Phytochemical characterization, antioxidant potential and antibacterial activity of the Croton argyrophylloides Muell. Arg. (Euphorbiaceae)

Croton argyrophylloides Muell. Arg., from the Euphorbiaceae family, popularly known as marmeleiro prateado or sacatinga, is a plant from the Caatinga biome commonly found in Brazil’s northeastern region. The present study aimed to evaluate the antioxidant activity of the species. The phytochemical study was performed through qualitative analysis of chemical constituents and quantitative determination of the total phenol content through the Folin-Ciocalteu test. The qualitative and quantitative antioxidant tests were performed using the DPPH method (2.2 diphenyl-1-picryl hydrazil) and ferric reducing antioxidant power (FRAP). The minimum inhibitory concentration (MIC) was determined by microdilution in 96-well plates. The ethanolic extract of the leaves of C. argyrophylloides manifested antioxidant action in the quantitative DPPH test with a significant bioactivity of 84.70 AAO% in 500 µg/mL, with an EC50 of 236.79. The content of total phenolic compounds was 946.06 mg of gallic acid equivalents/g of sample, and total flavonoids was 58.11 mg of quercetin equivalents/g of sample, the result obtained for FRAP was 15294.44 µM Trolox/g of sample and ABTS was 718 μM Trolox of sample. The prospecting of the chemical constituents of the leaves of C. argyrophylloides revealed the presence of the main compounds that manifests the antioxidant activity and it was proven by the DPPH method that there is antioxidant activity in the analyzed sample, in addition to demonstrating a significant content of phenolic compounds and total flavonoid content in the species, which corroborates the antioxidant activity of the plant sample. The leaf extracts presented growth inhibition halos of 10 and 12 mm upon Staphylococcus aureus ATCC 25923.

Phytochemical study: molecular docking of eugenol derivatives as antioxidant and antimicrobial agents

Eugenol (4-allyl-2-methoxyphenol) is a natural phenolic compound present in certain aromatic plants; however, it is generally extracted from essential oil of Eugenia caryophyllata (Syzygiumaromaticum) (L.) Merr. and L.M. Perry. This bioactive natural compound has generated considerable biological interest with well-known antimicrobial and antioxidant actions. The authors have aimed to the evaluations of eugenol derivatives and their as antimicrobial and antioxidant agent with the aid of molecular dynamic simulation. The starting material was extracted from cloves using hydrodistillation. Two eugenol derivatives, acetyleugenol (4-allyl-2-methoxyphenylacetate) and epoxyeugenol (4-allyl-2-methoxyphenol) were prepared and tested against two strains Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). The results have revealed that the three compounds (Eugenol, acetyleugenol and epoxyeugenol) possess important potentials of inhibition against E. coli and S. Aureus. The antioxidant activity of eugenol derivatives was evaluated by the reaction with DPPH (1,1-diphenyl-2-picrylhydrazyl), showed that the epoxyeugenol was the most active compound. The molecular docking scores of three compounds and the amino acids in the active site pockets of the selected proteins of the two bacteria have approved and explain the biological experimental outcomes.

Discovery of Polyoxypregnane Derivatives From Aspidopterys obcordata With Their Potential Antitumor Activity

The bioassay-guided phytochemical study of an ethnic medicinal plant Aspidopterys obcorda ta Hemsl. var. obcordata results in the isolation of eight new polyoxypregnane derivatives, named aspidatasides A–H (1–8), along with ten known analogs (9–18). The series polyoxypregnane derivatives were screened for their cytoxic activity against HL-60 cells, and compound 2 showed the highest potency with an IC50 8.03 μM. Preliminary structure–activity relationship studies displayed that the sugar chain and double bond could notably impact their biological activity.

Qualitative and Quantitative Determination of Secondary Metabolites and Antioxidant Potential of Plumbago indica Root Extracts

Due to their well-known attribute of having minimal side effects as compared to medicines, natural items with medical potential are progressively gaining prominence in clinical research. The roots of Plumbago indica (P. indica, Plumbaginaceae) are commercially significant since they are the primary source of plumbagin and its derivatives. Plumbagin is well-known for its many pharmacological properties. P. indica roots yielded three naphthoquinones: plumbagin, 3, 30-biplumbagin, and elliptinone, which were employed as standard markers for quantitative HPLC analysis. The goal of this research was to screen phytochemicals, assess alkaloids, phenolic and flavonoid content, and measure the antioxidant potential of P. indica roots. The well-known test methodology was used to determine qualitative analysis of several phytochemical ingredients as well as quantitative analysis of total alkaloids, phenol, and flavonoids. The antioxidant activity of an ethanolic extract of P. indica roots was investigated in vitro using the 1,1-diphenyl, 2-picrylhydrazyl (DPPH) test technique. Alkaloids, glycosides, flavonoids, saponins, phenolics, proteins, and glucose were found in the ethanol and aqueous extracts, according to phytochemical study. P. indica roots ethanolic extract had 5.55, 0.930, and 3.940 mg of total phenolic, flavonoids, and alkaloids respectively. For comparative purposes, ascorbic acid was employed as a benchmark. In the investigated models, the extract showed dose-dependent free radical scavenging properties. For the DPPH technique, P. indica roots extract had an IC50 value of 23.02 µg/ml, which was equivalent to that of ascorbic acid (IC50=17.68 µg/ml). These researches contributed to the accurate identification of this plant material. The plant's broad variety of phytochemicals implies that it has medicinal potential, which might be investigated in the pharmaceutical sector as well as in traditional medicine.