Additional Substitution Research Articles

Green Synthesis of 2-Mercapto 5,6-Dihydro-4H-1,3-Thiazines via Sequential C–S Couplings

The six-membered N,S-heterocyclic 1,3-thiazines and their derivatives are widely acknowledged as pharmaceutical molecules with a wide range of biological activities. In this study, we developed a unique thiol-involved cascade reaction that enables the efficient construction of the 5,6-dihydro-4H-1,3-thiazine scaffold through consecutive intermolecular thiol-isothiocyanate and intramolecular thiol-halogen click reactions. Structurally diverse 2-mercapto dihydrothiazines including three antitumour candidates of bis-dihydrothiazines were readily obtained in high yields from the readily available thiols and 3-chloroisothiocyanate in the green solvent EtOH/H2O (1:1) using K2CO3 (0.6 equiv.) as the base. Between the two synthesis procedures investigated, the microwave-assisted reaction generally behaved more efficiently than that under routine heating conditions. Furthermore, DFT calculation confirmed the sequential addition–substitution mechanism. This cascade C–S coupling reaction methodology offers several advantages, including rapid completion, high reliability, easy purification, and benign conditions.

Catalytic Asymmetric Conjugate Addition and Allylic Substitution of Cyclobutenones with Arylzinc Halides

Comprehensive SummaryConjugate addition and allylic substitution are two essential chemical transformations, and they could be competitive for substrates with multiple reactive sites. Herein, we report the diversified enantioselective synthesis of cyclobutenes via the functionalization of cyclobutenones. The conjugate addition of cyclobutenones with arylzinc halides provided enantioenriched cyclobutenes with all‐carbon quaternary centers. On the other hand, when cyclobutenones with gem‐dichloro groups were employed, a chemo‐ and enantioselective allylic substitution occurred. Further synthetic utility was demonstrated for synthesizing versatile cyclobutane derivatives, together with ring‐opening and expansion products.

Characterisation of the antibody-mediated selective pressure driving intra-host evolution of SARS-CoV-2 in prolonged infection.

Neutralising antibodies against the SARS-CoV-2 spike (S) protein are major determinants of protective immunity, though insufficient antibody responses may cause the emergence of escape mutants. We studied the humoral immune response causing intra-host evolution in a B-cell depleted, haemato-oncologic patient experiencing clinically severe, prolonged SARS-CoV-2 infection with a virus of lineage B.1.177.81. Following bamlanivimab treatment at an early stage of infection, the patient developed a bamlanivimab-resistant mutation, S:S494P. After five weeks of apparent genetic stability, the emergence of additional substitutions and deletions within the N-terminal domain (NTD) and the receptor binding domain (RBD) of S was observed. Notably, the composition and frequency of escape mutations changed in a short period with an unprecedented dynamic. The triple mutant S:Delta141-4 E484K S494P became dominant until virus elimination. Routine serology revealed no evidence of an antibody response in the patient. A detailed analysis of the variant-specific immune response by pseudotyped virus neutralisation test, surrogate virus neutralisation test, and immunoglobulin-capture enzyme immunoassay showed that the onset of an IgM-dominated antibody response coincided with the appearance of escape mutations. The formation of neutralising antibodies against S:Delta141-4 E484K S494P correlated with virus elimination. One year later, the patient experienced clinically mild re-infection with Omicron BA.1.18, which was treated with sotrovimab and resulted in an increase in Omicron-reactive antibodies. In conclusion, the onset of an IgM-dominated endogenous immune response in an immunocompromised patient coincided with the appearance of additional mutations in the NTD and RBD of S in a bamlanivimab-resistant virus. Although virus elimination was ultimately achieved, this humoral immune response escaped detection by routine diagnosis and created a situation temporarily favouring the rapid emergence of various antibody escape mutants with known epidemiological relevance.

Base-Promoted Aminoamidation of Cinnamoyl Chlorides with Aryl Amines: Access to β-Amino Amides.

Herein, a base-promoted strategy for the synthesis of β-amino acids derivatives from α,β-unsaturated acyl chlorides derivatives and aryl amines has been described. In the presence of triethylamine, a tandem Michael addition and nucleophilic substitution progress was generated. The current method features readily available raw materials, mild reaction conditions, high atom economy, and wide tolerance for the coupling partners.

Comparative Study of Spectral and Functional Properties of Wild Type and Double Mutant H(L173)L/I(L177)H Reaction Centers of the Purple Bacterium Cereibacter sphaeroides.

Previously, we found that in the reaction center (RC) of the purple bacterium Cereibacter sphaeroides, formation of heterodimeric primary electron donor (P) caused by the substitution of His-L173 by Leu, was compensated by the second mutation Ile-L177-His. Significant changes in the spectral properties, pigment composition, and redox potential of P observed in the H(L173)LRC, are restored to the corresponding characteristics of the native RC in the RC H(L173)L/I(L177)H, with the difference that the energy of the long-wavelength QY optical transition of P increases significantly (by ~75meV). In this work, it was shown using light-induced difference FTIR spectroscopy that the homodimeric structure of P is preserved in the RC with double mutation with partially altered electronic properties: electronic coupling in the radical-cation of the P+ dimer is weakened and localization of the positive charge on one of its halves is increased. Results of the study of the triple mutant RC, H(L173)L/I(L177)H/F(M197)H, are consistent with the assumption that the observed changes in the P+ electronic structure, as well as considerable blue shift of the QYP absorption band in the RC H(L173)L/I(L177)H, are associated with modification of the spatial position and/or geometry of P. Using femtosecond transient absorption spectroscopy, it was shown that the mutant H(L173)L/I(L177)H RC retains a sequence of reactions P*→P+BA-→P+HA-→P+QA- with electron transfer rates and the quantum yield of the final stateP+QA- close to those observed in the wild-type RC (P*is the singlet-excited state ofP; BA, HA, and QA are molecules of bacteriochlorophyll, bacteriopheophytin, and ubiquinone in the active A-branch of cofactors, respectively). The obtained results, together with the previously published data for the RC with symmetrical double mutation H(M202)L/I(M206)H, demonstrate that by introducing additional point amino acid substitutions, photochemical activity of the isolated RC from C.sphaeroides could be maintained at a high level even in the absence of important structural elements- axial histidine ligands ofthe primary electron donorP.

Особенности перевода окказиональных единиц в англоязычной версии повести А. Платонова «Котлован»

The aim of the research is to identify the mechanisms for translating occasional units (nonce formations) in the English version of A. Platonov’s dystopian novella “The Foundation Pit” (1930). The originality of the research lies in the differentiation of units of occasional syntagmatics, i.e., occasional words, phrases, and constructions, and the identification of methods for translating these units from Russian into English. As a result, the research revealed that occasional words in the analyzed work are primarily translated using loose and descriptive translation. Occasional phrases created through intentional violations of lexical-semantic compatibility are translated through contextual substitution, calquing, mixed, descriptive, and loose translation, as well as addition and grammatical substitution. Occasional constructions created based on intentional violations of grammatical compatibility of words are translated through calquing, mixed translation methods, and through grammatical and contextual substitution. In many analyzed contexts, more than one syntagmatic violation was identified, including violations of stylistic norms of the Russian language, which pose a particular challenge in translation.

Hybrid Exb/Mot stators require substitutions distant from the chimeric pore to power flagellar rotation.

Ion-powered rotary motors (IRMs) underpin the rotation of one of nature's oldest wheels, the flagellar motor. Recent structures show that this complex appears to be a fundamental molecular module with diverse biological utility where electrical energy is coupled to torque. Here, we attempted to rationally design chimeric IRMs to explore the cross-compatibility of these ancient motors. We succeeded in making one working chimera of a flagellar motor and a non-flagellar transport system protein. This had only a short hybrid stretch in the ion-conducting channel, and function was subsequently improved through additional substitutions at sites distant from this hybrid pore region. Our goal was to test the cross-compatibility of these homologous systems and highlight challenges arising when engineering new rotary motors.

Elasticity of the HIV-1 core facilitates nuclear entry and infection.

HIV-1 infection requires passage of the viral core through the nuclear pore of the cell, a process that depends on functions of the viral capsid. Recent studies have shown that HIV-1 cores enter the nucleus prior to capsid disassembly. Interactions of the viral capsid with the nuclear pore complex are necessary but not sufficient for nuclear entry, and the mechanism by which the viral core traverses the comparably sized nuclear pore is unknown. Here we show that the HIV-1 core is highly elastic and that this property is linked to nuclear entry and infectivity. Using atomic force microscopy-based approaches, we found that purified wild type cores rapidly returned to their normal conical morphology following a severe compression. Results from independently performed molecular dynamic simulations of the mature HIV-1 capsid also revealed its elastic property. Analysis of four HIV-1 capsid mutants that exhibit impaired nuclear entry revealed that the mutant viral cores are brittle. Adaptation of two of the mutant viruses in cell culture resulted in additional substitutions that restored elasticity and rescued infectivity and nuclear entry. We also show that capsid-targeting compound PF74 and the antiviral drug Lenacapavir reduce core elasticity and block HIV-1 nuclear entry at concentrations that preserve interactions between the viral core and the nuclear envelope. Our results indicate that elasticity is a fundamental property of the HIV-1 core that enables nuclear entry, thereby facilitating infection. These results provide new insights into the role of the capsid in HIV-1 nuclear entry and the antiviral mechanisms of HIV-1 capsid inhibitors.

Catechol-modified stabilizer facilitates impulsive ligand functionalization of particulates and membrane modification of cells

Ligand-functionalized particulates have received considerable attention for targeted drug delivery. Previous studies have reported several methods for functionalizing various molecules on the surfaces of nano- and micro-particulates which involve multiple steps, reaction buffers and chemicals, and long reaction times. Here, we report a single-step method that uses catechol chemistry to rapidly functionalize ligands on the surfaces of polymeric nanoparticles (NPs). We synthesized dopamine-conjugated poly (ethylene-alt-maleic acid) (D-PEMA) by performing a nucleophilic addition reaction between dopamine and poly (ethylene-alt-maleic anhydride) (PEMAnh). We then used D-PEMA as a stabilizer while preparing NPs which led to the construction of NPs that were non-adhesive per se but provided active sites for conjugating multiple different ligands in an alkaline buffer via Michael's addition and Schiff's base substitution reactions. The ligand-functionalized NPs were nontoxic and effectively internalized by both primary and cancer cells. In addition, NPs prepared using the modified stabilizer conjugated rapidly on the surfaces of pancreatic islets in alkaline conditions. Our study provides evidence that the modified stabilizer is versatile and has the potential for drug delivery applications and cell surface modifications.

Substitution of additives in horseradish sauce: technological strategies and efficacy

An additive-free horseradish sauce was produced by replacing citric acid and sulfites, commonly used as acidifying, and antimicrobial/anti-browning agents, respectively. Unripe grape juice was used as acidifier, while steam blanching was applied to inactivate horseradish peroxidase (HRP) to avoid browning. Unexpectedly, the heat treatment inactivated myrosinase, responsible for the release of the irritating allyl isothiocyanate from sinigrin's hydrolysis, causing undesired loss of pungency. To restore it, mustard seed powder was added as an ingredient naturally rich in myrosinase. The inactivation of HRP and restoration of myrosinase were evaluated through spectrophotometric measurements of HRP and chromatographic analysis of glucose, a reaction product of myrosinase. The experimental sauce, obtained by adding basic ingredients to horseradish, was stabilized through pasteurization and subjected to sensory analysis and colorimetric evaluation. An additive-free and sustainable horseradish sauce was obtained, using mustard seeds and exploiting thinned bunches as by-products instead of wasting them.

Longitudinal survey of insecticide resistance in a village of central region of Burkina Faso reveals co-occurrence of 1014F, 1014S and 402L mutations in Anopheles coluzzii and Anopheles arabiensis

BackgroundPyrethroid resistance is one of the major threats for effectiveness of insecticide-treated bed nets (ITNs) in malaria vector control. Genotyping of mutations in the voltage gated sodium channel (VGSC) gene is widely used to easily assess the evolution and spread of pyrethroid target-site resistance among malaria vectors. L1014F and L1014S substitutions are the most common and best characterized VGSC mutations in major African malaria vector species of the Anopheles gambiae complex. Recently, an additional substitution involved in pyrethroid resistance, i.e. V402L, has been detected in Anopheles coluzzii from West Africa lacking any other resistance alleles at locus 1014. The evolution of target-site resistance mutations L1014F/S and V402L was monitored in An. coluzzii and Anopheles arabiensis specimens from a Burkina Faso village over a 10-year range after the massive ITN scale-up started in 2010.MethodsAnopheles coluzzii (N = 300) and An. arabiensis (N = 362) specimens collected both indoors and outdoors by different methods (pyrethrum spray catch, sticky resting box and human landing collections) in 2011, 2015 and 2020 at Goden village were genotyped by TaqMan assays and sequencing for the three target site resistance mutations; allele frequencies were statistically investigated over the years.ResultsA divergent trend in resistant allele frequencies was observed in the two species: 1014F decreased in An. coluzzii (from 0.76 to 0.52) but increased in An. arabiensis (from 0.18 to 0.70); 1014S occurred only in An. arabiensis and slightly decreased over time (from 0.33 to 0.23); 402L increased in An. coluzzii (from 0.15 to 0.48) and was found for the first time in one An. arabiensis specimen. In 2020 the co-occurrence of different resistance alleles reached 43% in An. coluzzii (alleles 410L and 1014F) and 32% in An. arabiensis (alleles 1014F and 1014S).ConclusionsOverall, an increasing level of target-site resistance was observed among the populations with only 1% of the two malaria vector species being wild type at both loci, 1014 and 402, in 2020. This, together with the co-occurrence of different mutations in the same specimens, calls for future investigations on the possible synergism between resistance alleles and their phenotype to implement local tailored intervention strategies.

The Ile35 Residue of the ALS-Associated Mutant SOD1 Plays a Crucial Role in the Intracellular Aggregation of the Molecule.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with an unknown pathogenesis. It has been reported that mutations in the gene for Cu/Zn superoxide dismutase (SOD1) cause familial ALS. Mutant SOD1 undergoes aggregation and forms amyloid more easily, and SOD1-immunopositive inclusions have been observed in the spinal cords of ALS patients. Because of this, SOD1 aggregation is thought to be related to the pathogenesis of ALS. Some core regions of amyloid have been identified, but the issue of whether these regions form aggregates in living cells remains unclear, and the mechanism responsible for intracellular SOD1 aggregation also remains unclear. The findings reported in this study indicate that the aggregation of the ALS-linked mutant SOD1-EGFP was significantly enhanced when the BioID2 gene was fused to the N-terminus of the mutant SOD1-EGFP plasmid for cellular expression. Expression of a series of BioID2-(C-terminal deletion peptides of SOD1)-EGFP permitted us to identify 1-35 as a minimal N-terminal sequence and Ile35 as an essential amino acid residue that contributes to the intracellular aggregation of SOD1. The findings also showed that an additional substitution of Ile35 with Ser into the ALS mutant SOD1 resulted in the significant suppression of aggregate formation. The fact that no Ile35 mutations have been reported to date in ALS patients indicates that all ALS mutant SOD1s contain Ile35. Taken together, we propose that Ile35 plays a pivotal role in the aggregation of the ALS-linked SOD1 and that this study will contribute to our understanding of the mechanism responsible for SOD1 aggregation.

Effects of halogens and alkali metals on guanidinium-ethylammonium hybrid-doped perovskite photovoltaic devices

Effects of substitution of halogen anions and addition of alkali metal cations for guanidinium (GA)-ethylammonium (EA) hybrid-doped perovskite solar cells were investigated by fabricating devices and comparing their photovoltaic properties. The halogen compositions of the additives were found to contribute to the improvement of preferred orientations of perovskite crystals, and the order of the effectiveness was I, Cl, and Br. In addition, the addition of alkali metal cations contributed to improvement of the conversion efficiencies, and 3 % addition of cesium at the CH3NH3 site was the most effective. It was also found that the short-circuit current densities and fill factors depended on the (100) preferred crystal orientation of the perovskite compounds.

Research on the corrosion inhibition performance and mechanism of pyrimidine quaternary ammonium salt

PurposeAt present, research on the preparation of corrosion inhibitors using modified pyrimidine derivatives is still blank. The purpose of this study is to synthesize a new cationic mercaptopyrimidine derivative quaternary ammonium salt, known as DTEBTAC, that can be used as a corrosion inhibitor to slow down the metal corrosion problems encountered in oil and gas extraction processes.Design/methodology/approachA new corrosion inhibitor was synthesized by the reaction of anti-Markovnikov addition and nucleophilic substitution. The weight loss method was used to study the corrosion inhibition characteristics of synthetic corrosion inhibitors. Electrochemical and surface topography analyses were used to determine the type of inhibitor and the adsorption state formed on the surface of N80 steel. Molecular dynamics simulations and quantum chemistry calculations were used to investigate the synthetic corrosion inhibitor’s molecular structure and corrosion inhibition mechanisms.FindingsThe results of the weight loss method show that when the dosage of DTEBTAC is 1%, the corrosion rate of N80 steel in hydrochloric acid solution at 90? is 3.3325 g m-2 h-1. Electrochemical and surface morphology analysis show that DTEBTAC can form a protective layer on the surface of N80 steel, and is a hybrid corrosion inhibitor that can inhibit the main anode. Quantum chemical parameter calculation shows that DTEBTAC has a better corrosion inhibition effect than DTP. The molecular dynamics simulation results show that DTEBTAC has stronger binding energy than DTP, and forms a network packing structure through hydrogen bonding, and the adsorption stability is enhanced.Originality/valueA novel cationic mercaptopyrimidine derivative quaternium-ammonium salt corrosion inhibitor was designed and provided. Compared with the prior art, the preparation method of the synthesized mercaptopyrimidine derivative quaternary ammonium salt corrosion inhibitor is simple, and the presence of nitrogen-positive ions, sulfur atoms and nitrogen-rich atoms has an obvious corrosion inhibition effect, which can be used to inhibit metal corrosion during oil and gas field exploitation. It not only expands the application field of new materials but also provides a new idea for the research and development of new corrosion inhibitors.

A Plasmodium falciparum genetic cross reveals the contributions of pfcrt and plasmepsin II/III to piperaquine drug resistance.

Piperaquine (PPQ) is widely used in combination with dihydroartemisinin as a first-line treatment against malaria. Multiple genetic drivers of PPQ resistance have been reported, including mutations in the Plasmodium falciparum chloroquine resistance transporter (pfcrt) and increased copies of plasmepsin II/III (pm2/3). We generated a cross between a Cambodia-derived multidrug-resistant KEL1/PLA1 lineage isolate (KH004) and a drug-susceptible Malawian parasite (Mal31). Mal31 harbors a wild-type (3D7-like) pfcrt allele and a single copy of pm2/3, while KH004 has a chloroquine-resistant (Dd2-like) pfcrt allele with an additional G367C substitution and multiple copies of pm2/3. We recovered 104 unique recombinant parasites and examined a targeted set of progeny representing all possible combinations of variants at pfcrt and pm2/3. We performed a detailed analysis of competitive fitness and a range of PPQ susceptibility phenotypes with these progenies, including PPQ survival assay, area under the dose response curve, and a limited point IC50. We find that inheritance of the KH004 pfcrt allele is required for reduced PPQ sensitivity, whereas copy number variation in pm2/3 further decreases susceptibility but does not confer resistance in the absence of additional mutations in pfcrt. A deep investigation of genotype-phenotype relationships demonstrates that progeny clones from experimental crosses can be used to understand the relative contributions of pfcrt, pm2/3, and parasite genetic background to a range of PPQ-related traits. Additionally, we find that the resistance phenotype associated with parasites inheriting the G367C substitution in pfcrt is consistent with previously validated PPQ resistance mutations in this transporter.IMPORTANCEResistance to piperaquine, used in combination with dihydroartemisinin, has emerged in Cambodia and threatens to spread to other malaria-endemic regions. Understanding the causal mutations of drug resistance and their impact on parasite fitness is critical for surveillance and intervention and can also reveal new avenues to limiting the evolution and spread of drug resistance. An experimental genetic cross is a powerful tool for pinpointing the genetic determinants of key drug resistance and fitness phenotypes and has the distinct advantage of quantifying the effects of naturally evolved genetic variation. Our study was strengthened since the full range of copies of KH004 pm2/3 was inherited among the progeny clones, allowing us to directly test the role of the pm2/3 copy number on resistance-related phenotypes in the context of a unique pfcrt allele. Our multigene model suggests an important role for both loci in the evolution of this multidrug-resistant parasite lineage.

Improving the Nutritional Quality of Protein and Microbiota Effects in Additive- and Allergen-Free Cooked Meat Products.

The primary objective of the meat industry is to enhance the quality and positive attributes of meat products, driven by an increasing consumer demand for healthier, less processed options. One common approach to achieving this goal is the replacement of additives and allergens with natural ingredients. Nevertheless, the nutritional impact of these changes has not been extensively studied. To address these gaps, two new meat products were developed: cooked turkey breast and cooked ham. The products in question exclude additives and allergens and instead incorporate a blend of natural extracts containing vitamin C, chlorogenic acids, hydroxytyrosol, catechins, epicatechins, vinegar, and inulin fibre. The objective of this study was to evaluate the impact of these reformulations on protein quality and gut microbiota. Protein quality was evaluated using the Digestible Indispensable Amino Acid Score (DIAAS) following in vitro digestion. The microbial composition and short-chain fatty acid (SCFA) production were analysed through in vitro colonic fermentations in both normal-weight and obese participants in order to gauge their effect on gut microbiota. The results demonstrated that the reformulation of cooked turkey breast increased its digestibility by 6.4%, while that of cooked ham exhibited a significant 17.9% improvement. Furthermore, protein quality was found to have improved significantly, by 19.5% for cooked turkey breast and 32.9% for cooked ham. Notwithstanding these alterations in protein digestibility, the microbial composition at the phylum and genus levels remained largely unaltered. Nevertheless, total SCFA production was observed to increase in both groups, with a more pronounced effect observed in the normal-weight group. In conclusion, the substitution of artificial additives with natural ingredients in reformulated cooked meat products has resulted in enhanced digestibility, improved protein quality, and increased production of short-chain fatty acids.

Identification of genomic regions controlling spikelet degeneration under FRIZZLE PANICLE (FZP) defect genetic background in rice

The FZP gene plays a critical role in the formation of lateral branches and spikelets in rice panicle architecture. This study investigates the qSBN7 allele, a hypomorphic variant of FZP, and its influence on panicle architectures in different genetic backgrounds. We evaluated two backcross inbred lines (BILs), BC5_TCS10sbn and BC3_TCS10sbn, each possessing the homozygous qSBN7 allele but demonstrating differing degrees of spikelet degeneration. Our analysis revealed that BC5_TCS10sbn had markedly low FZP expression, which corresponded with an increase in axillary branches and severe spikelet degeneration. Conversely, BC3_TCS10sbn exhibited significantly elevated FZP expression, leading to fewer secondary and tertiary branches, and consequently decreased spikelet degeneration. Compared to BC5_TCS10sbn, BC3_TCS10sbn carries three additional chromosomal substitution segments from its donor parent, IR65598-112-2. All three segments significantly enhance the expression of FZP and reduce the occurrence of tertiary branch and spikelet degeneration. These findings enhance our understanding of the mechanisms regulating FZP and aid rice breeding efforts.

Assessment of Lightweight Concrete Properties with Zinc Oxide Nanoparticles: Structural and Morphological Analyses

In recent decades, the use of nanotechnology has increased in many disciplines. Specifically, in the concrete industry, nanotechnology has been used to develop more eco-efficient solutions. There is a rapidly growing interest in using nanoparticles in concrete to tackle environmental impacts. Among the nanoparticles investigated, zinc oxide (ZnO) shows great potential because of its material properties, such as reactivity, non-toxicity, a hard and rigid structure, photocatalytic and photoluminescence properties, and chemical, electrical, and thermal stabilities. This paper focuses on the analysis of the effect of ZnO nanoparticles in lightweight concrete at different concentrations (0.5, 1, 1.5, and 2.0 wt%) using two different methods including (i) addition and (ii) partial substitution for cement. Mechanical properties are determined by compressive strength tests. Chemical and morphological characterization is performed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. This study reveals that an increase in the percentage of ZnO nanoparticles as a substitute for cement directly decreases the compressive strength of lightweight concrete. For ZnO nanoparticles in the addition method, compressive strength is 10% lower than in the control specimens. However, the conclusions indicate constant compressive strength for all ZnO nanoparticle concentrations in the addition method.

#1377 Evaluation of state-wide health system implementation of renal supportive care shows substantial net benefits

Abstract Background and Aims In 2016, the New South Wales (NSW) Health system implemented a service to make the principles and practice of palliative medicine comprehensively available to patients receiving chronic kidney disease (CKD) care across NSW. Summative evaluation of the economic value that this multi-disciplinary State-wide RSC service provided following implementation was prospectively planned in the domains of patient experience and economic value. This abstract reports the first cost-benefit analysis of a RSC service. Method De-identified patient-level data was extracted from the NSW Renal Supportive Care Register (a linked dataset comprising admitted patient, non-admitted patient, emergency department episodes and death registrations). Data was compared between 2015/16, prior to implementation of the State-wide RSC service; and 2018/19, following settled operation of the service. A cost-benefit analysis model was constructed to estimate the economic value of the RSC service between 2015/16 and 2018/19; and the projected value to 2029/30 under different scenarios. Multivariate Cox regressions were estimated to measure survival benefits, and a polynomial regression model was employed to estimate the impact of RSC on the share of patients receiving dialysis. Results Considering the actual impact of the NSW RSC service; in 2015/16, 5% (n = 443) of all ESKD patients, (defined as receiving dialysis >3 months, non-dialysis conservative care or in receipt of a functioning transplant) received any RSC service. By 2018/19, 16% (n = 1460) of all ESKD patients had received RSC within NSW. The proportion of patients receiving RSC from a non-dialysis conservative care or dialysis context remained stable between 2015/16 and 2018/19 at 41% and 29% respectively. Patients receiving RSC were estimated to have increased survival by 3-21 weeks, depending on patient characteristics, compared to the scenario of no RSC service. Considering the projected value of ongoing RSC services; scenarios with different assumptions were modelled. Assuming that the proportion of patients receiving different ESKD modalities and the costs of care remained stable, the RSC service would deliver a net financial benefit to the commissioning health system (avoided costs of service minus RSC costs) of ${\$}$109 million Australian Dollars (AUD), with a return on investment of 212%, compared to the scenario of no RSC service. When the economic value for the whole NSW community from increased survival benefit was included, the projected value was ${\$}$275 million AUD, with return on investment of 535%. The projected economic value of RSC was modelled under scenarios of increasing access to the service by ESKD patients (Figure). Increasing RSC access from the achieved 16% to 20% of ESKD patients was projected to deliver maximal economic value, with a 3% fall in ESKD patients receiving dialysis, increasing survival benefit (${\$}$221 million AUD) and economic value ${\$}$94 million AUD. As access to RSC expands further, modelling indicates that additional dialysis substitution becomes less likely but benefits still accrue from survival up to a maximum viable rollout of 50% of the ESKD population receiving RSC, when survival benefits plateau. Conclusion Economic evaluation of this implementation of the Statewide RSC service across NSW Health shows it has been associated with both a net economic benefit and survival benefits four years after implementation. It is projected to provide an economic value of ${\$}$275 million AUD over ten years, which would increase with greater participation of ESKD patients suitable for RSC.

Essential residues in diterpene synthases for biosynthesis of oryzalexins A-F in rice phytoalexin.

Cultivated rice (Oryza sativa) produces a variety of diterpenoid-type phytoalexins. Diterpene synthase genes that are responsible for the biosynthesis of momilactones, phytocassanes, and oryzalexins have been identified in O. sativa cv. Nipponbare. OsKSL10 (Os12t0491800 in RAP and LOC_Os12g30824 in MSU) was previously identified as an enzyme catalyzing the conversion of ent-copalyl diphosphate to ent-sandaracopimaradiene for the production of oryzalexins A to F. Our previous study on Oryza rufipogon, a wild progenitor of Asian cultivated rice, showed that both OrKSL10 and OrKSL10ind from O. rufipogon accessions W1943 and W0106, respectively, closely related to the japonica and indica subspecies, converted ent-copalyl diphosphate to ent-miltiradiene. Thus, the functional conversion of ent-miltiradiene synthase into ent-sandaracopimaradiene synthase is implied to have occurred through natural amino acid mutations, the details of which have not been elucidated. In this study, we show that introduction of A654G substitution into OrKSL10 significantly alters its function into more closely resembling that of OsKSL10. Moreover, double substitution V546I/A654G almost completely converts the function of OrKSL10 into that of OsKSL10. On the other hand, the reversed substitution I546V/G654A was insufficient to convert the function of OsKSL10 into OrKSL10, indicating the introduction of additional substitution S522I is required for the functionality of OsKSL10. Lastly, point mutations atthe 654A residue in OrKSL10 suggest that hydrophobic side chains atthis position have a negative influence on the production of ent-sandaracopimaradiene.