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.

Dammarane triterpenes targeting α-synuclein: biological activity and evaluation of binding sites by molecular docking.

Parkinson's disease (PD) is a neurodegenerative disorder that affects adult people whose treatment is palliative. Thus, we decided to test three dammarane triterpenes 1, 1a, 1b, and we determined that 1 and 1a inhibit ß-aggregation through thioflavine T rather than 1b. Since compound 1 was most active, we determined the interaction between α-synuclein and 1 at 50 µM (Kd) through microscale thermophoresis. Also, we observed differences in height and diameter of aggregates, and α-synuclein remains unfolded in the presence of 1. Also, aggregates treated with 1 do not provoke neurites' retraction in N2a cells previously induced by retinoic acid. Finally, we studied the potential sites of interaction between 1 with α-synuclein fibrils using molecular modelling. Docking experiments suggest that 1 preferably interact with the site 2 of α-synuclein through hydrogen bonds with residues Y39 and T44.

Countercurrent chromatography separation of saponins by skeleton type from Ampelozizyphus amazonicus for off-line ultra-high-performance liquid chromatography/high resolution accurate mass spectrometry analysis and characterisation.

Ampelozizyphus amazonicus Ducke (Rhamnaceae), a medicinal plant used to prevent malaria, is a climbing shrub, native to the Amazonian region, with jujubogenin glycoside saponins as main compounds. The crude extract of this plant is too complex for any kind of structural identification, and HPLC separation was not sufficient to resolve this issue. Therefore, the aim of this work was to obtain saponin enriched fractions from the bark ethanol extract by countercurrent chromatography (CCC) for further isolation and identification/characterisation of the major saponins by HPLC and MS. The butanol extract was fractionated by CCC with hexane - ethyl acetate - butanol - ethanol - water (1:6:1:1:6; v/v) solvent system yielding 4 group fractions. The collected fractions were analysed by UHPLC-HRMS (ultra-high-performance liquid chromatography/high resolution accurate mass spectrometry) and MSn. Group 1 presented mainly oleane type saponins, and group 3 showed mainly jujubogenin glycosides, keto-dammarane type triterpene saponins and saponins with C31 skeleton. Thus, CCC separated saponins from the butanol-rich extract by skeleton type. A further purification of group 3 by CCC (ethyl acetate - ethanol - water (1:0.2:1; v/v)) and HPLC-RI was performed in order to obtain these unusual aglycones in pure form.

A new dammarane saponin and other triterpenoids from Siolmatra brasiliensis and evaluation of the antidiabetic activity of its extract.

Context Siolmatra brasiliensis (Cogn.) Baill (Cucurbitaceae) is a climbing plant widely used for the treatment of diabetes mellitus symptoms. Objective This work evaluates the antidiabetic activity of an extract of S. brasiliensis in streptozotocin-diabetic rats and promotes the phytochemical investigation to isolate the major compounds of the same extract. Materials and methods Male Wistar rats were divided into normal (N) and diabetic rats (DC) treated with water; diabetic rats treated with 3U insulin (DI) or with 250 (DSb250) or 500 mg/kg (DSb500) of hydroalcoholic extract of the stalks of S. brasiliensis, via oral gavage, for 21 days. Physiological and biochemical parameters classically altered in diabetes were monitored. The triterpenoids were isolated from the ethyl acetate fraction under silica gel column chromatography and Sephadex-LH20 methods and their structures were determined by NMR, HR-ESI-MS and DC analysis. Results When compared with DC, DSb250 rats showed a reduction in the hyperglycemia (DC: 26.46 ± 0.69 versus DSb250: 19.67 ± 1.06 mmol/L) and glycosuria (DC: 43.02 ± 3.19 versus DSb250: 28.46 ± 2.14 mmol/24 h) and increase in hepatic glycogen (DC: 14.44 ± 1.26 versus DSb250: 22.08 ± 4.26 mg/g). Three known cucurbitacins were isolated from a hydroalcoholic extract of S. brasiliensis, i.e., cayaponosides A1, B4, D, and a new dammarane saponin 3-O-ß-d-gentiobiosyl-26-O-ß-d-glucopyranosyl-20-hydroxydammar-24-ene. The structures of these compounds were elucidated by spectral data analysis of the natural products and their acetyl derivatives. Discussion and conclusion The known cucurbitacins and/or the new identified saponin may be related with the antidiabetic activity of S. brasiliensis.

1H and 13C NMR spectral assignments of four dammarane triterpenoids from carnauba wax.

The phytochemical investigation of carnauba wax led to the isolation of three new dammarane triterpenoids 1, 2 and 4, together with the known triterpene 3. The structures of the new compounds were determined by 1D and 2D NMR spectroscopy and by comparison with published data for closely related compounds.

New dammarane triterpenes from the aerial parts of Ibicella lutea grown in Argentina.

Two new dammarane triterpenes have been isolated from the aerial parts of Ibicella lutea, 3-acetyl-24-epi-polacandrin (1) and 1,3-diacetyl-24-epi-polacandrin (2), and were obtained along with the known compounds 20S,24S-epoxy-3beta,12beta,25-trihydroxydammarane (3) and apigenin. The structures of compounds 1 and 2 were deduced by spectroscopic studies and by chemical transformations leading to the preparation of derivatives 4-11. The structure and relative stereochemistry of 1 were verified by single-crystal X-ray analysis. The natural compounds and selected semisynthetic derivatives were evaluated against several tumor cells.

New triterpene glycosides from the stems of Anomospermum grandifolium.

Two new dammarane saponins identified as jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->6) beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (2) and jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[6-O-[3-hydroxy-3-methylglutaryl]-beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (3) and a new lupane saponin, 3beta-hydroxylup-20(29)-en-27,28-dioic acid 28-O-beta-d-glucopyranosyl(1-->2)-[beta-d-xylopyranosyl(1-->3)]-beta-d-xylopyranosyl(1-->2)-beta-d-glucopyranoside ester (5), along with the known jujubogenin 3-O-alpha-l-arabinofuranosyl(1-->2)-[beta-d-glucopyranosyl(1-->3)]-alpha-l-arabinopyranoside (1) and 3beta-hydroxylup-20(29)-ene-27,28-dioic acid (4), were isolated from the methanol extract of the stems of Anomospermum grandifolium. The structures of the new compounds were established by spectral analysis. Antimicrobial activity screening of compounds 1-3 revealed antifungal properties against C. albicans ATCC 3153 for compounds 2 and 3. The antibacterial and antifungal activities of the petroleum ether, chloroform, and methanol extracts of A. grandifolium stems were also evaluated.

Dammarane-type triterpenes from the Brazilian medicinal plant Cordia multispicata.

From the Brazilian medicinal plant Carucaá (Cordia multispicata), oleanane- and ursane-type triterpenoids were previously reported as anti-androgenic constituents of the plant. In this study, purification of the polar elements of the EtOAc-soluble fraction of the plant revealed nine novel dammarane-type triterpenes, named cordianols A-I (1-9) along with the known compound cordialin A (10). The structures of these new compounds were elucidated by means of spectral methods including HRFABMS, (1)H NMR, (13)C NMR, and 2D NMR (HMQC, HMBC, NOESY). Absolute configuration at C-23 of compound 7 was determined by an excitone chirality method. Some of these new compounds revealed a hemiketal structure on the A ring and a hydroxylated or epoxidated 20(22)-(E)-ene side chain and showed weak anti-androgenic activity.