Chemical Composition of Extracts and Fractions from Miconia Ibaguensis (Melastomataceae) Leaves and Evaluation of Biological Activities.

The study aimed to assess the chemical composition of Miconia ibaguensis leaves extracts and fractions obtained from the ethanolic extract (EE), along with evaluating their antifungal, antibacterial, antidiabetic, and antioxidant activities. The ethyl acetate fraction (EAF) exhibited potent antifungal activity against Candida spp (1.95-3.90 µg mL-1) and potent antioxidant activity in the DPPH (1.74±0.07 µg mL-1), FRAP (654.01±42.09 µmol ETrolox/gsample), and ORAC (3698.88±37.28 µmol ETrolox/gsample) methods. The EE displayed inhibition against the α-amylase enzyme (8.42±0.05 µg mL-1). Flavonoids, hydrolysable tannins, triterpenoids, and phenolic acids, identified in the EE and fractions via (-)-HPLC-ESI-MS/MS analysis, were found to contribute to the species' biological activity potentially. These findings suggest promising avenues for further research and potential applications in pharmacology and natural products, offering new possibilities in the fight against global health issues.

Tarballs on the Brazilian coast in late 2022 sustain Lepas anatifera Linnaeus, 1758 (Crustacea: Cirripedia): Occurrence and risk of petroleum hydrocarbon ingestion.

Since the 2019 oil spill on the northeastern coast of Brazil, oil materials have washed up on the beaches. A characteristic of the recent oil spill that began in late August was that some of the oiled material, such as tarballs, contained the goose barnacle species Lepas anatifera (Cirripedia, Lepadomorpha), which is well-known for its cosmopolitan distribution and wide occurrence in the oceans. The findings of this study provide information on the occurrence and contamination of petroleum hydrocarbons in animals adhered to the surfaces of tarballs sampled from beaches in the Brazilian states of Ceará and Rio Grande do Norte, between September and November 2022. The size of the barnacles varied from 0.122 to 2.20 cm, suggesting that the tarballs had been floating in the ocean for at least a month. All groups of L. anatifera collected from the tarballs had polycyclic aromatic hydrocarbons (PAHs) present (∑21PAHs from 476.33 to 3816.53 ng g-1). In comparison to high-molecular-weight PAHs, which are primarily from pyrolytic sources, low-molecular-weight PAHs, such as naphthalene and phenanthrene, which are mostly related to petrogenic sources, were shown to be more abundant. In addition, dibenzothiophene, which is exclusive of petrogenic origin, was found in all samples (30.74-537.76 ng g-1). The aliphatic hydrocarbons (AHs): n-alkanes, pristane, and phytane were also found and displayed petroleum characteristics. These results highlight the danger of increasing the absorption of petrogenic PAHs and AHs by organisms that use tarballs as substrates. L. anatifera is a crucial component of the food chain because many animals such as crabs, starfish, and gastropods consume it.

Antioxidant compounds from Banisteriopsis argyrophylla leaves as α-amylase, α-glucosidase, lipase, and glycation inhibitors.

Banisteriopsis argyrophylla belongs to the Malpighiaceae family, which is a species from Cerrado, also known as "cipó-prata" or "cipó-folha-de-prata." Several species of this family present biological potential. This work reports the chemical identification of the ethanol extract (EE) and its fractions from B. argyrophylla leaves and shows the analysis of the antioxidant activity and inhibitory effects on activities of α-amylase, α-glucosidase and lipase, and non-enzymatic glycation. The ethyl acetate fraction (EAF) and n-butanol fraction (BF) showed antioxidant activity, with IC50 values of 4.1 ± 0.1 and 4.8 ± 0.1 µg mL-1, respectively, by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, and IC50 values of 6046.3 ± 174.2 and 6264.2 ± 32.2 µmol Trolox eq g-1 by the oxygen radical absorbance capacity (ORAC) method. Furthermore, the DPPH method with these fractions presented electroactive species with antioxidant potential, as shown by the differential pulse voltammetry (DPV) method. The inhibitory effects of the EAF and BF were demonstrated by the following results: IC50 of 5.1 ± 0.3 and 2.5 ± 0.2 µg mL-1 for α-amylase, IC50 of 1093.5 ± 26.0 and 1250.8 ± 21.9 µg mL-1 for α-glucosidase, IC50 of 8.3 ± 4.1 and 4.4 ± 1.0 µg mL-1 for lipase, and IC50 of 1.3 ± 0.1 and 0.9 ± 0.1 µg mL-1 for glycation. Some bioactive compounds were identified by (-)-ESI-MS/MS, such as catechin, procyanidins, glycosylated flavonoids, kaempferol, and megastigmane glucosides. The antidiabetic activity of B.argyrophylla has been reported for the first time.

Fluorescence quantum yield of natural dye extracted from Tradescantia pallida purpurea as a function of the seasons: Preliminary bioapplication as a fungicide probe for necrotrophic fungi.

In this work, over the course of four seasons (12 months), we have monitored the fluorescence quantum efficiency (η) from two sets (S1 and S2) of fresh natural dye extracts from the leaves of Tradescantia pallida purpurea. The natural dye was extracted in aqueous solutions from leaves collected from regions with a predominance of shade (S1) and sun (S2) during the day. The thermo-optical parameter fractional thermal load (φ) was measured using conical diffraction (CD) patterns caused by thermally driven self-phase modulation, for η determination in both sets of solutions. Fluorescence measurements corroborate the CD results, and the η values are, on average, slightly higher (~ 11%) in the summer than in the other seasons for both sets of samples (S1 and S2). In addition, the experimental results are presented using natural dye extracted from Tradescantia pallida purpurea as a fungicide probe in Fusarium solani, Sclerotinia sclerotiorum, and Colletotrichum gloeosporioides fungi. The promising fungicide results obtained for the aqueous natural dye extract were compared with those obtained for other natural dyes and fungi. The fungi tested are of the necrotrophic group and constitute important pathosystems in Brazil, causing diseases in several crops that synthetic fungicides often cannot control or do so with low efficiency.

Chemical Composition, Antifungal, and Cytotoxicity Activities of Inga laurina (Sw.) Willd Leaves.

The species Inga laurina is native to the Brazilian Cerrado. There are no studies about the chemical composition and biological activities of extracts of this endangered species. The ethanolic extract and its successive fractions are rich in phenolic compounds and presented good antifungal activities. HPLC/MS-MS/MS and H1/C13 analysis led to the identification of seventeen compounds, most of which are gallic acid derivatives, myricetin and quercetin glycosides. The ethyl acetate fraction (EAF) contained high levels of total phenolics, expressed in milligrams of gallic acid equivalents per gram of extract (475.3 ± 1.9 mg GAE gextract -1) and flavonoids expressed in milligrams of quercetin equivalents per gram of extract (359.3 ± 10.6 mg QE gextract -1). This fraction was active against fungi of the Candida genus. The EAF showed MIC value 11.7 µg mL-1 against C. glabrata and a selectivity index of 1.6 against Vero cells. The flavonol glycoside myricetin-3-O-rhamnoside was isolated for the first time from the Inga laurina. These results make I. laurina a promising plant as a source of pharmaceutical and biological active antifungal compounds.

Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves.

OBJECTIVES: This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites. METHODS: The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSn . Then, EAF was submitted to column chromatography to give four new fractions (A1-A4). The cytotoxicity was determined against Vero cells. KEY FINDINGS: The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 µg/ml. The (-)-catechin (fraction A1) showed a MIC of 2.83 µg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86-46.87 µg/ml) against C. albicans, C. glabrata and C. tropicalis. CONCLUSIONS: The EtOH extract, fractions and the isolated (-)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.

Bioassay-guided fractionation and antimicrobial and cytotoxic activities of Cassia bakeriana extracts

ABSTRACT The antimicrobial potential of extracts of bark and leaves of Cassia bakeriana Craib, Fabaceae, against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method. For crude ethanol extracts and organic fractions tested, the bark dichloromethane phase showed a significant antibacterial effect, with MIC values ranging from 12.5 to 100 µg/ml for most of the microorganisms tested. Thus, a bioassay-guided fractionation of this fraction was performed. This fractionation led to isolation of the 1,8-dihydroxy-anthraquinone-3-carboxylic acid, also known as cassic acid or rhein. It is the first time that this bioactive anthraquinone has been isolated from this plant. Rhein exhibited good selectivity and high activity against anaerobic microorganisms, with MIC values ranging between 3.12 µg/ml (11.0 µM) and 25 µg/ml (88.0 µM). These results were considered very promising since the most active samples and rhein showed greater selectivity against oral microorganisms than toxicity to Vero cells.

Peel of araticum fruit (Annona crassiflora Mart.) as a source of antioxidant compounds with α-amylase, α-glucosidase and glycation inhibitory activities.

Annona crassiflora Mart., whose fruit is popularly known as araticum, is a member of the Annonaceae family found in the Brazilian Cerrado. Although this plant has several medicinal uses, its bioactive molecules are not fully understood. A bioguided assay was performed to identify the main bioactive compounds of A. crassiflora fruit peel from the ethanol extract fractions with antioxidant capacity and α-amylase, α-glucosidase and glycation inhibitory activities. Ethyl acetate and n-butanol fractions showed, respectively, higher antioxidant capacity (DPPH IC50 1.5±0.1 and 0.8±0.1µgmL-1, ORAC 3355±164 and 2714±79µmoltroloxeq/g, and FRAP 888±16 and 921±9µmoltroloxeq/g) and inhibitory activities against α-amylase (IC50 4.5±0.8 and 1.7±0.3µgmL-1), α-glucosidase (IC50 554.5±158.6 and 787.8±140.6µgmL-1) and glycation (IC50 14.3±3.3 and 16.0±4.2µgmL-1), and lower cytotoxicity, compared to the other fractions and crude ethanol extract. The HPLC-ESI-MS/MS analysis identified various biomolecules known as potent antioxidants, such as chlorogenic acid, (epi)catechin, procyanidins, caffeoyl-hexosides, quercetin-glucosides and kaempferol. The fruit peel of A. crassiflora, a specie from Cerrado, the Brazilian Savanna, provided a source of antioxidant compounds with properties to block carbohydrate digestive enzymes and formation of glycation products. Thus, there is potential to use the by-products of araticum in order to identify and isolate phytochemicals for application in nutraceutical supplements, food additives and pharmaceuticals products.

Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea Mart. & Zucc. Essential Oils.

Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL(-1)). The outer bark and wood EOs showed MICs of 100 µg mL(-1) for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest.

Seasonal variation of the chemical composition and antimicrobial and cytotoxic activities of the essential oils from Inga laurina (Sw.) Willd.

The seasonal chemical composition of essential oils from Inga laurina was determined by GC/MS. In the stem bark's essential oil extracted during the dry season, the presence of terpenoids (30.05%) stood out, and phytol (9.76%) was the major compound identified. For the stem bark oil obtained during the rainy season, in addition to terpenoids (26.63%), a large amount of fatty acids (46.84%) were identified, in particular palmitic acid (25.40%). Regarding the leaves' essential oil obtained in the dry season, esters (42.35%) were the main components. The main ester present was (Z)-hex-3-enyl benzoate (10.15%) and the major compound of this oil was (Z)-hex-3-en-1-ol (14.23%). Terpenoids (33.84%), long-chain alkanes (27.04%) and fatty acids (21.72%) were the main components of the essential oil from leaves in the rainy season. Phytol (33.21%), nonacosane (21.95%) and palmitic acid (15.20%) were the major compounds identified. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated by the microdilution broth method and cytotoxic activity was carried out with Vero cells. The essential oils from the rainy season showed a better inhibition of the bacterial growth with Minimal Inhibitory Concentrations (MIC) values of 25 or 50 µg·mL⁻¹ for aerobic bacteria, and high selectivity against bacteria was observed. The large amount of fatty acids in rainy season oils may be related to the better inhibitory effects observed.

Chemical composition, cytotoxic and antimicrobial activity of essential oils from Cassia bakeriana Craib. against aerobic and anaerobic oral pathogens.

The chemical composition of the essential oils from leaves, bark and wood of Cassia bakeriana Craib. was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Alcohols, aldehydes and fatty acids were the major components in leaf and bark oil, while wood essential oil was rich in fatty acids. Terpenes such as linalool, (E)-nerolidol and phytol were present in low concentrations. The antimicrobial activity against aerobic and anaerobic oral bacteria was evaluated using the microdilution method, as was the cell viability test carried out with Vero cells. The oils from leaves and bark showed high antimicrobial activity, with minimum inhibitory concentrations between 62.5 and 125 µg·mL⁻¹ for most of the tested bacteria, including Streptococcus mutans, the main etiological agent of dental caries. Leaves oil displayed the lowest cytotoxic effect (EC50 of 153 µg·mL⁻¹), while wood oil exhibited the highest toxicity to Vero cells. C. bakeriana oils are thus a source of biologically active compounds against aerobic and anaerobic oral microorganisms. This study is the first report on the chemical composition, antimicrobial activity and cytotoxicity of C. bakeriana.