Optimization,Purification, and Characterization of Extracellular Mesophilic Alkaline Cellulase from Sponge-Associated <Emphasis Type="Italic">Marinobacter</Emphasis> sp. MSI032

Marinobacter sp. (MSI032) isolated from the marine sponge Dendrilla nigra was optimized for the production of extracellular cellulolytic enzyme (CMCase) by submerged fermentation. Initial experiments showed that the culture medium containing 1% maltose as carbon source and 1% peptone and casein as nitrogen source supported maximal enzyme production at 27 °C and at a pH of 9.0. Further optimization carried out showed the maximal enzyme production was supported by the presence of 2% NaCl and 10 mM Zn²⁺ ions in the production media. The production of enzyme cellulase occurred at 48 h of incubation which proved the importance of this strain for cellulase production in large scale. Further, the enzyme was purified to 12.5-fold with a 37% yield and a specific activity of 2,548.75 U/mg. The purified enzyme displayed maximum activity at mesophilic temperature (27–35 °C) and at a broad pH range with optimal activity at pH 9.0. The purified enzyme was stable even at a higher alkaline pH of 12.0 which is greater than the pH stability that has not been reported in any of the cellulolytic isolates studied so far. Thus, from the present study, it is crucial that, instead of exploring the thermophilic resource that is limited in natural environments, the mesophilic bacteria that occurs commonly in nature can be added up to the database of cellulolytic bacteria. Thus, it is possible that a wide diversity of mesophilic bacteria associated with marine sponges opens up a new doorstep for the degradation of cellulosic waste material for the production of liquid fuels. This is the first report elucidating the prospects of sponge-associated marine bacterium for the production of extracellular alkaline cellulase.     

Recording multiple holographic gratings in silver-doped photopolymer using peristrophic multiplexing

Plane-wave transmission gratings were stored in the same location of silverdoped photopolymer film using peristrophic multiplexing techniques. Constant and variable exposure scheduling methods were adopted for storing gratings in the film using He-Ne laser (632.8 nm). The role of recording geometry on the dynamic range of the material was studied by comparing the results obtained from both techniques. Peristrophic multiplexing with rotation of the film in a plane normal to the bisector of the incident beams resulted in better homogenization of diffraction efficiencies and larger M/# value.     

Analysis of multitone microwave signals on optical fiber system using external laser modulation

In this paper, we Analyze multitone microwave signals on optical fiber with different tone signals and utilizing various possibilities of regeneration and amplification by different means. We compare out the performance analysis of Erbium doped fiber amplifiers (EDFAs) and Semi-conductor Optical Amplifiers (SOA). One tone's frequency varies from 1 to 20 GHz through parametric runs and other has fixed frequency of 5 GHz and third harmonic tones may be monitored.     

The reaction of 4-methoxycoumarins with prenyl bromide: Synthesis of 4′,4′,5′-trimethyl-dihydrofurano-coumarins and 2,2-dimethyl-chromenopyrans

The reaction of 7-hydroxy-4-methoxy- (1a), 7-hydroxy-4,5-dimethoxy-(1b) and 5-hydroxy-4,7-dimethoxy (1c) -2H-1-benzopyran-2-ones with prenyl bromide in acetone in the presence of anhydrous potassium carbonate gave the corresponding prenyloxycoumarins1d,1e, and1f. The prenyloxy coumarins1d,1e,1f onClaisen migration by refluxing inN,N-dimethyl aniline gave the corresponding 4,4,5-trimethyl-dihydrofuranocoumarins2a,2b, and3. However, the reaction of1a,1b, and1c with 3-chloro-3-methyl-but-1-yne in acetone in presence of potassium carbonate and potassium iodide gave the corresponding propargyl ethers1g,1h,1i, which on refluxing inN,N-dimethyl aniline gave the corresponding 2,2-dimethylchromenopyrans4a,4b, and5. These can also be obtained directly if the reaction is carried out in the presence of dioxan.

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Die Reaktion von 4-Methoxycumarinen mit Prenylbromid: Synthese von 4,4,5-Trimethyl-dihydro-furanocumarinen und 2,2-Dimethylchromenopyranen

Zusammenfassung Die Reaktion von 7-Hydroxy-4-methoxy-(1a), 7-Hydroxy-4,5-dimethoxy-(1b) und 5-Hydroxy-4,7-dimethoxy-2H-1-benzopyran-2-onen (1c) mit Prenylbromid in Aceton in der Gegenwart von wasserfreiem Kaliumcarbonat ergab die entsprechenden Prenylcumarine1d,1e und1f. Diese ergaben durchClaisen-Wanderung bei Rückfluß inN,N-Dimethylanilin die entsprechenden 4,4,5-Trimethyldihydrofuranocumarine2a,2b und3. Die Reaktion von1a,1b und1c mit 3-Chlor-3-methyl-1-butin in Aceton in Gegenwart von wasserfreiem Kaliumcarbonat und Kaliumjodid ergab die entsprechenden Propargylether1g,1h und1i, die ihrerseits bei Rückfluß inN,N-Dimethylanilin die jeweiligen 2,2-Dimethylchromenopyrane4a,4b und5 ergaben. Letztere können auch direkt erhalten werden, wenn die Reaktion in Gegenwart von Dioxan durchgeführt wird.

     

Multi-stimuli programmable FRET based RGB absorbing antennae towards ratiometric temperature,pH and multiple metal ion sensing

A red-green-blue (RGB) multichromophoric antenna 1 consisting of energy donors naphthalimides and perylenediimides and a central aza-BODIPY energy acceptor along with two subchromophoric red-blue (RB 6) and green-blue (GB 12) antennae was designed that showed efficient cascade Förster resonance energy transfer (FRET). RGB antenna 1 showed pronounced temperature-dependent emission behaviour where emission intensities in green and red channels could be tuned in opposite directions by temperature giving rise to unique ratiometric sensing with a temperature sensitivity of 0.4% °C. RGB antenna 1 showed reversible absorption modulation selectively in the blue region (RGB ↔ RG) upon acid/base addition giving rise to pH sensing behaviour. Furthermore, RGB antenna 1 was utilized to selectively sense metal ions such as Co²⁺ and Fe³⁺ through a FRET turn-off mechanism induced by a redox process at the aza-BODIPY site that resulted in the selective spectral modulation of the red band (i.e., RGB → GB). Model antenna RB 6 showed white light emission with chromaticity coordinates (0.32, 0.33) on acid addition. Antennae 1, 6 and 12 also exhibited solution state electrochromic switching characterized by distinct colour changes upon changing the potential. Finally, antennae 1, 6 and 12 served as reversible fluorescent inks in PMMA/antenna blends whereby the emission colours could be switched or tuned using different stimuli such as acid vapour, temperature and metal ions.

RGB antennae consisting of naphthalimides, perylenediimides and aza-BODIPY with efficient FRET show unique ratiometric temperature sensing, metal sensing (FRET-off) and pH sensing through various stimuli sensitive band tuning.     

Tilianin: A Potential Natural Lead Molecule for New Drug Design and Development for the Treatment of Cardiovascular Disorders

Cardiovascular disorders (CVDs) are the leading risk factor for death worldwide, and research into the processes and treatment regimens has received a lot of attention. Tilianin is a flavonoid glycoside that can be found in a wide range of medicinal plants and is most commonly obtained from Dracocephalum moldavica. Due to its extensive range of biological actions, it has become a well-known molecule in recent years. In particular, numerous studies have shown that tilianin has cardioprotective properties against CVDs. Hence, this review summarises tilianin’s preclinical research in CVDs, as well as its mechanism of action and opportunities in future drug development. The physicochemical and drug-likeness properties, as well as the toxicity profile, were also highlighted. Tilianin can be a natural lead molecule in the therapy of CVDs such as coronary heart disease, angina pectoris, hypertension, and myocardial ischemia, according to scientific evidence. Free radical scavenging, inflammation control, mitochondrial function regulation, and related signalling pathways are all thought to play a role in tilianin’s cardioprotective actions. Finally, we discuss tilianin-derived compounds, as well as the limitations and opportunities of using tilianin as a lead molecule in drug development for CVDs. Overall, the scientific evidence presented in this review supports that tilianin and its derivatives could be used as a lead molecule in CVD drug development initiatives.     

Jusanin,a New Flavonoid from Artemisia commutata with an In Silico Inhibitory Potential against the SARS-CoV-2 Main Protease

A new flavonoid, Jusanin, (1) has been isolated from the aerial parts of Artemisia commutata. The chemical structure of Jusanin has been elucidated using 1D, 2D NMR, and HR-Ms spectroscopic methods to be 5,2′,4′-trihydroxy-6,7,5′-trimethoxyflavone. Being new in nature, the inhibition potential of 1 has been estimated against SARS-CoV-2 using different in silico techniques. Firstly, molecular similarity and fingerprint studies have been conducted for Jusanin against co-crystallized ligands of eight different SARS-CoV-2 essential proteins. The studies indicated the similarity between 1 and X77, the co-crystallized ligand SARS-CoV-2 main protease (PDB ID: 6W63). To confirm the obtained results, a DFT study was carried out and indicated the similarity of (total energy, HOMO, LUMO, gap energy, and dipole moment) between 1 and X77. Accordingly, molecular docking studies of 1 against the target enzyme have been achieved and showed that 1 bonded correctly in the protein’s active site with a binding energy of −19.54 Kcal/mol. Additionally, in silico ADMET in addition to the toxicity evaluation of Jusanin against seven models have been preceded and indicated the general safety and the likeness of Jusanin to be a drug. Finally, molecular dynamics simulation studies were applied to investigate the dynamic behavior of the M^pro-Jusanin complex and confirmed the correct binding at 100 ns. In addition to 1, three other metabolites have been isolated and identified to be сapillartemisin A (2), methyl-3-[S-hydroxyprenyl]-cumarate (3), and β-sitosterol (4).     

Image-Feature Based Deep Learning Model for Plant Leaf Disease Detection

Currently, everyone is facing significant difficulties with food scarcity. There may be several causes for this, but food loss is a well-known issue. Specifically, crop losses bring on by plant and leaf diseases during farming operations. Plant disease is typically identified visually or through laboratory testing, which delays detection and reduces crop yields by the time it is finished. The wide use of smartphones along with recent advancements in computer vision has made it viable to diagnose any ailment by applying machine learning techniques. Smartphone-assisted disease diagnosis is now a reality. In this study, a multi-Support Vector Machine (SVM) model is used to detect four different diseases as well as healthy conditions of plant leaves. Using 13 feature vectors for each input, a total of 2400 leaves representing four distinct classes (four varieties) have been used to train and test the model. The experimental results give an average accuracy of 91.25% for diseased leaves detection and 99% accuracy for healthy leaves detection.