Advances in Flavonoid and Derivative Biosynthesis: Systematic Strategies for the Construction of Yeast Cell Factories.

Flavonoids, a significant group of natural polyphenolic compounds, possess a broad spectrum of pharmacological effects. Recent advances in the systematic metabolic engineering of yeast cell factories (YCFs) provide new opportunities for enhanced flavonoid production. Herein, we outline the latest research progress on typical flavonoid products in YCFs. Advanced engineering strategies involved in flavonoid biosynthesis are discussed in detail, including enhancing precursor supply, cofactor engineering, optimizing core pathways, eliminating competitive pathways, relieving transport limitations, and dynamic regulation. Additionally, we highlight the existing problems in the biosynthesis of flavonoid glucosides in yeast, such as endogenous degradation of flavonoid glycosides, substrate promiscuity of UDP-glycosyltransferases, and an insufficient supply of UDP-sugars, with summaries on the corresponding solutions. Discussions also cover other typical postmodifications like prenylation and methylation, and the recent biosynthesis of complex flavonoid compounds in yeast. Finally, a series of advanced technologies are envisioned, i.e., semirational enzyme engineering, ML/DL algorithn, and systems biology, with the aspiration of achieving large-scale industrial production of flavonoid compounds in the future.

Molecular Pro-Apoptotic Activities of Flavanone Derivatives in Cyclodextrin Complexes: New Implications for Anticancer Therapy.

This study evaluates the antiproliferative potential of flavanones, chromanones and their spiro-1-pyrazoline derivatives as well as their inclusion complexes. The main goal was to determine the biological basis of molecular pro-apoptotic activities and the participation of reactive oxygen species (ROS) in shaping the cytotoxic properties of the tested conjugates. For this purpose, changes in mitochondrial potential and the necrotic/apoptotic cell fraction were analyzed. Testing with specific fluorescent probes found that ROS generation had a significant contribution to the biological anticancer activity of complexes of flavanone analogues. TT (thrombin time), PT (prothrombin time) and APTT (activated partial tromboplastin time) were used to evaluate the influence of the compounds on the extrinsic and intrinsic coagulation pathway. Hemolysis assays and microscopy studies were conducted to determine the effect of the compounds on RBCs.

Metabolome Profiling of Marrubium peregrinum L. and Marrubium friwaldskyanum Boiss Reveals Their Potential as Sources of Plant-Based Pharmaceuticals.

Marrubium species have been used since ancient times as food additives and curative treatments. Their phytochemical composition and various pharmacological activities were the focus of a number of scientific investigations but no comprehensive metabolome profiling to identify the numerous primary and secondary metabolites has been performed so far. This study aimed to generate a comprehensive picture of the total metabolite content of two Marrubium species-M. peregrinum and M. friwaldskyanum-to provide detailed information about the main primary and secondary metabolites. In addition, the elemental composition was also evaluated. For this purpose, non-targeted metabolomic analyses were conducted using GC-MS, UPLC-MS/MS and ICP-MS approaches. Nearly 500 compounds and 12 elements were detected and described. The results showed a strong presence of phenolic acids, flavonoids and their glucosides, which are generally of great interest due to their various pharmacological activities. Furthermore, tissue-specific analyses for M. friwaldskyanum stem, leaves and flowers were carried out in order to outline the sources of potentially important bioactive molecules. The results generated from this study depict the Marrubium metabolome and reveal its dual scientific importance-from one side, providing information about the metabolites that is fundamental and vital for the survival of these species, and from the other side, defining the large diversity of secondary substances that are a potential source of phytotherapeutic agents.

Chemical compounds isolated from aerial parts of Bolanthus aziz-sancarii, a new species from Türkiye.

Bolanthus aziz-sancarii identified in 2019 for the first time is an endemic species of Bolanthus genus belonging to Caryophyllaceae family. Ten compounds were isolated from aerial parts of the plant. The potential antioxidant and anti-inflammatory effects of all four phases (hexane, chloroform, ethyl acetate, and water) from the methanol extract of the plant were investigated. After considering the findings regarding both antioxidant and anti-inflammatory capacities, it was decided to investigate the phytochemical profile of the EtOAc layer of B. aziz-sancarii. An abscisic acid-type sesquiterpene glucoside and nine flavonoid derivatives were isolated from the ethyl acetate fraction of the B. aziz-sancarii methanol extract through the use of column chromatography with silica gel.

Selected flavonoids exhibit antibiofilm and antibacterial effects against Vibrio by disrupting membrane integrity, virulence and metabolic activities.

Vibrio parahaemolyticus is a high-risk foodborne pathogen associated with raw or undercooked seafoods and its biofilm forming potential has become a threat to food safety and economic values. Hence, this study aims to examine the antibacterial and antibiofilm activities as well as virulence inhibitory effects of selected flavonoids against V. parahaemolyticus. Out of the sixteen flavonoid derivatives, 6-aminoflavone (6-AF), 3,2-dihydroxyflavone (3,2-DHF) and 2,2-dihydroxy-4-methoxybenzophenone (DHMB) were found as active biofilm inhibitors. 3,2-DHF and DHMB had minimum inhibitory concentrations of 20 and 50 µg/mL respectively against Vibrio planktonic cells and displayed superior antibacterial activities to standard controls. Also, they disrupted preformed biofilms and suppressed virulence properties including motilities, cell hydrophobicity and aggregation. They impaired iron acquisition mechanism and hemolysin production at sub-MICs as supported by transcriptomic studies. Interestingly, the flavonoids interfered with the metabolic activity, cell division and membrane permeability to exert antibiofilm and antibacterial activities. 6-AF and 3,2-DHF were non-toxic in the C. elegans model and showed excellent capacity to protect shrimps from biodeterioration. Furthermore, the flavonoids inhibited biofilm formation by V. harveyi, Staphylococcus aureus and Salmonella typhimurium and the mixed-species biofilm with Vibrio. This study discovered flavonoid derivatives, especially 3,2-DHF as potential bioactive compounds capable of offering protection from risks associated with biofilm formation by V. parahaemolyticus and other food pathogens.

Discovery of novel flavonoid-based CDK9 degraders for prostate cancer treatment via a PROTAC strategy.

CDK9 plays a vital role in regulating RNA transcription and significantly impacts the expression of short-lived proteins such as Mcl-1 and c-Myc. Thus, targeting CDK9 holds great promise for the development of antitumor drugs. Natural flavonoid derivatives have recently gained considerable attention in the field of antitumor drug research due to their broad bioactivity and low toxicity. In this study, the PROTAC strategy was used to perform structural modifications of the flavonoid derivative LWT-111 to design a series of flavonoid-based CDK9 degraders. Notably, compound CP-07 emerged as a potent CDK9 degrader, effectively suppressing the proliferation and colony formation of 22RV1 cells by downregulating Mcl-1 and c-Myc. Moreover, CP-07 exhibited significant tumor growth inhibition with a TGI of 75.1% when administered at a dose of 20 mg/kg in the 22RV1 xenograft tumor model. These findings demonstrated the potential of CP-07 as a powerful flavonoid-based CDK9 degrader for prostate cancer therapy.

Design and optimization of selective and potent CDK9 inhibitors with flavonoid scaffold for the treatment of acute myeloid leukemia.

Acute myeloid leukemia (AML) is a prevalent hematological tumor associated with a high morbidity and mortality rate. CDK9, functioning as a pivotal transcriptional regulator, facilitates transcriptional elongation through phosphorylation of RNA polymerase II, which further governs the protein levels of Mcl-1 and c-Myc. Therefore, CDK9 has been considered as a promising therapeutic target for AML treatment. Here, we present the design, synthesis, and evaluation of CDK9 inhibitors bearing a flavonoid scaffold. Among them, compound 21a emerged as a highly selective CDK9 inhibitor (IC50 = 6.7 nM), exhibiting over 80-fold selectivity towards most other CDK family members and high kinase selectivity. In Mv4-11 cells, 21a effectively hindered cell proliferation (IC50 = 60 nM) and induced apoptosis by down-regulating Mcl-1 and c-Myc. Notably, 21a demonstrated significant inhibition of tumor growth in the Mv4-11 xenograft tumor model. These findings indicate that compound 21a holds promise as a potential candidate for treating AML.

Novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives: synthesis and biological activity.

BACKGROUND: With the long-term use of traditional bactericides and antiviral agents, drug resistance has become increasingly prominent, resulting in impaired crop growth and yields. Based on this, the introduction of small molecular active groups into natural products has become the direction of research for green pesticides. RESULTS: In this study, novel 1,3,4-oxadiazole sulfonate/carboxylate flavonoid derivatives were explored. Among them, D4 exhibited good inhibitory effects on plant bacteria. It is worth mentioning that D4 (15 µg ml-1 ) exhibited an excellent median effective concentration (EC50 ) value against Xanthomonas oryzae pv. oryzae (Xoo), which was better than bismerthiazol (73 µg ml-1 ) and thiodiazole copper (100 µg ml-1 ). The EC50 for D4 was much lower than the two positive controls (bismerthiazol, thiodiazole copper), making D4 more potent in this assay of bacterial growth inhibition. In addition, mechanism research using scanning electron microscopy revealed that D4 could cause deformation or rupture of the cell membranes of Xoo and Pseudomonas syringae pv. actinidiae. Moreover, D4 exhibited the best EC50 for in vivo curative (132 µg ml-1 ) and protective (101 µg ml-1 ) activities against tobacco mosaic virus, which were more effective than ningnanmycin. Microscale thermophoresis data suggested that D4 [dissociation constant (Kd ) = 0.038 ± 0.011 µmol L-1 ] exhibited a stronger binding capacity than the control agent ningnanmycin (Kd = 4.707 ± 2.176 µmol L-1 ). CONCLUSION: The biological activity data and mode of action demonstrated that D4 had the best antibacterial and antiviral effects. Compound D4 discovered in the current work may be a very promising agricultural drug. © 2022 Society of Chemical Industry.

Theoretical Study on the Multiple Free Radical Scavenging Reactions of Pyranoanthocyanins.

The free radical trapping capacities of multiple pyranoanthocyanins in wine storage and ageing were theoretically explored by density functional theory (DFT) methods. Intramolecular hydrogen bonds were detected in all pyranoanthocyanins, and the planarity of the compounds worsened with an increasing dielectric constant in the environment. Solvents significantly influenced the reaction enthalpies; thus, the preferred thermodynamic mechanisms of the free radical scavenging reactions were modified in different phases. This study incorporates hydrogen atom transfer (HAT), proton loss (PL), electron transfer (ET) reactions, and demethylation (De) of methoxy group mechanisms. The three pyranoanthocyanins have the capacity to capture n1+1 free radicals, where n1 represents the number of methoxy groups. In the gas phase, they prefer employing the n1-De-HAT mechanism on the guaiacyl moiety of the B ring, resulting in the formation of a stable quinone or a quinone radical to scavenge free radicals. In the benzene phase, pyranoanthocyanins trap free radicals via a PL-n1-De-HAT mechanism. In the water phase, the targeted pyranoanthocyanins may dissociate in the form of carboxylate and tend to utilize the n2-PL-n1-De-ET mechanism, where n2 and n1 represent the number of phenolic groups and methoxy groups, respectively, facilitating multiple H+/e- reactions.

[Chemical constituents from Artocarpus incisus and their inhibitory effects on proliferation of synoviocytes in vitro].

The chemical constituents from the branches and leaves of Artocarpus incisus were isolated and purified via silica gel, ODS, and Sephadex LH-20 column chromatography as well as preparative HPLC. The chemical structures of all isolated compounds were identified in the light of their physicochemical properties, spectroscopic analyses, and comparisons of their physicochemical and spectroscopic data with the reported data in literature. As a result, 20 compounds were isolated and characterized from the 90% ethanol extract of the branches and leaves of A. incisus, which were identified as tephrosin(1), 6-hydroxy-6 a, 12 a-dehydrodeguelin(2), sarcolobin(3), lupiwighteone(4), 12-deoxo-12α-methoxyelliptone(5), 6 aα,12 aα-12 a-hydroxyelliptone(6), homopterocarpin(7), 3-hydroxy-8,9-dimethoxypterocarpan(8), pterocarpin(9), maackiain(10), medicarpin(11), calycosin(12), genistein(13), formononetin(14), 5-hydroxy-4',7-dimethoxy isoflavone(15), liquiritigenin(16), 4(15)-eudesmene-1ß,7α-diol(17), ent-4(15)-eudesmene-1ß,6α-diol(18), 1α-hydroxyisodauc-4-en-15-al(19), and guaianediol(20). Except compounds 13 and 16, all other compounds were isolated from the Artocarpus plants for the first time. Additionally, using MTS assay, compounds 1-20 were eva-luated for their anti-rheumatoid arthritis activities by measuring their anti-proliferative effects on synoviocytes in vitro. As a consequence, compounds 1-16 showed notable anti-rheumatoid arthritis activities, which displayed inhibitory effects on the proliferation of MH7 A synovial fibroblast cells, with the IC_(50) values in range of(9.86±0.09)-(218.07±1.96) µmol·L~(-1).

Biochemical, Structural Analysis, and Docking Studies of Spiropyrazoline Derivatives.

In this study, we evaluated the antiproliferative potential, DNA damage, crystal structures, and docking calculation of two spiropyrazoline derivatives. The main focus of the research was to evaluate the antiproliferative potential of synthesized compounds towards eight cancer cell lines. Compound I demonstrated promising antiproliferative properties, especially toward the HL60 cell line, for which IC50 was equal to 9.4 µM/L. The analysis of DNA damage by the comet assay showed that compound II caused DNA damage to tumor lineage cells to a greater extent than compound I. The level of damage to tumor cells of the HEC-1-A lineage was 23%. The determination of apoptotic and necrotic cell fractions by fluorescence microscopy indicated that cells treated with spiropyrazoline-based analogues were entering the early phase of programmed cell death. Compounds I and II depolarized the mitochondrial membranes of cancer cells. Furthermore, we performed simple docking calculations, which indicated that the obtained compounds are able to bind to the PARP1 active site, at least theoretically (the free energy of binding values for compound I and II were -9.7 and 8.7 kcal mol-1, respectively). In silico studies of the influence of the studied compounds on PARP1 were confirmed in vitro with the use of eight cancer cell lines. The degradation of the PARP1 enzyme was observed, with compound I characterized by a higher protein degradation activity.

Echinodorus macrophyllus fraction with a high level of flavonoid inhibits peripheral and central mechanisms of nociception.

BACKGROUND AND AIM: Echinodorus macrophyllus (Kunth.) Micheli is popularly used for acute and chronic inflammatory conditions. The anti-inflammatory activity was previously demonstrated for its flavonoid-enriched fractions. The aim of this work assessed the antinociceptive properties of both aqueous extract and its fractions. EXPERIMENTAL PROCEDURE: The antinociceptive activity was determined by acetic acid-induced writhing, formalin test, tail immersion test, hot-plate test, xylene-induced ear edema methods, and the evaluation of its mechanism was performed in the writhing model. The aqueous extract of Echinodorus macrophyllus (AEEm) was fractionated, yielding Fr20, and Fr40. Fr40 composition was determined by HPLC-DAD-ESI-MS. RESULTS AND CONCLUSION: Fr20 (all doses) and Fr40 (100 mg/kg) reduced the nociception in the tail-flick model. Both fractions increased the percentage of maximum possible effect with 25 mg/kg, in the hot-plate assay, at 60 min, while AEEm reduced pain only with 50 and 100 mg/kg. There was a reduction in xylene-edema index, with Fr40 (25 mg/kg), AEEm (50 mg/kg) and Fr20 (50 mg/kg). All doses of AEEm, Fr20, and Fr40 reduced both phases of the formalin model. In the abdominal contortion model, Fr40 presented the highest activity, reducing 96% of contortions and its antinociceptive mechanism was evaluated. The results indicated the involvement of NO and adrenergic activation pathways. The main components of Fr40 are swertisin, swertiajaponin, isoorientin 7,3'-dimethyl ether, swertisin-O-rhamnoside, isoorientin, isovitexin, isovitexin-Orhamnoside, and isovitexin-7-O-glucoside. The aqueous extract of E. macrophyllus leaves and its fractions exhibited significant analgesic effect, mediated through both peripheral and central mechanisms being considered a potentially antinociceptive drug.

Design and synthesis of adamantyl-substituted flavonoid derivatives as anti-inflammatory Nur77 modulators: Compound B7 targets Nur77 and improves LPS-induced inflammation in vitro and in vivo.

In continuing our study on discovering new Nur77-targeting anti-inflammatory agents with natural skeletons, we combined adamantyl group and hydroxamic acid moiety with flavonoid nucleus, synthesized three series of flavonoid derivatives with a similar structure like CD437, and evaluated their activities against LPS-induced inflammation. Compound B7 was found to be an excellent Nur77 binder (Kd = 3.55 × 10-7 M) and a potent inhibitor of inflammation, which significantly decreased the production of cytokines in vitro, such as NO, IL-6, IL-1ß, and TNF-α, at concentrations of 1.25, 2.5, and 5 µM. Mechanistically, B7 modulated the colocalization of Nur77 at mitochondria and inhibited the lipopolysaccharides (LPS)-induced inflammation via the blockade of NF-κB activation in a Nur77-dependent manner. Additionally, B7 showed in vivo anti-inflammatory activity in the LPS-induced mice model of acute lung injury (ALI). These data suggest that the Nur77-targeting flavonoid derivatives can be particularly useful for further pharmaceutical development for the treatment of inflammatory diseases such as ALI.

Insecticidal activity of copper (II) complexes with flavanone derivatives.

In this work, we describe the insecticidal activity against Spodoptera frugiperda of flavanone derivatives (naringin, naringenin and hesperidin) complexed to copper (II). For the assays, the compounds were incorporated into an artificial diet and offered to S. frugiperda during its larval period. The duration of larval and pupal phases, the weight of pupae and the percentage of dead insects at the end of the larval phase were evaluated. Among the tested compounds, the free flavanones 1 and 3 and the complexes 4 and 6 showed a shortening of the larval phase when compared to the control. Complex 9 showed the highest toxicity, with 96.66% larval mortality. This is the first report on the insecticidal activity of the Cu2+ complexes of the flavanones naringin, naringenin and hesperidin.[Formula: see text].

Molecular Modelling, Synthesis and Evaluation of Flavone and Flavanone Scaffolds as Anti-inflammatory Agents.

OBJECTIVE: The objective of the study was to develop new Cyclooxygenase-2 inhibitors as anti-inflammatory agents from the synthetic route. MATERIALS AND METHODS: The 2-phenyl-4H-chromen-4-one and 2-phenyl-2,3-dihydro-4H-chromenone hybrids were synthesised and characterised by using UV, IR, 1H-NMR, and mass spectrometry. An attempt was made for consolidated lead flavones and flavanones scaffolds by determining ADME/ T properties. Molecular docking simulations were performed by using Autodock.4 to understand the binding interaction over the targeted enzyme Cyclooxygenase-2. The titled compounds were evaluated for various in-vitro models for antioxidant and anti-inflammatory activities and based upon the IC50 values, the selected compounds were screened for in vivo anti-inflammatory activity by both acute and chronic models. RESULTS AND DISCUSSION: Twenty titled compounds were synthesised and elucidated their structure for confirmation of their functional groups by various spectroscopic techniques. Among the synthesized compounds, flavone derivatives such as HFc (7-hydroxy-3-(4-methoxy phenyl)-4H-chromen-4- one), HFd (2-(2,4-di methoxy-phenyl)-7-hydroxy-4H-chromen-4-one) and HFe (7-hydroxy-2- (thiophen-2-yl)-4H-chromen-4-one) produced higher potency. Flavanone derivatives HFAc (7- hydroxy-2-(4-hydroxy-3-methoxy phenyl)-2,3-dihydro-4H-chromen-4-one), HFAb (7-hydroxy-2-(4- methoxy phenyl)-2,3-dihydro-4H-chromen-4-one) and HFAd (7-hydroxy-2-(thiophen-2-yl)-2,3- dihydro-4H-chromen-4-one) showed significant anti-inflammatory activity compared to the standard COX-2 inhibitors. CONCLUSION: The flavone and flavanone scaffolds possess their excellent inhibitory action over the Cyclooxygenase-2 and act as a potential anti-inflammatory agent. The results of computational studies were also significantly correlated and concluded that those naturally mimicking flavonoid analogues were tremendous candidates to fight against the inflammatory diseases in drug discovery.

Overcoming Multidrug Resistance: Flavonoid and Terpenoid Nitrogen-Containing Derivatives as ABC Transporter Modulators.

Multidrug resistance (MDR) in cancer is one of the main limitations for chemotherapy success. Numerous mechanisms are behind the MDR phenomenon wherein the overexpression of the ATP-binding cassette (ABC) transporter proteins P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance protein 1 (MRP1) is highlighted as a prime factor. Natural product-derived compounds are being addressed as promising ABC transporter modulators to tackle MDR. Flavonoids and terpenoids have been extensively explored in this field as mono or dual modulators of these efflux pumps. Nitrogen-bearing moieties on these scaffolds were proved to influence the modulation of ABC transporters efflux function. This review highlights the potential of semisynthetic nitrogen-containing flavonoid and terpenoid derivatives as candidates for the design of effective MDR reversers. A brief introduction concerning the major role of efflux pumps in multidrug resistance, the potential of natural product-derived compounds in MDR reversal, namely natural flavonoid and terpenoids, and the effect of the introduction of nitrogen-containing groups are provided. The main modifications that have been performed during last few years to generate flavonoid and terpenoid derivatives, bearing nitrogen moieties, such as aliphatic, aromatic and heterocycle amine, amide, and related functional groups, as well as their P-gp, MRP1 and BCRP inhibitory activities are reviewed and discussed.

The Antiproliferative Effects of Flavonoid MAO Inhibitors on Prostate Cancer Cells.

Prostate cancer (PCa) patients commonly experience clinical depression. Recent reports indicated that monoamine oxidase-A (MAO-A) levels elevate in PCa, and antidepressant MAO-Is show anti-PCa properties. In this work, we aimed to find potential drugs for PCa patients suffering from depression by establishing novel anti-PCa reversible monoamine oxidase-A inhibitors (MAO-AIs/RIMA); with an endeavor to understand their mechanism of action. In this investigation, twenty synthesized flavonoid derivatives, defined as KKR compounds were screened for their inhibitory potentials against human MAO-A and MAO-B isozymes. Meanwhile, the cytotoxic and antiproliferative effects were determined in three human PCa cell lines. MAO-A-kinetics, molecular docking, SAR, cell morphology, and cell migration were investigated for the most potent compounds. The screened KKRs inhibited MAO-A more potently than MAO-B, and non-toxically inhibited LNCaP cell proliferation more than the DU145 and PC3 cell lines, respectively. The results showed that the three top MAO-AI KKRs compounds (KKR11, KKR20, and KKR7 (IC50s 0.02-16 µM) overlapped with the top six antiproliferative KKRs against LNCaP (IC50s ~9.4 µM). While KKR21 (MAO-AI) and KKR2A (MAO-I) were ineffective against the PCa cells. Furthermore, KKR21 and KKR11 inhibited MAO-A competitively (Kis ≤ 7.4 nM). Molecular docking of the two compounds predicted shared hydrophobic and distinctive hydrophilic interactions-between the KKR molecule and MAO-A amino acid residues-to be responsible for their reversibility. The combined results and SAR observations indicated that the presence of specific active groups-such as chlorine and hydroxyl groups-are essential in certain MAO-AIs with anti-PCa effects. Additionally, MAO-A inhibition was found to be associated more with anti-PCa property than MAO-B. Distinctively, KKR11 [(E)-3-(3,4-dichlorophenyl)-1-(2-hydroxy-4,6-dimethoxyphenyl)prop-2-en-1-one] exhibited anti-metastatic effects on the DU145 cell line. The chlorine substitution groups might play vital roles in the KKR11 multiple actions. The obtained results indicated that the flavonoid derivative KKR11 could present a novel candidate for PCa patients with depression, through safe non-selective potent inhibition of MAOs.

Cytotoxic phenolic constituents from Hypericum japonicum.

Nine undescribed compounds, including five xanthone derivatives, two flavonoids, one 2-pyrone derivative, and one undescribed naturally occurring compound, along with 30 known phenolic compounds, were isolated from Hypericum japonicum. In addition, hyperjaponols A and B were identified as racemates. The structures and absolute configurations of the undescribed compounds were determined by comprehensive MS, NMR spectroscopy, and electronic circular dichroism (ECD) calculations. The cytotoxic effects of the isolated compounds on two human tumour cell lines (HEL and MDA-MB-231) were evaluated by the MTT assay. Eighteen compounds showed good inhibitory activities against the HEL cell line, with IC50 values of 3.53-18.7 µM, while nine compounds exhibited moderate cytotoxicity against the MDA-MB-231 cancer cell line, with IC50 values ranging from 4.92 to 10.75 µM. Their preliminary structure-activity relationship of the isolated compounds was also discussed.

Antibacterial and antioxidant flavonoid derivatives from the fruits of Metaplexis japonica.

Metaplexis japonica (Thunb.) Makino is widely distribution and cultivated as a vegetable in China. Chemical studies revealed that its stem and root are rich in polysaccharides, flavonoids, polyphenols, and steroids, which also exhibited interesting activities. However, little attention has been focused on the biological constituents in the fruits of M. japonica. In order to achieve the best use of M. japonica, a chemical investigation of the secondary metabolites of the fruits of M. japonica was performed, and led to the isolation of one new (1), along with eight known flavoniod derivatives (2-9). The antioxidant and antibacterial properties of the crude extract and compound 1 were deeply evaluated through antioxidant and antimicrobial assays. Among them, the crude extract showed significant antioxidant activities in all assays, as well as broad-spectrum antibacterial effects. These results suggested that crude extract of M. japonica would be a potential source as a possible preservatives for foods.

Design, Synthesis and Biological Evaluation of Ligustrazine-Flavonoid Derivatives as Potential Anti-Tumor Agents.

In the clinic some anti-tumor drugs have shown damage to normal blood vessels, which could lead to vascular diseases. Therefore, it is necessary to evaluate the effects of anti-tumor drugs on normal blood vessels at the beginning of the drug design process. In this study, ligustrazine (TMP) and flavonoids were selected as raw materials. Sixteen novel TMP-flavonoid derivatives were designed and synthesized. Interestingly, compounds 14 and 16 were obtained by hydrolysis of a dihydroflavone to a chalcone under alkaline conditions. The cytotoxicity of the TMP-flavonoid derivatives was evaluated on five human tumor cell lines and one classical type of normal endothelial cell lines (HUVEC-12) by an MTT assay. Part of the derivatives showed better anti-tumor activities than the corresponding raw materials. Among them, compound 14 exhibited the closest activity to the positive control against the Bel-7402 cell line (IC50 = 10.74 ± 1.12 µM; DDP IC50 = 6.73 ± 0.37 µM) and had no toxicity on HUVEC-12 (IC50 > 40 µM). Subsequently, fluorescence staining and flow cytometry analysis indicated that compound 14 could induce apoptosis of Bel-7402 cell lines. Moreover, the structure-activity relationships of these derivatives were briefly discussed.