Stryphnosides G-P, 10 new triterpene glycosides from the pericarps of Stryphnodendron fissuratum

Total Synthesis of Clostrienose

This paper considers the total synthesis of a cellular differentiation regulator of Clostridium acetobutylicum, clostrienose, which is a unique fatty-acid glycosyl ester consisting of clostrienoic acid, (3R,5E,8E,10E)-3-hydroxy-tetradeca-5,8,10-trienoic acid and α-d-galactofuranosyl-(1 → 2)-α-l-rhamnose. The key features of our synthesis include stereoselective construction of a skipped-triene system in clostrienoic acid and its esterification with a disaccharide residue. The partially protected clostrienoic acid employed for the coupling also served for the preparation of l-rhamnosyl clostrienoate, thus leading to confirmation of the proposed structure unambiguously.

Novel Oleanane-Type Triterpene Glycosides from the Saponaria officinalis L. Seeds and Apoptosis-Inducing Activity via Mitochondria

Saponaria officinalis L., commonly known as “Soapwort”, is a rich source of triterpene glycosides; however, the chemical constituents of S. officinalis seeds have not been fully identified. In this study, we conducted a systematic phytochemical investigation of the seeds of S. officinalis and obtained 17 oleanane-type triterpene glycosides (1–17), including seven new glycosides (1–7). The structures of 1–7 were determined based on a detailed analysis of NMR spectroscopic data and chromatographic and spectroscopic analyses following specific chemical transformation. The cytotoxicities of the isolated compounds were evaluated against HL-60 human promyelocytic leukemia cells, A549 human adenocarcinoma lung cancer cells, and SBC-3 human small-cell lung cancer cells. The cytotoxicities of 1, 4, and 10 toward HL-60 cells and SBC-3 cells were nearly as potent as that of cisplatin. Compound 1, a bisdesmosidic triterpene glycoside obtained in good yield, arrested the cell cycle of SBC-3 cells at the G₂/M phase, and induced apoptosis through an intrinsic pathway, accompanied by ROS generation. As a result of the mitochondrial dysfunction induced by 1, mitochondria selective autophagy, termed mitophagy, occurred in SBC-3 cells.

Phytochemistry and poisoning in ruminants by Enterolobium contortisiliquum (Vell.) Morong (Fabaceae): A systematic review

Enterolobium contortisiliquum (Vell.) Morong (Fabaceae) is a plant widely distributed in several regions of Brazil, occurring in the phytogeographic domains of Atlantic Forest, Cerrado, and Caatinga. Cases of serious poisoning in cattle, goats, and sheep in the country caused by the ingestion of beans of this species have been reported by several studies. The present work aimed to carry out a systematic review of cases of poisoning by E. contortisiliquum in ruminants and list the main chemical compounds isolated from this plant. For this, searches were performed in the Google Academic, PubMed®, ScienceDirect®, and SciELO databases. A total of 26 articles published in the last 20 years (2001-2021) were included. Studies on cases of natural and experimental poisoning indicate that this species mainly causes photosensitization, abortions, digestive problems, and acute ruminal lactic acidosis in animals that ingest the pods of the plant. The main chemical compounds that occur in the species belong to the triterpene saponins, monoterpene, phenylpropene, and triterpene classes. It is likely that triterpene saponins isolated from E. contortisiliquum are associated with reported cases of photosensitization in cattle. New studies must be conducted to assess the mechanisms of action of chemical compounds isolated from this species in in vivo systems.

Feature-Based Molecular Network-Guided Dereplication of Natural Bioactive Products from Leaves of Stryphnodendron pulcherrimum (Willd.) Hochr

Stryphnodendron pulcherrimum is a species known to have a high content of tannins. Accordingly, its preparations are used in southern Pará, Brazil, for their anti-inflammatory and antimicrobial activities, but so far, its chemical profile composition remains essentially unknown. We herein describe the compounds present in a hydro-acetonic extract from S. pulcherrimum leaves as revealed by dereplication via ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry. The data were combined with spectral organization, spectral matching through the Global Natural Products Social platform, in silico annotation and taxonomical ponderation. Several types of phenolic compounds were identified such as gallic acids, flavan-3-ols and flavone-like compounds. From these, 5 have been recently reported by our group, whereas 44 are reported here for the first time in this tree species, and 41 (out of 49) for this genus. The results highlight the possible role of Stryphnodendron pulcherrimum as a renewable source for natural bioactive products with potential pharmaceutical applications.

Oleanane-type Triterpenes with Highly-Substituted Oxygen Functional Groups from the Flower Buds of Camellia sinensis and Their Inhibitory Effects against NO Production and HSV-1

Acylated oleanane-type triterpenes named chakasapogenins I (1), II (2), and III (3) were isolated from the hydrolysis product of the extract obtained from the flower buds of Camellia sinensis. The chemical structures of new triterpenes were elucidated on the basis of chemical and physicochemical evidence. chakasapogenin III (3) inhibited nitric oxide (NO) production in lipopolysaccharide- (LPS) activated RAW264.7 macrophages. In addition, R1-barrigenol (7) showed antiviral effect at 10μM against herpes simplex virus type-1 (HSV-1).