Cytotoxic Flavonoids from the Leaves and Twigs of Murraya Tetramera

Demethoxymurrapanine, an indole-naphthoquinone alkaloid, inhibits the proliferation of oral cancer cells without major side effects on normal cells

Antioral cancer drugs need a greater antiproliferative impact on cancer than on normal cells. Demethoxymurrapanine (DEMU) inhibits proliferation in several cancer cells, but an in-depth investigation was necessary. This study evaluated the proliferation-modulating effects of DEMU, focusing on oral cancer and normal cells. DEMU (0, 2, 3, and 4 μg/mL) at 48 h treatments inhibited the proliferation of oral cancer cells (the cell viability (%) for Ca9-22 cells was 100.0 ± 2.2, 75.4 ± 5.6, 26.0 ± 3.8, and 15.4 ± 1.4, and for CAL 27 cells was 100.0 ± 9.4, 77.2 ± 5.9, 57.4 ± 10.7, and 27.1 ± 1.1) more strongly than that of normal cells (the cell viability (%) for S-G cells was 100.0 ± 6.6, 91.0 ± 4.6, 95.0 ± 2.6, and 95.8 ± 5.5), although this was blocked by the antioxidant N-acetylcysteine. The presence of oxidative stress was evidenced by the increase of reactive oxygen species and mitochondrial superoxide and the downregulation of the cellular antioxidant glutathione in oral cancer cells, but these changes were minor in normal cells. DEMU also caused greater induction of the subG1 phase, extrinsic and intrinsic apoptosis (annexin V and caspases 3, 8, and 9), and DNA damage (γH2AX and 8-hydroxy-2-deoxyguanosine) in oral cancer than in normal cells. N-acetylcysteine attenuated all these DEMU-induced changes. Together, these data demonstrate the preferential antiproliferative function of DEMU in oral cancer cells, with the preferential induction of oxidative stress, apoptosis, and DNA damage in these cancer cells, and low cytotoxicity toward normal cells.

Two New Lactam Derivatives from Micromelum falcatum (Lour.) Tan. with Brine Shrimp Larvae Toxicity

Chemical investigation of the stems of Micromelum falcatum (Lour.) Tan. led to the isolation of two new lactam derivatives, named 3-(hydroxy(10-hydroxyphenyl)methyl)-4-(16-hydroxyphenyl)-1-methylpyrrolidin-2-one (1) and 3-(hydroxy(10-hydroxy-9-methoxyphenyl)methyl)-4-(16-hydroxyphenyl)-1-methylpyrrolidin-2-one (2), along with five known compounds, trans-4-hydroxycinnamic acid (3), 4-hydroxybenzaldehyde (4), m-hydroxybenzoic acid (5), p-hydroxybenzoic acid (6), and gallic acid (7). Their structures were determined on the basis of spectroscopic studies, including nuclear magnetic resonance (NMR) spectrum, mass spectrometry (MS) data, ultraviolet (UV) spectrum, infrared (IR) data, and comparison with the literature. All compounds were evaluated for toxicity against brine shrimp larvae and cytotoxicity to HeLa and HepG-2 cells. Compounds 1-2 exhibited moderate brine shrimp larvae toxicity with an LC50 value of 50.6 and 121.8 μg mL-1, respectively.

Perplexing Polyphenolics: The Isolations, Syntheses, Reappraisals, and Bioactivities of Flavonoids, Isoflavonoids, and Neoflavonoids from 2016 to 2022

Flavonoids, isoflavonoids, neoflavonoids, and their various subcategories are polyphenolics-an extensive class of natural products. These compounds are bioactive and display multiple activities, including anticancer, antibacterial, antiviral, antioxidant, and neuroprotective activities. Thus, these compounds can serve as leads for therapeutic agents or targets for complex synthesis; they are coveted and routinely isolated, characterized, biologically evaluated, and synthesized. However, data regarding the compounds' sources, isolation procedures, structural novelties, bioactivities, and synthetic schemes are often dispersed and complex, a dilemma this review aims to address. To serve as an easily accessible guide for researchers wanting to apprise themselves of the latest advancements in this subfield, this review summarizes seventy-six (76) articles published between 2016 and 2022 that detail the isolation and characterization of two hundred and forty-nine (249) novel compounds, the total and semisyntheses of thirteen (13) compounds, and reappraisals of the structures of twenty (20) previously reported compounds and their bioactivities. This article also discusses new synthetic methods and enzymes capable of producing or modifying flavonoids, isoflavonoids, or neoflavonoids.

Untargeted metabolomics study and identification of potential biomarkers in the six sections of the genus Stachys L. (Lamiaceae) using HPLC-MQ-API-MS/MS

INTRODUCTION

The genus Stachys L., belonging to the family Lamiaceae, is one of the largest genera with remarkable medicinal properties. Plants of this genus produce a broad range of secondary metabolites.

OBJECTIVES

Due to the incomplete comprehensive assessment of chemical profiles in Stachys species, we conducted an untargeted metabolomics study and identified potential biomarkers in the six sections of Stachys with chemotaxonomic importance.

MATERIAL AND METHODS

Dried leaves of 17 taxa were utilized for analysis of all the constituents using HPLC-MQ-API-MS. The obtained data were processed and analyzed using multivariate statistical methods, including heatmaps, PLS-DA score plots, functional analysis of metabolic pathways, metabolite set enrichment analysis, and biomarker and network analysis.

RESULTS

Among the 129 metabolites, 111 flavonoids and 18 non-flavonoids were recognized. The most represented flavonoids, including 41 flavones and 20 flavonols, displayed remarkable abundance. In non-flavonoid compounds, a total of six coumarins and six phenolic acids were present at high levels. In terms of approved markers in six sections, 76 chemical compounds, mainly flavonoids, coumarins, quinic acids, and cinnamic acids, were identified as potential biomarkers or chemotaxonomic indicators. Accordingly, the taxonomic complexities of some Stachys species in sections Fragilicaulis, Aucheriana, and Setifolia were properly resolved.

CONCLUSION

An HPLC-MS/MS-based metabolomics approach integrated with multivariate statistical methods was employed to identify (1) valuable markers and analyze metabolic diversity and (2) predict the pharmaceutical properties of Stachys species. The obtained chemical profiles provide a new perspective for investigation of the Stachys genus.

Insights into the leaves of Ceriscoides campanulata: Natural proanthocyanidins alleviate diabetes, inflammation, and esophageal squamous cell cancer via in vitro and in silico models

Fourteen flavones (1-14) including twelve polymethoxylated flavones, two A-type proanthocyanidins (oligomeric flavonoids) (15, 16), one benzoyl glucoside (17), one triterpenoid (18), and one phenylpropanoid (19) were isolated from the leaves of the South Asian medicinal plant Ceriscoides campanulata (Roxb.) Tirveng (Rubiaceae). The structures of the compounds were identified based on their spectroscopic and spectrometric data and in comparison with literature data. Isolated compounds were tested in vitro against inflammatory enzymes (COX-2, iNOS), pro-inflammatory cytokines (IL-1β, IL-6, TNF-α), esophageal squamous carcinoma cell line (TE13), and carbohydrate digestion enzymes (α-amylase, α-glucosidase). Proanthocyanidins 15 and 16 significantly attenuated the LPS-induced inflammatory response of COX-2, iNOS, IL-1β, IL-6, TNF-α in RAW 264.7 cells. Proanthocyanidins also satisfactorily inhibited the regrowth (64%), migration (51%), and formation of tumor-sphere (48%) in ESCC cell line TE13 at 50% toxic concentration. Compounds 15 and 16 showed the most potent effect against mammalian α-amylase (IC₅₀ 8.4 ± 0.3 μM and 3.5 ± 0.02 μM, respectively) compared to reference standard acarbose (IC₅₀ 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds 15 and 16 also displayed significant activities (IC₅₀ 6.2 ± 0.3 and 4.7 ± 0.1 μM, respectively), while compounds 1-6 displayed weaker α-glucosidase inhibitory activities, ranging from 49 to 142 μM, compared to acarbose (IC₅₀ 665 ± 42 μM). In an anticholinesterase assay, compounds 1, 2, 6 (IC₅₀ 51 ± 2, 53 ± 7, 64 ± 5 μM, respectively), and 4 (IC₅₀ 44 ± 1 μM) showed moderate inhibitory activities against acetylcholinesterase and butyrylcholinesterase, respectively. Furthermore, molecular docking and molecular dynamic simulation analyses of compounds 15 and 16 were performed against human pancreatic α-amylase and human lysosomal acid α-glucosidase to elucidate the interactions of these compounds in the respective enzymes' active sites.