Antiradical effect and phytochemical characterisation of the leaves of Parkia platycephala Benth.

The objective of this study was to isolate and identify compounds present in the leaves of Parkia platycephala Benth (Leguminosae-Mimosoideae) and evaluate the antiradical potential of the derived extracts and fractions. Seven compounds were successfully isolated from the ethanolic leaf extract, comprising gallic acid, flavonoids, triterpenoids, and phytosteroids. Structural identification was accomplished through comprehensive spectroscopic data analysis, including NMR and mass spectrometry (ESI-MS), and comparison with existing literature. The antiradical efficacy of both the extract and its fractions was determined in vitro through assays measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and quantifying total phenolics via UV/Vis, revealing notable antioxidant activity in extracts from P. platycephala Benth, especially in the EtOH, EtOAc, and aqueous fractions, attributed to their high phenolic content and prevalence of flavonoids. These findings contribute to a deeper understanding of Parkia's chemical composition and its potential biological benefits.

Simultaneous determination of cucurbitacins B, D, and E in Cucurbita seed oils by HPLC-DAD.

Cucurbitacins are triterpene bioactive constituents of natural products, particularly in the Cucurbitaceae plant family. The presence of cucurbitacins in seeds of the Cucurbita genus (pumpkin) has been only little studied. In this work, the content of cucurbitacins B, D, and E in seed oils from three cucurbits (Cucurbita moschata Duch, Cucurbita pepo Linn, and Cucurbita maxima Linn) was studied. An analytical method based on HPLC-DAD for the detection and quantification of these three cucurbitacins in seed oils was developed and validated according to ICH guidelines. The method showed good linearity, accuracy, and precision for the simultaneous quantification of cucurbitacins B, D, and E using C.moschata seed oil as a reference. When applied to C.pepo and C.maxima seed oils, cucurbitacin B and D were quantified but to a lesser extent. This is the first report of a simple, repeatable, and reproducible analytical tool to identify cucurbitacins in oilseeds from Cucurbita spp.

Antiviral, Cytoprotective, and Anti-Inflammatory Effect of Ampelozizyphus amazonicus Ducke Ethanolic Wood Extract on Chikungunya Virus Infection.

Chikungunya fever, a debilitating disease caused by Chikungunya virus (CHIKV), is characterized by a high fever of sudden onset and an intense arthralgia that impairs individual regular activities. Although most symptoms are self-limited, long-term persistent arthralgia is observed in 30-40% of infected individuals. Currently, there is no vaccine or specific treatment against CHIKV infection, so there is an urgent need for the discovery of new therapeutic options for CHIKF chronic cases. This present study aims to test the antiviral, cytoprotective, and anti-inflammatory activities of an ethanol extract (FF72) from Ampelozizyphus amazonicus Ducke wood, chemically characterized using mass spectrometry, which indicated the major presence of dammarane-type triterpenoid saponins. The major saponin in the extract, with a deprotonated molecule ion m/z 897 [M-H]-, was tentatively assigned as a jujubogenin triglycoside, a dammarane-type triterpenoid saponin. Treatment with FF72 resulted in a significant reduction in both virus replication and the production of infective virions in BHK-21-infected cells. The viability of infected cells was assessed using an MTT, and the result indicated that FF72 treatment was able to revert the toxicity mediated by CHIKV infection. In addition, FF72 had a direct effect on CHIKV, since the infectivity was completely abolished in the presence of the extract. FF72 treatment also reduced the expression of the major pro-inflammatory mediators overexpressed during CHIKV infection, such as IL-1ß, IL-6, IL-8, and MCP-1. Overall, the present study elucidates the potential of FF72 to become a promising candidate of herbal medicine for alphaviruses infections.

Diuretic activity of Euphorbia serpens extracts in Wistar rats.

Euphorbia serpens has been used in central-west region of Argentina in traditional medicine as diuretic plant. The aim of this present study was to evaluate the diuretic activity of E. serpens in-vivo. We used dried aerial parts, and infusions from these were orally administered to Wistar rats. Its effect was evaluated using furosemide as a positive drug and isotonic salt solution as negative control. Their urine output was quantified at several time intervals. The volume of urine excreted and Na+ increased significantly, being similar to furosemide. Mannitol, was the main component in aqueous extracts of E. serpens, and the acetone extract showed the presence of Δ12- oleanane-type triterpenoids compounds, mainly hederagenin. No toxic effects were observed.

New Tricholidic Acid Triterpenoids from the Mushroom Tricholoma ustaloides Collected in an Italian Beech Wood.

The secondary metabolites produced by Tricholoma ustaloides Romagn., a mushroom species belonging to the large Tricholoma genus (Basidiomycota, Tricholomataceae), are unknown. Therefore, encouraged by the interesting results obtained in our previous chemical analyses of a few Tricholoma species collected in Italian woods, we aimed to investigate the secondary metabolites of Tricholoma ustaloides. The chemical analysis involved the isolation and characterization of secondary metabolites through an extensive chromatographic study. The structures of isolated metabolites, including the absolute configuration, were established based on a detailed analysis of MS, NMR spectroscopic, optical rotation, and circular dicroism data, and on comparison with those of related compounds reported in the literature. Two novel lanostane triterpenoids, named tricholidic acids B and C, together with triglycerides, a mixture of free fatty acids, five unidentified metabolites, and the known rare saponaceolides F and J, tricholidic acid, and tricholomenyn C, were isolated from an EtOAc extract of fruiting bodies of Tricholoma ustaloides that were collected in an Italian beech wood. This is the second example of isolation of tricholidic acid derivatives from a natural source. Saponaceolides F and J exhibited high cytotoxicity (IC50 values ≤ 10 µM) against a panel of five human cancer cell lines. The toxicity against myeloid leukemia (HL-60), lung cancer (A-549), hepatocellular cancer (HepG2), renal cancer (Caki-1), and breast cancer (MCF-7) cells was higher than that shown by the very well-known cytotoxic drug cisplatin.

Antimicrobial Potential of Betulinic Acid and Investigation of the Mechanism of Action against Nuclear and Metabolic Enzymes with Molecular Modeling.

Natural products have important pharmacological activities. This study sought to investigate the activity of the compound betulinic acid (BA) against different strains of bacteria and fungi. The minimum inhibitory concentration (MIC) was determined and then the minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC). After performing the in vitro tests, molecular modeling studies were carried out to investigate the mechanism of action of BA against the selected microorganisms. The results showed that BA inhibited the growth of microbial species. Among the 12 species (Staphylococcus aureus, S. epidermidis, Pseudomonas aeruginosa, Escherichia coli, Mycobacterium tuberculosis, Candida albicans, C. tropicalis, C. glabrata, Aspergillus flavus, Penicillium citrinum, Trichophyton rubrum, and Microsporum canis) investigated, 9 (75%) inhibited growth at a concentration of 561 µM and 1 at a concentration of 100 µM. In general, the MBC and MFC of the products were between 561 and 1122 µM. In silico studies showed that BA presented a mechanism of action against DNA gyrase and beta-lactamase targets for most of the bacteria investigated, while for fungi the mechanism of action was against sterol 14α-demethylase (CYP51) targets and dihydrofolate reductase (DHFR). We suggest that BA has antimicrobial activity against several species.

Three new diterpenoids from the leaves of Salvia lachnostachys.

Three new diterpenoids, demethylfruticuline B (1), 20-hydroxyfruticuline B (2), and 6-hydroxyisofruticuline A (3) were isolated from the leaves of Salvia lachnostachys Benth, together with five known compounds: fruticuline B (4), fruticuline A (5), demethylfruticuline A (6), heterobetulinic acid (7), and maslinic acid (8). The known compounds 7-8 are being reported for the first time in this species. Compounds 1 and 4-6 were tested for antioxidant activity using the ORAC-FL method, and the antioxidant capacity was measured as relative trolox equivalent. All compounds were active, with values of relative trolox equivalent varying between 1.20-2.42. The most active compound was demethylfruticuline B (1).

The chemical composition of different leaf extracts of Lantana fucata Lindl. influences its cytotoxic potential: A study using the Allium cepa model.

ETHNOPHARMACOLOGICAL RELEVANCE: One of the most popular plants used to treat diseases in Brazil is Lantana fucata. Like most herbal medicines, its consumption is based on popular knowledge, which, despite being considered effective, may cause side effects. AIM OF THE STUDY: Since the scientific data on the pharmacological properties of L. fucata are still incipient, this research aimed to evaluate the cytotoxic and genotoxic potential of different types of extracts (infusion, aqueous and hydroalcoholic), characterizing them chemically. MATERIALS AND METHODS: The cytotoxicity assay was performed by the A. cepa model. The cytotoxicity parameters studied were number of dividing cells and percentage mitotic index (%MI). RESULTS: The result of the A. cepa assay showed that there was a decrease in the number of dividing cells and the percentage mitotic index as concentrations increased, for all extracts, indicating cytotoxicity. However, the hydroalcoholic extract was the most cytotoxic. Chromatography analysis allowed the characterization of secondary metabolites in the extracts, which were very similar. However, a greater abundance of flavonoids and triterpenoids was observed in the hydroalcoholic extract, suggesting that these compounds are responsible for its greater toxicity. CONCLUSIONS: Since the highest doses of extracts showed to have a cytotoxic effect, it is suggested that the ingestion of this species occurs in a moderate way.

Four new cycloartane-type triterpenoids from the leaves of Combretum mellifluum Eichler: assessment of their antioxidant and antileishmanial activities.

The beneficial pharmacological actions including antioxidant effects as an antileishmanial, antibacterial, antifungal, antidiabetic, anti-inflammatory, antitumor, antiviral, and analgesic of compounds isolated from Combretum mellifluum Eichler (Combretaceae) are well established. The aim of the present study was to determine the phytochemistry as well as assess the antioxidant and antileishmanial activities of the leaves from Combretum mellifluum Eichler (Combretaceae). Analysis of ethanolic extract resulted in isolation and identification of two epimeric mixtures of four previously unknown cycloartane-type triterpenoids, methyl quadrangularate M and methyl 24-epiquadrangularate M, and 2α,3ß,24ß-trihydroxy-cycloart-25-ene and 2α, 3ß, 24α-trihydroxy-cycloart-25-ene, and eight known compounds. Their structures were using one-dimensional nuclear magnetic resonance (1D NMR), 2D NMR and high-resolution electrospray ionization mass spectroscopy (HRESIMS) analysis. Further, the extract and fractions were tested for antioxidant potential. The ethyl acetate and aqueous fractions demonstrated the highest antioxidant activity against 2,2-dipheny-1-picrylhydrazl (DPPH) free radicals, which correlated directly with total flavonoid content. All extracts and fractions from C. mellifluum Eichler were assessed for antileishmanial activity. The supernatant fraction exhibited highest potential, inhibiting the growth of Leishmania amazonensis with IC50 value 31.29 µg/ml. Our findings provide information on the chemical composition of C. mellifluum and the potential beneficial therapeutic usefulness as an antioxidant agent in various diseases.

A highly complex stingless bee propolis: composition and influence of the period of collection

BACKGROUND Stingless bees or meliponines (family Apidae, subfamily Meliponinae, tribe Meliponini) are eusocial bees from tropical and subtropical regions. Propolis of Scaptotrigona aff. Postica (Latreille, 1807) is used in the state of Maranhão (Northeast Brazil) in ointments to treat tumors and wounds. Samples of propolis of Scaptotrigona aff. Postica (Apidae, Meliponini) were collected monthly from an apiary located in Barra do Corda (state of Maranhão, northeast Brazil). Extracts of the twelve samples were obtained with 80% ethanol. Constituents of the samples were characterized by HPLC-PAD-ESI-MS/MS analysis, amounting to 100 substances. RESULTS Representatives of several classes of secondary metabolites were characterized, including benzoic and cinnamic acids, flavonoids (chalcones, flavone-C-glycosides, flavonol aglycones and glycosides), alkyl and alkenyl resorcinols, xanthones, diterpenes, cycloartane-type triterpenoids, pentacyclic triterpenoids, pyrrolizidine alkaloids and hydroxycinnamic acid amides (HCAAs). Considerable qualitative differences in chemical composition among samples were observed, depending on the year period of collection. Principal Coordinate Analysis recognized three distinct year periods (Jan-Mar, April-Sep, Oct-Dec) according to the corresponding chemical profiles. CONCLUSION Comparing with previous studies, the present work indicates that considerable differences in chemical composition occur also from year to year. Contrary to most propolis types reported so far, which derives exclusively or mostly from a single botanical source, the propolis from Barra do Corda seemingly depends on several resin sources. It is suggested that chalcones and flavonols stem from Mimosa tenuiflora (Mimosoideae); resorcinols, xanthones and cycloartane-type triterpenoids, from fruits of Mangifera indica (Anacardiaceae); pyrrolizidine alkaloids, possibly from some Crotalaria species (Faboideae); HCAAs probably originate from pollen contaminating the propolis samples. The propolis of S. aff. Postica poses challenges and possibilities of study for apicultural researchers, chemists and pharmacologists.

How diverse is the chemistry and plant origin of Brazilian propolis?

Propolis is a honey bee product containing chiefly beeswax and resins originated from plant buds or exudates. Propolis resin exerts a diversity of biological activities, such as antitumoral, anti-inflammatory, antimicrobial, and defense of the hive against pathogens. Chemical standardization and identification of botanical sources is crucial for characterization of propolis. Types of Brazilian propolis are characteristic of geographical regions and respective biomes, such as savannas (Cerrado), mangroves, dry forest (Caatinga), rain forests (Amazon, Atlantic, and Interior forests), altitudinal fields ("Campos Rupestres"), Pantanal, and Araucaria forests. Despite the wide diversity of Brazilian biomes and flora, relatively few types of Brazilian propolis and corresponding resin plant sources have been reported. Factors accounting for the restricted number of known types of Brazilian propolis and plant sources are tentatively pointed out. Among them, the paper discusses constraints that honey bees must overcome to collect plant exudates, including the characteristics of the lapping-chewing mouthpart of honey bee, which limit their possibilities to cut and chew plant tissues, as well as chemical requirements that plant resins must fulfil, involving antimicrobial activity of its constituents and innocuity to the insects. Although much still needs to be done toward a more comprehensive picture of Brazilian propolis types and corresponding plant origins, the prospects indicate that the actual diversity of plant sources of honey bee propolis will remain relatively low.

Flavonoids, antioxidant potential and antimicrobial activity of Myrcia rufipila mcvaugh leaves (myrtaceae).

This paper reports the first chemical study of the non-volatile compounds, antioxidant capacity and antimicrobial effect of the methanol extract of the leaves of Myrcia rufipila McVaugh. Samples of the leaves were collected in Maracanã Municipality, Pará, Brazil. The chemical investigation led to the identification of the triterpenoids ß- and α-amyrin, the flavonoids 4'-O-galloyldihydromyricetin, myricetin, myricitrin, desmantin-I, myricetin-3-O-(3"-O-galloyl)-α-L-rhamnopyranoside and isovitexin, in addition to gallic acid. The methanol extract showed antioxidant capacity (>90%) against DPPH radical (IC50 356.3 ± 3.1 µg.mL-1) and was active only at high concentrations against the tested microorganisms, including the chloramphenicol resistant E. coli CCMB261 and S. aureus CCMB285 and a nystatin resistant C. parapsilosis CCMB 288. This study shows that M. rufipila, like other Myrcia species, is another source of flavonoids such as desmantin-I and myricitrin which have shown hypoglycemic potential, besides triterpenes and phenolic acids.

Cytotoxic Activity of Triterpenoids from Cheiloclinium cognatum Branches against Chronic and Acute Leukemia Cell Lines.

Cheiloclinium cognatum (Miers) A.C.Sm. is an endemic species of Brazilian Cerrado that belongs to Celastraceae family. The phytochemical study of C. cognatum branches led to the identification of ten triterpenoids (TPs), 3ß-acyloxyurs-12-ene (1), friedelin (2), ß-friedelinol (3), glut-5-en-3ß-ol (4), α-amyrin (5), ß-amyrin (6), ß-sitosterol (7), canophyllol (8), 29-hydroxyfriedelan-3-one (9) and friedelane-3ß,29-diol (10). TPs 4, 5 and 6 are described for the first Cheiloclinium genus and TPs 8 and 9 were isolated in expressive amounts. Their cytotoxic activities were evaluated against THP-1 and K562 leukemia cell lines. TPs 3 and 5 were the most active, exhibiting lower or similar IC50 against both cell lines when compared to the controls. Their mechanisms of action were investigated suggesting an intrinsic mitochondrial pathway of apoptosis evidenced by up-regulation of BAK mRNA expression. Chemometric studies indicated that their activities may be related to their molecular size and shape as well as electronic interactions of C-3 hydroxy group with molecular targets.

Targeting Peptidyl-prolyl Cis-trans Isomerase NIMA-interacting 1: A Structure-based Virtual Screening Approach to Find Novel Inhibitors.

BACKGROUND: Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) is an enzyme that isomerizes phosphorylated serine or threonine motifs adjacent to proline residues. Pin1 has important roles in several cellular signaling pathways, consequently impacting the development of multiple types of cancers. METHODS: Based on the previously reported inhibitory activity of pentacyclic triterpenoids isolated from the gum resin of Boswellia genus against Pin1, we designed a computational experiment using molecular docking, pharmacophore filtering, and structural clustering allied to molecular dynamics (MD) simulations and binding free energy calculations to explore the inhibitory activity of new triterpenoids against Pin1 structure. RESULTS: Here, we report different computational evidence that triterpenoids from neem (Azadirachta indica A. Juss), such as 6-deacetylnimbinene, 6-Oacetylnimbandiol, and nimbolide, replicate the binding mode of the Pin1 substrate peptide, interacting with high affinity with the binding site and thus destabilizing the Pin1 structure. CONCLUSIONS: Our results are supported by experimental data, and provide interesting structural insights into their molecular mechanism of action, indicating that their structural scaffolds could be used as a start point to develop new inhibitors against Pin1.

Leishmanicidal, Trypanocidal and Antioxidant Activity of Amyrin-Rich Extracts from Eugenia pyriformis Cambess.

AIMS: This study aimed to characterize and evaluate leishmanicidal and trypanocidal action as well as cytotoxicity on macrophages and antioxidant ability of extracts, obtained by supercritical CO2 and ultrasound-assisted extractions of Uvaia (Eugenia pyriformis) leaves. METHODS: Leaves from E. pyriformis were submitted to supercritical CO2 (E1) and ultrasound-assisted (E2) extractions. The characterization of extracts was done using GC-MS and HPLC. L. amazonensis (promastigotes) and T. cruzi (epimastigotes and trypomastigotes) were treated with crescent concentrations of E1 and E2. After this, parasites were counted and the percentage of inhibition and IC50/LC50 was calculated. Murine macrophages were treated with both extracts for 48 h and after that, the cellular viability was determined and CC50 was calculated. DPPH method was used to determine the antioxidant capacity of both extracts. RESULTS: The results of identification showed a great amount of α and ß-amyrin in E1 and E2. Both extracts showed growth inhibition of L. amazonensis with an IC50 of 5.98 and 9.38 µg/mL to E1 and E2, showing a selectivity index > 30. In trypanocidal tests, an LC50 of 16.69 and 7.80 µg/mL (trypomastigotes) and IC50 of 5.56 and 34.34 µg/mL (epimastigotes) was reached by E1 and E2. Both extracts showed no toxicity to macrophages and an antioxidant capacity similar to the positive control (tocopherol). CONCLUSIONS: This is the first study demonstrating the activity of an amyrin rich-extract against microorganisms that cause Chagas disease and leishmaniasis, as well as its antioxidant capacity, justifying further studies for future in - vivo tests.

Lupane Triterpenoids and New Derivatives as Antiproliferative Agents Against Prostate Cancer Cells.

BACKGROUND/AIM: This study examined the potential role of natural triterpenoids lupeol, calenduladiol and heliantriol B2, and a set of 19 derivatives, as antiproliferative and antimetastatic agents against prostate cancer cells. MATERIALS AND METHODS: Natural triterpenoids were isolated from Chuqiraga erinaceae. Analogs were obtained by transformations of lupeol and calenduladiol. The effects of compounds on PC-3 and LNCaP cells were determined using the MTT assay. Compounds with half-maximal inhibitory concentration <70 µM were evaluated as antimetastatic agents by a wound-healing assay. RESULTS: Lupeol-3ß-sulfate, a new semisynthetic lupane, was the most active compound. In general, sulfated derivatives displayed higher activity than the lead against both cell lines. A new analog, calenduladiol-3ß-monosulfate, inhibited the migration of PC-3 cells; heliantriol B2 and 3ß-aminolupane inhibited the migration of LNCaP cells in a concentration-dependent manner. CONCLUSION: Our study provides novel agents with cytotoxic effects on prostate cancer cells, which may represent a potential new therapeutic approach for prostate cancer.

New compounds of Siolmatra brasiliensis and inhibition of in vitro protein glycation damage.

Twenty compounds were isolated from the hydroethanolic extract of the stems of Siolmatra brasiliensis, five flavonoids, two lignans, one glucosyl phytosterol, seven nor-cucurbitacins, one new phenolic derivative named siolmatrin (1) and four new dammarane-type saponins named siolmatrosides II-V (2-5), the structures of the compounds were assigned by means of 1D and 2D NMR experiments and HRESIMS of the natural compounds and some acetyl derivatives. The effects of the crude hydroethanolic extract (SbExt) and the ethyl acetate fraction (SbEtAc) of Siolmatra brasiliensis stems on the formation of advanced glycation end-products (AGEs) were also investigated. In the in vitro model system of protein glycation using bovine serum albumin (BSA) and glucose, addition of SbExt or SbEtAc inhibited the formation of fluorescent AGEs, in parallel to minor levels of fructosamine (SbEtAc) and markers of tyrosine and tryptophan oxidation (SbExt and SbEtAc). Protein crosslinking, which represents changes of late stages of protein glycation, was reduced in the presence of SbExt and SbEtAc. Siolmatra brasiliensis stems seem to be a promising source of compounds having ability to prevent glycoxidation changes, arising as an interesting option to be studied as a complementary therapy for complications of diabetes.

Saponins from Quillaja saponaria and Quillaja brasiliensis: Particular Chemical Characteristics and Biological Activities.

Quillaja saponaria Molina represents the main source of saponins for industrial applications. Q. saponaria triterpenoids have been studied for more than four decades and their relevance is due to their biological activities, especially as a vaccine adjuvant and immunostimulant, which have led to important research in the field of vaccine development. These saponins, alone or incorporated into immunostimulating complexes (ISCOMs), are able to modulate immunity by increasing antigen uptake, stimulating cytotoxic T lymphocyte production (Th1) and cytokines (Th2) in response to different antigens. Furthermore, antiviral, antifungal, antibacterial, antiparasitic, and antitumor activities are also reported as important biological properties of Quillaja triterpenoids. Recently, other saponins from Q. brasiliensis (A. St.-Hill. & Tul.) Mart. were successfully tested and showed similar chemical and biological properties to those of Q. saponaria barks. The aim of this manuscript is to summarize the current advances in phytochemical and pharmacological knowledge of saponins from Quillaja plants, including the particular chemical characteristics of these triterpenoids. The potential applications of Quillaja saponins to stimulate further drug discovery research will be provided.

Chemical characterisation of the constituents of Eugenia protenta McVaugh and leishmanicidal activity of dimethylxanthoxylin.

The chemical study of Eugenia protenta McVaugh extracts performed by classical and high-performance liquid chromatography techniques and spectral methods has led to the identification of known triterpenoids, flavonoids and an acetophenone derivative (dimethylxanthoxylin). The effect of dimethylxanthoxylin on Leishmania (Leishmania) amazonensis was evaluated against the promastigotes forms after 96 h of treatment. Dimethylxanthoxylin reduced 57 and 59% of the promastigotes growth when treated with 50 and 100 µg/mL solutions, respectively (IC50 117.35 µg/mL or 52.3 µM). Cytotoxicity experiments using MTT assays showed that this substance did not promote cell death after 24 h of treatment. Dimethylxanthoxylin was active on the promastigotes and could be a promising agent for treating leishmaniasis.

Oxidation at C-16 enhances butyrylcholinesterase inhibition in lupane triterpenoids.

A set of triterpenoids with different grades of oxidation in the lupane skeleton were prepared and evaluated as cholinesterase inhibitors. Allylic oxidation with selenium oxide and Jones's oxidation were employed to obtain mono-, di- and tri-oxolupanes, starting from calenduladiol (1) and lupeol (3). All the derivatives showed a selective inhibition of butyrylcholinesterase over acetylcholinesterase (BChE vs. AChE). A kinetic study proved that compounds 2 and 9, the more potent inhibitors of the series, act as competitive inhibitors. Molecular modeling was used to understand their interaction with BChE, the role of carbonyl at C-16 and the selectivity towards this enzyme over AChE. These results indicate that oxidation at C-16 of the lupane skeleton is a key transformation in order to improve the cholinesterase inhibition of these compounds.