Kanchi Mamunivar Centre for Postgraduate Studies

ABSTRACT Visible‐light‐driven photocatalysis has emerged as a promising strategy for the removal of persistent organic dyes from wastewater. In this study, a ternary g‐C 3 N 4 /BiVO 4 /MoO 3 heterostructure was synthesized via a sol–gel method and evaluated for the photocatalytic degradation of Rhodamine 6G (Rh‐6G) under visible‐light irradiation. They were characterized by XRD, FTIR, XPS, UV–vis, FESEM, TEM, and EDS. The incorporation of BiVO 4 and MoO 3 with g‐C 3 N 4 enhanced visible‐light absorption, promoted interfacial interaction among the constituent phases, and reduced the optical band gap to 2.48 eV, facilitating improved charge separation and photocatalytic performance. The optimized photocatalyst achieved a Rh‐6G degradation efficiency of 90.2% within 180 min. Radical scavenger experiments revealed that photogenerated holes were the dominant reactive species responsible for dye degradation. Mass spectrometric analysis indicated the progressive decomposition of Rh‐6G into lower‐molecular‐weight intermediates, suggesting its effective degradation pathway. The photocatalytic activity was strongly dependent on the initial solution pH, with the highest degradation efficiency observed under neutral conditions. The photocatalyst exhibited good structural stability and reusability for repeated photocatalytic cycles. These findings demonstrate that the g‐C 3 N 4 /BiVO 4 /MoO 3 ternary heterostructure is an efficient visible‐light‐responsive photocatalyst for the degradation of organic dyes and represents a promising material for sustainable wastewater treatment applications.

The structural geometry, electronic and reactivity characteristics, vibrational assignments and the fundamental modes of 6-methylcoumarin have been carried out. The effect of methyl group on the pyrone skeletal vibrations was also discussed. The experimental vibrational frequencies were compared with the wavenumbers obtained theoretically from the B3LYP method employing the high level 6-311++G** and cc-pVTZ basis sets. Frontier molecular orbital (FMO) energy and the LUMO-HOMO energy gap was measured. The atomic charges and the bond properties were examined by natural bond orbital analysis. The hydrogen and carbon environment were examined by NMR spectra. The nuclophilic, electrophilic and free radical attacking sites of 6-methylcoumarin were also analyzed.

Hemidesmus indicus (L.) R. Br. ex Schult is commonly known as anantmul or Indian sarsaparilla. The roots of this plant, which display a wide range of medicinal, biological, and phytopharmaceutical properties, are used in the pharmaceutical and food industries. Conventionally, the plant is propagated by seed germination or vegetatively, but the efficacy of traditional methods has some limitations: plants derived from seed germination are prone to seed-borne diseases, or plantlet production using vegetative propagation is limited. In contrast, plant tissue culture allows for large-scale propagation and secondary metabolite production in vitro without sacrificing plants from their natural habitats. Many efforts have been made over 40 years of research to establish efficient micropropagation protocols to speed up cultivation of this plant, including callus-mediated in vitro propagation, somatic embryogenesis, and shoot multiplication using cotyledenory nodes, stem segments, shoot tips, and nodal explants. Among these explants, nodal explants are the most commonly used for H. indicus micropropagation. The application of adenine sulfate, citric acid, ascorbic acid, and arginine may be useful in preventing explant browning, premature leaf senescence, and shoot tip abscission during in vitro culture. This review provides insight into micropropagation, use of synthetic seeds for short-term germplasm preservation, and in vitro production of secondary metabolites such as 2-hydroxy-4-methoxybenzaldehyde, lupeol, vanillin, and rutin, from in vitro root and callus cultures. Furthermore, unexplored and possible innovative areas of research in Hemidesmus biotechnology are also discussed. • Hemidesmus indicus has multiple therapeutic applications. • H. indicus roots are used in confectionary and pharmacy. • This review comprehensively assesses H. indicus tissue culture. • Challenges and future research of H. indicus biotechnology are discussed.

Typhonium is a genus belonging to the Aroceae family, native to southern Asia and Australia. in folk medicine, Typhonium Is used for its analgesic, anti-inflammatory, anti-diarrheal, and wound-healing properties. We report a toxidrome of airway compromise due to Typhonium trilobatum tuber ingestion. We present an interesting case series of four patients who consumed raw tuber of T trilobatum with suicidal thoughts. They exhibited a constellation of symptoms such as swelling of lips and tongue, drooling of saliva, and severe throat pain. One patient had significant upper airway edema and severe respiratory distress requiring emergency endotracheal intubation. Laboratory investigations were grossly normal in all four individuals, expect for mild asymptomatic hypokalemia in one and eosinophilia in another patient. We successfully managed all our patients with repeated adrenaline nebulization, antihistamines, and steroids. Typhonium is believed to be a beneficial herb. Toxicity of Typhonium is not reported much in the literature till date. An emergency department (ED) physician should be aware of this tuber toxicity as it presents with airway compromise, which resolves over hours. The symptoms are due to the local effects of calcium oxalate crystals in the tuber. Airway management is the priority and repeated adrenaline nebulization together with supportive care is advised.

Hedyotis biflora (Linn.) Lam is an important herb, used in the Indian and Chinese traditional systems of medicines. Indiscriminate harvesting of this plant resulted in decline of its population from the natural habitats. The present study reports effective micropropagation and in vitro flowering in H. biflora. Healthy plants were maintained in the greenhouse to collect fresh explants (nodal segments). Average 3.2 shoot bud/node with 88% shoot regeneration obtained on Murashige and Skoog’s (MS) medium with 2.0 mg L−1 6-benzylaminopurine (BAP) and additives like 50 mg L−1 of ascorbic acid and 25 mg L−1 each of arginine, adenine sulphate and citric acid. About 84.5 shoots, with 8.1 cm shoot length were obtained on MS basal medium supplemented with 1.0 mg L−1 BAP, 0.5 mg L−1 kinetin (Kin) and 0.1 mg L−1 indole-3 acetic acid (IAA) and additives. In vitro flowers were induced in 91% cultures (6.8 flowers per shoot) when the shoots were cultured on MS medium supplemented with 1.5 mg L−1 BAP and 0.1 mg L−1 IAA at 12-h photoperiods. In vitro raised shoots were rooted with the help of indole-3 butyric acid (IBA) via in vitro and ex vitro techniques. The micropropagated plants were acclimatized with 91% survival rate in the field. Upon transfer of plantlets from the in vitro to ex vitro environments, there were significant changes in stomata, vein-islets and raphids. These micro-morphological changes may help micropropagated plantlets to establish under the field conditions. The present protocol is suitable for large scale micropropagation, conservation and commercial production of this plant. The protocol of in vitro flowering could be useful in understanding the in vitro pollination biology of H. biflora.