Identification of chemical composition in Gnetum montanum extract and plasma components after oral administration in cynomolgus monkey by UPLC-Q-TOF-MS and its anti-tumor active components analysis

Gnetum montanum Markgr. (Gnetaceae) is a commonly used traditional herbal medicine among the Yao ethnic group, with potential effects in preventing and treating tumors. However, the substance basis of its anti-tumor properties remains unclear. This study utilized ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) to identify the chemical components of G. montanum extract (GME) and its absorbed prototypes in cynomolgus monkey plasma after oral administration. A total of 57 compounds were detected in the GME, with 14 compounds in positive ion mode and 43 compounds in negative ion mode. In the cynomolgus monkey plasma, 17 compounds were identified, with 3 compounds in positive ion mode and 14 compounds in negative ion mode. Subsequently, we utilized high content screening technology to investigate the anti-tumor effects of GME on colon cancer, lung cancer, breast cancer, gastric cancer, liver cancer, and esophageal cancer. We found that the GME exhibited significant proliferation inhibition on colon cancer cells SW480, with an IC50 value of 50.77 μg/mL. Further research using component separation and pharmacological tracking revealed that the F2 component of the GME demonstrated notable anti-tumor effects. Through UPLC-MS identification, the chemical components in the F2 fraction were identified as pinoresinol diglucoside, (+)-pinoresinol-4-O-beta-D-glucopyranoside, ursolic acid, and gnetol. In conclusion, this study contributes to elucidating the anti-tumor pharmacological basis of GME and provides robust support for future drug design and development.

Inhibitory nitric oxide production and cytotoxic activities of phenolic compounds from Gnetum montanum Markgr

One new compound, styrene dimer-type listeanol-4-O-α-ʟ-rhamnopyranosyl-(1→4)-β-ᴅ-glucopyranoside (1), and four known compounds namely listeanol (2), isorhapotigenin (3), genetifolin E (4), gnetifolin K (5) were isolated from the methanolic extract from the aerial part of the Gnetum montanum Markgr. in Viet Nam. Their chemical structures were determined by modern spectroscopic methods (NMR and HR-ESI-MS) and comparison with those of published data. These compounds were evaluated for their anti-inflammatory and cytotoxic activities. Among them, compound 3 exhibited the NO inhibitory production on the RAW264.7 cell line, and inhibited the HepG2 cell line with respective IC50 values of 79.88 ± 5.51 (µg/mL) (L-NMMA 7.90 ± 0.63 µg/mL), and 63.48 ± 3.63 (µg/mL) (Ellipticine 0.40 ± 0.01 µg/mL).

Gnetum montanum extract induces apoptosis by inhibiting the activation of AKT in SW480 human colon cancer cells

CONTEXT

Gnetum montanum Markgr. (Gnetaceae) is used to treat rheumatic arthralgia and bruises in the clinic.

OBJECTIVE

To exam the activity and mechanism of G. montanum extract (GME) against colon cancer cells SW480.

MATERIALS AND METHODS

The anti-proliferative activity of GME (0-120 μg/mL) on SW480 cells was determined using MTS assay at 24, 48, and 72 h. The in vitro activity of GME (0-120 μg/mL) on SW480 cells was investigated using flow cytometry and western blotting analysis. The in vivo activity of GME was evaluated using xenograft tumour model of zebrafish and nude mice. The chemical composition of GME was detected by using HPLC-MS/MS.

RESULTS

The IC₅₀ value SW480 cells viability by GME were 126.50, 78.25, and 50.77 μg/mL, respectively, for 24, 48, and 72 h. The experiments showed that apoptotic cells and G2/M phase cells increased from 20.81 to 61.53% (p < 0.01) and 25.76 to 34.93% with 120 μg/mL GME, respectively. GME also down-regulated the protein expression of P-AKT, P-GSK-3β, P-PDK1, P-c-Raf, caspase-3, and Bcl-2, and up-regulated the expression cleaved caspase-3, cleaved PARP, and Bax. In vivo study found that GME can significantly inhibit the growth and migration of SW480 cells in xenograft zebrafish. GME reduced the nude mice tumour weight to approximately 32.19% at 28 mg/kg/day and to 53.17% (p < 0.01) at 56 mg/kg/day. Forty-two compounds were identified from the GME.

DISCUSSION AND CONCLUSIONS

GME has a significant antitumor effect on colon cancer cells SW480, and it has the potential to be developed as an anticancer agent.

Oxidative dehydrogenative couplings of alkenyl phenols

Alkenyl phenols are utilized by nature in the construction of one of the most important biopolymers, lignin. Using similar building blocks, an array of distinct structures can be formed by selective dimerization of the starting phenols to form lignans, neolignans, oxyneolignans, and norlignans. Given the multitude of possible outcomes, many methods have been reported to affect the desired bond formations and access these biologically relevant scaffolds. The most biomimetic of these methods, discussed here, involve the unprotected phenols undergoing oxidative bond formation that proceeds via dehydrogenative coupling. This review aims to place the known literature in context, highlight the progress made toward the synthesis of these important molecules, and recognize the gaps and limitations that still exist.

Neuraminidase Inhibitors from the Roots of Caragana sinica

Two new oligostilbenes, caragasinins D and E, along with four known compounds, kobophenol A, α-viniferin, wistin, and 5-hydroxy-2-[(4-hydroxyphenyl)acetyl]-3-methoxybenzoic acid, were isolated from the roots of Caragana sinica. These compounds were spectroscopically analyzed for their structures and configurations and compared with existing data. The configurations of caragasinins D and E were elucidated by ¹ H-NMR spectroscopy, CD spectroscopy, and time-dependent density-functional theory simulated ECD spectral data. All six compounds were evaluated for their inhibitory activity against neuraminidase (NA) from Clostridium perfringens. Among the tested compounds, 5-hydroxy-2-[(4-hydroxyphenyl)acetyl]-3-methoxybenzoic acid demonstrated statistically significant NA inhibitory activity, which was comparable to the positive control, mangiferin.

Catalytic Asymmetric [4 + 2] Cycloaddition of ortho-Alkenyl Naphthols/Phenols with ortho-Quinone Methides: Highly Stereoselective Synthesis of Chiral 2,3,4-Trisubstituted Chromans

Chiral phosphoric acid-catalyzed biomimetic asymmetric [4 + 2] cycloaddition of ortho-alkenyl naphthols/phenols and ortho-quinone methides (o-QMs) has been demonstrated to afford various important 2,3,4-trisubstituted chromans in high yields with excellent enantio- and diastereoselectivities (up to 99% yield, 99% ee, >20:1 dr). Notably, this methodology not only enabled access to the trans-cis chiral trisubstituted chromans from 1-alkenyl 2-naphthols but also is compatible with 2-alkenyl 1-naphthols and phenols to deliver trans-trans chiral trisubstituted chromans.

Alopecines A-E, five chloro-containing matrine-type alkaloids with immunosuppressive activities from the seeds of Sophora alopecuroides

Alopecines A-E (1-5), five unusual matrine-type alkaloids featuring with an additional dichlorocyclopropane (1-3) or a di/tri-chloromethyl (4/5) attached on the D ring, were isolated from the seeds of Sophora alopecuroides. Their structures and absolute configurations were elucidated by extensive spectroscopic techniques, and X-ray diffraction analyses or time-dependent density functional theory-based electronic circular dichroism (TDDFT-ECD) calculations. Alkaloid 4 exhibited potent inhibitory effects on the proliferation of ConA-induced T lymphocytes or LPS-induced B cells with IC₅₀ value of 3.98 or 3.74 μM, respectively.

Oligostilbenes from the leaves of Gnetum latifolium and their biological potential to inhibit neuroinflammation

Oligostilbenes are polyphenol oligomers derived from resveratrol and are commonly produced by members of the Gnetaceae family, and many researchers have focused on their anti-inflammatory activities. The EtOAc fraction of a Gnetum latifolium extract showed inhibitory activity against neuroinflammation induced by the transfection of Aβ_1-42 into microglial BV-2 cells. The bioassay-guided isolation of the 70% EtOH extract of this plant resulted in three previously undescribed resveratrol oligostilbenes and ten known stilbene derivatives. The structures of the isolated compounds were established based on extensive NMR spectroscopic analysis. The absolute configurations of the three undescribed compounds were confirmed by comparison with available compounds with known stereochemistry and by ECD calculations and molecular modelling. Latifoliols A and B are the first reported oligostilbenes with a bridged 3-oxabicyclo[3.3.0]octane moiety, and latifoliol C was formed by the condensation of gnemontanin G with oxyresveratrol. Moreover, the hypothetical biogenetic pathway of latifoliols A, B and C was proposed. The potential anti-inflammatory activities of the thirteen isolated compounds were tested by measuring their effect on the secreted NO concentrations induced by transfection with plasmids expressing the Aβ_1-42 gene in the BV-2 cell line. Interestingly, cis- and trans-shegansu B and latifolol, whose structures contained double bonds, strongly inhibited NO secretion in BV-2 cells, supporting the double binding effect of the stilbene derivative on inhibitory activity.

Update on Phytochemistry and Pharmacology of Naturally Occurring Resveratrol Oligomers

Resveratrol oligomers (REVs), a major class of stilbenoids, are biosynthesized by regioselective oxidative coupling of two to eight units of resveratrol monomer. Due to their unique structures and pleiotropic biological activities, natural product chemists are increasingly focusing on REVs in the last few decades. This study presents a detailed and thorough examination of REVs, including chemical structures, natural resources, and biological activities, during the period of 2010–2017. Ninety-two new REVs compounds, including 39 dimers, 23 trimers, 13 tetramers, six resveratrol monomers, six hexamers, four pentamers, and one octamer, have been reported from the families of Dipterocarpaceae, Paeoniaceae, Vitaceae, Leguminosae, Gnetaceae, Cyperaceae, Polygonaceae Gramineae, and Poaceae. Amongst these families, Dipterocarpaceae, with 50 REVs, accounts for the majority, and seven genera of Dipterocarpaceae are involved, including Vatica, Vateria, Shorea, Hopea, Neobalanocarpus, Dipterocarpus, and Dryobalanops. These REVs have shown a wide range of bioactivities. Pharmacological studies have mainly focused on potential efficacy on tumors, bacteria, Alzheimer’s disease, cardiovascular diseases, and others. The information updated in this review might assist further research and development of novel REVs as potential therapeutic agents.