Phenolic Monoterpenes Conversion of Conobea scoparioides Essential Oil by Hydrotalcite Synthesized from Blast-Furnace Slag.

Conobea scoparioides (Plantaginaceae) is an herbaceous plant known as "pataqueira" that grows wild in seasonally wet areas of the Amazon region. It is used for aromatic baths and anti-protozoan remedies by the Brazilian Amazon native people. The main volatile compounds identified in the essential oil of "Pataqueira" were the phenolic monoterpenes thymol and thymol methyl ether and their precursors, the monoterpene hydrocarbons α-phellandrene and p-cymene. A hydrotalcite synthesized from blast-furnace slag exhibited a 3:2 (Mg/Al) molar ratio, and this layered double hydroxide (LDH) was evaluated as a catalyst in converting the main monoterpenes of the "Pataqueira" oil. This action significantly increased the thymol content, from 41% to 95%, associated with the percentual reduction in other main components, such as thymol methyl ether, α-phellandrene, and p-cymene. The LDH reaction showed a strong tendency towards producing hydroxylated derivatives, and its behavior was similar to the hypothetical plant biosynthetic pathway, which leads to the production of the monoterpenes of "Pataqueira" oil. Thymol and its derivatives are potent antiseptics applied in pharmaceutical and hygienic products as antibacterial, antifungal, and antioxidant properties, among others. The present work reports a natural source with a high thymol content in aromatic plants from the Amazon, with evident economic value.

Volatile Profiles and DNA Barcodes of Myrtaceae species with Occurrence in the Brazilian Amazon.

Myrtaceae family includes many species with taxonomic challenges, making it one of the most complex families to identify. This study used DNA barcoding to find molecular markers for species authentication based on the Myrtaceae family's chemical composition and genetic diversity. Essential oils and genetic material were extracted from the leaves of six different species: Eugenia uniflora, E. patrisii, Myrcia splendens, Psidium guajava, P. guineense, and Psidium sp. The samples were analyzed based on compound classes and grouped into two categories. Group I included samples with high amounts of oxygenated sesquiterpenes (3.69-76.05%) and fatty acid derivatives (0.04-43.59%), such as E. uniflora, Myrcia splendens, and E. patrisii. Group II included samples P. guajava, P. guineense, and Psidium sp., which had a significant content of monoterpene hydrocarbons (0.69-72.35%), oxygenated sesquiterpenes (8.06-68.1%), phenylpropanoids (0.45-22.59%), and sesquiterpene hydrocarbons (0.27-21.84%). The PsbA-trnH gene sequences had a high genetic variability, allowing the species to be distinguished. A phylogenetic analysis showed two main clusters with high Bootstrap values corresponding to the subtribes Eugeniineae, Myrciinae, and Pimentinae. The results suggest a weak correlation between genetic and chemical data in these Myrtaceae species.

Volatile Constituents of Some Myrtaceous Edible and Medicinal Fruits from the Brazilian Amazon.

Native and exotic fruits from the Amazon have varied characteristics, with aroma being a decisive factor in their acceptance for medicinal use as a nutraceutical supplement. This work aimed to analyze the chemical constituents of the volatile concentrates of some Myrtaceous fruit species sampled in the Brazilian Amazon. The fruit's pulps were subjected to simultaneous distillation-extraction, and gas chromatography-mass spectrometry was used to analyze their volatile chemical composition. In the volatile concentrate of Eugenia stipitata (Araçá-boi) α-pinene (17.5%), citronellyl butanoate (15.6%), and pogostol (13.5%) were identified as primary constituents; Eugenia uniflora (Ginja) concentrate comprised curzerene (30.5%), germacrone (15.4%), atractylone (13.1%), and (E)-ß-ocimene (11.1%); in Myrciaria dubia (Camu-Camu), α-pinene (55.8%), (E)-ß-ocimene (13.1%), and α-terpineol (10.0%) were present; in Psidium guajava (Goiaba) were (2E)-hexenal (21.7%), hexanal (15.4%), caryophylla-4(12),8(13)-dien-5-ß-ol (10.5%), caryophyllene oxide (9.2%), and pogostol (8.3%); and in Psidium guineense (Araçá), limonene (25.2%), ethyl butanoate (12.1%), epi-ß-bisabolol (9.8%), and α-pinene (9.2%) were the main constituents. The analyzed volatile concentrates of these fruit species presented a significant diversity of constituents with a predominance of functional groups, such as monoterpenes, sesquiterpenes, and fatty acid derivatives, originating from the plant's secondary metabolism and playing an important role in their nutritional and medicinal uses.

Antifungal chemosensitization through induction of oxidative stress: A model for control of candidiasis based on the Lippia origanoides essential oil.

In this work, evaluated the antifungal chemosensitizing effect of the Lippia origanoides essential oil (EO) through the induction of oxidative stress. The EO was obtained by hydrodistillation and analyzed by GC-MS. To evaluate the antifungal chemosensitizing effect through induction of oxidative stress, cultures of the model yeast Saccharomyces cerevisiae ∆ycf1 were exposed to sub-inhibitory concentrations of the EO, and the expression of genes known, due be overexpressed in response to oxidative and mutagenic stress was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) method. Carvacrol and thymol were identified as the main components. The EO was effective in preventing or reducing the growth of the microorganisms tested. The gene expression profiles showed that EO promoted changes in the patterns of expression of genes involved in oxidative and mutagenic stress resistance. The combined use of the L. origanoides EO with fluconazole has been tested on Candida yeasts and the strategy resulted in a synergistic enhancement of the antifungal action of the azolic chemical product. Indeed, in association with EO, the fluconazole MICs dropped. Thus, the combinatorial use of L. origanoides EO as a chemosensitizer agent should contribute to enhancing the efficiency of conventional antifungal drugs, reducing their negative side effects.

Exploring the impact of seasonal variations on the chemical composition, antinociceptive, and anti-inflammatory properties of Pogostemon heyneanus Benth. essential oil.

Background: Pogostemon heyneanus leaves infusions are relevant in ethnopharmacology for treating colds, coughs, headaches, and asthma. Purpose: The essential oil chemical composition of a Pogostemon heyneanus specimen was monthly monitored from October 2021 to July 2022 to evaluate the climatic influences on its yield and chemical composition and antinociceptive, andanti-inflammatory properties. Methods: The leaves, collected monthly over a 10-month period, were submitted to hydrodistillation. The oils obtained were analyzed by gas chromatography coupled to a mass spectrometer and gas chromatography coupled to flame ionization detector. The P. heyneanus essential oil (PhEO) was tested in vivo to evaluate its peripheral analgesic actions through the abdominal writhing test induced by acetic acid, and peripheral analgesia by tail immersion. Neurogenic and inflammatory pain were evaluated by formalin test, and acute oral toxicity of the oil was also verified. Results: PhEO presented 27 chemical constituents with the highest predominance of patchoulol (43.6%-76.9%), α-bulnesene (0.2%-12.7%), α-guaiene (0.4%-8.9%), seychellene (3.8%-5.1%) and pogostol (0.0%-8.2%). The climatic parameters insolation, humidity, rainfall, and temperature did not influence the essential oil yield or the main chemical constituents, except for pogostol, which presented a strong (r = 0.73) and statistically significant (p < 0.05) correlation with temperature. PhEO did not display toxicity at the maximum 300 mg/kg dosage. The oil showed low peripheral and central analgesic action at 100 mg/kg, while in the neurogenic and inflammatory pain inhibition tests, no actions related to PhEO were observed. In the carrageenan-induced peritonitis test, PhEO did not reduce the migration of leukocytes to the peritoneal cavity compared to the control group. Conclusion: Pogostemon heyneanus is a resistant plant to seasonal influences and a source of patchoulol. Despite ethnopharmacological indications, no in-vivo biological activities such as neurogenic or inflammatory pain were identified in the present work. So, the low influence of the climatic parameters on chemical composition can infer that the low pharmacological activity is also not subject to climatic variations, that is, it does not change due to the climate.

Seasonal Variation in Essential Oil Composition and Antioxidant Capacity of Aniba canelilla (Lauraceae): A Reliable Source of 1-Nitro-2-phenylethane.

Aniba canelilla (Kunth) Mez essential oil has many biological activities due to its main compound 1-nitro-2-phenylethane (1N2F), followed by methyleugenol, a carcinogenic agent. This study analyzed the influence of seasonality on yields, antioxidant capacity, and 1N2F content of A. canelilla leaf and twig essential oils. Essential oils (EOs) were extracted with hydrodistillation and analyzed with gas chromatography coupled to mass spectrometry and a flame ionization detector. Antioxidant capacity was measured using the free radical scavenging method (DPPH). Chemometric analyses were carried out to verify the influence of climatic factors on the production and composition of EOs. 1-Nitro-2-phenylethane was the major constituent in A. canelilla EOs throughout the seasonal period (68.0-89.9%); methyleugenol was not detected. Essential oil yields and the 1N2F average did not show a statistically significant difference between the dry and rainy seasons in leaves and twigs. Moderate and significant correlations between major compounds and climate factor were observed. The twig oils (36.0 ± 5.9%) a showed greater antioxidant capacity than the leaf oils (20.4 ± 5.0%). The PCA and HCA analyses showed no statistical differences between the oil samples from the dry and rainy seasons. The absence of methyleugenolin in all months of study, described for the first time, makes this specimen a reliable source of 1N2F.

Seasonal and Circadian Evaluation of the Essential Oil of Dizygostemon riparius (Plantaginaceae), a Wild Flavoring Herb from East Maranhão, Brazil.

Dizygostemon riparius (Plantaginaceae) is an aromatic herbal species known as "Melosa", endemic to the Municipality of São Benedito do Rio Preto, East Maranhão state, Brazil. It has a refreshing and pleasant aroma and is used for food flavoring and controlling domestic animal parasites. This work aimed to evaluate the seasonal and circadian influence on the composition and production of essential oils (EOs) from D. riparius. The plant aerial parts were hydrodistilled, and the oils were analyzed by GC and GC/MS. The seasonal study was conducted from August 2019 to July 2020, and the circadian study in dry (November) and rainy (May) periods, at 6 am, 12 am, and 6 pm. The results showed that the medium EOs yield was 2.8 %, and the primary constituents (>2 %) were endo-fenchyl acetate (30.5-42.1 %) and endo-fenchol (31.6-37.4 %), (E)-caryophyllene (2.8-7.6 %), α-fenchene (3.3-6.5 %), p-cymene (0.7-4.5 %), and caryophyllene oxide (1.4-2.7 %). Yield and composition of EOs did not significantly correlate with the climatic parameters, but their seasonal percentages influenced their two main components due to precipitation and solar radiation environmental factors. Quantitative variability in the EOs composition during the dry and rainy seasons was observed in the circadian period. These data may be significant for the plant's economic use.

Essential oil Ageratum conyzoides chemotypes and anti-tick activities.

Rhipicephalus (Boophilus) microplus represents a significant obstacle to animal productivity in tropical and subtropical areas, leading to considerable economic losses for the dairy and meat production industries. Essential oils (EO) extracted from Ageratum conyzoides are known to cause death and induce morphogenetic abnormalities in several insect species. This plant, however, presents morphological flower variations, which range from white to purple, associated to different chemotypes. In this context, this study aimed to conduct a novel assessment on the effects of EO extracted from two A. conyzoides chemotypes in the control of the bovine tick R. microplus. The primary constituents of the oil obtained from white flower samples (WFs) were precocene I (80.4 %) and (E)-caryophyllene (14.8 %), while purple flower oil samples (PFs) contained predominantly ß-acoradiene (12.9 %), γ-amorphene (12.3 %), α-pinene (9.9 %), bicyclogermacrene (8.9 %), α-santalene (8.7 %), and andro encecalinol (5.6 %). Interestingly, only the EO chemotype from A. conyzoides PFs displayed acaricidal activity towards R. microplus larvae, with an LC50 of 1.49 mg/mL.

Chemometrics of the Composition and Antioxidant Capacity of Hyptis crenata Essential Oils from Brazil.

Hyptis crenata (Pohl) ex Benth is used in traditional medicine as an analgesic to treat general pain. Six Hyptis crenata samples (Hc-1 to Hc-6) were collected in Pará state, Brazil. The leaf essential oils were obtained by hydrodistillation, and GC-MS and GC-FID were used to analyze their chemical compositions. The antioxidant capacity was measured in vitro using DPPH and carotene/linoleic acid assays. Chemometrics analysis (PCA, HCA, and clustered heat map) were used to identify the sample relationships between those collected in this study and those from the literature (Hc-7 to Hc-16) samples. According to the main chemical constituents identified in the samples described in this work and the literature, the sixteen samples were classified into ten groups. Group I was characterized by 1,8-cineole (31.0%), α-pinene (13.6%), (E)-caryophyllene (7.8%), and ß-pinene (7.6%); and Group IV was characterized by 1,8-cineole (17.4-23.5%), α-pinene (15.7-23.5%), ß-pinene (10.5-13.4%), and limonene (8.5-9.7%). Both groups are described for the first time. The total antioxidant capacity was expressed in Trolox Equivalent Antioxidant Capacity values (TEAC): TEAC of Hc-5 (551.9 mg.TE/g) and Hc-6 (475.1 mg.TE/g). In the ß-carotene/linoleic acid assay, the highest inhibition was from Hc-2 (40.0%), Hc-6 (39.0%), and Hc-3 (29.4%).

Stability and Antioxidant Activity of Pouteria macrophylla Fruit Extract, a Natural Source of Gallic Acid.

Pouteria macrophylla (cutite) fruits are rich in phenolic acids, resulting in antioxidant and skin depigmenting activity. The aim of this study, then, is to evaluate the cutite extract stability under three variations of light, time, and temperature using a Box-Behnken experimental design to analyze through the surface response the variations of the total phenolic content (TPC), antioxidant activity (AA), and gallic acid content (GA). A colorimetric assay was also performed, and a decrease in the darkening index was noticed due to the high phenolic coloration in the presence of light, indicating less degradation to extract stability. The experimental planning showed variations in all responses, and second-order polynomial models were calculated and considered predictable, as well as the effects were significant. The TPC exhibited a variation in less concentrated samples (0.5% p/v) at higher temperatures (90 °C). In contrast, the temperature was the only influential variable for AA, where only higher temperatures (60-90 °C) were able to destabilize the fruit extract. Differently, GA showed only the concentration as the influential variable, exhibiting that neither temperature nor time of exposure could affect the gallic acid content stability of P. macrophylla extract. For this, P. macrophylla extract was shown to be highly stable, providing a great perspective on cosmetic application.

Volatile Constituents from Catasetum (Orchidaceae) Species with Occurrence in the Brazilian Amazon.

BACKGROUND: Catasetum Rich. ex Kunth is a genus of Neotropical orchids distributed in Central and South American regions. In the Brazilian Amazon, there are more than 60 species of Catasetum. The floral aromas of orchids are little known, particularly of Catasetum species. This work aimed to analyze the chemical constituents of the volatile concentrates of eight Catasetum specimens from the Amazon: C. alatum (1), C. albovirens (2), C. barbatum (1), C. ciliatum (2), C. galeritum (1), and C. gnomus (1). METHODS: Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyzed and identified the constituents of the volatile concentrates, and principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used in the multivariate statistical analysis. RESULTS: The Catasetum main constituents in descending order and above 10% were trans-geranylgeraniol, 1,4-dimethoxybenzene, linalool, 2-phenylethyl acetate, geraniol, 7-epi-1,2-dehydro-sesquicineole, 1,8-cineole, benzyl acetate, limonene, methyl salicylate, (E)-ß-farnesene, anisyl butyrate, cis-carvone oxide, cadin-4-en-10-ol, indole, α-pinene, and δ-cadinene. CONCLUSIONS: Multivariate statistical analysis of Catasetum species showed that C. barbatum, C. albovirens, and C. gnomus are distinct from the other studied species, while C. alatum, C. ciliatum, and C. galeritum presented the same primary classes of compounds. These results contribute to a better understanding of the genus Catasetum chemotaxonomy.

Aniba canelilla (Kunth) Mez essential oil and its primary constituent, 1-nitro-2-phenylethane, inhibits acetylcholinesterase and reverse memory impairment in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Aniba canelilla, distributed in the Amazon region, stands out for its diverse economic and medicinal applications. Studies of the A. canelilla essential oil and its primary constituent, 1-nitro-2-phenylethane, have confirmed its anti-inflammatory, antinociceptive, anti-hypertensive potential, and anticholinesterase, among other therapeutic activities. AIM OF THE STUDY: In addition, the present work aims to evaluate the potential of oil and NPE in the learning and memory of rodents. MATERIAL AND METHODS: The oil was hydrodistilled and analyzed by GC and GC-MS. The learning and memory action in mice was evaluated through the scopolamine-induced cognitive deficit model, followed by behavioral analysis using Morris's water maze paradigm. RESULTS: Oil provided a yield of 0.5%, and in its chemical composition, 1-nitro-2-phenylethane (NPE) (76.2%) and methyleugenol (19.6%) were identified as primary constituents. Oil fractionation furnished NPE with 99.4%, which was used to evaluate its effects in animal models. Wistar rats were submitted to the mnemonic impairment-scopolamine-induced protocol for 7 days. The oil, NPE, and the positive control donepezil were administered from the 8th to 12th days. Morris water maze results demonstrated that oil and NPE reversed spatial learning and long-term memory similarly induced by muscarinic antagonist scopolamine to donepezil, the positive control. CONCLUSION: These beneficial effects have led the work to further investigations of the oil and NPE to elucidate their pharmacological mechanism, focusing on the cholinergic pathway of the central nervous system and opening up to the knowledge of other adjacent mechanisms, whose results are still under analysis.

Chemical composition and antinociceptive and anti-inflammatory activity of the essential oil of Hyptis crenata Pohl ex Benth. from the Brazilian Amazon.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaf tea of Hyptis crenata has its practical use in the Brazilian Amazon for treating gastrointestinal and liver disorders, sweating induction, and as an anti-inflammatory. AIM OF THE STUDY: Evaluation of the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the H. crenata essential oil. MATERIAL AND METHODS: The essential oil was hydrodistilled and analyzed by GC and GC-MS. The antinociceptive action in mice was evaluated for the peripheral and central analgesic activity (abdominal contortion and hot plate tests), and the xylene-induced ear swelling was carried out for the nociception test. RESULTS: Oxygenated monoterpenes (53.0%) and monoterpene hydrocarbons (38.9%) predominated in the H. crenata oil, being 1,8-cineo1e (35.9%), α-pinene (20.8%), camphor (10.0%), and ß-pinene (7.3%) their primary constituents. The oral oil administration in the mice did not display changes in behavior patterns or animal mortality at 300 and 2000 mg/kg doses. The control group's biochemical parameters (ALP, AST, ALT) displayed a statistical difference from the treated group, unlike the renal parameters, which showed no variation between the groups. Oil reduced the abdominal contortions at doses of 100 (79.5%) and 300 mg/kg (44.4%), while with endodontacin, the dose was 5 mg/kg (75.2%). In addition, the oil could not decrease the paw licking/biting time at doses of 30, 100, and 300 mg/kg. However, it showed a significant antinociceptive effect on the second phase in the formalin test inhibiting licking time, with a reduction of 50.8% (30 mg/kg), 63.4% (100 mg/kg), 58.0% (300 mg/kg), and morphine (4 mg/kg, 78.3%). The oil administration produced significant inhibition of ear edema at all tested doses, with a better effect produced at 30 mg/kg (64.0% inhibition). CONCLUSION: The oil of Hyptis crenata, rich in 1,8-cineole, camphor, α-pinene, and ß-pinene, totaling 74%, displayed low acute toxicity and significant anti-inflammatory activity, with peripheral and no central antinociceptive action. Thus, these results show an actual perspective on using H. crenata oil in developing a phytotherapeutic product.

Variability in the Chemical Composition of Myrcia sylvatica (G. Mey) DC. Essential Oils Growing in the Brazilian Amazon.

Myrcia sylvatica (G. Mey) DC. is known as "insulin plant" because local communities use the infusions of various organs empirically to treat diabetes. The leaves of seven specimens of Myrcia sylvatica (Msy-01 to Msy-07) were collected in the Brazilian Amazon. Furthermore, the essential oils were extracted by hydrodistillation and analyzed by gas chromatography coupled to mass spectrometry, and their chemical compositions were submitted to multivariate analysis (Principal Component Analysis and Hierarchical Cluster Analysis). The multivariate analysis displayed the formation of four chemical profiles (chemotypes), described for the first time as follows: chemotype I (specimen Msy-01) was characterized by germacrene B (24.5%), γ-elemene (12.5%), and ß-caryophyllene (10.0%); chemotype II (specimens Msy-03, -06 and -07) by spathulenol (11.1-16.0%), germacrene B (7.8-20.7%), and γ-elemene (2.9-7.6%); chemotype III (Msy-04 and -05) by spathulenol (9.8-10.1%), ß-caryophyllene (2.5-10.1%), and δ-cadinene (4.8-5.6%); and chemotype IV, (Msy-02) by spathulenol (13.4%), caryophyllene oxide (15.0%), and α-cadinol (8.9%). There is a chemical variability in the essential oils of Myrcia sylvatica occurring in the Amazon region.

Essential Oil Chemotypes and Genetic Variability of Cinnamomum verum Leaf Samples Commercialized and Cultivated in the Amazon.

Cinnamomum verum (Lauraceae), also known as "true cinnamon" or "Ceylon cinnamon" has been widely used in traditional folk medicine and cuisine for a long time. The systematics of C. verum presents some difficulties due to genetic variation and morphological similarity between other Cinnamomum species. The present work aimed to find chemical and molecular markers of C. verum samples from the Amazon region of Brazil. The leaf EOs and the genetic material (DNA) were extracted from samples cultivated and commercial samples. The chemical composition of the essential oils from samples of C. verum cultivated (Cve1-Cve5) and commercial (Cve6-c-Cv9-c) was grouped by multivariate statistical analysis of Principal Component Analysis (PCA). The major compounds were rich in benzenoids and phenylpropanoids, such as eugenol (0.7-91.0%), benzyl benzoate (0.28-76.51%), (E)-cinnamyl acetate (0.36-32.1%), and (E)-cinnamaldehyde (1.0-19.73%). DNA barcodes were developed for phylogenetic analysis using the chloroplastic regions of the matK and rbcL genes, and psbA-trnH intergenic spacer. The psbA-trnH sequences provided greater diversity of nucleotides, and matK confirmed the identity of C. verum. The combination of DNA barcode and volatile profile was found to be an important tool for the discrimination of C. verum varieties and to examine the authenticity of industrial sources.

The Volatile Profiles and DNA Barcodes of Lauraceae Species from the Ocotea Complex with Occurrence in the Brazilian Amazon.

The Ocotea complex accommodates most of the taxonomic diversity of Neotropical Lauraceae with economic importance and biological potential attributed to their essential oils (EOs) and extracts. However, the botanical taxonomy has had limitations due to the difficulty of identifying and delimiting species and genera. The chemical and molecular markers of Ocotea complex species in Pará state, Brazil, were assessed according to their EO compositions and DNA sequences of matK, trnL-trnF, and ITS regions. The multivariate analysis of EOs constituents has classified them into two main clusters characterized by oils rich in (I) terpenoids and phenylpropanoids and (II) sesquiterpenes. We conducted a phylogenetic analysis of species based on DNA barcode sequences on the Bayesian Inference (PP: 0.70-1,0) and Maximum Likelihood (BS: 72-100 %). The comparison between the volatile profiles and phylogenetic data indicates two main groups for these species collected from the Ocotea complex.

Phytochemical Analysis of the Fruit Pulp Extracts from Annona crassiflora Mart. and Evaluation of Their Antioxidant and Antiproliferative Activities.

Annona crassiflora Mart., the marolo fruit of the Cerrado biome, is one of the most frequently consumed species from the Brazilian Midwest. This study aimed to evaluate the chemical composition and the antioxidant and cytotoxic properties of the fruit pulp of A. crassiflora collected at Chapada das Mesas, Maranhão, Brazil. The volatile concentrate was identified as mainly ethyl octanoate, ethyl hexanoate, and methyl octanoate. From the ethanol (LFP-E) and ethyl acetate (LFP-A) extracts were identified phenolic acids (p-coumaric, gallic, quinic, and ferulic), flavones and derivatives (apigenin, epicatechin, 2'-5-dimethoxyflavone, 3',7-dimethoxy-3-hydroxyflavone, kaempferol-3-O-glucoside and 3-O-rutinoside, quercetin-3-O-glucoside, procyanidin B2, and rutin), aporphine alkaloids (xylopine, stephagine, and romucosine), and acetogenin (annonacin). For the LFP-E and LFP-A extracts, the total phenolic compound values were 15.89 and 33.16 mg GAE/g, the flavonoid compound content values were 2.53 and 70.55 mg QE/g, the DPPH radical scavenging activity showed EC50 values of 182.54 and 57.80 µg/mL, and the ABTS radical activity showed TEAC values of 94.66 and 192.61 µM TE/g. The LFP-E extract showed significant cytotoxicity and cell selectivity for the U251-glioma strain, presenting a GI50 value of 21.34 µg/mL, which is close to doxorubicin (11.68 µg/mL), the standard chemotherapeutic drug. The marolo fruit seems to be a promising source for developing innovative and healthy products for the food industry.

Seasonal Variability of a Caryophyllane Chemotype Essential Oil of Eugenia patrisii Vahl Occurring in the Brazilian Amazon.

Eugenia patrisii Vahl is a native and non-endemic myrtaceous species of the Brazilian Amazon. Due to few botanical and phytochemical reports of this species, the objective of the present work was to evaluate the seasonal variability of their leaf essential oils, performed by GC and GC-MS and chemometric analysis. The results indicated that the variation in oil yields (0.7 ± 0.1%) could be correlated with climatic conditions and rainy (R) and dry seasons (D). (E)-caryophyllene (R = 17.1% ± 16.0, D = 20.2% ± 17.7) and caryophyllene oxide (R = 30.1% ± 18.4, D = 14.1% ± 19.3) are the major constituents and did not display significant differences between the two seasons. However, statistically, a potential correlation between the main constituents of E. patrisii essential oil and the climatic parameters is possible. It was observed that the higher temperature and insolation rates and the lower humidity rate, which are characteristics of the dry season, lead to an increase in the (E)-caryophyllene contents, while lower temperature and insolation and higher humidity, which occur in the rainy season, lead to an increase in the caryophyllene oxide content. The knowledge of variations in the E. patrisii essential oil composition could help choose the best plant chemical profile for medicinal purposes.

Chemical Composition and Variability of the Volatile Components of Myrciaria Species Growing in the Amazon Region.

Myrciaria (Myrtaceae) species have been well investigated due to their chemical and biological relevance. The present work aimed to carry out the chemotaxonomic study of essential oils of the species M. dubia, M. floribunda, and M. tenella, sampled in the Brazilian Amazon and compare them with the volatile compositions from other Myrciaria species reported to Brazil and Colombia. The leaves of six Myrciaria specimens were collected (PA, Brazil) during the dry season, and their chemical compositions were analyzed by gas chromatography-mass spectrometer (GC-MS) and gas chromatography-flame ionization detector (GC-FID). The main compounds identified in the essential oils were monoterpenes with pinane and menthane skeletons, followed by sesquiterpenes with caryophyllane and cadinane skeletons. Among the sampled Myrciaria specimens, five chemical profiles were reported for the first time: profile I (M. dubia, α-pinene, 54.0-67.2%); profile II (M. floribunda, terpinolene 23.1%, α-phellandrene 17.7%, and γ-terpinene 8.7%); profile III (M. floribunda, γ-cadinene 17.5%, and an unidentified oxygenated sesquiterpene 15.0%); profile IV (M. tenella, E-caryophyllene 43.2%, and α-humulene 5.3%); and profile V (M. tenella, E-caryophyllene 19.1%, and caryophyllene oxide 41.1%). The Myrciaria chemical profiles showed significant variability in extraction methods, collection sites, plant parts, and genetic aspects.

Molluscicidal and cercaricidal activities of the essential oil of Dysphania ambrosioides (L.) Mosyakin & Clemants: Implications for the control of schistosomiasis.

Schistosomiasis is one of the most important tropical diseases. A fundamental strategy to control its spread is the use of natural products against its vectors, which are snails of the genus Biomphalaria. The present study evaluated the chemical composition, the molluscicidal and cercaricidal effects, and the ecotoxicity of the essential oil from the aerial parts of Dysphania ambrosioides (L.) Mosyakin & Clemants (DAEO). The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS). Molluscicidal and cercaricidal activities were determined by the immersion method. Environmental toxicity was assessed from bioassays using Artemia salina larvae and Danio rerio fish. DAEO presented a 0.8% yield. The GC-MS analysis revealed the predominance of hydrocarbon monoterpenes in the oil. A total of 32 constituents was identified, with α-terpinene (50.69%) being the major compound, followed by p-cymene (13.27%) and ascaridole (10.26%). DAEO was active against adult Biomphalaria glabrata snails and demonstrated lethal effect against Schistosoma mansoni cercariae, with LC50 values of 25.2 (22.7-27.8) and 62.4 (61.8-62.9) µg/mL, respectively. Regarding toxicity to non-target aquatic organisms, the oil showed LC50 values of 86.9 (84.7-87.6) and 18.6 µg/mL (15.5-22.8) for A. salina and D. rerio, respectively. DAEO proved to be a promising natural product for the control of schistosomiasis, acting on both the vectors and the etiological agent of the disease. However, the use of the oil is safer in transmission sites where there are no non-target organisms, as it has showed toxicity to D. rerio fish.