Constrained photophysics of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine in micellar environments: a spectrofluorometric study

Photophysical properties of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ) have been studied in different aqueous micellar environments using steady-state and time-resolved emission spectroscopy. The charge transfer (CT) fluorescence exhibits appreciable hypsochromic shift, along with an enhancement in the fluorescence intensity in all the micellar media. This is associated with an increase in the fluorescence anisotropy (r), which suggests that the fluorophore molecule experiences motionally restricted environments upon binding with the micelles. Fluorescence spectral position and fluorescence quenching studies suggest that the fluorescing moiety does not penetrate into the core of the micellar units; rather it binds at the micelle-water interfacial region. The binding constant and free energy change during probe-micelle binding have been evaluated from relevant fluorescence data. Light has been thrown on the mode of action of urea on micelle bound probes. The results are interpreted in terms of the model that urea displaces water molecules from the micellar interface and the consequent destabilization leads to the expulsion of the probe molecules from the interfacial region. Polarity and viscosity of the microenvironments around the probe have been determined in the micellar systems

Fluorometric investigation of interaction of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine with bovine serum albumin

Interaction of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ) with a model transport protein, bovine serum albumin (BSA), has been studied using steady state fluorescence and fluorescence anisotropy experiments. Upon binding with BSA, the charge transfer (CT) fluorescence exhibits appreciable hypsochromic shift along with an enhancement in the fluorescence intensity. Gradual addition of BSA leads to the marked increase in the fluorescence anisotropy (r). From the high value of fluorescence anisotropy (r=0.30) it is argued that the probe molecule is located in motionally restricted environment of the protein. Addition of urea to the protein bound AODIQ leads to the decrease in fluorescence intensity as well as fluorescence anisotropy (r) indicating the release of AODIQ molecule to the aqueous buffer medium, thus supporting the idea that the protein, in its native form, binds with the probe. The binding constant and free energy change (ΔG0) for the interaction of AODIQ with BSA have been evaluated from relevant fluorescence data. Polarity of the microenvironment has been determined from a comparison of the variation of fluorescence property of the probe in dioxane-water mixture with varying composition

Photophysics of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine: emission from two states

Steady state photophysics of 3-acetyl-4-oxo-6,7-dihydro-12H indolo-[2,3-a] quinolizine (AODIQ) has been studied in different pure and mixed solvents. The fluorometric behaviour of AODIQ is modified dramatically with a change in the solvent polarity. The fluorescence quantum yield, when plotted against the solvent polarity parameter (E<SUB>T</SUB>(30)), passes through a maximum. Plot of the fluorescence parameters in a graded series of dioxane-water mixture against E<SUB>T</SUB>(30) shows segmented linearity with two independent slopes; reflecting a lower sensitivity in the less polar region and a much higher sensitivity in higher polarity range. The observations lead to the proposition that the fluorescence of AODIQ originates from two different states, viz., a locally excited (LE) and a charge transfer (CT) one. Studies of the phosphorescence and heavy atom quenching of the fluorescence reveal that the CT state lies above the lowest triplet state even in a very polar environment

Reliable technique of Endoscopic Dacryocystorhinostomy – A Pilot Study

Introduction Over last two decades endoscopic dacryocystorhinostomy has gained popularity over external dacryocystorhinostomy for post-canalicular obstruction. But the success rate is not very satisfactory. Our objective is to describe a technique where near 100% success can be achieved. Materials and Methods The study was conducted on 92 patients over 4 years and 6 months. The technique we describe involves creation of a large ostium, creation and apposition of nasal and lacrimal sac mucosal flaps. All the patients were under regular follow-up for12 months after operation. We also compared our result with other techniques. Results                                        The neo-ostium was well healed and free flow of normal saline was seen in 90 cases (97.83%) post-operatively. In one case there was ostium fibrosis and in another case granulations were seen. Conclusion For the past few decades many approaches have been tried for endoscopic dacryocystorhinostomy. But the long term success rates have not been satisfactory. Our technique of creating large stoma and proper mucosal apposition, when done properly gives near 100% success

Photophysical study of 3-acetyl-4-oxo-6, 7-dihydro-12H-indolo [2, 3-a] quinolizine in biomimetic reverse micellar nanocavities: a spectroscopic approach

Photophysical properties of 3-acetyl-4-oxo-6,7-dihydro-12H-indolo[2,3-a]quinolizine (AODIQ), a bioactive molecule, has been investigated in well-characterized, monodispersed biomimicking nanocavities formed by sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in heptane using steady-state and picosecond time resolved fluorescence and fluorescence anisotropy. The emission behavior of AODIQ is very much dependent upon the water/surfactant mole ratio (W), i.e., on the water pool size of the reverse micellar core. AODIQ exhibits a sharp decrease in fluorescence anisotropy with increasing W, implying that the overall motional restriction experienced by the molecule is decreased with increased hydration. Some of the depth-dependent relevant fluorescence parameters, namely, fluorescence maxima and fluorescence anisotropy (r), have been monitored for exploiting the distribution and microenvironment around the probe in the reverse micelles. Fluorescence spectral position and fluorescence quenching studies suggest that the probe does not penetrate into the reverse micellar core; rather it binds at the interfacial region. Quantitaive estimates of the micropolarity and microviscosity at the binding sites of the probe molecule have been determined as a function of W

Synthesis of Biaryl Pentacyclic Quinolonoquinoxalino-Oxazocines in Aqueous Medium Using Amberlite IRA 402(OH)

Amberlite IRA 402(OH) effectively mediates biarylation via Suzuki–Miyaura cross-coupling reaction on complex systems such as dihalo quinolonoquinoxalino-oxazocine

Incidence, clinical features, risk factors, and outcomes of Intraocular inflammation following Brolucizumab in Indian eyes – A multicentric study

Purpose: To report the incidence, clinical features, potential risk factors, and outcomes of intraocular inflammation (IOI) following brolucizumab in Indian eyes. Methods: All consecutive patients diagnosed with brolucizumab-induced IOI from 10 centers in eastern India between October 2020 and April 2022 were included. Results: Of 758 injections given during the study period across centers, 13 IOI events (1.7%) were recorded attributable to brolucizumab. The IOI occurred after the first dose in two eyes (15%) (median 45 days after brolucizumab), second dose in six eyes (46%) (median = 8.5 days), and third dose (39%) in the remaining five eyes (median 7 days). Reinjections of brolucizumab were administered at a median interval of 6 weeks (interquartile range = 4–10 weeks) in the 11 eyes, where IOI occurred after the second or third dose. Eyes that experienced IOI after the third dose had received a significantly greater number of previous antivascular endothelial growth factor injections (median = 8) compared to those who developed it after the first or second dose (median = 4) (P = 0.001). Anterior chamber cells were seen in almost all eyes (n = 11, 85%), while peripheral retinal hemorrhages were seen in two eyes, and one eye showed branch artery occlusion. Two-thirds of patients (n = 8, 62%) recovered with a combination of topical and oral steroids, while remaining recovered with topical steroids alone. Irreversible visual loss was not seen in any eye, and median vision recovered to pre-IOI levels by 3 months' time point. Conclusion: Brolucizumab-induced IOI was relatively rare, occurring in 1.7% of eyes, was more common after the second or third injection, especially in those who required frequent reinjections every 6 weeks, and occurred earlier with increasing number of previous brolucizumab injections. Continued surveillance is necessary even after repeated doses of brolucizumab

Efficient Synthesis of 3,3-diheteroaromatic Oxindole Analogues And Their in Vitro Evaluation For Spermicidal Potential

Syntheses of 3,3-diheteroaromatic oxindole derivatives has been achieved by coupling indole-2,3-dione (isatin) with differently substituted indoles and pyrrole in presence of I2 in i-PrOH. The in vitro spermicidal potentials and the mode of spermicidal action of the synthesized analogues were evaluated and the derivative, 3,3-bis (5-methoxy-1H-indol-3-yl) indolin-2-one (3d) exhibited most significant activity