Carbamate Group Research Articles

β-d-Ribofuranose as a Core with a Phosphodiester Moiety as the Enzyme Recognition Site for Codrug Development.

An ideal codrug design should be able to control drug release, offer selectivity during drug delivery, and break down into non-toxic fragments after biodegradation. Our design incorporates d-ribofuranose as the core, with carbamate and carbonate groups as linking joints, a phosphodiester moiety as an enzyme recognition site, and lenalidomide and paclitaxel as the constituent drugs. The codrug synthesis involves seven steps with a 33% overall yield. The target codrug increases its water solubility 685 times versus paclitaxel.

Bonding of rubber to steel: Effects of hydroxyl-terminated polybutadiene on the adhesion of waterborne polyurethane adhesives

Rubber as a substrate exhibits very different surface physical and chemical characteristics from steel. It still remains challenging to achieve a complete interface stripping of steel while maintaining double-sided adhesion between rubber and steel. Hydroxyl-terminated polybutadiene (HTPB) possesses remarkable low-temperature flexibility that contributes to migration and orientation of molecular chains, and contains abundant C=C bonds that facilitate cross-linking reaction. In this work, the hydroxyethyl acrylate (HEA)-terminated waterborne polyurethane (WPUH) adhesive was prepared by introducing HTPB into polyurethane backbone. The impact of HTPB on the properties of WPUH adhesive was investigated by changing HTPB/poly(tetramethylene ether) glycol (PTMG) molar ratio. The reasons for such change were studied focusing on the structure and bonding mechanism of WPUH adhesive. When rubber and steel were bonded together by WPUH adhesive, the rubber would induce non-polar HTPB segments to approach the bonding interface while the steel would attract the polar carbamate groups to its surface. The adhesion was strengthened by the interfacial interaction once WPUH adhesive wetted two substrates. In addition, the 1,2-isomer C=C bonds of HTPB could undergo free radical polymerization with HEA to form a cross-linked network, which improved the cohesion. This study provides a feasible strategy for achieving the goal of effectively bonding rubber-to-steel without residual adhesive stripping.

Cholesterol Decorated Diazocine Gelator with Photo‐ and Thermo‐Responsive Properties for Smart Window

Comprehensive SummaryA new gelator (BAzo‐Chol) comprising a diazocine core and two cholesterol units linked via carbamate groups has been designed and synthesized. Its gelation ability in several kinds of organic solvents is identified. Investigations with scanning electron microscopy (SEM), transmission electron microscopy (TEM), rheological measurements, and UV‐vis absorption and 1H NMR spectroscopy reveal that BAzo‐Chol can self‐assemble into elastically interpenetrating one‐dimensional nanostructures in organogels through a cooperative effect of the π‐π interactions, hydrogen‐bonding, and van der Waals forces. Moreover, the unconventional Z/E conformational transitions of these organogels, due to the inclusion of diazocine, endow the BAzo‐Chol gels with excellent photo‐responsive gel‐sol transition and remarkable visible light‐induced chromic properties. Lastly, due to its sensitive response to visible light accompanied by distinct changes in both colour and transparency of the gel‐sol transitions, the potential application of the current gelator in smart windows is signified.

Bioisosteres at C9 of 2-Deoxy-2,3-didehydro-N-acetyl Neuraminic Acid Identify Selective Inhibitors of NEU3.

Human neuraminidases play critical roles in many physiological and pathological processes. Humans have four isoenzymes of NEU, making selective inhibitors important tools to investigate the function of individual isoenzymes. A typical scaffold for NEU inhibitors is 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA) where C9 modifications can be critical for potency and selectivity against human NEU. To design improved DANA analogues, we generated a library of compounds with either a short alkyl chain or a biphenyl substituent linked to the C9 position through one of six amide bioisosteres. Bioisostere linkers included triazole, urea, thiourea, carbamate, thiocarbamate, and sulfonamide groups. Within this library, we identified a C9 biphenyl carbamate derivative (963) that showed high selectivity and potency for NEU3 (Ki = 0.12 ± 0.01 μM). In contrast, NEU1 and NEU4 isoenzymes preferred amide and triazole linkers, respectively. Finally, analogues with urea, sulfonamide, and amide linkers showed enhanced inhibitory activity for a bacterial NEU, NanI from Clostridium perfringens.

Formation of Titanosilicate N,N‐dialkyl Carbamates by CO2 Insertioninto the [(tBuO)3SiO]3TiNR2 Scaffold

Molecular titanosilicates {(tBuO3)3SiO}2Ti(NR2)2 (1, R= Et; 2, R= Me) and {(tBuO3)3SiO}3TiNR2 (TSA1, R= Et; 3, R= Me) were obtained from the reaction between silanol (tBuO3)3SiOH (S1) and titanium amides Ti(NR2)4 (R= Et, R= Me). Additionally, the reaction of 3 and TSA1 with CO2 led to the exclusive formation of carbamates {(tBuO)3SiO}3Ti(O2NCR2) (4, R= Et; 5, R= Me). The molecular structure of 5 confirmed the proposed connectivity and presence of SiO4 and Ti(O2NCR2) units. In compound 5, titanium is coordinated to five oxygen atoms belonging to one bidentate carbamate group and three silicate ligands in a distorted square‐base pyramidal geometry. Also, we have performed DFT calculations and QTAIM analysis to study the distribution of the electron density in the carbamatecarbamate {(tBuO)3SiO}3Ti(O2CNEt2) (4) and salt {(tBuO)3SiO}3TiO(H2NMe2) 6 which was obtained by the hydrolysis of compound 5.

Study of multifunctional anti-AD ligands: design, synthesis, X-ray crystal structure and biological evaluation of diosmetin derivatives.

The development of anti-AD drugs has attracted much attention as the number of AD patients is increasing year by year. Five diosmetin derivatives (1-5) were designed and synthesized by introducing carbamate groups. The crystal structure of 1 was analyzed by X-ray diffraction, which showed a large conjugated coplanar structure and might be favorable for the insertion into the Aβ folding. Meanwhile, in vitro experiments were carried out to investigate the anticholinesterase activity, metal chelating property, antioxidant activity, and anti-Aβ aggregation ability of 1-5. The results showed that 1-5 had good cholinesterase inhibitory activities. Compound 4 showed the highest inhibitory activities against butyrylcholinesterase (IC50 = 0.0760μM). Further kinetic experiments and molecular docking studies showed that 4 could bind well to butyrylcholinesterase. The molecular dynamics simulations also signified that compared with diosmetin, 4 could reduce the flexibility of the butyrylcholinesterase protein skeleton to a greater extent, and thus had a better inhibitory effect. In addition, 1-5 could selectively chelate copper ions and all of them had good antioxidant activity as well as anti-Aβ aggregation ability. Among them, 4 had the strongest activity to inhibit Cu2+-induced Aβ aggregation (51.09%) and had low cytotoxicity. In addition, in vivo ROS activity assay (Caenorhabditis elegans) showed that 4 had the ability to scavenge ROS. Besides, the in vivo Aβ aggregation assay showed that 4 could reduce Aβ aggregation. In conclusion, 4 has the potential to be developed into a multifunctional anti-AD drug.

Life-Saving Resin: Hemoperfusion's Role in Overcoming Acute Organophosphate and Carbamate Poisoning

Background: Acute poisoning from organophosphates and carbamates is a major public health concern. These poisons inhibit acetylcholinesterase, leading to severe clinical manifestations. Traditional treatments, such as atropine and oximes, often fall short in severe cases, necessitating alternative therapeutic approaches. Hemoperfusion, an extracorporeal blood purification technique, has shown promise in improving outcomes for poisoning cases. This study aimed to estimate the clinical outcomes of resin-based HOD in individuals with acute organophosphate and carbamate poisoning admitted to a South Asian tertiary care hospital. Methods: A prospective observational study was carried out involving 50 patients diagnosed with acute organophosphate (n=30) or carbamate (n=20) poisoning. Patients underwent standard treatment protocols, and eligible individuals received resin-based hemoperfusion. Data on demographic details, clinical outcomes, complications, and biochemical parameters were collected and analysed using SPSS version 25.0. Results: The study found an overall recovery rate of 84%, with 80% recovery in the organophosphate group and 90% in the carbamate group. The complication rate was 12%, and the mortality rate was 4%. Cholinesterase levels significantly increased post-hemoperfusion, with a mean rise of 600 U/L. Time to treatment was a significant predictor of positive outcomes (p=0.011). Conclusion: Resin-based hemoperfusion is effective in treating acute organophosphate and carbamate poisoning, significantly improving recovery rates and reducing mortality. Early intervention is crucial for optimal outcomes. This treatment modality should be considered a valuable component of poisoning management protocols, especially in resource-limited settings. Recommendations: Further research with larger sample sizes and randomized controlled trials is recommended to confirm these findings and explore additional factors influencing treatment outcomes. Implementation of resin-based hemoperfusion in standard treatment protocols for severe poisoning cases is advised to enhance patient care and survival rates. Keywords: Organophosphate poisoning, Carbamate poisoning, Hemoperfusion, Clinical outcomes

Disazo disperse dyes crosslinked with varied characteristic groups: Their synthesis, characterization, and application on polyester fabrics

We previously synthesized a group of carbamate-linked disazo disperse dyes that showed excellent fastness properties on polyester fabric by using the thermosol dyeing process. However, the color yield of the dyed fabric was not sufficiently high to be accepted by users, especially when using a high-temperature dyeing process. To further optimize the structures of disazo disperse dyes and observe the effect of the linking groups on the dyeing properties, in this work, we used p-phenylene diisocyanate or terephthaloyl chloride as crosslinking agents and aniline derivatives containing hydroxyl or amino groups as reactants to synthesize four disazo disperse dyes containing various characteristic groups, including ester, carbamate, amide, and urea groups. The structures of these new dyes were characterized by nuclear magnetic resonance, mass spectrometry, and Fourier-transform infrared spectroscopy analyses. The spectral properties in an N,N-dimethylformamide solvent were measured, the structural parameters of the dyes were calculated using the density functional theory method, and the dyeing properties were investigated by using high-temperature and thermosol dyeing processes, and also compared with these for the commercial dye, C·I.Disperse Red 153. The results showed that there were slight differences in the molar extinction coefficients and maximum absorbance wavelengths between the new dyes, but the effects of characteristic groups on the structural features and the dyeing properties of the new dyes were significant. The ester-linked dye (D1) had the highest color depth when a high-temperature process was used in the presence of 50 mL/L of methyl salicylate because of its highest ClogP (N-octanol/water partition coefficient) value, corresponding to its more hydrophobic nature, while all the other dyes produced lower color yields. When used in the thermosol dyeing process, the carbamate-linked dye (D2) yielded the highest color depth, followed by the ester-linked dye (D1) and amide-linked dye (D3), and the urea-linked dye (D4) produced the lowest color depth due to its highest hydrophilic properties. Finally, it was demonstrated that the new dyes had excellent color fastnesses except for the urea-linked dye (D4), which exhibited a slightly lower light fastness, While the commercial dye used as the control showed a relatively poor sublimation and light fastness although its color depth and chroma value performed slightly better than the new dyes as used by the thermosol dyeing process.

Chitosan toughened epoxy resin by chemical cross-linking: Enabling excellent mechanical properties and corrosion resistance

There is a growing demand for the development of epoxy resin modified with biomaterials, aiming to achieve high toughness. Herein, chitosan crosslinked epoxy resin (CE) was synthesized by diisocyanate as a bridge. With 4,4′-diamino-diphenylmethane (DDM) as the curing agent, thanks to the unique cross-linking structure of the CE resin and the presence of carbamate groups, the cured CE/DDM exhibited superior properties compared to commercially available epoxy resin (E51). The tensile strength of the cured CE-3/DDM reached 90.17 MPa, the elongation at break was 11.2 %, and the critical stress intensity factor (KIC) measured 1.78 MPa m1/2. These values were 21.4 %, 151.6 %, and 81.6 % higher than those of the cured E51/DDM, respectively. It is worth noting that the addition of biomass material chitosan did not reduce the thermal stability of the resin. Additionally, the CE coatings on the metal substrate exhibited exceptional corrosion resistance, as evidenced by higher impedance values in electrochemical impedance spectroscopy (EIS) and polarization voltages in the Tafel curve compared to those of the E51 coating. This study opens up a novel approach to modifying epoxy resin with biomass materials with high toughness and corrosion resistance, without sacrificing other performance.

Development of cellulose/ZnO based bioplastics with enhanced gas barrier, UV-shielding effect and antibacterial activity

Development of renewable and biodegradable plastics with good properties, such as the gas barrier, UV-shielding, solvent resistance, and antibacterial activity, remains a challenge. Herein, cellulose/ZnO based bioplastics were fabricated by dissolving cellulose carbamate in an aqueous solution of NaOH/Zn(OH)42−, followed by coagulation in aqueous Na2SO4 solution, and subsequent hot-pressing. The carbamate groups detached from cellulose, and ZnO which transformed from cosolvent to nanofiller was uniformly immobilized in the cellulose matrix during the dissolution/regeneration process. The appropriate addition of ZnO (below 10.67 wt%) not only improved the mechanical properties but also enhanced the water and oxygen barrier properties of the material. Additionally, our cellulose/ZnO based bioplastic demonstrated excellent UV-blocking capabilities, increased water contact angle, and enhanced antibacterial activity against S. aureus and E. coli, deriving from the incorporation of ZnO nanoparticles. Furthermore, the material exhibited resistance to organic solvents such as acetone, THF, and toluene. Indeed, the herein developed cellulose/ZnO based bioplastic presents a promising candidate to replace petrochemical plastics in various applications, such as plastic toys, anti-UV guardrails, window shades, and oil storage containers, offering a combination of favorable mechanical, gas barrier, UV-blocking, antibacterial, and solvent-resistant properties.

Molecular structure and selective theophylline complexation by conformational change of diethyl N,N'-(1,3-phenylene)dicarbamate.

The receptor ability of diethyl N,N'-(1,3-phenylene)dicarbamate (1) to form host-guest complexes with theophylline (TEO) and caffeine (CAF) by mechanochemistry was evaluated. The formation of the 1-TEO complex (C12H16N2O4·C7H8N4O2) was preferred and involves the conformational change of one of the ethyl carbamate groups of 1 from the endo conformation to the exo conformation to allow the formation of intermolecular interactions. The formation of an N-H...O=C hydrogen bond between 1 and TEO triggers the conformational change of 1. CAF molecules are unable to form an N-H...O=C hydrogen bond with 1, making the conformational change and, therefore, the formation of the complex impossible. Conformational change and selective binding were monitored by IR spectroscopy, solid-state 13C nuclear magnetic resonance and single-crystal X-ray diffraction. The 1-TEO complex was characterized by IR spectroscopy, solid-state 13C nuclear magnetic resonance, powder X-ray diffraction and single-crystal X-ray diffraction.

Insights into the structure–activity relationship of the anticancer compound ZJ-101: A role played by the amide moiety

ZJ-101, a structurally simplified analog of marine natural product superstolide A, was previously designed and synthesized in our laboratory. In the present study four new analogs of ZJ-101 were designed and synthesized to investigate the structure–activity relationship of the acetamide moiety of the molecule. The biological evaluation showed that the amide moiety is important for the molecule’s anticancer activity. Replacing the amide with other functional groups such as a sulfonamide group, a carbamate group, and a urea group resulted in the decrease in anticancer activity.

Synthesis and antihepatoma activity of guaianolide dimers derived from lavandiolide I

Guaianolide dimers represent a unique class of natural products with anticancer activities, but their low content in plants has limited in-depth pharmacological studies. Lavandiolide I is a guaianolide dimer isolated from Artemisia species, and had been synthesized on a ten-gram scale in four steps with 60 % overall yield, which showed potent antihepatoma activity on the HepG2, Huh7, and SK-Hep-1 cell lines with IC50 values of 12.1, 18.4, and 17.6 µM, respectively. To explore more active dimers, 33 lavandiolide I derivatives were designed, synthesized, and evaluated for their inhibitory activity on human hepatoma cell lines. Among them, 10 derivatives were more active than lavandiolide I and sorafenib on the three cell lines. The primary structure–activity relationship concluded that the introduction of aldehyde, ester, azide, amide, carbamate and urea functional groups at C-14′ of the guaianolide dimer significantly enhanced the antihepatoma activity. Among these compounds, derivatives 25, 27, and 33 enhanced antihepatoma activity more than 1.2–5.8 folds than that of lavandiolide I, and demonstrated low toxicity to the human liver cell lines (THLE-2) and good safety profiles with selective index ranging from 1.3 to 3.4, while lavandiolide I was more toxic to THLE-2 cells. This work provides new insights into enhancing the antihepatoma efficacy and reducing the toxicity of sesquiterpenoid dimers.

Enhanced adhesive and mechanically robust silicone-based coating with excellent marine anti-fouling and anti-corrosion performances.

Poly(dimethylsiloxane) (PDMS) is widely used in marine antifouling coatings due to its low surface energy property. However, certain drawbacks of PDMS coatings such as poor surface adhesion, weak mechanical properties, and inadequate static antifouling performance have hindered its practical applications. Herein, condensation polymerization is utilized to prepare PDMS-based polythiamine ester (PTUBAF) coatings that consist of PDMS, polytetrahydrofuran (PTMG), 2, 3, 5, 6-tetrafluoro-1, 4-benzenedimethanol (TBD) as the main chains and isobornyl acrylate(IBA) as the antifouling group. The surface adhesion to the substrate is enhanced due to the hydrogen bond between the coated carbamate group and the hydroxyl group on the surface of the substrate. Mechanical properties of PTUBAF are significantly improved due to the benzene ring and six-membered ring biphase hard structure. The strong synergistic effect of bactericidal groups and low surface energy surface endows the PTUBAF coating with outstanding antifouling performance. Due to the low surface energy surface, the PTUBAF coatings are also found to possess excellent anti-corrosion. Furthermore, since the PTUBAF coatings exhibit a visible light transmittance of 91 %, they can applied as protective films for smartphones. The proposed method has the potential to boost the production and practical applications of silicone-based coatings.

Degradation of carbofuran and acetamiprid in wolfberry by dielectric barrier discharge plasma: Kinetics, pathways, toxicity and molecular dynamics simulation

Carbofuran and acetamiprid pose the highest residual risk among pesticides found in wolfberries. This study aimed to degrade these pesticides in wolfberries using a multi-array dielectric barrier discharge plasma (DBD), evaluate the impact on safety and quality and explore their degradation mechanism. The results showed that DBD treatment achieved 90.6% and 80.9% degradation rates for carbofuran and acetamiprid, respectively, following a first-order kinetic reaction. The 120 s treatment successfully reduced pesticide contamination to levels below maximum residue limits. Treatment up to 180 s did not adversely affect the quality of wolfberries. QTOF/MS identification and degradation pathway analysis revealed that DBD broke down the furan ring and carbamate group of carbofuran, while replacing the chlorine atom and oxidizing the side chain of acetamiprid, leading to degradation. The toxicological evaluation showed that the degradation products were less toxic than undegraded pesticides. Molecular dynamics simulations revealed the reactive oxygen species (ROS) facilitated the degradation of pesticides through dehydrogenation and radical addition reactions. ROS type and dosage significantly affected the breakage of chemical bonds associated with toxicity (C4–O5 and C2–Cl1). These findings deepen insights into the plasma chemical degradation of pesticides.

Total chemical synthesis of PSMA-617: an API for prostate cancer endotherapeutic applications

Abstract Synthesis of PSMA-617, a peptide based ligand used in the preparation of nuclear medicine, 177Lu-PSMA-617, for the treatment of prostate cancer, is demonstrated in 6 steps, starting from appropriately protected amino acid building blocks. A solution phase Boc-strategy was adopted for the synthesis of peptide, wherein deprotection of carbamate group using HCl (g), was employed as the key step. The synthesis furnished PSMA-617 in purity >99.5 % as confirmed by HPLC analysis. ESI-MS and NMR analysis supported the structural integrity of the compound. The synthesized ligand was radiolabelled using 177Lu to generate the desired radiopharmaceutical, 177Lu-PSMA-617, in radiochemical purity >98 %, as revealed by radio HPLC and TLC analysis. This establishes its potential as a nuclear medicine for therapeutic application.

Cytotoxicity Activity of Some meso-Dihydroguaiaretic Acid Derivatives and Mode of Action of the Most Active Compound.

The aim of this study was to screen sixteen meso-1 semi-synthetic derivatives bearing ether, esther, carbamate, phosphate or aminoether functional groups against five cancer cell lines: MCF-7 (breast), A549 (lung), HepG2 (liver), HeLa (cervix), and DU145 (prostate) at 25 μM using the MTT assay. Results from the screening showed that two derivatives had the lowest percentage of cell viability at 25 μM, the aminoether derivative meso-11 and the esther derivative meso-20 against A549 (44.15±0.78 %) and MCF-7 (41.60±0.92 %), respectively. Then, it was determined the IC50 value of each compound against their most sensitive cancer cell line. Results showed that aminoether derivative meso-11 showed potent cytotoxicity against A549 (IC50 =17.11±2.11 μM), whereas it resulted more cytotoxic against the LL-47 lung normal cell line (IC50 =9.49±1.19 μM) having a Selective Index (SI) of 0.55. On the other hand, the esther derivative meso-20 exhibited potent activity against MCF-7 (IC50 =18.20±1.98 μM), whereas it displayed moderate cytotoxicity against the MCF-10 breast normal cell line (IC50 =41.22±2.17 μM) with a SI of 2.2. Finally, studies on the mechanism of action of meso-20 indicated disruption of MCF-7 plasma membrane in vitro and the AMPK activation in silico.

Constructing Novel High Dielectric Constant Polyimides Containing Dipolar Pendant Groups with Enhanced Orientational Polarization.

Polymer dielectrics with high dielectric constant are urgently demanded for potential electrical and pulsed power applications. The design of polymers with side chains containing dipolar groups is considered an effective method for preparing materials with a high dielectric constant and low loss. This study synthesizes and comprehensively compare the dielectric properties of novel polyimides with side chains containing urea (BU-PI), carbamate (BC-PI), and sulfonyl (BS-PI) functional groups. The novel polyimides exhibit relatively high dielectric constant and low dielectric loss values due to the enhanced orientational polarization and suppressed dipole-dipole interactions of dipolar groups. In particular, BU-PI containing urea pendant groups presents the highest dielectric constant of 6.14 and reasonably low dielectric loss value of 0.0097. The strong γ transitions with low activation energies derived from dielectric spectroscopy measurements have been further evaluated to demonstrate the enhanced free rotational motion of urea pendant dipoles. In energy storage applications, BU-PI achieves a discharged energy density of 6.92 J cm-3 and a charge-discharge efficiency above 83% at 500 MV m-1. This study demonstrates that urea group, as dipolar pendant group, can provide polymers with better dielectric properties than the most commonly used sulfonyl groups.

Biocatalytic hydrolysis of di-urethane model compounds in ionic liquid reaction media

The suitability of different enzymes to carry out the hydrolysis of two-different toluene-based urethane model compounds (i.e. bis(2-methoxyethyl) (4-methyl-1,3-phenylene)dicarbamate, and bis(2-methoxyethyl) (2-methyl-1,3-phenylene)dicarbamate) has been demonstrated for the first time by taking advantage of ionic liquid (IL) technologies. Toluene-based urethane compounds were prepared from usual substrates in polyurethane industrial synthesis. Afterwards, their carbamate groups were target of a biocatalytic hydrolysis by means of different commercial hydrolases (i.e. lipase, urease and proteases) in either water, hydrophilic organic solvents (i.e. ethylene glycol or 1,2-dimethyl-1,3-dioxolane-4-methanol, (solketal)), or hydrophobic ILs (e.g. [C4mim][NTf2], etc.) as reaction media. Because of the insolubility of these compounds in water, most of the enzymes were unable to catalyse the hydrolysis of the di-urethane substrates in pure water, being clearly improved (up to 31.6 mU/mg for the urease case) in solketal:water (90:10, v/v) reaction media. When hydrophobic ILs were added into this reaction medium, the urease activity increased by more than twice (74.1 mU/mg). The most promising results for the hydrolysis of these urethane compounds were obtained by combining lipase and urease biocatalysts in a IL:solketal:H2O (70:25:5, v/v/v) reaction medium. These results demonstrate a possible biocatalytic approach for the hydrolytic depolymerization of polyurethane foam wastes.

Fluorescent probes for investigating the internalisation and action of bioorthogonal ruthenium catalysts within Gram-positive bacteria.

Bioorthogonal reactions are extremely useful for the chemical modification of biomolecules, and are already well studied in mammalian cells. In contrast, very little attention has been given to the feasibility of such reactions in bacteria. Herein we report modified coumarin dyes for monitoring the internalisation and activity of bioorthogonal catalysts in the Gram-positive bacterial species Bacillus subtilis. Two fluorophores based on 7-aminocoumarin were synthesised and characterised to establish their luminescence properties. The introduction of an allyl carbamate (R2N-COOR') group onto the nitrogen atom of two 7-aminocoumarin derivatives with different solubility led to decreased fluorescence emission intensities and remarkable blue-shifts of the emission maxima. Importantly, this allyl carbamate group could be uncaged by the bioorthogonal, organometallic ruthenium catalyst investigated in this work, to yield the fluorescent product under biologically-relevant conditions. The internalisation of this catalyst was confirmed and quantified by ICP-OES analysis. Investigation of the bacterial cytoplasm and extracellular fractions separately, following incubation of the bacteria with the two caged dyes, facilitated their localisation, as well as that of their uncaged form by catalyst addition. In fact, significant differences were observed, as only the more lipophilic dye was located inside the cells and importantly remained there, seemingly avoiding efflux mechanisms. However, the uncaged form of this dye is not retained, and was found predominantly in the extracellular space. Finally, a range of siderophore-conjugated derivatives of the catalyst were investigated for the same transformations. Even though uptake was observed, albeit less significant than for the non-conjugated version, the fact that similar intracellular reaction rates were observed regardless of the iron content of the medium supports the notion that their uptake is independent of the iron transporters utilised by Gram-positive Bacillus subtilis cells.