the anticancer activity of structurally modified curcumin: An up-to-date review

Curcumin is a pharmacologically active polyphenol derived from the popular spice element-Turmeric. The therapeutic activity of curcumin has been extensively investigated over the last few decades and reports suggest the role of curcumin in a large number of biological activities, particularly its prominent anticancer activity. Curcumin, being a pleiotropic molecule, is a regulator of multiple molecular targets which play crucial roles in various cell signaling pathways. It is known to suppress transformation, inhibit proliferation as well as induce apoptosis. However, despite all these benefits, the efficacy of curcumin remains limited due to its poor bioavailability, poor absorption within the systemic circulation and rapid elimination from the body. To overcome these limiting factors, researchers all around the world are working towards designing a synthetic and superior curcuminoid by making suitable structural modifications to the parent skeleton. These curcuminoids, mainly analogues and derivatives, will not only improve the physicochemical properties but also enhance the efficacy simultaneously. The present review will provide a comprehensive account of the analogues and derivatives of curcumin that have been reported since 2014 which have indicated a better anticancer activity than curcumin.

Uric acid analogue as a possible xenobiotic marker of uric acid transporter Urat1 in rats

The inhibitor of uric acid reabsorptive transporter URAT1 in kidney is drawing attention as a drug target for hyperuricemia. However, it is difficult to evaluate efficacy of URAT1 inhibitors in vivo using laboratory animals due to species difference in uric acid metabolism. In the present study, the usefulness of exogenously administering uric acid analogues resistant to uricase was investigated for in vivo evaluation of transport activity of rUrat1 in rats. Uptake of examined four uric acid analogues by rUrat1-expressing Xenopus oocytes was significantly higher than that by water-injected oocytes. In metabolism studies, disappearance of these compounds was negligible, while uric acid was significantly decreased. When oxypurinol was administered to rats, fractional excretion (FE) was 0.4, suggesting reabsorption of oxypurinol. Moreover, FE of oxypurinol was tended to be increased, but not statistically different, by co-administration of a uricosuric agent FYU-981, while plasma concentration of oxypurinol was not affected. These results suggested that oxypurinol is a potential uric acid analogue, although it was not suitable as a probe of uric acid in in vivo study. Our findings may contribute to discovery and development of novel uricosuric agent targeting URAT1.

Solid pseudopapillary neoplasm (SPN) of the testis: Comprehensive mutational analysis of 6 testicular and 8 pancreatic SPNs

BACKGROUND

Recently, we came with the theory of a possible relationship between a group of testicular and pancreatic tumors. We used one case of a pancreatic analogue solid pseudopapillary neoplasm of the testis composed partially of areas reminiscent of solid pseudopapillary neoplasm (SPN) of the pancreas and partially of structures identical to primary signet ring stromal tumor of the testis (PSRSTT) as a connecting link between these two entities. After demonstrating that PSRSTT and pancreatic analogue SPN of the testis share the same immunoprofile and genetic features characteristic for pancreatic SPN, we came to the conclusion that pancreatic analogue SPN of the testis and PSRSTT represent a morphological spectrum of a single entity and that both are related to the pancreatic SPN.

DESIGN

The aim of this study is to present a series of 6 cases of testicular tumors, which lacked the signet ring cell component and were thus morphologically very similar to the SPN of the pancreas. The goal of this study is to compare the genetic background of these testicular tumors that are obviously related to the PSRSTT/pancreatic analogue SPN of the testis with the series of 8 pancreatic SPN.

RESULTS

The mutational analysis revealed an oncogenic somatic mutation in the exon 3 of the CTNNB1 (β-catenin) gene in all analyzable (5/6) testicular and all pancreatic (8/8) tumors. The immunoprofile (positivity with β-catenin, CD10, vimentin, NSE, CD56, and negativity with inhibin, calretinin, chromogranin) was identical in all testicular and pancreatic tumors.

CONCLUSION

This study expanded the morphological spectrum of the PSRSTT/pancreatic analogue SPN of the testis by adding 6 cases without the signet ring cell component. Considering the obvious analogy of PSRSTT/pancreatic analogue SPN of the testis/SPN of the testis and their relationship to the pancreatic SPN we propose the collective term "solid pseudopapillary neoplasm of the testis" for these tumors. The mutational profile of the SPN of the testis and pancreas was the same in both groups of tumors which we consider as a final proof that SPN of the testis is identical to the SPN of the pancreas.

Part 1: Early structural modifications to the nucleoside scaffold

This is the first of two invited articles reviewing the development of nucleoside-analogue antiviral drugs, written for a target audience of virologists and other non-chemists, as well as chemists who may not be familiar with the field. Rather than providing a simple chronological account, we have examined and attempted to explain the thought processes, advances in synthetic chemistry and lessons learned from antiviral testing that led to a few molecules being moved forward to eventual approval for human therapies, while others were discarded. The present paper focuses on early, relatively simplistic changes made to the nucleoside scaffold, beginning with modifications of the nucleoside sugars of Ara-C and other arabinose-derived nucleoside analogues in the 1960's. A future paper will review more recent developments, focusing especially on more complex modifications, particularly those involving multiple changes to the nucleoside scaffold. We hope that these articles will help virologists and others outside the field of medicinal chemistry to understand why certain drugs were successfully developed, while the majority of candidate compounds encountered barriers due to low-yielding synthetic routes, toxicity or other problems that led to their abandonment.

•

This is the first of two invited articles reviewing the development of nucleoside-analogue antiviral drugs.

•

It is written for a target audience of virologists and other non-chemists, and for chemists unfamiliar with the field.

•

Numerous modifications have been made to the nucleoside scaffold in order to impart therapeutic benefits.

•

Nucleoside modifications led to the development of potent antivirals such as acyclovir, entecavir, and tenofovir.

•

We examine thought processes, progress in synthetic chemistry and results of antiviral testing that led to approved drugs.

Antitumoral effects of the alkynylphosphonate analogue of calcitriol EM1 on glioblastoma multiforme cells

Glioblastoma multiforme (GBM) is the worst and most common brain tumor, characterized by high proliferation and invasion rates. The current standard treatment is mainly based on chemoradiotherapy and this approach has slightly improved patient survival. Thus, novel strategies aimed at prolonging the survival and ensuring a better quality of life are necessary. In the present work, we investigated the antitumoral effect of the novel analogue of calcitriol EM1 on GBM cells employing in vitro, in silico, and in vivo assays. In vitro, we demonstrated that EM1 treatment selectively decreases the viability of murine and human tumor cells without affecting that of normal human astrocytes. The analysis of the mechanisms showed that EM1 produces cell cycle arrest in the T98G cell line, which is accompanied by an increase in p21, p27, p57 protein levels and a decrease in cyclin D1, p-Akt-S473, p-ERK1/2 and c-Jun expression. Moreover, EM1 treatment also exerts in GBM cells anti-migratory effects and decreases their invasive capacity by a reduction in MMP-9 proteolytic activity. In silico, we demonstrated that EM1 is able to bind to the vitamin D receptor with greater affinity than calcitriol. Finally, we showed that EM1 treatment of nude mice administered at 50ug/kg body weight during 21days neither induces hypercalcemia nor toxicity effects. In conclusion, all the results indicate the potential of EM1 analogue as a promising therapeutic alternative for GBM treatment.

A study of the intermolecular interactions of lipid components from analogue fingerprint residues

A compositionally simplified analogue of a latent fingermark was created by combining single representatives of each major component of a natural fingermark. Further modified analogues were also produced each having one component removed. The aim of this study was to investigate the intermolecular interactions that occurred within these analogue samples using Fourier Transform Infrared (FT-IR) Microspectroscopy. FT-IR microspectroscopy showed that the absence of squalene and cholesterol significantly restricted the interactions between the other organic constituents within the analogue samples. Investigating the intermolecular interactions of organic compounds within a simplified analogue solution could indicate corresponding interactions that occur within natural fingermarks. These potential interactions could go on to be the target of further investigation of latent fingermark chemistry, and ultimately contribute to a better understanding of the aging processes and degradation mechanisms that take place post-deposition.

Neurotoxic effect of oxaliplatin: Comparison with its oxalate-free analogue cis-[PtII(1R,2R-DACH)(3-acetoxy-1,1-cyclobutanedicarboxylato)] (LLC-1402) in mice

Studies suggest that oxalate is involved in the development oxaliplatin-induced peripheral sensory neuropathy (OPSN). This study aimed to compare the neurotoxic effects of oxaliplatin with its oxalate-free cytotoxic analogue cis-[Pt^II(1R,2R-DACH)(3-acetoxy-1,1-cyclobutanedicarboxylato)] (LLC-1402) in mice. Oxaliplatin and LLC-1402 were intravenously injected in male Swiss mice with a total of nine injections. Oxalate was intraperitoneally injected in other animals. The development of OPSN was evaluated using mechanical and thermal sensitivity tests. Dorsal root ganglia of the mice were removed to evaluate c-Fos, ATF3 and iNOS expression and a sample of blood was collected for leukocyte count and hepatic and renal biochemical function tests. Oxaliplatin and LLC-1402 decreased the mechanical and thermal nociceptive threshold, whilst oxalate lead to a partial and later increase in the mechanical sensitivity (P<0.05). c-Fos, ATF3 and iNOS expressions were increased in neuronal cells during and after the end of the injections in animals treated with oxaliplatin and LLC-1402 (P<0.05), even though oxaliplatin lead to an earlier increase. Only c-Fos expression was elevated during the period of injections in the oxalate group (P<0.05), but this expression reduced after the end of the treatment. c-Fos expression was also shown in glial satellite cells only in the oxaliplatin-treated animals. Oxaliplatin and LLC-1402 reduced leukocyte count (P<0.05), but did not change renal and liver functions. In conclusion, oxalate may contribute to an earlier development of peripheral sensory neuropathy. However, the antitumor cytotoxic mechanism of oxaliplatin seems to be the main responsible by its neurotoxic effect.

Thyroid Hormones and Derivatives: Endogenous Thyroid Hormones and Their Targets

More than a century after the discovery of L-Thyroxine, the main thyroid hormone secreted solely by the thyroid gland, several metabolites of this iodinated, tyrosine-derived ancestral hormone have been identified. These are utilized as hormones during development, differentiation, metamorphosis, and regulation of most biochemical reactions in vertebrates and their precursor species. Among those metabolites are the thyromimetically active 3,3',5-Triiodo-L-thyronine (T3) and 3,5-Diiodo-L-thronine, reverse-T3 (3,3',5'-Triiodo-L-thyronine) with still unclear function, the recently re-discovered thyronamines (e.g., 3-Iodo-thyronamine), which exert in part T3-antagonistic functions, the thyroacetic acids (e.g., Tetrac and Triac), as well as various sulfated or glucuronidated metabolites of this panel of iodinated signaling compounds. In the blood most of these hydrophobic metabolites are tightly bound to the serum distributor proteins thyroxine binding globulin (TBG), transthyretin (TTR), albumin or apolipoprotein B100. Cellular import and export of these charged, highly hydrophobic amino acid derivatives requires a number of cell-membrane transporters or facilitators such as MCT8 or MCT10 and members of the OATP and LAT families of transporters. Depending on their structure, the thyroid hormone metabolites exert their cellular action by binding and thus modulating the function of various receptors systems (e.g., ανβ3 integrin receptor and transient receptor potential channels (TRPM8) of the cell membrane), in part linked to intracellular downstream kinase signaling cascades, and several isoforms of membrane-associated, mitochondrial or nuclear thyroid hormone receptors (TR), which are members of the c-erbA family of ligand-modulated transcription factors. Intracellular deiodinase selenoenzymes, which obligatory are membrane integrated enzymes, ornithine decarboxylase and monoamine oxidases control local availability of biologically active thyroid hormone metabolites. Inactivation of thyroid hormone metabolites occurs mainly by deiodination, sulfation or glucuronidation, reactions which favor their renal or fecal elimination.

Flaviviridae viruses use a common molecular mechanism to escape nucleoside analogue inhibitors

The RNA-dependent RNA polymerases of Flaviviridae viruses are crucial for replication. The Flaviviridae polymerase is organized into structural motifs (A-G), with motifs F, A, C and E containing interrogating, priming and catalytic substrate-interacting sites. Modified nucleoside analogues act as antiviral drugs by targeting Flaviviridae polymerases and integrating into the synthesized product causing premature termination. A threonine mutation of a conserved serine residue in motif B of Flaviviridae polymerases renders resistance to 2'-C-methylated nucleoside analogues. The mechanism how this single mutation causes Flaviviridae viruses to escape nucleoside analogues is not yet known. Given the pivotal position of the serine residue in motif B that supports motif F, we hypothesized the threonine mutation causes alterations in nucleoside exploration within the entry tunnel. Implementing a stochastic molecular software showed the all-atom 2'-C-methylated analogue reaction within the active sites of wild type and serine-threonine mutant polymerases from Hepacivirus and Flavivirus. Compared with the wild type, the serine-threonine mutant polymerases caused a significant decrease of analogue contacts with conserved interrogating residues in motif F and a displacement of metal ion cofactors. The simulations significantly showed that during the analogue exploration of the active site the hydrophobic methyl group in the serine-threonine mutant repels water-mediated hydrogen bonds with the 2'-C-methylated analogue, causing a concentration of water-mediated bonds at the substrate-interacting sites. Collectively, the data are an insight into a molecular escape mechanism by Flaviviridae viruses from 2'-C-methylated nucleoside analogue inhibitors.

Vitamin D analogues: Potential use in cancer treatment

The vitamin D receptor (VDR) is a member of the thyroid-steroid family of nuclear transcription factors. Following binding of the active form of vitamin D, i.e., 1,25(OH)₂D3 (also known as calcitriol) and interaction with co-activators and co-repressors, VDR regulates the expression of several different genes. Although relatively little work has been carried out on VDR in human cancers, several epidemiological studies suggest that low circulating levels of vitamin D are associated with both an increased risk of developing specific cancer types and poor outcome in patients with specific diagnosed cancers. These associations apply especially in colorectal and breast cancer. Consistent with these findings, calcitriol as well as several of its synthetic analogues have been shown to inhibit tumor cell growth in vitro and in diverse animal model systems. Indeed, some of these vitamin D analogues with low calcemic inducing activity (e.g., EB1089, inecalcitol, paricalcitol) have progressed to clinical trials in patients with cancer. Preliminary results from these trials suggest that these vitamin D analogues have minimal toxicity, but clear evidence of efficacy remains to be shown. Although evidence of efficacy for mono-treatment with vitamin D analogues is currently lacking, several studies have reported that supplementation with calcitriol or the presence of high endogenous circulating levels of vitamin D enhances response to standard therapies.

Curcumin Analogue GO-Y030 Significantly Improves Pressure Overload-induced Heart Failure in Vivo

Collapse

The UVB1 Vitamin D analogue inhibits colorectal carcinoma progression

Vitamin D has been shown to display a wide variety of antitumour effects, but their therapeutic use is limited by its severe side effects. We have designed and synthesized a Gemini vitamin D analogue of calcitriol (UVB1) which has shown to display antineoplastic effects on different cancer cell lines without causing hypercalcemia. The aim of this work has been to investigate, by employing in silico, in vitro, and in vivo assays, whether UVB1 inhibits human colorectal carcinoma progression. We demonstrated that UVB1 induces apoptotic cell death and retards cellular migration and invasion of HCT116 colorectal carcinoma cells. Moreover, the analogue reduced the tumour volume in vivo, and modulated the expression of Bax, E-cadherin and nuclear β-catenin in tumour animal tissues without producing toxic effects. In silico analysis showed that UVB1 exhibits greater affinity for the ligand binding domain of vitamin D receptor than calcitriol, and that several characteristics in the three-dimensional conformation of VDR may influence the biological effects. These results demonstrate that the Gemini vitamin D analogue affects the growth of the colorectal cancer and suggest that UVB1 is a potential chemotherapeutic agent for treatment of this disease.

Memory amplification for trauma: Investigating the role of analogue PTSD symptoms in the laboratory

Victims of trauma often remember their experience as being more traumatic later, compared to immediately after, the event took place. This finding-the "memory amplification effect"-is associated with increased re-experiencing symptoms. However, the effect has been found almost exclusively in field-based studies. We examined whether the effect could be replicated in the laboratory. In two studies, we exposed participants to negative photographs and assessed their memory for the photographs and analogue PTSD symptoms on two occasions. In Study 1, analogue symptoms at follow-up were positively associated with remembering more negative photos over time. In Study 2, we focused on "memory amplifiers": people whose memory of the photos amplified over time. Consistent with field research, analogue re-experiencing symptoms were associated with memory amplification. Overall, our findings confirm that analogue PTSD symptoms are also associated with an amplified memory for a trauma analogue.

First synthesis of 22-oxa-chenodeoxycholic acid analogue

In this study, we report the first synthesis of 22-oxa-chenodeoxycholic acid analogue via androstenedione and progesterone, in 11 and 8 steps with overall yields of 6.4% and 12.7%, respectively. We anticipate this will help to facilitate the development of new drugs.

The alkynylphosphonate analogue of calcitriol EM1 has potent anti-metastatic effects in breast cancer

The active form of vitamin D3, calcitriol, plays a major role in maintaining calcium/phosphate homeostasis. In addition, it is a potent antiproliferative and prodifferentiating agent. However, when effective antitumor doses of calcitriol are employed, hypercalcemic effects are observed, thus precluding its therapeutic application. To overcome this problem, structural analogues have been designed with the aim at retaining or even increasing the antitumor effects while decreasing its calcemic activity. This report shows the biological evaluation of an alkynylphosphonate vitamin D less-calcemic analogue in a murine model of breast cancer. We demonstrate that this compound has potent anti-metastatic effects through its action over cellular migration and invasion likely mediated through the up-regulation of E-cadherin expression. Based on the current in vitro and in vivo results, EM1 is a promising candidate as a therapeutic agent in breast cancer.

A mini review on pyridoacridines: Prospective lead compounds in medicinal chemistry

Natural products are increasingly being considered “critical and important” in drug discovery paradigms as a number of them such as camptothecin, penicillin, and vincristine serve as “lead molecules” for the discovery of potent compounds of therapeutic interests namely irinotecan, penicillin G, vinblastine respectively. Derived compounds of pharmacological interests displayed a wide variety of activity viz. anticancer, anti-inflammatory, antimicrobial, anti-protozoal, etc.; when modifications or derivatizations are performed on a parent moiety representing the corresponding derivatives. Pyridoacridine is such a moiety which forms the basic structure of numerous medicinally important natural products such as, but not limited to, amphimedine, ascididemin, eilatin, and sampangine. Interestingly, synthetic analogues of natural pyridoacridine exhibit diverse pharmacological activities and in view of these, natural pyridoacridines can be considered as “lead compounds”. This review additionally provides a brief but critical account of inherent structure activity relationships among various subclasses of pyridoacridines. Furthermore, the current aspects and future prospects of natural pyridoacridines are detailed for further reference and consideration.

A comparison of analogue and digital methods

AIMS

To determine whether the size of the prostheses used in revision knee arthroplasty may be accurately and reproducibly predicted using analogue or digital pre-operative templating techniques.

METHODS

Pre-operative radiographs were templated using analogue radiographs and acetate templates, digital radiographs and acetate templates and digital radiographs and digital templating software.

RESULTS

Overall accuracy of predicting the size of implant used at surgery was 44%. There was no significant difference in the accuracy of the various templating techniques (p = 0.098).

CONCLUSIONS

Templating in revision knee arthroplasty is neither of suitable accuracy nor reliability enough to safely recommend its use for implant size prediction.

Comparison of stability, cellular, glucose-lowering and appetite supressing effects of oxyntomodulin analogues modified at the N-terminus. Eur J Pharmacol. 2014;743:69-78. [PMID: 25246014 DOI: 10.1016/j.ejphar.2014.09.018]

Oxyntomodulin (Oxm) possesses beneficial biological actions for the potential treatment of obesity-diabetes. However, rapid inactivation by dipeptidyl peptidase-4 (DPP-4) results in a short half-life, hindering therapeutic applicability. In the present study, six Oxm analogues namely, (Thr(2))Oxm, (Asp(3))Oxm, (Aib(2))Oxm, (d-Ser(2))Oxm, (N-acetyl)Oxm and (d-Ser(2))Oxm-Lys-γ-glutamyl-PAL were synthesised and tested for DPP-4 stability and biological activity. Native Oxm, (Thr(2))Oxm and (Asp(3))Oxm were rapidly degraded by DPP-4, while (Aib(2))Oxm, (d-Ser(2))Oxm, (N-acetyl)Oxm and (d-Ser(2))Oxm-Lys-γ-glutamyl-PAL were resistant to degradation. All peptides stimulated cAMP production (P<0.01 to P<0.001) in GLP-1-R, but not in GIP-R, transfected cells. In glucagon-R transfected cells, all peptides except (N-acetyl)Oxm and (Thr(2))Oxm evoked significant cAMP generation. Similarly, all analogues, except (N-acetyl)Oxm, exhibited prominent (P<0.05 to P<0.001) insulinotropic activity in BRIN BD11 cells. When administered in conjunction with glucose to normal mice only native Oxm, (Aib(2))Oxm and (d-Ser(2))Oxm significantly (P<0.05 to P<0.01) increased overall plasma insulin levels. The corresponding glycaemic excursion was significantly (P<0.05 to P<0.001) lowered by all Oxm peptides, barring (N-acetyl)Oxm. Further investigations revealed persistent glucose-lowering and insulin-releasing actions of (d-Ser(2))Oxm-Lys-γ-glutamyl-PAL. Studies in GIP- and GLP-1-receptor KO mice with (Aib(2))Oxm, (d-Ser(2))Oxm, and (d-Ser(2))Oxm-Lys-γ-glutamyl-PAL highlighted the importance of GLP-1 receptor signalling for the beneficial glucose homoeostatic actions of these analogues. All peptides, except (N-acetyl)Oxm, possessed significant appetite suppressive effects in mice. These data highlight the significant therapeutic promise of enzymatically stable Oxm-based peptides, particularly with position 2 modifications, for the treatment of obesity-diabetes.

Deoxysugar pathway interchange for erythromycin analogues heterologously produced through Escherichia coli

The overall erythromycin biosynthetic pathway can be sub-divided into macrocyclic polyketide formation and polyketide tailoring to produce the final bioactive molecule. In this study, the native deoxysugar tailoring reactions were exchanged for the purpose of demonstrating the production of alternative final erythromycin compounds. Both the d-desosamine and l-mycarose deoxysugar pathways were replaced with the alternative d-mycaminose and d-olivose pathways to produce new erythromycin analogues through the Escherichia coli heterologous system. Both analogues exhibited bioactivity against multiple antibiotic-resistant Bacillus subtilis strains. Besides demonstrating an intrinsic flexibility for the biosynthetic system to accommodate alternative tailoring pathways, the results offer an initial attempt to leverage the E. coli platform for erythromycin analogue production.

Evaluation of GnRH analogue testing in diagnosis and management of children with pubertal disorders

CONTEXT

Gonadotrophin releasing hormone (GnRH) stimulation test is pivotal in the assessment of children with pubertal disorders. However, lack of availability and high cost often result in the test falling into disfavor. We routinely use the GnRH analogue stimulation test as an alternative at our center.

AIM

To present the data on children with endocrine disorders who underwent GnRH agonist stimulation test in pediatric endocrine clinic of a tertiary care referral hospital.

SETTING AND DESIGN

Pediatric endocrine clinic of a tertiary care referral hospital. Retrospective analysis of case records.

MATERIALS AND METHODS

The details pertaining to clinical and radiological parameters and hormonal tests were retrieved from case records of 15 children who underwent GnRH agonist stimulation test from May 2010 to April 2011.

RESULTS

Indications for testing with GnRH analogue were evaluation of delayed puberty, diagnosis of precocious puberty, assessment of hormonal suppression in treatment of precocious puberty and micropenis in two, nine, three and one cases, respectively. The results of the test and clinical and radiological parameters were in concordance. The test was also crucial in diagnosing the onset of central precocious puberty in two children with congenital adrenal hyperplasia.

CONCLUSION

GnRH agonist test is a convenient, safe test that can be performed on an out-patient basis and can help the clinicians in the correct diagnosis and appropriate treatment of various puberty-related disorders.

Process standardization for rennet casein based Mozzarella cheese analogue

A process for manufacture of Mozzarella cheese analogue (MCA) using rennet casein and plastic cream as protein and fat sources respectively was standardized. The formulation comprised of 25% plastic cream (72% fat), 27% rennet casein along with 3% tri-sodium citrate as emulsifying salt, 2% maltodextrin as binder, 0.55% lactic acid as pH regulator, 1% common salt for seasoning, 1% Mozzarella cheese bud as flavouring and 40.4% water. The process involved (a) dissolving the dry mixture of casein, maltodextrin, flavouring and common salt in hot emulsifying salt solution, (b) incorporation of half the quantity of acid solution in casein-maltodextrin dough, followed by addition and emulsification of plastic cream, and (c) addition of remaining half of the acid solution and heating the mass to 80 °C until a plastic cheese mass was obtained. The analogue was shaped in ball form, cooled and packaged in polyethylene bag. The MCA conformed to the PFA requirements for pizza cheese and had all the requisite baking characteristics expected of pizza cheese topping.