On-Off-On Fluorometric Detection of Hg(II) and L-Cysteine Using Red Emissive Nitrogen-Doped Carbon Dots for Environmental and Clinical Sample Analysis.

This research introduces a novel fluorescence sensor 'on-off-on' employing nitrogen-doped carbon dots (N-CDs) with an 'on-off-on' mechanism for the selective and sensitive detection of Hg(II) and L-cysteine (L-Cys). N-CDs was synthesized using citric acid as the carbon precursor and urea as the nitrogen source in dimethylformamide (DMF) solvent, resulting in red emissive characteristics under UV light. Comprehensive spectroscopic analyses, including UV-Vis, fluorescence, FT-IR, XRD, XPS, Raman, and Zeta potential techniques, validated the structural and optical characteristics of the synthesized N-CDs. The maximum excitation and emission of N-CDs were observed at 548 and 622 nm, respectively. The quantum yield of N-CDs was calculated to be 16.1%. The fluorescence of N-CDs effectively quenches upon the addition of Hg(II) due to the strong coordination between Hg(II) and the surface functionalities of N-CDs. Conversely, upon the subsequent addition of L-Cys, the fluorescence of N-CDs was restored. This restoration can be attributed to the stronger affinity of the -SH group in L-Cys towards Hg(II) relative to the surface functionalities of N-CDs. This dual-mode response enabled the detection of Hg(II) and L-Cys with impressive detection limits of 15.1 nM and 8.0 nM, respectively. This sensor methodology effectively detects Hg(II) in lake water samples and L-Cys levels in human urine, with a recovery range between 99 and 101%. Furthermore, the N-CDs demonstrated excellent stability, high sensitivity, and selectivity, making them a promising fluorescence on-off-on probe for both environmental monitoring of Hg(II) and clinical diagnostics of L-Cys.

Turn-Off Fluorometric Determination of Bilirubin Using Facile Synthesized Nitrogen-Doped Carbon Dots as a Fluorescent Probe.

Bilirubin plays a significant role in human health management, particularly in the case of jaundice. Because of the need for the monitoring of bilirubin levels in jaundice patients, the development of a robust sensitive method becomes essential. Here, we describe the development of a highly sensitive and selective turn-off fluorometric detection method for bilirubin in blood serum samples using nitrogen-doped carbon dots (N-CDs). N-CDs was synthesized by the pyrolysis process, using citric acid and L-asparagine as the carbon and nitrogen sources, respectively. The prepared N-CDs solution showed highly intense blue emission with good stability. The HR-TEM image of N-CDs revealed spherical dot-like structures with an average size calculated to be 7.16 nm. Further, the surface functional groups of N-CDs were analyzed by FT-IR, Raman, XRD, and XPS techniques. Fluorescence spectra showed the maximum emission intensity at 443 nm (λex). The linear range of addition was performed from 1 to 150 µM, and the limit of detection (LOD) was determined to be 1.97 nM. The emission of N-CDs was quenched by Förster Resonance Energy Transfer (FRET) by adding bilirubin. These N-CDs showed extraordinary sensitivity and selectivity in the detection of bilirubin. Hence, this fluorescent probe has been proven successful in detecting the concentration of free bilirubin in human serum samples.

Independent hydrothermal synthesis of the undoped, nitrogen, boron and sulphur doped biogenic carbon nanodots and their potential application in the catalytic chemo-reduction of Alizarine yellow R azo dye.

This research study highlights the catalytic usage of hetero atoms doped and undoped biogenic carbon nano dots (BCNDs) in the reduction of Alizarine yellow R (AYR) dye. Hydrothermal route was followed to synthesize the eco-friendly and fluorescent undoped as well as, N, B & S doped BCNDs from Syzygium cumini (S. cumini) fruit extract. Synthesized BCNDs exhibited good fluorescent and optical properties. From the HR-TEM results, the sizes of the spherically shaped undoped, N, B & S doped BCNDs were found to be 4.75 nm, 4.31 nm, 4.07 nm & 3.96 nm respectively. XRD results highlighted their amorphous nature. Functional groups and elemental percentages were elucidated from the results of FT-IR, EDS and XPS. Graphitic texture of the BCNDs were explained from Raman spectroscopy results and SAED. Thermal stability of BCNDs was evident from the results of TGA analysis. Further, BCNDs were used as green catalyst in the reduction of Alizarine Yellow R (AYR) dye. Langmuir- Hinshelwood mechanism was applied to evaluate the catalytic influence of BCNDs on AYR dye.

Biogenic robust synthesis of silver nanoparticles using Punica granatum peel and its application as a green catalyst for the reduction of an anthropogenic pollutant 4-nitrophenol.

A robust synthesis of silver nanoparticles (AgNPs) using the peel extract of Punica granatum is reported in this article. The formation of AgNPs was confirmed by the appearance of brownish yellow color and the Surface Plasmon Resonance (SPR) peak at 432 nm. The biogenic AgNPs were found to have the size approximately 30 nm with distorted spherical shape. The high negative zeta potential values of AgNPs revealed their high stability which could be attributed to the capping of AgNPs by the phytoconstituents of the Punica granatum peel. The biogenic AgNPs were also found to function as an effective green catalyst in the reduction of anthropogenic pollutant viz., 4-nitrophenol (4-NP) by solid sodium borohydride, which was evident from the instantaneous color change of bright yellow (400 nm) to colorless (294 nm) solution, after the addition of AgNPs. The catalytic action of biogenic AgNPs in the reduction of 4-NP could be explained on the basis of Langmuir-Hinshelwood model.

Anti-inflammatory activity of roots of Ecbolium viride (Forsk) Merrill.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditionally the aqueous extracts of dried roots of the plant Ecbolium viride are used for menorrhagia, rheumatism and jaundice. AIM OF THE STUDY: The aim was to evaluate the anti-inflammatory activity of Ecbolium viride extract in an in vivo model. MATERIALS AND METHODS: The ethyl acetate fraction of Ecbolium viride root extract was prepared and administered orally to rats. The anti-inflammatory activity of Ecbolium viride was determined by carrageenan-induced paw edema and cotton pellet granuloma models. RESULTS: Oral administration of Ecbolium viride extract reduced inflammation significantly (P<0.01) in both the carageenan paw edema and the cotton pellet granuloma models. CONCLUSIONS: The results of the study supported the traditional use of Ecbolium viride in the treatment for inflammatory disease.

Physico-Phytochemical investigation and Anti-inflammatory screening of Capsicum annum L. and Hemidesmus indicus (Linn.) R. Br.

Capsicum annum L. (Family: Solanaceae) and Hemidesmus indicus (Linn.) R.Br. (Family: Asclepiadaceae) are commonly used in Tamilnadufor treating various ailments in the native system of medicine. The hydroalcoholic extracts of both plants at dose level of 100 mg/kg body weight showed demonstrable anti-inflammatory activity in the carrageenan-induced hind paw model in rats. Nevertheless, the overall anti-inflammatory activity exhibited by the extracts are found to be less as compared with that of standard drug Indometacin. Preliminary physico-phytochemical analysis of the plants in question were attempted. The results are highlighted and discussed.

Isolation and characterisation of bioactive isoflavonoids from the roots of Dalbergia horrida.

The roots of Dalbergia horrida yielded two new isoflavanones, Dalhorridin (I) - 5,5'-dihydroxy-3',4'-methylenedioxy-5''-prenyl-6'',6''-dimethyl-dihydropyrano(2'',3'' : 7,8)-isoflavanone and Dalhorridinin (II) - 5,7,5'-trihydroxy-3',4'-methylenedioxy-8-[5-methyl-2-(2-hydroxyisopropyl)-1,4-hexadienyl]isoflavanone along with two known isoflavones, Dalspinin and Dalspinosin. Preliminary biological screening of the enriched extract revealed that it showed analgesic, anti-inflammatory, CNS depressant and mild anti-bacterial properties.

Two new isoflavonoids from the roots of Dalbergia congesta (Grah).

A systematic examination of the roots of Dalbergia congesta, yielded a new oligomeric isoflavonoid (1), a new tetramethoxy isoflavone (2) along with two known compounds, an isoflavone dalspinin (3) and a benzophenone, cearoin (4). On the basis of chemical and spectral evidences, compounds 1 and 2 were determined to be 5,7-dihydroxy-6,4'-dimethoxy-6'[2''-hydroxy-2''(2''',5'''-dimethoxy neoflavonyl) ethenyl] isoflavone (dalcongestin) and 5,7-dihydroxy-2',3',5',6'-tetramethoxy isoflavone, respectively.

Dalsympathetin--a new isoflavone gentiobioside from Dalbergia sympathetica (Dennst.).

Two isoflavonoids isolated from Dalbergia sympathetica were identified as 5,4'-dihydroxy-7-methoxyisoflavone (1) (Prunetin) and Prunetin-4'-O-beta-D-gentiobioside (2) (Dalsympathetin). The natural occurrence of Dalsympathetin is reported for the first time. The position of glycosylation in Dalsympathetin at 4'-position has been confirmed by 2D-NMR spectral studies.

Diversity and divergence among the tribal populations of India.

Tribal populations of the Indian subcontinent have been of longstanding interest to anthropologists and human geneticists. To investigate the relationship of Indian tribes to Indian castes and continental populations, we analyzed 45 unlinked autosomal STR loci in 9 tribal groups, 8 castes, and 18 populations from Africa, Europe and East Asia. South Indian tribal populations demonstrate low within-population heterozygosity (range: 0.54 - 0.69), while tribal populations sampled further north and east have higher heterozygosity (range: 0.69 - 0.74). Genetic distance estimates show that tribal Indians are more closely related to caste Indians than to other major groups. Between-tribe differentiation is high and exceeds that for eight sub-Saharan African populations (4.8% vs. 3.7%). Telugu-speaking populations are less differentiated than non-Telugu speakers (F(ST): 0.029 vs. 0.079), but geographic distance was not predictive of genetic affinity between tribes. South Indian tribes show significant population structure, and individuals can be clustered statistically into groups that correspond with their tribal affiliation. These results are consistent with high levels of genetic drift and isolation in Indian tribal populations, particularly those of South India, and they imply that these populations may be potential candidates for linkage disequilibrium and association mapping.

Piperidone derivative from Dalbergia sympathetica.

An alcoholic extract of Dalbergia sympathetica, on column chromatography, yielded a compound which analyzed for C(6)H(11)NO(3) (M(+) 145). The IR spectrum of the compound showed the presence of carbonyl and hydroxyl groups. PMR, (13)C and DEPT NMR spectral studies of the compound showed the presence of one N-methyl, two methine and two methylene groups. A quaternary carbon signal at delta 172.88 ppm was assigned to C-2 carbonyl of the compound. From all the above observations and also from the HMQC 2D NMR spectrum, the compound was identified as 3, 6-dihydroxy-N-methyl-2-piperidone. This is the first report of the natural occurrence of this compound from plant sources.

Ethnobiology of the Nilgiri hills, India.

The Nilgiri is a popular massif towering high in the Western Ghats in South India with an altitude of 2623 m. Nature has been magnanimous in bestowing Nilgiri district with rich evergreen temperate to tropical forests. A high degree of biodiversity, marked by varied flora and fauna of good therapeutic potential as well as the varied number of indigenous groups of people in this area, makes it very popular among herbalists. The district has six anthropologically well defined ethnic groups namely Todas, Kotas, Kurumbas, Irulas, Paniyas and Kattunayakas living here possibly since 1200 B.C. The present review highlights the ethnobiological profile of six indigenous populations and their dependence on ambient flora and fauna for traditional health care needs. It has been observed that about 2700 therapeutically potent plant species are available in this hill station of which almost all have come from local medicine. Some have been explored scientifically. However, about 150 plant species are still to be explored for their therapeutic potential. The ethnography, phytochemical and therapeutic uses as well as the anthropological perspectives of the local medicines have been discussed in this review.

Monoterpenoids from the seeds of Heracleum candolleanum.

The isolation and NMR spectra of 2-exo,3-endo-camphanediol (1) and 2-pinene-4,10-diol (2) from the seeds of Heracleum candolleanum are reported.

Plants from the traditional medical system of the nilgiri tribes.

This study highlights the medico-ethono botanical information interviewed from Nilgin tribes. The results of this study brought forth 41 medicinal applications involving 34 plants that have been found incorporated into their traditional therapeutic relam of herbal cure for various common ailments the observations are discussed in the light of cross-cltural perspective among nilgiri abongies.

Anti-pyretic activity of some plants in female albino rats: a preliminary report.

Ethanolic extracts of Ailanthus exceisa (AE). Toddalia asiatica (TA) and Araucaria bidwilli (AB) were screened by the anti-pyretic activity in yeast induced hyperthermic test model in the laboratory. Dose of AE (100), TA (60) and AB (30) mg., equivalent of the plant material per kg. Body weight of the extracts were administered orally to the female albino rats. Acute toxicity and preliminary phytochemical screening were conducted for all the extracts. LD 50 values on oral administration of the extracts were found to be AE (1000), AB (350) and TA (250) mg. per kg. body weight respectively. Both the root and aerial part fractions of TA displayed a pronounced anti-pyretic activity comparable to the standard drug paracetamol. AB oleoresin fraction was also found to show anti-pyretic effect. These observations however, confirm the folk-medical practices still prevailing among the tribes.

An in vitro study on the antimicrobial effect of select heterocyclic nitrogen compounds.

In vitro antimicrobial activity of seventeen heterocyclic nitrogen compounds {2-substituted pyrido [1,2-a] pyrimidin -4-oxo-1 [4]-3-Carbonitriles and ethyl 5-amino-3-(substituted) - pyrazole-3-Carboxylates} was tested against Escherichia coli, Bacillus subtilis and candida albicans strains, Antimicrobial activity was measured using standard two -fold serial dilution method and the minimum inhibitory concentration (MIC) values are determined, The MIC of pyrazoles and pyrido[1,2 -a] pyrimidines are found to be 25 µg/ml to 50 µg/ml against E. Coli and 50 µg/ml against B.subtilis respectively. Both pyrazole and pyrido [1,2-a] Pyrimidines are found to be totally ineffective against C. albicans.

A simple method for determination of caffeine content in tea samples.

The present communication describes a simple and modified colorimetric procedure for the estimation of caffeine content in both commercial and locally available tea samples. Comparative data of caffeine content in different brands of tea samples are shown here. The present method is no doubt an improvised procedure for estimating directly caffeine content from the tea extracts. A possible explanation to account for the variability in caffeine content in different samples is offered.

Antifertility activity of Ailanthus excelsa Linn. in female albino rats.

Alcoholic extract of leaf and stem bark of A. excelsa at a dose of 250 mg equivalent of plant material/kg body weight, exhibited remarkably high anti-implantation and early abortifacient activities. The results are in agreement with the traditional use of this plant as a abortifacient by the Irula women of the Nilgiri district.

Pharmacological studies of araucaria bidwilli hook.

Leaf and oleoresin fractions of both alcoholic and petroleum ether extracts of Araucaria bidwillii exhibited significant prolongation of pentobarbitones sleeping time at a dose of 300 and 100 mg/kg body weight respectively in mice. This effect is more pronounced for oleoresin than the leaf extracts. Further, the two extracts seem to possess analgesic effect comparable to aspirin by writing method. The analgesic activity is found to be higher in oleoresin than the leaf extracts. Both the extracts are found to show high anti inflammatory activity comparable to phenylbutzaone by cotton pellet granuloma method.