A biflavonoid from stems and leaves of <Emphasis Type="Italic">Lonicera macranthoides</Emphasis>

A new biflavonoid, 3′′′-O-methylamentoflavone (1), as well as a known biflavonoid, amentoflavone (2), was isolated from the stems and leaves of Lonicera macranthoides Hand.-Mazz.Their structures were established on the basis of 1D, 2D NMR (HSQC and HMBC), and ESI-TOF-MS spectroscopic methods and chemical evidence.     

A new prenylated biflavonoid from the leaves of Garcinia dulcis

A new prenylated biflavonoid, named dulcisbiflavonoid A, together with five biflavonoids were isolated from the leaves of Garcinia dulcis. Their structures were elucidated by analysing their spectroscopic data, especially 1D and 2D NMR.     

Platelet-Activating Factor (PAF) Antagonistic Activity of a New Biflavonoid from <em>Garcinia nervosa</em> var. <em>pubescens</em> King

The methanol extract of the leaves of Garcinia nervosa var. pubescens King, which showed strong inhibitory effects on platelet-activating factor (PAF) receptor binding, was subjected to bioassay-guided isolation to obtain a new biflavonoid, II-3,I-5, II-5,II-7,I-4',II-4'-hexahydroxy-(I-3,II-8)-flavonylflavanonol together with two known flavonoids, 6-methyl-4'-methoxyflavone and acacetin. The structures of the compounds were elucidated by spectroscopic methods. The compounds were evaluated for their ability to inhibit PAF receptor binding to rabbit platelets using ³H-PAF as a ligand. The biflavonoid and acacetin showed strong inhibition with IC₅₀ values of 28.0 and 20.4 μM, respectively. The results suggest that these compounds could be responsible for the strong PAF antagonistic activity of the plant.     

A New Biflavonoid from Stellera chamaejasme L.

A new biflavonoid, stelleranol, was isolated from the roots of Stellera chamaejasme L..Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.     

Biflavonoids from Cycas beddomei

Chemical investigation on the constituents of the cones of Cycas beddomei has resulted in the isolation of a new biflavonoid, 2,3-dihydro-4'-O-methyl amentoflavone, along with 2,3,2',3'-tetrahydro hinokiflavone, 2,3,2',3'-tetrahydro amentoflavone, 2,3-dihydro amentoflavone. The last two compounds were not reported earlier from this plant. The structure of the new compound was established by detailed analysis of its spectral (mainly 1D and 2D NMR) data.     

A biflavonoid glycoside from Lomatogonium carinthiacum (Wulf) Reichb

A biflavonoid glycoside with a new carbon skeleton, named carinoside A, was isolated from the n-BuOH crude extract of the whole plant of Lomatogonium carinthiacum (Wulf) Reichb. The structure of the new compound was elucidated by using spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.     

A new biflavonoid from Selaginella labordei Hieron.ex Christ

A new biflavonoid,2,3-dihydro-5,5″,7,7″,4′-pentahydroxy-6,6″-dimethyl-[3′-O-4′″]-biflavone 1 and two known biflavonoids 2,3″-dihydroochnaflavone 2 and 2″,3″-dihydro-3′,3′″-biapigenin 3 were isolated from the herb of Selaginella labordei Hieron.ex Christ.Their structures were elucidated by spectroscopic methods.     

Lophirone A,A biflavonoid with unusual skeleton from Lophira lanceolata.

Lophirone A, a new biflavonoid have been isolated from the stem bark of Lophira lanceolata. The structure was elucidated by MS, 2D ¹H and ¹³C NMR including INADEQUATE to determine the carbon framework. It involved an aryl shift from one flavonoid unit to the second.     

Identification of a new cytotoxic biflavanone from Selaginella doederleinii

A new biflavanone, 2,2',3,3'-tetrahydrorobustaflavone 7,4',7'-trimethyl ether (1) was isolated from the whole plant of Selaginella doederleinii HIERON. (Selaginellaceae) together with the known biflavonoid, robustaflavone 7,4',7'-trimethyl ether (2) as the cytotoxic constituents against the three human cancer cell lines, HCT, NCI-H358, and K562. The structure of the new compound 1 was elucidated by spectral analysis including various 1D- and 2D-NMR experiments.     

A new biflavonoid and an isobiflavonoid from Rhus tripartitum

A new biflavonoid masazinoflavanone (1) and the isobiflavonoid calodenone (2) have been isolated and characterized from the methanolic aerial part extract of the plant Rhus tripartitum. Their structures have been deduced from extensive spectral analysis (NMR and MS). Interpretation of the nuclear overhauser effects (NOESY) permitted us to establish relative stereochemistry of these natural products.     

A new biflavonoid from leaves of Garcinia nervosa

The isolation of a new biflavonoid, identified as I-3, II-3, I-5, II-5, I-7, II-7, I-4', II-4'-octahydroxy [I-2', II-2'] biflavone, from the leaves of Garcinia nervosa is reported. The structure was established by chemical and physical means (IR, UV, 1H-NMR, 13C-NMR data).     

Application of preparative high-speed counter-current chromatography for the separation of flavonoids from the leaves of Byrsonima crassa Niedenzu (IK)

The methanolic extract of the leaves of the medicinal plant Byrsonima crassa (Malpighiaceae) contain flavonoids with antioxidant activity. They were separated in a preparative scale using high-speed counter-current chromatography. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80 (v/v/v)) and led to a successful separation between monoglucosilated flavonoids (quercetin-3-O-alpha-L-arabinoside, quercetin-3-O-beta-D-galactoside) and the biflavonoid amentoflavone in only 3.5 h. The purities of quercetin-3-O-alpha-L-arabinoside (95 mg), quercetin-3-O-beta-D-galactoside (16 mg) and the biflavonoid amentoflavone (114 mg) were all isolated at purity over 95%. Identification was performed by 1H NMR, 13C NMR and UV analyses.     

苔藓植物短肋羽藓Thuidium kanedae sak 中的双二氢黄酮类化合物

A new bidihydroflavonoid, thuidinin 1, together with 5 known compounds including one known biflavonoid 3＇,3＂＇-binaringenin （2） and four other known natural products pentadecane （3）, methyl β-orcinolarboxylate （4）, β-sitosterol （5） and daucostenol （6）, were isolated from leaves of Thuidium kanedae Sak. Their structures were established on the basis of 1D and 2D spectroscopic analysis. The absolute stereochemistry of compounds 1 and 2 was determined by CD spectra.     

Isolation and On‐Line LC/CD Analysis of 3,8″‐Linked Biflavonoids from Gnidia involucrata

Investigation of the methanol extract of the roots of Gnidia involucrata (Thymelaeaceae) led to the isolation and characterization of two new 3,8″‐biflavonoid diastereoisomers, named GB‐4 ( 6a ) and GB‐4a ( 6b ). Their absolute configurations were determined in mixture by on‐line LC/CD measurements, which also allowed the revision of absolute configurations of the biflavanoids GB‐1 and GB‐2, and the configurational assignment of GB‐3.     

A novel biflavonoid from roots of Glycyrrhiza uralensis cultivated in China

A novel biflavonoid named licobichalcone was isolated from the roots of Glycyrrhiza uralensis cultivated in China, along with twelve known compounds, including five chalcones, two isoflavones, two flavanones, two flavones and one pterocarpan. Their structures were respectively elucidated on the basis of chemical and spectroscopic evidence.     

Chamaechromone,a novel rearranged biflavonoid from Stellera chamaejasme L.

A novel biflavonoid, chamaechromone was isolated from $\text{Stellera chamaejasme}$ L. (Thymelaeaceae) and its structure elucidated by spectroscopic and chemical methods.     

Effectiveness of Bioactive Compound as Antibacterial and Anti-Quorum Sensing Agent from Myrmecodia pendans: An In Silico Study

Background: antibiotic resistance encourages the development of new therapies, or the discovery of novel antibacterial agents. Previous research revealed that Myrmecodia pendans (Sarang Semut) contain potential antibacterial agents. However, specific proteins inhibited by them have not yet been identified as either proteins targeted by antibiotics or proteins that have a role in the quorum-sensing system. This study aims to investigate and predict the action mode of antibacterial compounds with specific proteins by following the molecular docking approach. Methods: butein (1), biflavonoid (2), 3″-methoxyepicatechin-3-O-epicatechin (3), 2-dodecyl-4-hydroxylbenzaldehyde (4), 2-dodecyl-4-hydroxylbenzaldehyde (5), pomolic acid (6), betulin (7), and sitosterol-(6′-O-tridecanoil)-3-O-β-D-glucopyranoside (8) from M. pendans act as the ligand. Antibiotics or substrates in each protein were used as a positive control. To screen the bioactivity of compounds, ligands were analyzed by Prediction of Activity Spectra for Substances (PASS) program. They were docked with 12 proteins by AutoDock Vina in the PyRx 0.8 software application. Those proteins are penicillin-binding protein (PBP), MurB, Sortase A (SrtA), deoxyribonucleic acid (DNA) gyrase, ribonucleic acid (RNA) polymerase, ribosomal protein, Cytolysin M (ClyM), FsrB, gelatinase binding-activating pheromone (GBAP), and PgrX retrieved from UniProt. The docking results were analyzed by the ProteinsPlus and Discovery Studio software applications. Results: most compounds have Pa value over 0.5 against proteins in the cell wall. In nearly all proteins, biflavonoid (2) has the strongest binding affinity. However, compound 2 binds only three residues, so that 2 is the non-competitive inhibitor. Conclusion: compound 2 can be a lead compound for an antibacterial agent in each pathway.     

Biflavonoids from Selaginella doederleinii as Potential Antitumor Agents for Intervention of Non-Small Cell Lung Cancer

Four new biflavonoids (1–4) were isolated from Selaginella doederleinii together with a known biflavonoid derivative (5). Their structures contained a rare linker of individual flavones to each other by direct C-3-O-C-4′′′ bonds, and were elucidated by extensive spectroscopic data, including HRESIMS, NMR and ECD data. All isolates significantly inhibited the proliferation of NSCLC cells (IC₅₀ = 2.3–8.4 μM) with low toxicity to non-cancer MRC-5 cells, superior to the clinically used drug DDP. Furthermore, the most active compound 3 suppressed XIAP and survivin expression, promoted upregulation of caspase-3/cleaved-caspase-3, as well as induced cell apoptosis and cycle arrest in A549 cells. Together, our findings suggest that 3 may be worth studying further for intervention of NSCLC.     

High-performance quantitative thin-layer chromatography of flavonoid glycosides and biflavonoids ofCupressus sempervirens in relation to cypress canker

Summary The flavonoid glycosides and the biflavonoids of cypress leaves have been separted by means of high-performance thin-layer chromatography with quantitation by densitometry. Some flavonoid glycosides and biflavonoids have been identified, other than from their chromatographic characteristics, by means of UV spectra recorded directly on the layer. Different clones, resistant and susceptible to cypress canker, have been analyzed; some differences between these two classes of trees have been found in their biflavonoid content.