Euphane- and 19(10 → 9)abeo-euphane-type triterpenoids from Jatropha gossypiifolia

Diversity of sesquiterpenoids from Stellera chamaejasme with neuroprotective effects

Chromatographic fractionation of the 95% EtOH extract of the roots of Stellera chamaejasme yielded 20 sesquiterpenoids of four different types, guaiane-, carotane-, sesquicarane-, and alpiniane-types. Among them, sesquistrachanoids A-F were previously undescribed ones, whose structures including absolute configurations were elucidated by spectroscopic methods, the Mo₂(OAc)₄-induced ECD experiment, and analysis of experimental and calculated 1D NMR and ECD data. Sesquistrachanoid A is a 2,3-seco-guaiane-type sesquiterpenoid with a α-pyrone core and sesquistrachanoid B is the first example of 8,9-seco-guaiane-type sesquiterpenoid featured with an 1,8-δ-lactone core. Sesquistrachanoid C is a guaiane sesquiterpenoid characterized by a peroxide bridge between C-8 and C-10. All sesquiterpenoids were evaluated for their neuroprotective effects on cell damage induced by sodium nitroprusside in PC-12 cells. The bioassay results showed that six compounds at 10 μM could restore the cell viability, being comparable to that of the positive control edaravone. The mechanistic study on the most pronounced activity compound, stelleraguaianone B, demonstrated that it played a neuroprotective role by promoting the mRNA expression of antioxidant enzymes to reduce oxidative stress.

Phytochemical Characterization and In Vitro Anti-Inflammatory Evaluation in RAW 264.7 Cells of Jatropha cordata Bark Extracts

The inflammatory process, although beneficial, can produce tissue damage and systemic damage when uncontrolled. Effective therapeutic alternatives with little or no side effects are of great therapeutic interest. This study aimed to determine the phytochemical composition of bark extracts from J. cordata, an endemic plant from México, and evaluate their in vitro anti-inflammatory activity. Hexane, ethyl acetate, and methanol extracts were characterized by qualitative phytochemical tests, and their bioactive groups were identified by ¹H NMR and gas chromatography coupled to mass spectrometry (GC-MS). The extract's anti-inflammatory activity was evaluated as nitric oxide (NO) production and their cytotoxicity by an MTS cell proliferation assay in lipopolysaccharide (LPS)-activated RAW 264.7 cells at concentrations of 1-100 μg/mL. The hexane extract contained fatty acids, fatty esters, phytosterols, alkanes, vitamin E, and terpenoids; the ethyl acetate extract showed fatty acids, fatty esters, aromatic aldehyde, phytosterols, vitamin E, and terpenoids, while the methanolic extract showed fatty esters, fatty acid, aromatics aldehydes, and alcohol. The ethyl acetate extract showed the highest inhibition of NO production, followed by the methanolic extract and the hexane extract, without affecting the viability of RAW 264.7 macrophage cells. The results suggest that J. cordata extracts are a potential source of bioactive compounds with anti-inflammatory potential.

Glochodpurnoid B from Glochidion puberum Induces Endoplasmic Reticulum Stress-Mediated Apoptosis in Colorectal Cancer Cells

Glochidpurnoids A and B (1 and 2), two new coumaroyl or feruloyl oleananes, along with 17 known triterpenoids (3-19) were obtained from the stems and twigs of Glochidion puberum. Their structures were elucidated by extensive spectroscopic data analyses, chemical methods, and single crystal X-ray diffraction. All compounds were screened for cytotoxicity against the colorectal cancer cell line HCT-116, and 2, 3, 5, 6, 11, and 17 showed remarkable inhibitory activities (IC₅₀: 0.80-2.99 μM), being more active than the positive control 5-fluorouracil (5-FU). The mechanistic study of 2, the most potent compound, showed that it could induce endoplasmic reticulum (ER) stress-mediated apoptosis and improve the sensitivity of HCT-116 cells to 5-FU.

Triterpenoids, steroids and other constituents from Euphorbia kansui and their anti-inflammatory and anti-tumor properties

Six undescribed triterpenoids (euphokanols A-F), two undescribed C21-steroidal glycosides (euphokanosides A and B), together with fifty-four known compounds were isolated from the roots of Euphorbia kansui. Their structures were demonstrated by extensive spectroscopic data (1D, 2D NMR and HR-ESI-MS), and the absolute configuration of euphokanol A was elucidated based on electronic circular dichroism (ECD) calculation. Among them, euphokanol A was a tetracyclic triterpenoid with a 5,10-epoxy moiety and concurrent rearrangement of Me-19(10 → 9) and Me-30 (14 → 8), while euphokanols B and C were rare 19(10 → 9) abeo-tirucallane-type triterpenoids with Δ5(10) double bonds and 7,8-epoxy moieties. In addition, ten C21-steroidal glycosides were isolated from Euphorbia plants for the first time. Moreover, cynotophylloside B, caudatin, 5α,8α-epidioxy-22E-ergosta-6,22-diene-3β-ol, 6β,7β-epoxy-3β,4β,5β-trihydroxyl-20-deoxyingenol, 13-hydroxyingenol-3-(2,3- dimethylbutanoate)-13-dodecanoate, ingenol, 3-O-benzoyl-13-O-dodecanoateingenol, 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol, 20-O-acetylingenol and 20- deoxyingenol exhibited significant inhibition on NO production with IC50 values of 9.10, 17.38, 1.71, 0.55, 0.57, 12.22, 0.56, 0.30, 11.21 and 2.98 μM, respectively. Furthermore, wilfoside KIN, cynsaccatol L, kanesulone A, and 3β,7β,15β-triacetyloxy-5α-benzoyloxy-2α,8α-dihydroxyjatropha-6(17),11E-diene-9, 14-dione showed cytotoxicity against HepG2 cell line, with IC50 values of 12.55, 12.61, 18.24 and 18.26 μM, respectively. 13-Hydroxyingenol-3-(2,3-dimethylbutanoate)-13- dodecanoate exhibited anti-proliferation activity on MCF-7 cell line with an IC50 value of 17.12 μM. Specifically, euphol selectively inhibited the growth of human glioma stem cells (GSC-3# and GSC-12#), with IC50 values of 8.89 and 13.00 μM, respectively.

Antimicrobial Triterpenoids and Ingol Diterpenes from Propolis of Semi-Arid Region of Morocco

The chemical composition and antimicrobial activity of propolis from a semi-arid region of Morocco were investigated. Fifteen compounds, including triterpenoids (1, 2, 7–12), macrocyclic diterpenes of ingol type (3–6) and aromatic derivatives (13–15), were isolated by various chromatographic methods. Their structures were elucidated by a combination of spectroscopic and chiroptical methods. Compounds 1 and 3 are new natural compounds, and 2, 4–6, and 9–11 are newly isolated from propolis. Moreover, the full nuclear magnetic resonance (NMR) assignments of three of the known compounds (2, 4 and 5) were reported for the first time. Most of the compounds tested, especially the diterpenes 3, 4, and 6, exhibited very good activity against different strains of bacteria and fungi. Compound 3 showed the strongest activity with minimum inhibitory concentrations (MICs) in the range of 4–64 µg/mL. The combination of isolated triterpenoids and ingol diterpenes was found to be characteristic for Euphorbia spp., and Euphorbia officinarum subsp. echinus could be suggested as a probable and new plant source of propolis.

Pentacyclic Triterpenoids from Sabia discolor Dunn and Their α-Glycosidase Inhibitory Activities

Four new pentacyclic triterpenoids named Sabiadiscolor A–D (1 and 7–9) together with eleven known ones were isolated by repeated column chromatography. Their structures were identified and characterized by NMR and MS spectral data as 6 oleanane-type pentacyclic triterpenoids (1–6), 7 ursane-type ones (7–13), and 2 lupanane-type ones (14–15). Except for compound 15, all other compounds were isolated from Sabia discolor Dunn for the first time. Their α-glycosidase inhibitory activities were evaluated, which showed that compounds 1, 3, 8, 9, 13, and 15 implied remarkable activities with IC₅₀ values ranging from 0.09 to 0.27 μM, and the preliminary structure–activity relationship was discussed.

Structurally diverse triterpenoids with cytotoxicity from Euphorbia hypericifolia

Extensive phytochemical investigation on the whole herbs of Euphorbia hypericifolia led to the isolation of 18 structurally diverse tetracyclic and pentacyclic triterpenoids, including four 4α,14α-dimethyl-5α-ergostanes (1-4), two seco-adiananes (5 and 6), three dammaranes (7-9), four cycloartanes (10-13), one tirucallane (14), two fernanes (15 and 16), one ursane (17), and one oleanane (18). Among them, euphypenoids A (1) and B (5) were new triterpenoids. Their structures were elucidated on the basis of extensive spectroscopic analysis, single-crystal X-ray diffraction, and chemical transformation. All isolates were screened for their cytotoxic activities against the colorectal cancer cell line HCT-116, and compounds 1, 12, and 15 showed remarkable activities with IC50 values of 12.8 ± 1.6, 7.4 ± 0.2, and 10.6 ± 1.2 μM, respectively.