Simultaneous Stereoinvertive and Stereoselective C(sp3)-C(sp3) Cross-Coupling of Boronic Esters and Allylic Carbonates.

With increasing interest in constructing more three-dimensional entities, there has been growing interest in cross-coupling reactions that forge C(sp3)-C(sp3) bonds, which leads to additional challenges as it is not just a more difficult bond to construct but issues of stereocontrol also arise. Herein, we report the stereocontrolled cross-coupling of enantioenriched boronic esters with racemic allylic carbonates enabled by iridium catalysis, leading to the formation of C(sp3)-C(sp3) bonds with single or vicinal stereogenic centers. The method shows broad substrate scope, enabling primary, secondary, and even tertiary boronic esters to be employed, and can be used to prepare any of the four possible stereoisomers of a coupled product with vicinal chiral centers. The new method, which combines the simultaneous enantiospecific reaction of a chiral nucleophile with the enantioselective reaction of a chiral electrophile in a single process, offers a solution for stereodivergent cross-coupling of two C(sp3) fragments.

Developing an alternative care pathway for emergency ambulance responses for adults with epilepsy: A Discrete Choice Experiment to understand which configuration service users prefer. Part of the COLLABORATE project.

INTRODUCTION: To identify service users' preferences for an alternative care pathway for adults with epilepsy presenting to the ambulance service. METHODS: Extensive formative work (qualitative, survey and knowledge exchange) informed the design of a stated preference discrete choice experiment (DCE). This hypothetical survey was hosted online and consisted of 12 binary choices of alternative care pathways described in terms of: the paramedic's access to medical records/ 'care plan', what happens next (described in terms of conveyance), time, availability of epilepsy specialists today, general practitioner (GP) notification and future contact with epilepsy specialists. DCE scenarios were described as: (i) typical seizure at home. (ii) typical seizure in public, (iii) atypical seizure. Respondents were recruited by a regional English ambulance service and by national public adverts. Participants were randomised to complete 2 of the 3 DCEs. RESULTS: People with epilepsy (PWE; n = 427) and friends/family (n = 167) who completed the survey were representative of the target population. PWE preferred paramedics to have access to medical records, non-conveyance, to avoid lengthy episodes of care, availability of epilepsy specialists today, GP notification, and contact with epilepsy specialists within 2-3 weeks. Significant others (close family members or friends) preferred PWE experiencing an atypical seizure to be conveyed to an Urgent Treatment Centre and preferred shorter times. Optimal configuration of services from service users' perspective far out ranked current practice (rank 230/288 possible configurations). DISCUSSION: Preferences differ to current practice but have minimal variation by seizure type or stakeholder. Further work on feasibility of these pathways in England, and potentially beyond, is required.

Service users' preferences and feasibility - which alternative care pathway for adult ambulance users achieves the optimal balance? Workshops for the COLLABORATE project.

INTRODUCTION: Adults presenting to the ambulance service for diagnosed epilepsy are often transported to emergency departments (EDs) despite no clinical need. An alternative care pathway (CP) could allow paramedics to divert them from ED and instigate ambulatory care improvements. To identify the most promising CP configuration for subsequent testing, the COLLABORATE project surveyed people with epilepsy and family/friends who had recently used the English ambulance service to elicit preferences for 288 CP configurations for different seizures. This allowed CPs to be ranked according to alignment with service users' preferences. However, as well as being acceptable to users, a CP must be feasible. We thus engaged with paramedics, epilepsy specialists and commissioners to identify the optimal configuration. METHODS: Three Knowledge Exchange workshops completed. Participants considered COLLABORATE's evidence on service users' preferences for the different configurations. Nominal group techniques elicited views on the feasibility of users' preferences according to APEASE criteria. Workshop groups specified the configuration/s considered optimum. Qualitative data was analysed thematically. Utility to users of the specified CP configurations estimated using the COLLABORATE preference survey data. RESULTS: Twenty-seven participants found service users' preferences broadly feasible and outlined delivery recommendations. They identified enough commonality in preferences for different seizures to propose a single CP. Its configuration comprised: 1) patients staying where they were; 2) paramedics having access to medical records; 3) care episodes lasting <6 h; 4) paramedics receiving specialist advice on the day; 5) patient's GP being notified; and 6) a follow-up appointment being arranged with an epilepsy specialist. Preference data indicated higher utility for this configuration compared to current care. DISCUSSION: Stakeholders are of the view that the CP configuration favoured by service users could be NHS feasible. It should be developed and evaluated.

'Knowledge exchange' workshops to optimise development of a risk prediction tool to assist conveyance decisions for suspected seizures - Part of the Risk of ADverse Outcomes after a Suspected Seizure (RADOSS) project.

PURPOSE: Suspected seizures present challenges for ambulance services, with paramedics reporting uncertainty over whether or not to convey individuals to emergency departments. The Risk of ADverse Outcomes after a Suspected Seizure (RADOSS) project aims to address this by developing a risk assessment tool utilizing structured patient care record and dispatch data. It proposes a tool that would provide estimates of an individual's likelihood of death and/or recontact with emergency care within 3 days if conveyed compared to not conveyed, and the likelihood of an 'avoidable attendance' occurring if conveyed. Knowledge Exchange workshops engaged stakeholders to resolve key design uncertainties before model derivation. METHOD: Six workshops involved 26 service users and their significant others (epilepsy or nonepileptic attack disorder), and 25 urgent and emergency care clinicians from different English ambulance regions. Utilizing Nominal Group Techniques, participants shared views of the proposed tool, benefits and concerns, suggested predictors, critiqued outcome measures, and expressed functionality preferences. Data were analysed using Hamilton's Rapid Analysis. RESULTS: Stakeholders supported tool development, proposing 10 structured variables for predictive testing. Emphasis was placed on the tool supporting, not dictating, care decisions. Participants highlighted some reasons why RADOSS might struggle to derive a predictive model based on structured data alone and suggested some non-structured variables for future testing. Feedback on prediction timeframes for service recontact was received, along with advice on amending the 'avoidable attendance' definition to prevent the tool's predictions being undermined by potential overuse of certain investigations in hospital. CONCLUSION: Collaborative stakeholder engagement provided crucial insights that can guide RADOSS to develop a user-aligned, optimized tool.

Raring to go? A cross-sectional survey of student paramedics on how well they perceive their UK pre-registration course to be preparing them to manage suspected seizures.

BACKGROUND: Paramedics convey a high proportion of seizure patients with no clinical need to emergency departments (EDs). In a landmark study, only 27% of UK paramedics reported being "Very…"/ "Extremely confident" making seizure conveyance decisions. Improved pre-registration education on seizures for paramedics is proposed. Clarity is needed on its potential given recent changes to how UK paramedics train (namely, degree, rather than brief vocational course). This study sought to describe UK student paramedics' perceived readiness to manage seizures and educational needs; compare this to what they report for other presentations; and, explore subgroup differences. METHODS: Six hundred thirty-eight students, in year 2 or beyond of their pre-registration programme completed a cross-sectional survey. They rated perceived confidence, knowledge, ability to care for, and educational needs for seizures, breathing problems and, headache. Primary measure was conveyance decision confidence. RESULTS: For seizures, 45.3% (95% CI 41.4-49.2) said they were "Very…"/"Extremely confident" to make conveyance decisions. This was similar to breathing problems, but higher than for headache (25.9%, 95% CI 22.6-29.5). Two hundred and thirty-nine participants (37.9%, 95% CI 34.1-41.8) said more seizure education was required - lower than for headache, but higher than for breathing problems. Subgroup differences included students on university-based programmes reporting more confidence for conveyance decisions than those completing degree level apprenticeships. CONCLUSIONS: Student paramedics report relatively high perceived readiness for managing seizures. Magnitude of benefit from enhancements to pre-registration education may be more limited than anticipated. Additional factors need attention if a sizeable reduction to unnecessary conveyances for seizures is to happen.

Stereospecific Conversion of Boronic Esters into Enones using Methoxyallene: Application in the Total Synthesis of 10-Deoxymethynolide.

Enones are widely utilized linchpin functional groups in chemical synthesis and molecular biology. We herein report the direct conversion of boronic esters into enones using commercially available methoxyallene as a three-carbon building block. Following boronate complex formation by reaction of the boronic ester with lithiated-methoxyallene, protonation triggers a stereospecific 1,2-migration before oxidation generates the enone. The protocol shows broad substrate scope and complete enantiospecificity is observed with chiral migrating groups. In addition, various electrophiles could be used to induce 1,2-migration and give a much broader range of α-functionalized enones. Finally, the methodology was applied to a 14-step synthesis of the enone-containing polyketide 10-deoxymethynolide.

Convergent Deboronative and Decarboxylative Phosphonylation Enabled by the Phosphite Radical Trap "BecaP".

Carbon-phosphorus bond formation is significant in synthetic chemistry because phosphorus-containing compounds offer numerous indispensable biochemical roles. While there is a plethora of methods to access organophosphorus compounds, phosphonylations of readily accessible alkyl radicals to form aliphatic phosphonates are rare and not commonly used in synthesis. Herein, we introduce a novel phosphorus radical trap "BecaP" that enables facile and efficient phosphonylation of alkyl radicals under visible light photocatalytic conditions. Importantly, the ambiphilic nature of BecaP allows redox neutral reactions with both nucleophilic (activated by single-electron oxidation) and electrophilic (activated by single-electron reduction) alkyl radical precursors. Thus, a broad scope of feedstock alkyl potassium trifluoroborate salts and redox active carboxylate esters could be employed, with each class of substrate proceeding through a distinct mechanistic pathway. The mild conditions are applicable to the late-stage installation of phosphonate motifs into medicinal agents and natural products, which is showcased by the straightforward conversion of baclofen (muscle relaxant) to phaclofen (GABAB antagonist).

Copper-Mediated Dehydrogenative C(sp3)-H Borylation of Alkanes.

Borylations of inert carbon-hydrogen bonds are highly useful for transforming feedstock chemicals into versatile organoboron reagents. Catalysis of these reactions has historically relied on precious-metal complexes, which promote dehydrogenative borylations with diboron reagents under oxidant-free conditions. Recently, photoinduced radical-mediated borylations involving hydrogen atom transfer pathways have emerged as attractive alternatives because they provide complimentary regioselectivities and proceed under metal-free conditions. However, these net oxidative processes require stoichiometric oxidants and therefore cannot compete with the high atom economy of their precious-metal-catalyzed counterparts. Herein, we report that CuCl2 catalyzes radical-mediated, dehydrogenative C(sp3)-H borylations of alkanes with bis(catecholato)diboron under oxidant-free conditions. This is a result of an unexpected dual role of the copper catalyst, which promotes oxidation of the diboron reagent to generate an electrophilic bis-boryloxide that acts as an effective borylating agent in subsequent redox-neutral photocatalytic C-H borylations.

Photoredox-Catalyzed Decarboxylative Bromination, Chlorination and Thiocyanation Using Inorganic Salts.

Decarboxylative halogenation reactions of alkyl carboxylic acids are highly valuable reactions for the synthesis of structurally diverse alkyl halides. However, many reported protocols rely on stoichiometric strong oxidants or highly electrophilic halogenating agents. Herein, we describe visible-light photoredox-catalyzed decarboxylative halogenation reactions of N-hydroxyphthalimide-activated carboxylic acids that avoid stoichiometric oxidants and use inexpensive inorganic halide salts as the halogenating agents. Bromination with lithium bromide proceeds under simple, transition-metal-free conditions using an organic photoredox catalyst and no other additives, whereas dual photoredox-copper catalysis is required for chlorination with lithium chloride. The mild conditions display excellent functional-group tolerance, which is demonstrated through the transformation of a diverse range of structurally complex carboxylic acid containing natural products into the corresponding alkyl bromides and chlorides. In addition, we show the generality of the dual photoredox-copper-catalyzed decarboxylative functionalization with inorganic salts by extension to thiocyanation with potassium thiocyanide, which was applied to the synthesis of complex alkyl thiocyanates.

Iridium-Catalyzed Asymmetric Difunctionalization of C-C σ-Bonds Enabled by Ring-Strained Boronate Complexes.

Enantioenriched organoboron intermediates are important building blocks in organic synthesis and drug discovery. Recently, transition metal-catalyzed enantioselective 1,2-metalate rearrangements of alkenylboronates have emerged as an attractive protocol to access these valuable reagents by installing two different carbon fragments across C═C π-bonds. Herein, we report the development of an iridium-catalyzed asymmetric allylation-induced 1,2-metalate rearrangement of bicyclo[1.1.0]butyl (BCB) boronate complexes enabled by strain release, which allows asymmetric difunctionalization of C-C σ-bonds, including dicarbonation and carboboration. This protocol provides a variety of enantioenriched three-dimensional 1,1,3-trisubstituted cyclobutane products bearing a boronic ester that can be readily derivatized. Notably, the reaction gives trans diastereoisomers that result from an anti-addition across the C-C σ-bond, which is in contrast to the syn-additions observed for reactions promoted by PdII-aryl complexes and other electrophiles in our previous works. The diastereoselectivity has been rationalized based on a combination of experimental data and density functional theory calculations, which suggest that the BCB boronate complexes are highly nucleophilic and react via early transition states with low activation barriers.

Synthesis of Dihydropyridine Spirocycles by Semi-Pinacol-Driven Dearomatization of Pyridines.

The identification of the beneficial pharmacokinetic properties of aza-spirocycles has led to the routine incorporation of these highly rigid and three-dimensional structures in pharmaceuticals. Herein, we report an operationally simple synthesis of spirocyclic dihydropyridines via an electrophile-induced dearomative semi-pinacol rearrangement of 4-(1'-hydroxycyclobutyl)pyridines. The various points for diversification of the spirocyclization precursors, as well as the synthetic utility of the amine and ketone functionalities in the products, provide the potential to rapidly assemble medicinally relevant spirocycles.

Strain-Release Driven Epoxidation and Aziridination of Bicyclo[1.1.0]butanes via Palladium Catalyzed σ-Bond Nucleopalladation.

The development of preparative methods for the synthesis of four-membered carbocycles is gaining increasing importance due to the widespread utility of cyclic compounds in medicinal chemistry. Herein, we report the development of a new methodology for the production of spirocyclic epoxides and aziridines containing a cyclobutane motif. In a two-step one-pot process, a bicyclo[1.1.0]butyl sulfoxide is lithiated and added to a ketone, aldehyde or imine, and the resulting intermediate is cross-coupled with an aryl triflate through C-C σ-bond alkoxy- or aminopalladation with concomitant epoxide or aziridine formation. After careful optimization, a remarkably efficient reaction was conceived that tolerated a broad variety of both aromatic and aliphatic substrates. Lastly, through several high yielding ring-opening reactions, we demonstrated the excellent applicability of the products as modular building blocks for the introduction of three-dimensional structures into target molecules.

Statins as an antiepileptogenic or disease-modifying treatment? A survey of what UK patients and significant others think about repurposing and trialing them for epilepsy.

OBJECTIVE: To identify the views of people with epilepsy (PWE), and their significant others, on the repurposing and trialing of statins as a potential antiepileptogenic or disease-modifying treatment for those who have had the first seizure. METHODS: Online questionnaire. Participants needed to be aged ≥ 16 years, UK residents, and able to independently complete a questionnaire in English. User groups distributed study adverts. Embedded infographics explained repurposing, why anti-seizure treatment is not typically started after a first seizure and the nature of randomized placebo-controlled trials (RCTs). The questionnaire asked participants to reflect and rate their expected willingness to have started an unspecified treatment after their first seizure/s (or that of the person with epilepsy they knew). They also rated willingness if the treatment were a statin, views of statins, the importance of an RCT of statins to their community, the outcomes it should assess, and their willingness to have taken part in it. The estimated number needed for the survey was 324. RESULTS: Responses from 213 persons were analyzed; 111 (52.1%) were PWE and 102 (47.9%) significant others. The median years diagnosed was 10 and PWE suffered from relatively severe epilepsy. One hundred and seventeen (54.9%) said they would have started an unspecified treatment after their first seizure/s (or supported the person with epilepsy they knew to have). A similar proportion (55.4%) said they would have started the treatment if it were a statin. Participants' main concern about statins, expressed by 79%, was their possible side effects. Repurposing was a concern for only 25%. Most (85.8%) rated an RCT of statins as of extreme or high importance; 54.4% said they would have participated. CONCLUSION: The PWE and significant others (SOs) responding to our survey expressed views towards repurposing statins that were generally positive and indicate a trial in those who have had a first seizure might be feasible. Concerns regarding side effects are common. Our findings could help optimize a future trial's design and the case for funding. Limitations include that we did not survey persons who had experienced a first seizure and did not go on to develop epilepsy. Also, persons with uncontrolled epilepsy were overrepresented.

Iterative synthesis of 1,3-polyboronic esters with high stereocontrol and application to the synthesis of bahamaolide A.

Polyketide natural products often contain common repeat motifs, for example, propionate, acetate and deoxypropionate, and so can be synthesized by iterative processes. We report here a highly efficient iterative strategy for the synthesis of polyacetates based on boronic ester homologation that does not require functional group manipulation between iterations. This process involves sequential asymmetric diboration of a terminal alkene, forming a 1,2-bis(boronic ester), followed by regio- and stereoselective homologation of the primary boronic ester with a butenyl metallated carbenoid to generate a 1,3-bis(boronic ester). Each transformation independently controls the stereochemical configuration, making the process highly versatile, and the sequence can be iterated prior to stereospecific oxidation of the 1,3-polyboronic ester to yield the 1,3-polyol. This methodology has been applied to a 14-step synthesis of the oxopolyene macrolide bahamaolide A, and the versatility of the 1,3-polyboronic esters has been demonstrated in various stereospecific transformations, leading to polyalkenes, -alkynes, -ketones and -aromatics with full stereocontrol.

Strain-Release Driven Epoxidation and Aziridination of Bicyclo[1.1.0]butanes via Palladium Catalyzed σ-Bond Nucleopalladation.

The development of preparative methods for the synthesis of four-membered carbocycles is gaining increasing importance due to the widespread utility of cyclic compounds in medicinal chemistry. Herein, we report the development of a new methodology for the production of spirocyclic epoxides and aziridines containing a cyclobutane motif. In a two-step one-pot process, a bicyclo[1.1.0]butyl sulfoxide is lithiated and added to a ketone, aldehyde or imine, and the resulting intermediate is cross-coupled with an aryl triflate through C-C σ-bond alkoxy- or aminopalladation with concomitant epoxide or aziridine formation. After careful optimization, a remarkably efficient reaction was conceived that tolerated a broad variety of both aromatic and aliphatic substrates. Lastly, through several high yielding ring-opening reactions, we demonstrated the excellent applicability of the products as modular building blocks for the introduction of three-dimensional structures into target molecules.

Protocol for the development of an international Core Outcome Set for treatment trials in adults with epilepsy: the EPilepsy outcome Set for Effectiveness Trials Project (EPSET).

BACKGROUND: A Core Outcome Set (COS) is a standardised list of outcomes that should be reported as a minimum in all clinical trials. In epilepsy, the choice of outcomes varies widely among existing studies, particularly in clinical trials. This diminishes opportunities for informed decision-making, contributes to research waste and is a barrier to integrating findings in systematic reviews and meta-analyses. Furthermore, the outcomes currently being measured may not reflect what is important to people with epilepsy. Therefore, we aim to develop a COS specific to clinical effectiveness research for adults with epilepsy using Delphi consensus methodology. METHODS: The EPSET Study will comprise of three phases and follow the core methodological principles as outlined by the Core Outcome Measures in Effectiveness Trials (COMET) Initiative. Phase 1 will include two focused literature reviews to identify candidate outcomes from the qualitative literature and current outcome measurement practice in phase III and phase IV clinical trials. Phase 2 aims to achieve international consensus to define which outcomes should be measured as a minimum in future trials, using a Delphi process including an online consensus meeting involving key stakeholders. Phase 3 will involve dissemination of the ratified COS to facilitate uptake in future trials and the planning of further research to identify the most appropriate measurement instruments to use to capture the COS in research practice. DISCUSSION: Harmonising outcome measurement across future clinical trials should ensure that the outcomes measured are relevant to patients and health services, and allow for more meaningful results to be obtained. CORE OUTCOME SET REGISTRATION: COMET Initiative as study 118 .

Supporting the ambulance service to safely convey fewer patients to hospital by developing a risk prediction tool: Risk of Adverse Outcomes after a Suspected Seizure (RADOSS)-protocol for the mixed-methods observational RADOSS project.

INTRODUCTION: Ambulances services are asked to further reduce avoidable conveyances to emergency departments (EDs). Risk of Adverse Outcomes after a Suspected Seizure seeks to support this by: (1) clarifying the risks of conveyance and non-conveyance, and (2) developing a risk prediction tool for clinicians to use 'on scene' to estimate the benefits an individual would receive if conveyed to ED and risks if not. METHODS AND ANALYSIS: Mixed-methods, multi-work package (WP) project. For WP1 and WP2 we shall use an existing linked data set that tracks urgent and emergency care (UEC) use of persons served by one English regional ambulance service. Risk tools are specific to clinical scenarios. We shall use suspected seizures in adults as an exemplar.WP1: Form a cohort of patients cared for a seizure by the service during 2019/2020. It, and nested Knowledge Exchange workshops with clinicians and service users, will allow us to: determine the proportions following conveyance and non-conveyance that die and/or recontact UEC system within 3 (/30) days; quantify the proportion of conveyed incidents resulting in 'avoidable ED attendances' (AA); optimise risk tool development; and develop statistical models that, using information available 'on scene', predict the risk of death/recontact with the UEC system within 3 (/30) days and the likelihood of an attendance at ED resulting in an AA.WP2: Form a cohort of patients cared for a seizure during 2021/2022 to 'temporally' validate the WP1 predictive models.WP3: Complete the 'next steps' workshops with stakeholders. Using nominal group techniques, finalise plans to develop the risk tool for clinical use and its evaluation. ETHICS AND DISSEMINATION: WP1a and WP2 will be conducted under database ethical approval (IRAS 307353) and Confidentiality Advisory Group (22/CAG/0019) approval. WP1b and WP3 have approval from the University of Liverpool Central Research Ethics Committee (11450). We shall engage in proactive dissemination and knowledge mobilisation to share findings with stakeholders and maximise evidence usage.

Four-Component Strain-Release-Driven Synthesis of Functionalized Azetidines.

Despite the favorable properties that azetidine rings can engender on drug-compounds, methods for the diversity-oriented synthesis of azetidine-based structures are significantly underdeveloped. Herein, we report the successful realization of a multicomponent [1,2]-Brook rearrangement/strain-release-driven anion relay sequence and its application to the modular synthesis of substituted azetidines. The rapidity of the reaction, as confirmed by in situ infra-red spectroscopy, leverages the strain-release ring-opening of azabicyclo[1.1.0]butane to drive the equilibrium of the Brook rearrangement. The three electrophilic coupling partners, added sequentially to azabicyclo[1.1.0]butyl-lithium, could be individually varied to access a diverse compound library. The utility of this methodology was demonstrated in a 4-step synthesis of the EP2 receptor antagonist PF-04418948.

Dual Nickel/Photoredox-Catalyzed Site-Selective Cross-Coupling of 1,2-Bis-Boronic Esters Enabled by 1,2-Boron Shifts.

Site-selective transition-metal-catalyzed mono-deboronative cross-couplings of 1,2-bis-boronic esters are valuable methods for the synthesis of functionalized organoboron compounds. However, such cross-couplings are limited to reaction of the sterically less hindered primary boronic ester. Herein, we report a nickel/photoredox-catalyzed mono-deboronative arylation of 1,2-bis-boronic esters that is selective for coupling of the more sterically hindered secondary/tertiary position. This is achieved by taking advantage of a 1,2-boron shift of primary ß-boryl radicals to the thermodynamically favored secondary/tertiary radicals, which are subsequently intercepted by the nickel catalyst to enable arylation. The mild conditions are amenable to a broad range of aryl halides to give ß-aryl boronic ester products in good yields and with high regioselectivity. This method also allows stereodivergent coupling of cyclic cis-1,2-bis-boronic esters to give trans-substituted products.

Facile Conversion of α-Amino Acids into α-Amino Phosphonates by Decarboxylative Phosphorylation using Visible-Light Photocatalysis.

Amino phosphonates exhibit potent inhibitory activity for a wide range of biological processes due to their specific structural and electronic properties, making them important in a plethora of applications, including as enzyme inhibitors, herbicides, antiviral, antibacterial, and antifungal agents. While the traditional synthesis of α-amino phosphonates has relied on the multicomponent Kabachnik-Fields reaction, we herein describe a novel and facile conversion of activated derivatives of α-amino acids directly to their respective α-amino phosphonate counterparts via a decarboxylative radical-polar crossover process enabled by the use of visible-light organophotocatalysis. The novel method shows broad applicability across a range of natural and synthetic amino acids, operates under mild conditions, and has been demonstrated to successfully achieve the late-stage functionalization of drug molecules.