Lassomycin and lariatin lasso peptides as suitable antibiotics for combating mycobacterial infections: current state of biosynthesis and perspectives for production.

Lasso peptides are ribosomally synthesized and post-translationally modified natural products with a characteristic slipknot-like structure, which confers these peptides remarkable stability and diverse pharmacologically relevant bioactivities. Among all the reported lasso peptides, lassomycin and lariatins are unique lasso peptides that exhibit noticeable anti-tuberculosis (TB) activity. Due to the unique threaded structure and the unusual bactericidal mechanism toward Mycobacterium tuberculosis, these peptides have drawn considerable interest, not only in the field of total synthesis but also in several other fields including biosynthesis, bioengineering, and structure-activity studies. During the past few years, significant progress has been made in understanding the biosynthetic mechanism of these intriguing compounds, which has provided a solid foundation for future work. This review highlights recent achievements in the discovery, structure elucidation, biological activity, and the unique anti-TB mechanism of lasso peptides. Moreover, the discovery of their biosynthetic pathway has laid the foundation for combinatorial biosynthesis of their analogs, which provides new perspectives for the production of novel anti-TB lasso peptides.

Eco-benign approach to synthesize spherical iron oxide nanoparticles: A new insight in photocatalytic and biomedical applications.

Iron oxide nanoparticles (Fe2O3NPs) are an interested and attractive area of research as they have numerous effective environmental and biomedical applications. Herein we have reported a simple and eco-benign synthesis Fe2O3NPs using Tamarix aphylla extract. The extract of the Tamarix aphylla acts both as a reducing and capping agent which leads to the fast and successful eco-benign synthesis of Fe2O3NPs.UV/Vis spectroscopy, XRD, EDX, SEM and TEM techniques were used to characterize and explore different features of Fe2O3NPs. UV/Vis studies showed asharppeak at 390 nm due to surface plasmon resonance absorption of Fe2O3NPs. XRD studies indicated that Fe2O3NPs were crystalline in nature. Structural features, elemental composition and geometry of Fe2O3NPswere confirmed by SEM, EDX and TEM. The as synthesized Fe2O3NPs showed efficient efficacy to degrade 100% of Methylene blue (MB) dye by 4 mg/25 ml MB and revealed 90% scavenging of the more stable DPPH free radical(1 mg/ml). Furthermore, Fe2O3NPs showed excellent antimicrobial activity against pathogenic multidrug resistant bacterial strains. The results of the present study explored the potential reducing, capping property of Tamarix aphylla extract, photocatalytic and biomedical applications of eco-benignly synthesized Fe2O3NPs which could be an alternative material for effective remediation of lethal organic pollutants and microbes.

Facile synthesis of laccase mimic Cu/H3BTC MOF for efficient dye degradation and detection of phenolic pollutants.

Herein, we report an effectual method for designing a novel form of nanozyme laccase mimic namely Cu/H3BTC, using copper ions and 1,3,5-benzene tricarboxylic acid (1,3,5-H3BTC). This Cu-based metal-organic framework (MOF) was synthesized through a simple procedure of mixing of two usual reagents at room temperature. Amido Black 10B (AB-10B) was chosen as a model dye for degradation consequences. Results showed that Cu/H3BTC MOF revealed significantly higher catalytic efficacy under certain conditions like high pH, extreme temperature and high salt conditions and it has long-term storage stability, which can lead to a significant decline in catalytic activity of laccase. In addition, the degradation of AB-10B was up to 60% after ten cycles, showing good recyclability of Cu/H3BTC MOF. The UV-visible spectral changes clearly showed that Cu/H3BTC MOF is an effective laccase mimic for the degradation of azo dye AB-10B, which was degraded more easily within the time duration of 60 min. The Cu/H3BTC MOF also possessed fundamental activities like laccase with regard to oxidation of the phenolic compounds. Moreover, a technique for the quantitative detection of epinephrine by Cu/H3BTC MOF was established. These findings help to understand the laccase-like reactivity and provide a basis for the future design and application of metal-based catalysts.

Facile and eco-benign synthesis of Au@Fe2O3 nanocomposite: Efficient photocatalytic, antibacterial and antioxidant agent.

The development of eco-benign experimental procedures for the synthesis of nanomaterials is a fundamental developing branch of green nanotechnology. In this paper, green synthetic route was followed to synthesize novel Au@Fe2O3nanocomposite using Citrus sinensis fruit extract as a reducing and stabilizing agent. The as synthesized Au@Fe2O3nanocomposite was successfully characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy-dispersive X-ray (EDX), Fourier transform infrared (FT1R) spectrophotometry and Zeta potential. UV-vis spectroscopy showed two SPR peaks for Fe2O3 and coated Au at 290 and 520 nm respectively. XRD confirmed the crystallinity of Au@Fe2O3. Au@Fe2O3 nanocomposite showed better antioxidant activity to effectively scavenge DPPH. The Au@Fe2O3 has been also tested for antibacterial activity which showed an effective antibacterial activity against multi drug resistant E.coli and Bacillus subtilis. Furthermore, Au@Fe2O3 also demonstrated better photo catalytic activity for methylene blue (MB) degradation. We proposed that the existence of organic acids (citric acids) also played a significant role in the stabilization of Au@Fe2O3, and plant (Citrus sinensis Var Kozan yerly) containing such component may be more effective for the green synthesis of Au@Fe2O3 nanocomposite. The findings of this study prove the overwhelming therapeutic and photocatalytic potential of bio-inspired Au@Fe2O3nanocomposite which can be a novel candidate for the effective remediation of microbes and toxic organic pollutants.

Tuber extract of Arisaema flavum eco-benignly and effectively synthesize silver nanoparticles: Photocatalytic and antibacterial response against multidrug resistant engineered E. coli QH4.

Metal nanoparticles, synthesized using Phyto-constituents are the most economically and environmentally benign materials ever. Biogenic silver nanoparticles (AgNPs) from three fractions of Arisaema flavum tuber extract were synthesized and characterized by UV-visible spectroscopy, XRD (X-rays diffraction), FT-IR (Fourier transform infrared spectroscopy) TEM (transmission electron microscopy) and EDX (Energy dispersive Microscopy). XRD pattern show the face centred cubic crystalline (Fcc) structure of AgNPs. FTIR spectra confirmed the presence of different Polyphenolic compounds capping the AgNps. UV-visible spectroscopy result confirmed the presence of Ag because of the particular surface plasmon Resonance (SPR) in the area of 400-430 nm. The electron microscope studies revealed the formation of spherical AgNPs with diameter ranging from 12 nm to 20 nm. Strong signals of AgNPs were confirmed with EDX analysis. The antibacterial properties of the AgNPs prepared with various extracts were tested against multi-drug resistant bacteria. Which showed significant antibacterial activity against all the multidrug resistant bacterial strains and especially multidrug resistant engineered E.ColiQH4. AgNPs synthesized by methanolic, Ethyl Acetate and aqueous Extracts of Areseama Flavum exhibited significant Photocatalytic activity to reduce methylene blue. Small size, spherical shape and high dispersion are the key properties due to which the AgNPs are having significant biological and photocatalytic activity. To the best of our knowledge, it is the first report of biogenic AgNPs regarding antibacterial activity against multidrug resistant Engineered E.Coli QH4.