Sesquiterpene lactones are an important class of secondary metabolites frequently isolated from Vernonanthura genus that present a variety of biological properties, including antiproliferative activity. Due to the limitation of pharmacological studies on Vernonanthura nudiflora, the aim of this work was to investigate their antioxidant potential and antiproliferative activity against human tumor cells, as well as to isolate and identify the chemical constituents present in their aerial parts. The phytochemical investigation resulted in the isolation of the sesquiterpene lactones piptocarphins A, B, D, and a new hirsutinolide derivative, 8α-tigloyloxy-10α-hydroxy-hirsutinolide, besides triterpenes, glycosylated steroids, flavonoids, and one chlorogenic acid derivative. Also, other sesquiterpene lactones were identified by ultra-high performance liquid chromatography-high resolution tandem mass spectrometry (UHPLC-HRMS/MS) from dichloromethane fraction. This fraction showed activity against the tumor cells tested, mainly against leukemia, glioma, ovarian and kidney, with growth inhibitory activity (GI50) less than 0.80 µg mL-1. Piptocarphins A and B, in mixture, showed strong activity against all human cancer cell lines tested, with GI50 values ≤ 0.15 µg mL-1. Piptocarphin D was selective for glioma and resistant ovarian cell lines. The new hirsutinolide derivative showed potent activity against breast (GI50= 0.96 µg mL-1) and resistant ovarian (GI50 = 3.60 µg mL-1) cell lines.

O estudo fitoquímico das folhas de Calycorectes psidiiflorus (O. Berg) Sobral, Myrtaceae, resultou no isolamento e identificação de: sesquiterpeno [8-hidroxicalameneno (1)], triterpenos [α-amirina (2a) e β-amirina (2b)], flavonóide [3-O-α-ramnopiranosil-7-O-bglucopiranosil canferol (3)], e alcalóide [1,2,3,4-tetraidro-1-metil-β-carbolina (4)]. As estruturas das substâncias isoladas foram elucidadas com base nos seus dados de RMN em comparação com os da literatura. A substância 8-hydroxicalameneno apresentou atividade antibacteriana (MIC = 7,8 µg/mL) e antifúngica (MIC = 15,6 µg/mL).

The phytochemical study of Calycorectes psidiiflorus (O. Berg) Sobral leaves resulted in isolation and identification of the sesquiterpene 8-hydroxycalamenene (1), triterpenes α-amyrin (2a) and β-amyrin (2b), flavonoid 3-O-α-rhamnopyranosyl-7-O-β-glucopyranosyl kaempferol (3), and of the alkaloid 1,2,3,4-tetrahydro-1-methyl-β-carboline (4). The structures of the isolated compounds were elucidated based on their spectroscopic NMR data and comparison with those reported in literature. Substance 1 presented antibacterial (MIC = 7.8 µg/mL) and antifungal (MIC = 15.6 µg/ mL) activities.

Extratos de Croton fluribundus (Euphorbiaceae), ácido caurenóico e dois derivados do ácido caurenóico foram avaliados como moluscicida, cercaricida e também foi verificada a letalidade destas amostras frente a larvas de Artemia salina Leach. Nestes ensaios foram observadas significantes atividades moluscicida e cercaricida associadas a uma reduzida toxicidade frente ao camarão de água salgada.

Lethality of the extracts of Croton floribundus (Euphorbiaceae), a medicinal plant from south Brazil, and of the kaurenoic acid, an isolated compound, and two of its derivatives against adult Biomphalaria glabrata snails, Schistosoma mansoni cercariae and Artemia salina Leach. brine shrimp larvae are reported. Both extracts and the isolated compound showed significant molluscicidal and cercaricidal activities and reduced toxicity in brine shrimp assays.

Um novo triterpeno caracterizado como ácido 6alfa-hidroxibetulínico foi isolado das folhas e caule da planta, vulgarmente conhecida no Brasil como Cambuí, Eugenia moraviana (Myrtaceae), juntamente com três outras substâncias conhecidas, identificadas como ácido platânico, ácido betulínico e beta-sitosterol. Através da análise de espectros incluindo NOE e experimentos de RMN em duas dimensões foi realizada a atribuição inequívoca dos deslocamentos químicos de ¹H e de 13C do ácido 6alfa-hidroxibetulínico(ácido-3beta,6alfa-diidróxi-20(29)-lupen-28-óico) e do ácido platânico.

A novel triterpene, characterized as 6alpha-hydroxybetulinic acid, was isolated from the leaves and stems of Eugenia moraviana (Myrtaceae), known in Brazil as Cambuí, together with three known compounds, platanic acid, betulinic acid and beta-sitosterol. Unequivocal ¹H and 13C assignments of 6alpha-hydroxybetulinic acid (3beta,6alpha-dihydroxy-20(29)-lupen-28-oic acid) and platanic acid were undertaken by spectral analysis including NOE and 2 D NMR experiments.