Brazilian Journal of Science

Synthesis and biological evaluation of oxygen-, nitrogen-, and sulphur-containing non-fused heterocycles and tricyclic fused pyrimidines

Mohammad Mizanur Rahman — 2025-10-31

A series of non-fused heterocycles containing oxygen, nitrogen, and sulfur (compounds 2, 3, 6, 9, 10, and 12), as well as furo-imidazo and thiazolo-thieno fused pyrimidines (compounds 7 and 13), were synthesized in good yields using a catalyst-free, convenient, general, and facile method. The molecular structures of all newly synthesized compounds were confirmed by spectral data and elemental microanalyses. Furthermore, the biological activities of all synthesized heterocyclic derivatives were evaluated in vitro against various common pathogenic microorganisms.

Effects of light spectrum and UV-A radiation on in vitro seed germination and seedlings of Massai grass (Panicum maximum cv. Massai)

Selton Sales de Souza — 2025-10-28

The objective of this study was to evaluate the effects of different visible light spectra and UV-A radiation on the germination and morphology of Massai grass (Panicum maximum cv. Massai) seedlings in vitro. Seeds of cv. Massai from the 2024/2025 harvest were used. The experiment was conducted in germination boxes maintained at 25 ºC for 17 days under different light sources: white, red, green, yellow, absence of light (black), and UV-A radiation. Germination was monitored daily by counting the number of germinated seeds, with a 16-hour photoperiod. At the end of the experiment, seedlings were collected and evaluated for shoot length, root length, and fresh and dry mass. Results showed that the highest germination rates occurred between days 2 and 4 under green, red, and white light spectra. The lowest germination rate was observed under UV-A, reaching a maximum of 42%. Regarding seedling morphology, yellow light provided the best results, enhancing shoot length, root length, and fresh mass. In conclusion, visible light spectra such as green, red, and white promote rapid germination in a shorter time, while the yellow spectrum (570–590 nm) optimizes seedling morphological development in Massai grass. UV-A radiation, however, exerts deleterious effects from germination through early seedling growth.

First record of the long-winged harrier, Circus buffoni (Aves, Accipitridae) from the Northeastern extreme of Brazil

José Arthur Felipe Pequeno — 2025-10-31

We present the first record of the Long-winged harrier, Circus buffoni (Gmelin, 1788), from the state of Rio Grande do Norte, in the Northeastern extreme of Brazil, specifically, the East Potiguar Microregion, which is located within the Atlantic Forest phytogeographic domain. During the study, we recorded at least two individuals between January and June, and recorded their foraging behavior and predation events. We also compiled all published data available on C. buffoni, as well as records from ornithological collections and online databases, which resulted in a total of 13 documented records for the Brazilian Northeast. Breeding populations of C. buffoni are known to exist in both northern and southern South America, providing conflicting evidence on the possible origin of the study individuals and their migratory patterns in Brazil. Given the persistent lacunas in our understanding of the dispersal patterns of Circus buffoni, we recommend further surveys in areas with similar habitats to provide more comprehensive data for defining the species' distribution in South America and its migratory patterns.

Orexin gene expression analysis in two Nigerian indigenous and exotic chickens using quantitative polymerase chain reaction (qPCR)

Hameed Olayemi Salawu — 2025-10-31

This study investigated orexin gene expression patterns in two Nigerian indigenous chicken ecotypes (Fulani and Yoruba) compared to the exotic Cobb-500 breed using quantitative polymerase chain reaction (qPCR) technology. A total of 135 birds (45 per breed) were reared for four weeks, after which liver tissue samples were collected for RNA extraction and analysis. The orexin gene serves as a crucial regulator of appetite, energy balance, and stress responses in poultry, making it an important molecular marker for understanding breed-specific physiological adaptations. RNA was extracted using the Zymo RNA mini prep kit, followed by cDNA synthesis and qPCR analysis using Luna^® Universal qPCR Mastermix. The TATA box binding protein served as the housekeeping gene for normalization. Gene expression was quantified using the 2^-ΔΔCT method (Livak method) to determine fold changes between breeds. Results revealed significant inter-breed variations in orexin expression levels (P < 0.05). The Fulani ecotype demonstrated the highest expression (1.37-fold), followed by Cobb-500 broilers (0.35-fold), while Yoruba ecotype chickens showed the lowest expression (0.02-fold). Melt curve analysis confirmed primer specificity and amplification consistency across all samples. These findings suggest that elevated orexin expression in Fulani chickens may reflect superior physiological adaptability and energy regulation capabilities, supporting their resilience in variable environmental conditions. The differential expression patterns highlight orexin's potential as a molecular marker for selective breeding programs aimed at improving indigenous chicken productivity while maintaining genetic diversity and environmental adaptability in Nigerian poultry systems.

First Documented Record of Progne subis (Hirundinidae) from Rio Grande do Norte State, Brazil

Glauber Henrique Borges de Oliveira Souto — 2025-10-31

We report the first confirmed record of the Purple Martin (Progne subis Linnaeus, 1758) for the state of Rio Grande do Norte, Brazil. The record was obtained on 19 February 2025 in the municipality of Lajes/RN, located in the Central Potiguar mesoregion, where the Caatinga biome predominates. This finding represents a significant addition to the avifauna of Rio Grande do Norte, as it expands the known distribution of the species in northeastern Brazil. The confirmation of its occurrence in Lajes contributes to updating the state bird checklist and may support future surveys aimed at detecting additional regional populations.