Assessment of allelopathic potential of the salicylic acid on target plants: Euphorbia heterophylla and Bidens pilosa

Salicylic acid has one of its characteristics the allelopathic potential. The present paper, is a research quantitative in nature aimed to assess the allelopathic potential of salicylic acid to identify the best concentration range for other pure substances. The bioassays were performed in a BOD incubator, seeking to assess the seedling growth by measuring the radicle and hypocotyl length. Each bioassay occurred for 12 days. The concentrations of salicylic acid used in the bioassays were: 1000, 750, 500, 250, 125, and 62.5 ppm and control. The obtained data were submitted to the tests: Kolmogorov-Smirnov normality, the two-way ANOVA with repetition, and Tukey. Based on the results obtained, it was possible to observe that several concentrations demonstrated significant differences, i.e., there is an allelopathic activity in both species (Euphorbia heterophylla and Bidens pilosa). The highlights were for the concentrations of 750 and 1000 ppm for E. heterophylla and 500, 750 and 1000 ppm for B. pilosa. However, there was no significant difference between these concentration groups. The radicle’s length was the part most negatively affected. These results can be used to identify better concentrations for other pure substances, which are usually obtained in small quantities, being useful in the formulation of a product with characteristics of bio-herbicides.

An investigation of the effect of the extracts from the seeds of Bidens pilosa on the growth of Escherichia coli and Bacillus subtilis

Escherichia coli is a Gram-negative bacterium also found in the human. Bacillus subtilis is a Gram-positive, non-pathogenic, endospore-forming bacterium. The spores can survive the heat and B. subtilis to cause food poisoning. The study hypothesized that the extracts from B. pilosa would inhibit the growth of E. coli and B. subtilis. The seeds of B. pilosa were purchased from the seed company. The seeds were dried, ground, and shaken in acetone, ethanol, methanol, and water for 72 hours. Solvents were evaporated and the crude extracts were used for antibacterial activity using a modified Kirby-Bauer disc method. The results revealed that the growth of E. coli was inhibited by the extracts using ethanol. The zones of inhibition were 13 mm. The extracts that were extracted using acetone and water were not effective in inhibiting the growth of E. coli. The growth of B. subtilis was inhibited by the extracts from acetone and methanol. The zones of inhibition were 13 mm. The results revealed that the extracts from ethanol and water were not effective in inhibiting the growth of B. subtilis. Seeds of B. pilosa have the potential to be used as antimicrobials.

Allelopathy and allelochemical quantitative analysis in Pinto peanut (Arachis pintoi)

Pinto peanut (Arachis pintoi) considered as a perennial legume animal fed plant with good soil fertility improvement was uesed for its allelopathy that had been reported on the germination of Ageratum conyzoides L, Comnyza canadensis L. Cronq., Bidens pilosa L., Solanum lycopersicum and Capsicum annum. through the solutions extracted from different parts of pinto peanut on mustard greens (Brassica juncea), barnyardgrass (Echinochloa crus-galli) and junglerice (Echinochloa colonum). Consideration of the growth of hypocotyls and rootlets at 48 hours after incubation with pinto peanut extracts, results showed that 1.0 g/ml of the methanolic pinto peanut stem extract greatly inhibited 100% mustard greens growth, 77.7% and 93.5% the hypocotyls and rootlets growth of barnyardgrass, 57.2% and 92.7% the hypocotyls and rootlets growth of junglerice, respectively. The allelopathic activity after liquid-liquid extraction of the ethyl acetate phase greater than the aqueous phase. Allelopathic extract loading from C18 chromatographic column was purified by HPLC to obtain 6 phenolic compounds with the contents in 1 g fresh pinto peanut weight were 0.214 μg (cinamic acid), 0.8344 μg (caffeic acid), 7.7676 μg (coumaric acid), 2.2354 μg (ferullic acid), 0.045 μg (2-4 dimehydroxy benzoic) and 32.1162 μg (salicylic acid). These results should be accordingly considered in the production of biological herbicides.

Feature-Based Molecular Networks Identification of Bioactive Metabolites from Three Plants of the Polynesian Cosmetopoeia Targeting the Dermal Papilla Cells of the Hair Cycle

The term cosmetopoeia refers to the use of plants in folks’ cosmetics. The aerial parts of Bidens pilosa L., the leaves of Calophyllum inophyllum L. and the fruits of Fagraea berteroana A.Gray ex Benth are traditionally used in French Polynesia for hair and skin care. During the hair cycle, dermal papilla cells and their interaction with epithelial cells are essential to promote hair follicle elongation. The aim of our investigations was the identification of metabolites from these three plants and chemical families responsible for their hair growth activity. A bioactivity-based molecular network was produced by mapping the correlation between features obtained from LC-MS/MS data and dermal papilla cell proliferation, using the Pearson correlation coefficient. The analyses pointed out glycosylated flavonols and phenolic acids from B. pilosa and C. inophyllum, along with C-flavonoids, iridoids and secoiridoids from F. berteroana, as potential bioactive molecules involved in the proliferation of hair follicle dermal papilla cells. Our results highlight the metabolites of the plant species potentially involved in the induction of hair follicle growth and support the traditional uses of these plants in hair care.

Percepção de alunos do Ensino Médio sobre o uso de Plantas Medicinais: uma ferramenta didática nas disciplinas de Biologia e Química em Quirinópolis, Goiás, Brasil

As disciplinas de Biologia e Química podem ser utilizadas como ferramentas para disseminação e ampliação do conhecimento etnobotânico quanto ao uso de plantas medicinais. O despertar deste conhecimento nos alunos contribui para a melhora do interesse pelas ciências experimentais e, consequentemente, propicia um sentimento de pertencimento à natureza por parte dos envolvidos. Neste contexto, esta pesquisa objetivou avaliar a percepção de alunos do Ensino Médio sobre o uso de plantas medicinais em Quirinópolis, Goiás. A pesquisa foi conduzida com a aplicação do questionário 1, seguida por uma aula prática utilizando o método de tintura na preparação do medicamento com plantas medicinais, e, finalizando com a aplicação do questionário 2. Para realização da aula prática, os alunos coletaram as plantas e as trouxeram para o Laboratório de Química/Biologia. A maioria dos estudantes afirmou fazer uso de plantas para fins medicinais com orientação de familiares. Foram citadas 12 espécies vegetais, a maioria exótica, adquiridas, pela maioria, de cultivo próprio, e as mais citadas Plectranthus barbatus Andrews, Chenopodium ambrosioides L., Matricaria chamomilla L. e Bidens pilosa L. A parte mais usada foram as folhas, a forma de preparo predominante foi infusão e o principal uso foi para o tratamento da gripe. A aula prática foi considerada pelos alunos como uma vivência inovadora e de profícuo saber científico. A maioria deles acredita que o conhecimento sobre plantas medicinais pode contribuir para o aprendizado de Química e Biologia e a experiência desperta o interesse nas aplicações práticas dos conceitos científicos abordados em sala de aula.

On the assessment of the sources of inoculum of bacterial wilt in Brazil.

Dispersal of Ralstonia spp. cells by water and contaminated plant material and the importance of weeds as inoculum sources have been poorly investigated. Water of rivers, soil from fields of diverse crops and areas of natural vegetation both from the Amazonia, Cerrado and Mata Atlantica biomes, besides soil of the rhizosphere of weeds present in tomato fields with records of bacterial wilt were sampled and analyzed to detect Ralstonia spp. Seeds of tomato plants artificially and naturally infected with Ralstonia spp. were also processed. All samples were enriched a priori in selective medium South Africa (SMSA) and colonies were isolated in plates containing solid SMSA. Detection of Ralstonia spp. was confirmed by polymerase chain reaction with specific primers. The Co-operational PCR (CO-PCR) was also used to detect Ralstonia spp. Colonies were obtained from soil samples and from a commercial substrate sample. Five soil samples from eggplant fields, one from coffee field, one substrate from potato seed tuber production, two soil samples from the rhizosphere of Amaranthus spp., one from Bidens pilosa and one from Solanum americanum tested positive for Ralstonia spp. Besides these soil samples, five water samples of rivers were positive for CO-PCR detection: two samples from Amazonia, one from Cerrado and two samples from irrigation water collected from tomato fields located in the Mata Atlantica biome. Ralstonia spp. were not detected in tomato seeds. These results revealed potential inoculum sources, especially weeds, in areas with historical records of bacterial wilt. Additionally, rivers may act as dispersal agents of inoculum of Ralstonia spp.

Nutritional and Functional Properties of Wild Leafy Vegetables for Improving Food Security in Southern Angola

In Southern Angola, numerous non-woody forest products are sold at local markets, namely in Lubango (Huíla Province). Such is the case of herbaceous wild plants, locally known as lombi, which are sold fresh throughout the year and cooked as a vegetable. Although these wild leafy vegetables are commercialized and widely used in local food, there is still a lack of scientific knowledge about their properties. Thus, this study aimed to identify and characterize the species sold, and to determine their nutritional and functional properties. Our results revealed that three species—Amaranthus hybridus, Bidens pilosa, and Galinsoga parviflora—are usually sold at Lubango markets and consumed by local populations. These are annual exotic plants, native to Southern America, and usually occur spontaneously in croplands or disturbed areas, but can also be cultivated, particularly A. hybridus. Physico-chemical analyses of lombi species and mixtures sold at the markets included measurements of moisture, protein, lipid, and mineral content, as well as total phenolic content, antioxidant activity, and levels of heavy metal contaminants. The results revealed that lombi contain a significant amount of protein (20–28 g/100 g, dry basis), high values of macronutrients and micronutrients, as well as of phenolic compounds (10–40 mg GAE/g) and a good antioxidant capacity. Given the availability of lombi throughout the year, our study demonstrated the importance of wild edible plants in Angola, both as a valuable natural resources and as a complementary food sources, as well as additional sources of income for many families.

Comparative Chemical Profiles and Phytotoxic Activity of Essential Oils of Two Ecospecies of Pulicaria undulata (L.) C.A.Mey

The Asteraceae (Compositae) family is one of the largest angiosperm families that has a large number of aromatic species. Pulicaria undulata is a well-known medicinal plant that is used in the treatment of various diseases due to its essential oil (EO). The EO of both Saudi and Egyptian ecospecies were extracted via hydrodistillation, and the chemical compounds were identified by GC–MS analysis. The composition of the EOs of Saudi and Egyptian ecospecies, as well as other reported ecospecies, were chemometrically analyzed. Additionally, the phytotoxic activity of the extracted EOs was tested against the weeds Dactyloctenium aegyptium and Bidens pilosa. In total, 80 compounds were identified from both ecospecies, of which 61 were Saudi ecospecies, with a preponderance of β-pinene, isoshyobunone, 6-epi-shyobunol, α-pinene, and α-terpinolene. However, the Egyptian ecospecies attained a lower number (34 compounds), with spathulenol, hexahydrofarnesyl acetone, α-bisabolol, and τ--cadinol as the main compounds. The chemometric analysis revealed that the studied ecospecies and other reported species were different in their composition. This variation could be attributed to the difference in the environmental and climatic conditions. The EO of the Egyptian ecospecies showed more phytotoxic activity against D. aegyptium and B. pilosa than the Saudi ecospecies. This variation might be ascribed to the difference in their major constituents. Therefore, further study is recommended for the characterization of authentic materials of these compounds as allelochemicals against various weeds, either singular or in combination.