Stigmastane-type steroid saponins from the leaves of Vernonia amygdalina and their α-glucosidase and xanthine oxidase inhibitory activities.

Two new vernonioside K (1) and vernonioside L (2) and four known Δ7,9(11) stigmastane-type steroidal saponins-vernonioside B2 (3), vernoniacum B (4), vernonioside B1 (5), and vernoamyoside A (6)-were isolated from the leaves of Vernonia amygdalina. Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (1-6) were evaluated to determine their inhibitory effects on α-glucosidase and xanthine oxidase. Among them, two new compounds 1 and 2 showed significant inhibition of α-glucosidase with IC50 values of 78.56 ± 7.28 and 14.74 ± 1.57 (µM), respectively, comparable with acarbose as a positive control (127.53 ± 1.73 µM); none of these compounds inhibited xanthine oxidase activity. Compounds 1 and 2 are promising candidates for the development of antidiabetic agents from natural sources.

Acylated flavonoid glycosides from Barringtonia pendula and their inhibition on lipopolysaccharide-induced nitric oxide production in RAW264.7 cells.

Six new acylated flavonoid glycosides namely barringosides J - O (1-6) along with tephrokaempferoside and barringoside D were isolated from the branches and leaves of Barringtonia pendula. The structural elucidation was confirmed by extensive analysis of their spectroscopic data including HRQTOFMS, 1D and 2D NMR experiments. Moderate inhibitory effects on LPS-induced NO production in RAW264.7 cells were observed for barringosides M (4) and N (5) with IC50 values of 48.40 ± 3.01 and 56.61 ± 3.87 µM, whereas weak inhibition was found for compounds 1-3, 6, and 7 with IC50 values ranging from 64.91 ± 3.68 to 79.80 ± 3.90 µM.

Acetylcholinesterase inhibition studies of alkaloid components from Crinum asiaticum var. sinicum: in vitro assessments by molecular docking and molecular dynamics simulations.

Alkaloids are among the most important and best-known secondary metabolites as sources of new drugs from medicinal plants and marine organisms. A phytochemical investigation of the whole plant of Crinum asiaticum var. sinicum resulted in the isolation of seven alkaloids (1-7), including one new dimeric compound, bis-(-)-8-demethylmaritidine (1). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of new compound 1 was established by circular dichroism spectroscopy. All isolated compounds were evaluated for their inhibitory effects on acetylcholinesterase (AChE) activity in vitro. Among them, compound 1 exhibited the most potent AChE inhibition. Moreover, molecular docking and molecular dynamics simulations were carried out for the most active compound to investigate their binding interactions and dynamics behavior of the AChE protein-ligand complex. Therefore, compound 1 may be a potential candidate for effectively treating Alzheimer's disease.

Chemical Composition, Antimicrobial, Nitric Oxide Inhibition and Cytotoxic Activity of Essential Oils from Zanthoxylum acanthopodium DC. Leaves and Stems from Vietnam.

This study was aimed to investigate the chemical composition and biological activities of leaf and stem essential oils of Zanthoxylum acanthopodium DC. from Vietnam. Their chemical composition was analyzed by GC/MS. Antimicrobial activities were evaluated by microdilution broth assay. Anti-inflammatory activity was evaluated by the ability to inhibit nitric oxide production in macrophage cells. Cytotoxic activity was evaluated using the sulforhodamine B assay on three human cancer cell lines. Forty-four compounds were identified in the leaf oil, among which dehydroaromadendrane (23.4 %), (E)-carpacin (17.6 %), 2-tridecanone (12.2 %), and 9-methyl-2-decanone (11.8 %) were the most abundant. The stem oil contained fifty-five identified constituents, mainly γ-gurjunene (51.1 %) and butyl acetate (11.8 %). Both oils exhibited inhibitory effects on three bacterial strains, namely S. aureus, E. coli, P. aeruginosa and a fungal strain C. albican, while showed insignificant effects on B. subtilis, L. fermentum, and S. enterica. Both oils showed weak NO production inhibition in LPS-induced RAW264.7 cells, but exhibited potent cytotoxic activity against all three tested cell lines SK-LU-1, MCF-7, and HepG2 with the IC50 values ranging from 16.03±0.77 to 35.60±1.62 µg/mL. This is the first report on the antimicrobial, anti-inflammatory and cytotoxic activities of essential oils from the leaves and stems of Z. acanthopodium.

Enrichment of soy isoflavone extracts through macroporous resin for characterization of toxicity and estrogenic activities.

Soy isoflavone extracts are widely researched for their distinctive potential in contributing to various functional foods. The research work focuses on testing the toxicity of purified soy isoflavone extracts in mice models. With an agreement of the animal ethics, acute toxicity is firstly used to screen the effects of test compounds in mice for therapeutic purposes. Moreover, tests were conducted on BALB/c for estrogen in vivo and MCF7 for in vitro, screening active protection of liver cells, lipid peroxidation and scavenging free radicals 2,2-diphenyl-1-picrylhydrazyl (DPPH). Genistin and daidzin were found to be the two major compounds accounting for 47% and 35% of total purified soy isoflavones. The acute toxicity test results exhibited no effect against physiological accretion of BALB/c after 7-day administration with the given dose of 10 g/kgBW. Moreover, modified E-screen assay on MCF7 cells proved that the estrogen of isoflavone extracts induces cell proliferation by 15% compared with other non-steroid culture techniques. Therefore, this research contributes to helping researchers apply soy isoflavones in functional food, to alleviate the difficulties in menopausal symptoms for women in the future. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05491-4.

Sesquiterpenoids from Tithonia diversifolia (Hemsl.) A. Gray induce apoptosis and inhibit the cell cycle progression of acute myeloid leukemia cells.

Three sesquiterpene lactones (1-3) were isolated from the aerial part of Tithonia diversifolia (Hemsl.) A. Gray grown in the Hoa Binh province in Viet Nam. The structures of these three sesquiterpene lactones were identified as tagitinin A (1), 1ß-hydroxytirotundin 3-O-methyl ether (2), and tagitinin C (3) by analyzing spectroscopic data. For the first time, compound 2 was isolated from T. diversifolia growing in Viet Nam. Furthermore, contrary to existing literature, we determined that compound 1 was the major isolate. Compounds 1 and 3 significantly decreased numbers of acute myeloid leukemia OCI-AML3 cells by promoting apoptosis and causing cell cycle arrest at G0/G1 phase at concentrations as low as 2.5 µg/mL (compound 1) and 0.25 µg/mL (compound 3). Additionally, all three compounds showed cytotoxic activity against five human cancer cell lines (A549, T24, Huh-7, 8505, and SNU-1), with IC50 values ranging from 1.32 ± 0.14 to 46.34 ± 2.74 µM. Overall, our findings suggest that compounds 1 and 3 may be potential anti-cancer therapeutics and thus warrant further study.

Chemical constituents of Impatiens parvisepala and their α-glucosidase inhibition activity.

The first chemical study of the whole Impatiens parvisepala S. X. Yu & Y. T. Hou led to the isolation of a new triterpene saponin, named Iparvisepala-1 (6) along with ten known compounds, which cover three flavonoid glycosides (1-3), one dihydrochalcone glucoside (4), one triterpenoid saponin (5), one triterpene (7) and four miscellaneous compounds (8-11). Their structures were elucidated by MS, NMR spectroscopic analyses as well as by comparisons of spectra data with those of the related published literatures. Additionally, flavonoid glucoside 2 showed impressive effect on α-glucosidase inhibition with the IC50 value of 12.53 ± 0.39 µM, much better than that of the positive control acabose (IC50 = 197.53 ± 2.68 µM).

A flexible and stretchable photonic crystal film with sensitive structural color-changing properties for spoiled milk detection.

This study proposes a flexible and stretchable 3D polymer film with photonic crystals for the visible detection of spoiled milk. Thermoplastic polyurethane (TPU) was used as the substrate for the photonic crystal structure. The back barrier layer with a regular array of nanohemispheres of anodic aluminum oxide film was used as a template for electroforming a nickel mold. The nanohemisphere array was then nanoimprinted onto the TPU substrate to form a strain-controllable photonic crystal (SCPC) structure on it. Food spoilage can be easily detected by the structural color change caused by the gas it produces. Experimental results confirmed that the structural color change of the fabricated SCPC TPU film occurred when the elongation (ΔL) of the film reached 0.2 mm (1.2 %). Furthermore, spoiled milk detection experiments showed that the proposed SCPC TPU film is a highly intelligent and cost-effective biosensor for detecting spoiled food in a container.

Synthesis and In Vitro Testing of YVO4:Eu3+@silica-NH-GDA-IgG Bio-Nano Complexes for Labelling MCF-7 Breast Cancer Cells.

We present a visual tool and facile method to detect MCF-7 breast cancer cells by using YVO4:Eu3+@silica-NH-GDA-IgG bio-nanocomplexes. To obtain these complexes, YVO4:Eu3+ nanoparticles with a uniform size of 10-25 nm have been prepared firstly by the hydrothermal process, followed by surface functionalization to be bio-compatible and conjugated with cancer cells. The YVO4:Eu3+@silica-NH-GDA-IgG nanoparticles exhibited an enhanced red emission at 618 nm under an excitation wavelength of 355 nm and were strongly coupled with MCF-7 breast cancer cells via biological conjugation. These bio-nanocomplexes showed a superior sensitiveness for MCF-7 cancer cell labelling with a detection percentage as high as 82%, while no HEK-293A healthy cells were probed under the same conditions of in vitro experiments. In addition, the detection percentage of MCF-7 breast cancer cells increased significantly via the functionalization and conjugation of YVO4:Eu3+ nanoparticles. The experimental results demonstrated that the YVO4:Eu3+@silica-NH-GDA-IgG bio-nanocomplexes can be used as a promising labelling agent for biomedical imaging and diagnostics.

Aplydactylonins A-C, three new sesquiterpenes from the Vietnamese sea hare Aplysia dactylomela and their cytotoxicity.

Aplydactylonins A-C (1-3), three new sesquiterpenes, were isolated from the Vietnamese sea hare Aplysia dactylomela. Their structures and absolute configurations were elucidated based on spectroscopic analysis, X-ray crystallography, and density functional theory (DFT) calculations of NMR and ECD data. Compound 2 exhibited cytotoxicity against HepG2, DU145 and A549 cells with respective IC50 values of 4.08 ± 0.63, 38.64 ± 1.04 and 12.33 ± 0.95 µM. In addition, HepG2 cells treated with 5 µM compound 2 for 48 h showed a significant increase in early apoptotic cells (P < 0.05) and increased caspase 3 activity (P < 0.01). Moreover, compound 2 induced sub-G1 phase arrest in HepG2 cells.

Chemical constituents of Impatiens chapaensis Tard. and their α-glucosidase inhibition activities.

Sixteen compounds (1-16) were isolated from Impatiens chapaensis. Chemical structures were determined by spectroscopic analyses and comparisons with previously published data. This report is the first to identify compounds 1, 5-7, 10, 12-14, and 16 from the genus Impatiens. Seven chosen isolates (5, 7, 10, 11, 12, 15, and 16) were submitted for α-glucosidase inhibition assays with acarbose as the positive control (IC50 = 227.14 ± 13.71 µM). Flavonoid 5 exhibited a significant inhibitory effect (IC50 = 101.00 ± 9.01 µM).

Polyhydroxylated steroid derivatives from the starfish Pentaceraster regulus.

A new polyhydroxysteroid glycoside, regulusoside D (1), and a new polyhydroxylated steroid, (24S)-cholestane-3ß,5,6ß,8,15α,24-hexol (2), together with seven known compounds were purified from the starfish Pentaceraster regulus collected near Con Co Islands, Vietnam. The structure elucidation was confirmed by extensive analysis of their NMR and HR-QTOF mass experiments. Among isolated compounds, regulusoside D (1), (24S)-cholestane-3ß,5,6ß,8,15α,24-hexol (2), granulatoside A (4), 5α-cholestane-3ß,6ß,7α,15α,16ß,26-hexol (6), 5α-cholestane-3ß,6ß,7α,8ß,15α,16ß,26-heptol (7) and 5α-cholestane-3ß,6α,8,15α,16ß,26-hexol (8) exhibited strong inhibitory effects on LPS-induced NO production in RAW264.7 cells with IC50 values of 9.13 ± 1.17, 9.19 ± 0.77, 8.63 ± 3.31, 12.61 ± 0.51, 14.83 ± 3.02 and 10.98 ± 1.22 µM, respectively.

Chemical Constituents from the Leaves of Pachyrhizus erosus Collected in Vietnam.

A phytochemical investigation of methanol extract from leaves of Pachyrhizus erosus (L.) Urban, a leguminous shrub distributed in Vietnam and other tropical and subtropical countries led to the isolation of a new prenylated chalcone, erosusone (1) and a new megastigmane glycoside epimer, 3-episedumoside F1 (9), together with thirteen known compounds including flavonoids (2-6), a 3-benzoxepine lactone (7), a pyridine-4,5-diol derivative (8), megastigmanes and megastigmane glycosides (10-15). Their structures were elucidated by means of high resolution-electrospray ionization (HR-ESI)-MS, one dimensional (1D) and two-dimensional NMR (2D-NMR) spectroscopy as well as comparison with the data reported in the literature. The cytotoxic effects on LU-1 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MCF7 (breast carcinoma) cell lines were assessed. Prenylated chalcones 1-2 and isoflavone 3 exhibited cytotoxicity against all tested cell lines with IC50 values ranging from 22.04 to 45.03 µM.

Polyhydroxylated steroids from the Vietnamese soft coral Sarcophyton ehrenbergi.

Fourteen polyhydroxylated steroids including six new compounds, ehrensteroids A - F (1-6), were isolated from the Vietnamese soft coral Sarcophyton ehrenbergi after applying various chromatographic separations. The structure elucidation was done by detailed analysis of 1D, 2D NMR and HR QTOF mass spectra. In addition, significant cytotoxicity (IC50 values ranging from 8.45 ± 0.56 to 38.27 ± 2.39 µM) against all five tested cancer cell lines as LU-1 (lung cancer), HepG2 (hepatoma cancer), MCF-7 (breast cancer), HL-60 (acute leukemia), and SW480 (colon adenocarcinoma) was observed for compounds 1, 2, 6-10, and 12-14, whereas this activity on LU-1 (IC50 = 21.91 ± 2.72 µM) and HepG2 (IC50 = 20.32 ± 0.03 µM) cell lines was also observed for 4.

Identification Of Potential Cytotoxic Inhibitors From Physalis Minima.

A phytochemical investigation of Physalis minima led to the isolation of six withanolides, including withanolide E (1), withaperuvin C (2), 4ß-hydroxywithanolide E (3), 28-hydroxywithaperuvin C (4), physaperuvin G (5), and 4-deoxywithaperuvin (6). Their chemical structures were elucidated by 1 D-NMR and 2 D-NMR data, as well as comparison with the data reported in the literature. All isolated compounds were evaluated for their cytotoxic activity against HepG2, SK-LU-1, and MCF7 cancer cell lines. As the obtained results, compounds 1 and 3 displayed the strongest cytotoxicity against HepG2, SK-LU-1, and MCF7 cell lines with IC50 value ranging from 0.051 ± 0.004 to 0.86 ± 0.09 µg/mL.

Cyclodextrin glycosyltransferase-treated germinated brown rice flour improves the cytotoxic capacity of HepG2 cell and has a positive effect on type-2 diabetic mice.

Germinated brown rice (GBR) consists of bioactive compounds (BCs) that are very useful for diabetes treatment. Modified GBR-based flour (MGBRF) was produced by modifying the starch in GBR with 0, 299.19, 598.38, and 897.57 U/ml of cyclodextrin glycosyltransferase (CGTase) for 1 hr and then spray-dried to examine its antidiabetic and cytotoxic effects. The results showed that the slowly digestible starch and resistant starch by modifying the starch in GBR with 598.38 U/ml of CGTase were 55.8% and 5.92% corresponding to the increase of γ-amino butyric acid (GABA) and ferulic acid (FA) with 4.31 ± 0.68 mg/ml and 3.10 ± 0.02 mg/ml, respectively. The extract from MGBRF showed strong cytotoxic capacity against HepG2. Furthermore, the in vivo study revealed the stability of the glycemic index (GI) by consuming MGBRF with significant impacts on diabetes. These results suggest that MGBRF through the action of CGTase plays a major role in antidiabetes and HepG2 cell product value addition. PRACTICAL APPLICATIONS: GBR consists of BCs that are useful for diabetes and cancer treatment. However, when using this or GBR-based products, it is difficult to evaluate the effect of functional properties, especially for diabetes and/or cancer diseases due to high starch content. Therefore, the modification of starch to limit digestible starch, increase SDS and RS as well as to enhance the effect of BCs on diabetes and cytotoxic activity on cancer cell should be studied before producing various based products from GBR. The results in this study indicated that CGTase increased BCs without any glycosides BCs in the extract. The MGBRF changed to higher RS and SDS while increasing the BCs. The extract of MGBRF showed strong cytotoxic activity against HepG2 cell and a positive effect on type 2-diabetic mice. Hence, this study produces new information for effective use of GBR-based food as a functional food.

Cell Growth Inhibition of Saponin XII from Dipsacus japonicus Miq. on Acute Myeloid Leukemia Cells.

In previous studies, we isolated the known compound saponin XII from the roots of Dipsacus japonicus Miq. Here, we show that this compound reduced the number of acute myeloid leukemia OCI-AML3 cells as evaluated by a hemocytometer. Flow cytometry analyses demonstrated that the reported activity was associated with a significant increase of apoptosis and of cells in the G0/G1 phase of the cell cycle, with a decrease of cells in the S and G2/M phases. Thus, the inhibition of cell growth in OCI-AML3 cells was due to antiproliferative and pro-apoptotic effects. Interestingly, the bioactivity of saponin XII exerted its effect at a concentration as low as 1 µg/mL.

Dendrodoristerol, a cytotoxic C20 steroid from the Vietnamese nudibranch mollusk Dendrodoris fumata.

Using various chromatographic separations, four steroids including one new C20 steroid namely dendrodoristerol (1), were isolated from the Vietnamese nudibranch mollusk Dendrodoris fumata. The structure elucidation was confirmed by combination of spectroscopic experiments including 1D and 2D NMR, HR QTOF MS, and CD. Compound 1 was found to exhibit significant in vitro cytotoxic activity against six human cancer cell lines as HL-60, KB, LU-1, MCF-7, LNCaP, and HepG2. In addition, 1 induced HL-60 cancer cell death by apoptosis and necrosis.

Cytotoxic steroids from the Vietnamese gorgonian Verrucella corona.

Using various chromatographic separations, seventeen steroids including seven new compounds, verrucorosteroids A-F (1-6) and verrucorosterone (7), were isolated from the Vietnamese gorgonian Verrucella corona. Their structures were elucidated by spectroscopic analysis, including HR QTOF MS, 1D and 2D NMR. Among isolates, verrucorosterone (7), 5,6α-epoxy-3ß-hydroxy-(22E)-ergosta-8,22-dien-7-one (14), and 5,6α-epoxy-3ß-hydroxy-(22E)-ergosta-8(14),22-dien-7-one (15) showed significant cytotoxicity (IC50 values ranging from 12.32 ±â€¯1.47 to 33.77 ±â€¯1.28 µM) against eight human cancer cell lines as LNCaP (prostate cancer), HepG2 (hepatoma cancer), KB (epidermoid carcinoma), MCF-7 (breast cancer), SK-Mel2 (melanoma), HL-60 (acute leukemia), LU-1 (lung cancer), and SW480 (colon adenocarcinoma).

Degalactotigonin, a Steroidal Glycoside from Solanum nigrum, Induces Apoptosis and Cell Cycle Arrest via Inhibiting the EGFR Signaling Pathways in Pancreatic Cancer Cells.

Degalactotigonin (1) and three other steroidal compounds solasodine (2), O-acetyl solasodine (3), and soladulcoside A (4) were isolated from the methanolic extract of Solanum nigrum, and their chemical structures were elucidated by spectroscopic analyses. The isolated compounds were evaluated for cytotoxic activity against human pancreatic cancer cell lines (PANC1 and MIA-PaCa2) and lung cancer cell lines (A549, NCI-H1975, and NCI-H1299). Only degalactotigonin (1) showed potent cytotoxicity against these cancer cell lines. Compound 1 induced apoptosis in PANC1 and A549 cells. Further study on its mechanism of action in PANC1 cells demonstrated that 1 significantly inhibited EGF-induced proliferation and migration in a concentration-dependent manner. Treatment of PANC1 cells with degalactotigonin induced cell cycle arrest at G0/G1 phase. Compound 1 induced downregulation of cyclin D1 and upregulation of p21 in a time- and concentration-dependent manner and inhibited EGF-induced phosphorylation of EGFR, as well as activation of EGFR downstream signaling molecules such as Akt and ERK.