Graphene quantum dot doped viscoelastic lyotropic liquid crystal nanocolloids for antibacterial applications.

Graphene quantum dots (GQDs) are prepared and characterized via X-ray diffraction (XRD), UV-Visible spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM) and photoluminescence (PL). GQDs are doped (5 mg and 10 mg) in the lyotropic liquid crystalline (LLC) lamellar and hexagonal phases to prepare GQD/LLC nanocolloids. Polarizing optical microscopy and X-ray diffraction measurement reveals that GQDs do not affect the lamellar and hexagonal LLC structures and may organize on their interface. Pure LLC phases and nanocolloids are studied for steady and dynamic rheological behavior. LLC phases and GQD/LLC nanocolloids possess shear thinning and frequency dependent liquid viscoelastic behavior. A complex moduli study of LLCs and GQD/LLC nanocolloids is carried out which indicates the gel to viscous transition in LLCs and GQD/LLC nanocolloids as a function of frequency. LLC phases and GQD/LLC nanocolloids are tested for antibacterial activity against Listeria ivanovii. The effect of surfactant concentration, LLC phase geometry and GQD concentration has been studied and discussed. A probable mechanism for the strong antimicrobial activity of LLCs and GQD/LLC nanocolloids is presented considering intermolecular interactions. The viscoelastic behavior and strong antibacterial activity (inhibition zone 49.2 mm) of LLCs and GQD/LLC nanocolloids make them valuable candidates for lubrication, cleaning, cosmetics and pharmaceutical applications.

GC-MS fingerprinting, nutritional composition, in vitro pharmacological activities and molecular docking studies of Piper chaba from Uttarakhand region.

This study aimed to evaluate the potential therapeutic effects of Piper chaba (PC) growing in the northern region of India, having differences in the phytochemicals, nutritional content, antimicrobial and antioxidant properties by reducing power assay (RPA), 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, phosphomolybdate assay, and antidiabetic potential by α-amylase assay with change in the geographical location. Outcomes of the gas chromatography-mass spectrometry (GC-MS) analysis revealed that phytochemicals such as piperine (46.69%), kusunokinin (8.9%), and sitostenone (7.57%) are the prominent compounds found in PC. The plant has also shown a good nutritional value, i.e., iron (11.25 mg), calcium (147 mg), and vitamin C (9.30 mg) per 100 g. PC has a higher phenolic content than other species (⁓ 13.75 g/100 g plant powder). Among the four tested bacterial strains, the extract is best responsive toward Escherichia coli (35 ± 0.68 mm) which is more than the standard ciprofloxacin (24 ± 0.8 mm). Similarly, among two tested fungal strains, Saccharomyces cerevisiae shows the best zone of inhibition (ZOI) (27.5 ± 0.8 mm), which is greater than tat of standard amphotericin (20.25 ± 0.28 mm). The DDPH method demonstrated the highest antioxidant activity (⁓ 42.61 ± 1.82 µg/ml). IC50 for the antidiabetic potential of PC was found to be 23.09 ± 0.3 µg/ml against α-amylase assay. A molecular docking study revealed that three compounds, piperine, sitostenone and kusunokinin, showed strong binding affinity toward bacterial tyrosyl-tRNA synthetases, fungal dihydrofolate reductase, and α-amylase, respectively. Therefore, the findings of the current study indicate that PC can be considered as a source of food and medicines, either in the form of traditional preparations or as pure active constituents. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-03996-7.

Identification of Bioactive Phytoconstituents, Nutritional Composition and Antioxidant Activity of Calyptocarpus vialis.

This study is focused to highlight the phytochemical, nutrient content and in vitro antioxidant capacity of the wildly growing plant Calyptocarpus vialis (CV) of the Asteraceae family collected from the Garhwal region of India. Phytochemical and nutritional analysis of CV is done by qualitative and quantitative methods. Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed the presence of phenols, alkanes, aliphatic primary amines, carboxylic acids, nitrile, aromatics and alcohols. Gas chromatography and mass spectroscopy (GC-MS) revealed the presence of terpenoids, plant sterols and phenols such as phytol (14.9%), stigmasterol (10.02%), viridiflorol (4.19%), squalene (2.54%) and various other phytochemicals. The plant's study reveals the existence of numerous nutritious elements, including proteins, vitamins, carbohydrates and amino acids. It also revealed the presence of the huge amount of phenolic content ⁓13.49 g in a 100-g dried CV plant sample. The antioxidant potential of methanolic extract of CV was estimated using DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging assay, phosphomolybdate assay and reducing power assay. The highest percentage of antioxidant activity determined from three assays is 74 to 87% for 1 mg of dry extract. It is observed that the CV extract act as a good antioxidant when compared to other plants of the Asteraceae family even at very low concentration of the sample. Hence, CV found in the foothills of Himalayas can be further explored as a source of potent bioactive compounds and natural and economical antioxidant for biomedical and immunity-boosting applications.