Nanofiber-reinforced self-healing polysaccharide-based hydrogel dressings for pH discoloration monitoring and treatment of infected wounds.

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.

Hydroxypropyl chitosan/ε-poly-l-lysine based injectable and self-healing hydrogels with antimicrobial and hemostatic activity for wound repair.

The biggest obstacle to treating wound healing continues to be the production of simple, inexpensive wound dressings that satisfy the demands associated with full process of repair at the same time. Herein, a series of injectable composite hydrogels were successfully prepared by a one-pot method by utilizing the Schiff base reaction as well as hydrogen bonding forces between hydroxypropyl chitosan (HCS), ε-poly-l-lysine (EPL), and 2,3,4-trihydroxybenzaldehyde (TBA), and multiple cross-links formed by the reversible coordination between iron (III) and pyrogallol moieties. Notably, hydrogel exhibits excellent physicochemical properties, including injectability, self-healing, water retention, and adhesion, which enable to fill irregular wounds for a long period, providing a suitable moist environment for wound healing. Interestingly, the excellent hemostatic properties of the hydrogel can quickly stop bleeding and avoid the serious sequelae of massive blood loss in acute trauma. Moreover, the powerful antimicrobial and antioxidant properties also protect against bacterial infections and reduce inflammation at the wound site, thus promoting healing at all stages of the wound. The study of biohydrogel with multifunctional integration of wound treatment and smart medical treatment is clarified by this line of research.

A comparative study of two thienopyrimidine Schiff base probes for sequential monitoring of Ga3+ and Pd2.

Two Schiff base probes (S1 and S2) were prepared and synthesized by incorporating thienopyrimidine into salicylaldehyde or 3-ethoxysalicylaldehyde individually, with the aim of detecting Ga3+ and Pd2+ sequentially. Upon chelation with Ga3+, S1 and S2 exhibited fluorescence enhancement in DMSO/H2O buffer. Both S1-Ga3+ and S2-Ga3+ were quenched by Pd2+. The limit of detection for S1 in response to Ga3+ and Pd2+ was 2.86 × 10-7 and 4.4 × 10-9 M, respectively. For S2, the limit of detection for Ga3+ and Pd2+ was 4.15 × 10-8 and 3.0 × 10-9 M, respectively. Furthermore, the complexation ratios of both S1 and S2 with Ga3+ and Pd2+ were determined to be 1:2 through Job's plots, ESI-MS analysis, and theoretical calculations. Two molecular logic gates were constructed, leveraging the response behaviors of S1 and S2. Moreover, the potential utility of S1 and S2 for monitoring Ga3+ and Pd2+ in domestic water was verified.

Design, synthesis, molecular docking study, and α-glucosidase inhibitory evaluation of novel hydrazide-hydrazone derivatives of 3,4-dihydroxyphenylacetic acid.

A series of novel Schiff base derivatives (1-28) of 3,4-dihydroxyphenylacetic acid were synthesized in a multi-step reaction. All the synthesized Schiff bases were obtained in high yields and their structures were determined by 1HNMR, 13CNMR, and HR-ESI-MS spectroscopy. Except for compounds 22, 26, 27, and 28, all derivatives show excellent to moderate α-glucosidase inhibition. Compounds 5 (IC50 = 12.84 ± 0.52 µM), 4 (IC50 = 13.64 ± 0.58 µM), 12 (IC50 = 15.73 ± 0.71 µM), 13 (IC50 = 16.62 ± 0.47 µM), 15 (IC50 = 17.40 ± 0.74 µM), 3 (IC50 = 18.45 ± 1.21 µM), 7 (IC50 = 19.68 ± 0.82 µM), and 2 (IC50 = 20.35 ± 1.27 µM) shows outstanding inhibition as compared to standard acarbose (IC50 = 873.34 ± 1.67 µM). Furthermore, a docking study was performed to find out the interaction between the enzyme and the most active compounds. With this research work, 3,4-dihydroxyphenylacetic acid Schiff base derivatives have been introduced as a potential class of α-glucosidase inhibitors that have remained elusive till now.

Schiff base crosslinked hyaluronic acid hydrogels with tunable and cell instructive time-dependent mechanical properties.

The dynamic interplay between cells and their native extracellular matrix (ECM) influences cellular behavior, imposing a challenge in biomaterial design. Dynamic covalent hydrogels are viscoelastic and show self-healing ability, making them a potential scaffold for recapitulating native ECM properties. We aimed to implement kinetically and thermodynamically distinct crosslinkers to prepare self-healing dynamic hydrogels to explore the arising properties and their effects on cellular behavior. To do so, aldehyde-substituted hyaluronic acid (HA) was synthesized to generate imine, hydrazone, and oxime crosslinked dynamic covalent hydrogels. Differences in equilibrium constants of these bonds yielded distinct properties including stiffness, stress relaxation, and self-healing ability. The effects of degree of substitution (DS), polymer concentration, crosslinker to aldehyde ratio, and crosslinker functionality on hydrogel properties were evaluated. The self-healing ability of hydrogels was investigated on samples of the same and different crosslinkers and DS to obtain hydrogels with gradient properties. Subsequently, human dermal fibroblasts were cultured in 2D and 3D to assess the cellular response considering the dynamic properties of the hydrogels. Moreover, assessing cell spreading and morphology on hydrogels having similar modulus but different stress relaxation rates showed the effects of matrix viscoelasticity with higher cell spreading in slower relaxing hydrogels.

A chemo-enzymatic pathway to expand cellooligosaccharide chemical space through amine bond introduction.

Enzymatic functionalization of oligosaccharides is a useful and environmentally friendly way to expand their structural chemical space and access to a wider range of applications in the health, food, feed, cosmetics and other sectors. In this work, we first tested the laccase/TEMPO system to generate oxidized forms of cellobiose and methyl ß-D-cellobiose, and obtained high yields of novel anionic disaccharides (>60 %) at pH 6.0. Laccase/TEMPO system was then applied to a mix of cellooligosaccharides and to pure D-cellopentaose. The occurrence of carbonyl and carboxyl groups in the oxidation products was shown by LC-HRMS, MALDI-TOF and reductive amination of the carbonyl groups was attempted with p-toluidine a low molar mass amine to form the Schiff base, then reduced by 2-picoline borane to generate a more stable amine bond. The new grafted products were characterized by LC-HRMS, LC-UV-MS/MS and covalent grafting was evidenced. Next, the same procedure was adopted to successfully graft a dye, the rhodamine 123, larger in size than toluidine. This two-step chemo-enzymatic approach, never reported before, for functionalization of oligosaccharides, offers attractive opportunities to anionic cellooligosaccharides and derived glucoconjugates of interest for biomedical or neutraceutical applications. It also paves the way for more environmentally-friendly cellulose fabric staining procedures.

Synthesis and real-time characterization of self-healing, injectable, fast-gelling hydrogels based on alginate multi-reducing end polysaccharides (MREPs).

Polysaccharide-based hydrogels are promising for many biomedical applications including drug delivery, wound healing, and tissue engineering. We illustrate herein self-healing, injectable, fast-gelling hydrogels prepared from multi-reducing end polysaccharides, recently introduced by the Edgar group. Simple condensation of reducing ends from multi-reducing end alginate (M-Alg) with amines from polyethylene imine (PEI) in water affords a dynamic, hydrophilic polysaccharide network. Trace amounts of acetic acid can accelerate the gelation time from hours to seconds. The fast-gelation behavior is driven by rapid Schiff base formation and strong ionic interactions induced by acetic acid. A cantilever rheometer enables real-time monitoring of changes in viscoelastic properties during hydrogel formation. The reversible nature of these crosslinks (imine bonds, ionic interactions) provides a hydrogel with low toxicity in cell studies as well as self-healing and injectable properties. Therefore, the self-healing, injectable, and fast-gelling M-Alg/PEI hydrogel holds substantial promise for biomedical, agricultural, controlled release, and other applications.

Structural, dynamic behaviour, in-vitro and computational investigations of Schiff's bases of 1,3-diphenyl urea derivatives against SARS-CoV-2 spike protein.

The COVID-19 has had a significant influence on people's lives across the world. The viral genome has undergone numerous unanticipated changes that have given rise to new varieties, raising alarm on a global scale. Bioactive phytochemicals derived from nature and synthetic sources possess lot of potential as pathogenic virus inhibitors. The goal of the recent study is to report new inhibitors of Schiff bases of 1,3-dipheny urea derivatives against SARS COV-2 spike protein through in-vitro and in-silico approach. Total 14 compounds were evaluated, surprisingly, all the compounds showed strong inhibition with inhibitory values between 79.60% and 96.00% inhibition. Here, compounds 3a (96.00%), 3d (89.60%), 3e (84.30%), 3f (86.20%), 3g (88.30%), 3h (86.80%), 3k (82.10%), 3l (90.10%), 3m (93.49%), 3n (85.64%), and 3o (81.79%) exhibited high inhibitory potential against SARS COV-2 spike protein. While 3c also showed significant inhibitory potential with 79.60% inhibition. The molecular docking of these compounds revealed excellent fitting of molecules in the spike protein receptor binding domain (RBD) with good interactions with the key residues of RBD and docking scores ranging from - 4.73 to - 5.60 kcal/mol. Furthermore, molecular dynamics simulation for 150 ns indicated a strong stability of a complex 3a:6MOJ. These findings obtained from the in-vitro and in-silico study reflect higher potency of the Schiff bases of 1,3-diphenyl urea derivatives. Furthermore, also highlight their medicinal importance for the treatment of SARS COV-2 infection. Therefore, these small molecules could be a possible drug candidate.

Oxidovanadium(V) Schiff Base Complexes Derived from Chiral 3-amino-1,2-propanediol Enantiomers: Synthesis, Spectroscopic Studies, Catalytic and Biological Activity.

Oxidovanadium(V) complexes, [(+)VOL1-5] and [(-)VOL1-5], with chiral tetradentate Schiff bases, which are products of monocondensation of S(‒)-3-amino-1,2-propanediol or R(+)-3-amino-1,2-propanediol with salicylaldehyde derivatives, have been synthesized. Different spectroscopic methods, viz. 1H and 51V NMR, IR, UV-Vis, and circular dichroism, as well as elemental analysis, have been used for their detailed characterization. Furthermore, the epoxidation of styrene, cyclohexene, and two monoterpenes, S(‒)-limonene and (‒)-α-pinene, using two oxidants, aqueous 30% H2O2 or tert-butyl hydroperoxide (TBHP) in decane, has been studied with catalytic amounts of all complexes. Finally, biological cytotoxicity studies have also been performed with these oxidovanadium(V) compounds for comparison with cis-dioxidomolybdenum(VI) Schiff base complexes with the same chiral ligands, as well as to determine the cytoprotection against the oxidative damage caused by 30% H2O2 in the HT-22 hippocampal neuronal cells in the range of their 10-100 µM concentration.

An injectable, chitosan-based hydrogel prepared by Schiff base reaction for anti-bacterial and sustained release applications.

Injectable hydrogels, providing sustained release as implanted materials, have received tremendous attention. In this study, chitosan-based hydrogels were prepared via Schiff base reaction of the aldehyde groups on Poly(NIPAM-co-FBEMA) and the amine groups on chitosan. Owing to the dynamic covalent linkage, the SC/PNF hydrogels exhibit pH-responsive, reversible sol-gel transition, injectable, and self-healing capacity. The mechanical strength of SC/PNF hydrogels can be operated simply by switching the composition or solid content of Poly(NIPAM-co-FBEMA) copolymers. Rheological analyses, including frequency sweeps, strain sweep scanning, and dynamic time sweeps, were employed to demonstrate the relationship between storage modulus (G'), loss modulus (G″), and composition of the SC/PNF hydrogels. In vitro release behaviors reveal that vancomycin-loaded SC/PNF hydrogel could contribute to both the initial burst release (over 1000 ppm within 4 h) and the sustained release (3000 ppm for at least 30 days). Pristine SC/PNF hydrogel holds good biocompatibility toward L929 cells and S. aureus that it degrades as incubated with S. aureus. However, vancomycin-wrapped SC/PNF hydrogel possesses a rapid bacterial-killing effect with a clear inhibition zone. In short, the SC/PNF hydrogels deliver not only sustainable release ability but also tunable physical properties, which are expected to be an outstanding candidate for non-invasive, anti-infection applications.

Experimental and Computational Studies on the Interaction of DNA with Hesperetin Schiff Base CuII Complexes.

The interactions with calf thymus DNA (CT-DNA) of three Schiff bases formed by the condensation of hesperetin with benzohydrazide (HHSB or L1H3), isoniazid (HIN or L2H3), or thiosemicarbazide (HTSC or L3H3) and their CuII complexes (CuHHSB, CuHIN, and CuHTSC with the general formula [CuLnH2(AcO)]) were evaluated in aqueous solution both experimentally and theoretically. UV-Vis studies indicate that the ligands and complexes exhibit hypochromism, which suggests helical ordering in the DNA helix. The intrinsic binding constants (Kb) of the Cu compounds with CT-DNA, in the range (2.3-9.2) × 106, from CuHTSC to CuHHSB, were higher than other copper-based potential drugs, suggesting that π-π stacking interaction due to the presence of the aromatic rings favors the binding. Thiazole orange (TO) assays confirmed that ligands and Cu complexes displace TO from the DNA binding site, quenching the fluorescence emission. DFT calculations allow for an assessment of the equilibrium between [Cu(LnH2)(AcO)] and [Cu(LnH2)(H2O)]+, the tautomer that binds CuII, amido (am) and not imido (im), and the coordination mode of HTSC (O-, N, S), instead of (O-, N, NH2). The docking studies indicate that the intercalative is preferred over the minor groove binding to CT-DNA with the order [Cu(L1H2am)(AcO)] > [Cu(L2H2am)(AcO)] ≈ TO ≈ L1H3 > [Cu(L3H2am)(AcO)], in line with the experimental Kb constants, obtained from the UV-Vis spectroscopy. Moreover, dockings predict that the binding strength of [Cu(L1H2am)(AcO)] is larger than [Cu(L1H2am)(H2O)]+. Overall, the results suggest that when different enantiomers, tautomers, and donor sets are possible for a metal complex, a computational approach should be recommended to predict the type and strength of binding to DNA and, in general, to macromolecules.

Monitoring of singlet oxygen generation of a novel Schiff-base substituted silicon phthalocyanines by sono-photochemical studies and in vitro activities on prostate cancer cell.

This study demonstrates the potential of sono-photodynamic therapy as an effective approach for enhancing singlet oxygen generation using the synthesized Schiff-base diaxially substituted silicon phthalocyanines. In photochemical studies, the singlet oxygen quantum yields (Φ∆) were determined as 0.43 for Si1a, 0.94 for Q-Si1a, 0.58 for S-Si1a, and 0.49 for B-Sia1. In sono-photochemical studies, the Φ∆ values were reached to 0.67 for Si1a, 1.06 for Q-Si1a, 0.65 for S-Si1a, and 0.67 for B-Sia1. In addition, this study demonstrates the therapeutic efficacy of phthalocyanines synthesized as sensitizers on the PC3 prostate cancer cell line through in vitro experiments. The application of these treatment modalities exhibited notable outcomes, leading to a substantial decrease in cell viability within the PC3 prostate cancer cell line. These findings highlight the potential of utilizing these synthesized phthalocyanines as promising therapeutic agents for prostate cancer treatment.

A subgroup of light-driven sodium pumps with an additional Schiff base counterion.

Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region essential for sodium transport. Here we identify a subgroup of the NDQ rhodopsins bearing an additional glutamic acid residue in the close vicinity to the retinal Schiff base. We thoroughly characterize a member of this subgroup, namely the protein ErNaR from Erythrobacter sp. HL-111 and show that the additional glutamic acid results in almost complete loss of pH sensitivity for sodium-pumping activity, which is in contrast to previously studied NaRs. ErNaR is capable of transporting sodium efficiently even at acidic pH levels. X-ray crystallography and single particle cryo-electron microscopy reveal that the additional glutamic acid residue mediates the connection between the other two Schiff base counterions and strongly interacts with the aspartic acid of the characteristic NDQ motif. Hence, it reduces its pKa. Our findings shed light on a subgroup of NaRs and might serve as a basis for their rational optimization for optogenetics.

Synthesis of new quaternized chitosan Schiff bases and their N-alkyl derivatives as antimicrobial and anti-biofilm retardants in membrane technology.

New quaternized salicylidene chitosan Schiff bases (QSCSBs) and their N-octyl derivatives (OQCs) have been synthesized and characterized, aiming to develop innovative antimicrobial and anti-biofilm agents. This research holds immense potential, as these compounds could be utilized as anti-biofouling additives in membrane technology in the future. The synthesis involved the modification of low molecular-weight-chitosan (LMC) through simultaneous Schiff base formation and quaternization processes to create QSCSBs. Subsequently, QSCSBs were catalytically reduced to form quaternized N-benzyl chitosan (QBCs) intermediates, which then underwent nucleophilic substitution reactions affording N-octyl quaternized chitosans (OQCs). Characterization techniques such as elemental, spectral, and microscopic analyses were used to confirm the successful synthesis of these materials. As membrane technology relies on surface charge, QSCSBs and OQCs with large zeta potentials could be used as positively charged additives. Moreover, SEM image revealed the regular distribution of pores and voids across the additives' surfaces raises intriguing questions about their implications for membrane performance. Meanwhile, the superior antibacterial and antibiofilm potential of these materials, particularly QSCSB2 and OQC2, indicate that the utilization of these compounds as anti-biofouling additives in membrane technology could significantly improve the performance and longevity of membranes used in various applications such as water treatment and desalination.

The crucial role of stability of intercalating agent for DNA binding studies in DMSO/water system.

In recent years, extensive research has been directed towards understanding the interactions between various zinc complexes with DNA, specifically delving into their intercalation and binding behaviors. The binding of zinc complexes to DNA is particularly intriguing due to their distinctive intercalating capabilities. This study unveils a remarkable phenomenon observed with a specific Zn complex, ([B-Zn-N3], where B is a Schiff base ligand), during DNA intercalation investigations in the popular DMSO-Water binary solvent mixture. An unanticipated observation revealed time-dependent changes in the UV-visible absorption spectroscopic studies, coupled with the existence of an isosbestic point. This observation questions the stability of the intercalating agent itself during the intercalation process. The emergence of a decomposed product during the intercalation study has been confirmed through various analytical techniques, including CHN analysis, MALDI mass, XPS, Raman spectroscopy, and Powder XRD. The change in the chemical species on intercalation is further substantiated by theoretical studies, adding depth to our understanding of the intricate dynamics at play during DNA intercalation with the [B-Zn-N3] complex in the DMSO-Water system.

Schiff bases and their metal complexes to target and overcome (multidrug) resistance in cancer.

Overcoming multidrug resistance (MDR) is one of the major challenges in cancer therapy. In this respect, Schiff base-related compounds (bearing a R1R2CNR3 bond) gained high interest during the past decades. Schiff bases are considered privileged ligands for various reasons, including the easiness of their preparation and the possibility to form complexes with almost all transition metal ions. Schiff bases and their metal complexes exhibit many types of biological activities and are used for the treatment and diagnosis of various diseases. Until now, 13 Schiff bases have been investigated in clinical trials for cancer treatment and hypoxia imaging. This review represents the first collection of Schiff bases and their complexes which demonstrated MDR-reversal activity. The areas of drug resistance covered in this article involve: 1) Modulation of ABC transporter function, 2) Targeting lysosomal ABCB1 overexpression, 3) Circumvention of ABC transporter-mediated drug efflux by alternative routes of drug uptake, 4) Selective activity against MDR cancer models (collateral sensitivity), 5) Targeting GSH-detoxifying systems, 6) Overcoming apoptosis resistance by inducing necrosis and paraptosis, 7) Reactivation of mutated p53, 8) Restoration of sensitivity to DNA-damaging anticancer therapy, and 9) Overcoming drug resistance through modulation of the immune system. Through this approach, we would like to draw attention to Schiff bases and their metal complexes representing highly interesting anticancer drug candidates with the ability to overcome MDR.

Zinc(II) Iminopyridine Complexes as Antibacterial Agents: A Structure-to-Activity Study.

Antibiotic resistance is currently a global health emergency. Metallodrugs, especially metal coordination complexes, comprise a broad variety of candidates to combat antibacterial infections. In this work, we designed a new family of Schiff base zinc(II) complexes with iminopyridine as an organic ligand and different inorganic ligands: chloride, nitrate, and acetate. The antibacterial effect of the Zn(II) complexes was studied against planktonic bacterial cells of Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) strains. The results showed a moderate biocide activity in both types of planktonic bacteria, which arises from the metal complexation to the Schiff base ligand. Importantly, we confirmed the crucial effect of the metal, with Zn(II) improving the activity of Cu(II) counterparts previously reported. On the other hand, the impact of the inorganic ligands was not significant for the antibacterial effect but was relevant for the complex solubility. Finally, as proof of concept of topical antibacterial formulation, we formulated an emulsion containing the most lipophilic Zn(II) complex and confirmed a sustained release for 24 h in a vertical cell diffusion assay. The promising activity of iminopyridine Zn(II) complexes is potentially worth exploring in more detailed studies.

Dendritic Pyridine-Imine Copper Complexes as Metallo-Drugs.

Since the discovery of cisplatin in the 1960s, the search for metallo-drugs that are more efficient than platinum complexes with negligible side effects has attracted much interest. Among the other metals that have been examined for potential applications as anticancer agents is copper. The interest in copper was recently boosted by the discovery of cuproptosis, a recently evidenced form of cell death mediated by copper. However, copper is also known to induce the proliferation of cancer cells. In view of these contradictory results, there is a need to find the most suitable copper chelators, among which Schiff-based derivatives offer a wide range of possibilities. Gathering several metal complexes in a single, larger entity may provide enhanced properties. Among the nanometric objects suitable for such purpose are dendrimers, precisely engineered hyperbranched macromolecules, which are outstanding candidates for improving therapy and diagnosis. In this review article, we present an overview of the use of a particular Schiff base, namely pyridine-imine, linked to the surface of dendrimers, suitable for complexing copper, and the use of such dendrimer complexes in biology, in particular against cancers.

Design of New Schiff Bases and Their Heavy Metal Ion Complexes for Environmental Applications: A Molecular Dynamics and Density Function Theory Study.

Schiff bases (SBs) are important ligands in coordination chemistry due to their unique structural properties. Their ability to form complexes with metal ions has been exploited for the environmental detection of emerging water contaminants. In this work, we evaluated the complexation ability of three newly proposed SBs, 1-3, by complete conformational analysis, using a combination of Molecular Dynamics and Density Functional Theory studies, to understand their ability to coordinate toxic heavy metal (HMs) ions. From this study, it emerges that all the ligands present geometries that make them suitable to complex HMs through the N-imino moieties or, in the case of 3, with the support of the oxygen atoms of the ethylene diether chain. In particular, this ligand shows the most promising coordination behavior, particularly with Pb2+.

Transfer Hydrogenation of Vinyl Arenes and Aryl Acetylenes with Ammonia Borane Catalyzed by Schiff Base Cobalt(II) Complexes.

A series of bench-stable Co(II) complexes containing hydrazone Schiff base ligands were evaluated in terms of their activity and selectivity in carbon-carbon multiple bond transfer hydrogenation. These cobalt complexes, especially a Co(II) precatalyst bearing pyridine-2-yl-N(Me)N=C-(1-methyl)imidazole-2-yl ligand, activated by LiHBEt3, were successfully used in the transfer hydrogenation of substituted styrenes and phenylacetylenes with ammonia borane as a hydrogen source. Key advantages of the reported catalytic system include mild reaction conditions, high selectivity and tolerance to functional groups of substrates.