Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• -economical CDC reaction of coumarin and flavonoids with different ethers through a C(sp3)–H activation process and obtained two novel ether-substituted derivatives (Scheme 24) [85]. This method can introduce ether substituents at the electron-rich α-position of coumarin and the β-H position of flavonoids. In

• -catalyzed formation of 1,1-bis-indolylmethane derivatives. Alkylation of coumarins and flavonoids. Direct CDC α-arylation of azoles with ethers. CDC of terminal alkynes with C(sp3)–H bonds adjacent to oxygen, sulfur or nitrogen atoms. Alkylation of terminal alkynes. Co-catalyzed functionalization of glycine

Discrimination of β-cyclodextrin/hazelnut (Corylus avellana L.) oil/flavonoid glycoside and flavonolignan ternary complexes by Fourier-transform infrared spectroscopy coupled with principal component analysis

• Nicoleta G. Hădărugă,
• Gabriela Popescu,
• Dina Gligor (Pane),
• Cristina L. Mitroi,
• Sorin M. Stanciu and
• Daniel Ioan Hădărugă

Beilstein J. Org. Chem. 2023, 19, 380–398, doi:10.3762/bjoc.19.30

• solubility and bioaccessibility of the hazelnut oil components and antioxidants can be increased, as well as the controlled release of bioactive compounds (fatty acid glycerides and antioxidant flavonoids, namely hesperidin, naringin, rutin, and silymarin). The appropriate method for obtaining the ternary

• evaluated by thermogravimetry and differential scanning calorimetry. Discrimination of the ternary complexes was easily performed through the FTIR–PCA coupled method, especially based on the stretching vibrations of CO groups in flavonoids and/or CO/CC groups in the ternary complexes at 1014.6 (± 3.8) and

• total number of 26 variables). Other valuable classifications were obtained for the antioxidant flavonoids, with a high similarity for hesperidin and naringin, according to FTIR–PCA, as well as for ternary complexes depending on molar ratios. The FTIR–PCA coupled technique is a fast, nondestructive and

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• treatment of cholecystitis, hepatitis, nephritis, eczema and bleeding [6]. Previous phytochemical studies showed the presence of flavonoids, lignans, glucosides and pigments in the plant [7][8] while pharmacological evaluations showed that some of the compounds possessed anti-oxidant and antiviral

A Streptomyces P450 enzyme dimerizes isoflavones from plants

• Run-Zhou Liu,
• Shanchong Chen and
• Lihan Zhang

Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113

• plate. We further identified a cytochrome P450 monooxygenase, CYP158C1, which is able to catalyze the dimerization of isoflavones. CYP158C1 can also dimerize plant-derived polyketides, such as flavonoids and stilbenes. Our work represents a unique bacterial P450 that can dimerize plant polyphenols

• -ring (see 7) prevented the dimerization. Two isoflavone glucosides, 8 and 9, failed to be transformed, presumably due to the excessive molecular size. When using the other flavonoids 10–17 as substrates, we observed the corresponding dimeric products for the substrates 10–12 (Figures S16–S18

• , Supporting Information File 1) but not for 13–17, suggesting that CYP158C1 is also compatible with compounds with flavone scaffold. Apart from flavonoids, this enzyme also dimerized umbelliferone (18), a substrate of the fungal P450 KtnC [14][18], and RVT with relatively low efficiency (Figures S19 and S20

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• , lignans, flavonoids, and phenolic compounds that show anti-inflammatory, cytotoxic, and/or cytoprotective effects [3][4][5][6][7]. However, bioactive terpenoids of G. hederacea var. longituba with antineurodegenerative effects remain largely unknown. In this study, nine terpenoids (1–9) including five new

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• diversity of the secondary metabolites from the genus Wikstroemia. Keywords: coumarin glucosides; flavonoids; lignans; structure elucidation; Wikstroemia nutans; Introduction The genus Wikstroemia (Thymelaeaceae) contains approximately 62 species, which are widespread throughout the subtropical regions of

• antimicrobial activities. This is the first report of the isolation of coumarins, flavonoids, lignans and phenylpropanoid glycosides from W. nutans, while compounds 1–3, 8, and 11 was encountered from the genus Wikstroemia for the first time. Our work will enrich the chemistry and structure diversity of natural

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• that the molecular size of the flavonoids and the length of the sugar chains have a greater impact on the assembly mode of supramolecular systems. Results and Discussion Host–guest interactions The host–guest interaction can be effectively observed using 1H NMR spectroscopy, and the mode of action of

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• bioactive natural products and pharmaceutical drugs [20][21][22]. Thioaurones (2-benzylidene benzo[b]thiophen-3(2H)-one) are sulfur-containing heterocyclic compounds, an important subclass of flavonoids which were first introduced by O’Sullivan in 1977 [23]. Specifically, thioaurones and their analogs show

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• antitumor promotors, like flavonoids or dihydroxycembranoids from tobacco leaves, which has to be applied at a factor of thousand or more compared to the promotor quantity to be reasonably active. Moreover, sarcophytol A (15) inhibits the expression of the tumor necrosis factor-α (TNF-α) mRNA and the

A golden opportunity: benzofuranone modifications of aurones and their influence on optical properties, toxicity, and potential as dyes

• Joza Schmitt and
• Scott T. Handy

Beilstein J. Org. Chem. 2019, 15, 1781–1785, doi:10.3762/bjoc.15.171

• –vis spectrum; Introduction Aurones are a fascinating minor sub-family of the flavonoid natural products [1][2]. While they feature the same C15 composition as other flavonoids, the skeleton is quite different, featuring a benzofuranone connected to an aromatic ring via an exocyclic alkene. This

• unusual skeleton has attracted a modest amount of synthetic attention and fairly recently significant biological focus. At the same time, aurones were first noted (and indeed their name is derived from) for their golden yellow color. The colors of flavonoids in general have been appreciated and used for

Molecular basis for the plasticity of aromatic prenyltransferases in hapalindole biosynthesis

• Takayoshi Awakawa and
• Ikuro Abe

Beilstein J. Org. Chem. 2019, 15, 1545–1551, doi:10.3762/bjoc.15.157

• compounds, including dihydroxynaphthalenes, flavonoids, and resorcinols as prenyl acceptors, and C10 geranyl diphosphate (GPP) as a prenyl donor, to generate a variety of O- or C-prenylated aromatic compounds [4][10]. Some PTases accept multiple lengths of isoprenoid diphosphates, as exemplified by the ABBA

A simple and effective preparation of quercetin pentamethyl ether from quercetin

• Jin Tatsuzaki,
• Tomohiko Ohwada,
• Yuko Otani,
• Reiko Inagi and
• Tsutomu Ishikawa

Beilstein J. Org. Chem. 2018, 14, 3112–3121, doi:10.3762/bjoc.14.291

• results. Keywords: computational calculation; per-O-methylation; quercetin; quercetin pentamethyl ether; reactivity; Introduction Flavonoids are distributed widely in plants, and exhibit various biological activities [1]. Polymethoxyflavones (PMFs) in particular have attracted much attention due to

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• cancer cells towards apoptosis through the mitochondrial pathway. Mitrasinovic has reported sequence-dependent binding of various structurally different flavonoids (quercetin (QUE) and flavopiridol (FLP)), a family of prospective anticancer agents, to duplex DNAs [104]. The five hydroxy groups in QUE

Synthesis of naturally-derived macromolecules through simplified electrochemically mediated ATRP

• Paweł Chmielarz,
• Tomasz Pacześniak,
• Katarzyna Rydel-Ciszek,
• Izabela Zaborniak,
• Paulina Biedka and
• Andrzej Sobkowiak

Beilstein J. Org. Chem. 2017, 13, 2466–2472, doi:10.3762/bjoc.13.243

• naturally-derived macromolecules showed narrow MWDs (Đ = 1.08–1.11). 1H NMR spectral results confirm the formation of quercetin-based polymers. These new flavonoid-based polymer materials may find applications as antifouling coatings and drug delivery systems. Keywords: flavonoids; on-demand seATRP

• efficient polymerization [56]. Therefore, seATRP offers a new opportunity to synthesize well-defined star-like polymers with predefined molecular structure. The main objective of this study is to present the first example of a synthesis of a macromolecule initiator from the group of flavonoids and with well

Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound

• Joana M. Pais,
• Maria João Barroca,
• Maria Paula M. Marques,
• Filipe A. Almeida Paz and
• Susana S. Braga

Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212

• compound is evaluated by the DPPH assay. Keywords: antioxidant activity; co-lyophilization; fisetin; gamma-cyclodextrin; molecular encapsulation; solid-state analysis; Introduction Flavonoids, natural compounds with numerous beneficial actions on human health, including antioxidant [1], anti-inflammatory

Use of costic acid, a natural extract from Dittrichia viscosa, for the control of Varroa destructor, a parasite of the European honey bee

• Kalliopi Sofou,
• Demosthenis Isaakidis,
• Apostolos Spyros,
• Anita Büttner,
• Athanassios Giannis and
• Haralambos E. Katerinopoulos

Beilstein J. Org. Chem. 2017, 13, 952–959, doi:10.3762/bjoc.13.96

• –0.60 fraction. Three compounds were isolated from this fraction using the chromatographic methods described above. The major one (1.17% based on the dry-leaves weight) proved to be costic acid by NMR and MS techniques, while the other two were tentatively identified as the flavonoids 7-O

Biomimetic synthesis and HPLC–ECD analysis of the isomers of dracocephins A and B

• Viktor Ilkei,
• András Spaits,
• Anita Prechl,
• Áron Szigetvári,
• Zoltán Béni,
• Miklós Dékány,
• Csaba Szántay Jr,
• Judit Müller,
• Árpád Könczöl,
• Ádám Szappanos,
• Attila Mándi,
• Sándor Antus,
• Ana Martins,
• Attila Hunyadi,
• György Tibor Balogh,
• György Kalaus (†),
• Hedvig Bölcskei,
• László Hazai and
• Tibor Kurtán

Beilstein J. Org. Chem. 2016, 12, 2523–2534, doi:10.3762/bjoc.12.247

• alkaloids are a small subgroup of flavonoids possessing a five- or six-membered nitrogen heterocycle attached to C-6 or C-8 of ring A of the flavonoid moiety. They have been reported to exhibit a wide range of pharmacological activities [1]. Dracocephins A and B were isolated as a mixture of four

• the stereochemical studies of flavanoid alkaloids, the solution TDDFT–ECD calculation method [6] was applied to 2a–d and 3a–d. For the validation of our computational approach on flavonoids, the ECD spectra of (R)-naringenin ((R)-1), the building blocks of dracocephins A and B, were calculated first

Biosynthesis of oxygen and nitrogen-containing heterocycles in polyketides

• Franziska Hemmerling and
• Frank Hahn

Beilstein J. Org. Chem. 2016, 12, 1512–1550, doi:10.3762/bjoc.12.148

• thiotetronates 166–168, it was postulated that this mechanism is general for the formation of this type of heterocycle. 1.7.2 Oxidative cyclisation: Aurones. Aurones are yellow coloured pigments of ornamental flowers that belong to the flavonoids. They are structurally closely related to chalcones, from which

Antibacterial structure–activity relationship studies of several tricyclic sulfur-containing flavonoids

• Lucian G. Bahrin,
• Henning Hopf,
• Peter G. Jones,
• Laura G. Sarbu,
• Cornelia Babii,
• Alina C. Mihai,
• Marius Stefan and
• Lucian M. Birsa

Beilstein J. Org. Chem. 2016, 12, 1065–1071, doi:10.3762/bjoc.12.100

• –activity relationship study concerning the antibacterial properties of several halogen-substituted tricyclic sulfur-containing flavonoids has been performed. The compounds have been synthesized by cyclocondensation of the corresponding 3-dithiocarbamic flavanones under acidic conditions. The influence of

• different halogen substituents on the antibacterial properties has been tested against Staphylococcus aureus and Escherichia coli. Amongst the N,N-dialkylamino-substituted flavonoids, those having an N,N-diethylamino moiety exhibited good to excellent antimicrobial properties against both pathogens

• . Fluorine-substituted flavonoids were found to be less active than those bearing other halogen atoms. Keywords: antibacterial activity; dithiocarbamates; dithiolium salts; flavonoids; SAR studies; Introduction The extensive use of antibiotics in human treatment and agriculture has led to the development

Three new trixane glycosides obtained from the leaves of Jungia sellowii Less. using centrifugal partition chromatography

• Luíse Azevedo,
• Larissa Faqueti,
• Marina Kritsanida,
• Antonia Efstathiou,
• Despina Smirlis,
• Gilberto C. Franchi Jr,
• Grégory Genta-Jouve,
• Sylvie Michel,
• Louis P. Sandjo,
• Raphaël Grougnet and
• Maique W. Biavatti

Beilstein J. Org. Chem. 2016, 12, 674–683, doi:10.3762/bjoc.12.68

• -inflammatory and antioxidant effects of J. paniculata were associated to the presence of flavonoids and other polyphenols [4]. Recently, we reported the in vivo anti-inflammatory properties of an aqueous fraction of the leaves of J. sellowii, that is in agreement with its popular use in Brazil [5]. Apart from

• sesquiterpenes including a rare skeleton (trixane). Only few of them were described from the genus Jungia along with polyacetylenes, coumarins and flavonoids [6][7][24][25][26]. Globally, the tested glycosylated sesquiterpenes displayed no or weak activity against Leishmania strains, and displayed no

Unconventional application of the Mitsunobu reaction: Selective flavonolignan dehydration yielding hydnocarpins

• Guozheng Huang,
• Simon Schramm,
• Jörg Heilmann,
• David Biedermann,
• Vladimír Křen and
• Michael Decker

Beilstein J. Org. Chem. 2016, 12, 662–669, doi:10.3762/bjoc.12.66

• combine the structural moieties of flavonoids and phenylpropanoids (lignans). Among the group of flavonolignans, the medicinally most important ones can be found in Silybum marianum (L.) Gaertn., the milk thistle. The phenolic secondary metabolites of this plant have been intensively studied due to their

Thermal and oxidative stability of Atlantic salmon oil (Salmo salar L.) and complexation with β-cyclodextrin

• Daniel I. Hădărugă,
• Mustafa Ünlüsayin,
• Alexandra T. Gruia,
• Cristina Birău (Mitroi),
• Gerlinde Rusu and
• Nicoleta G. Hădărugă

Beilstein J. Org. Chem. 2016, 12, 179–191, doi:10.3762/bjoc.12.20

• natural antioxidants are flavonoids, anthocyanins and their glycosides. Huber and collaborators [18] revealed the inhibition of PUFA oxidation by quercetin and its 3-O-glucoside. They were as effective as butylated hydroxytoluene (BHT, a synthetic antioxidant) against the oxidation of DHA and methylated

Physical properties and biological activities of hesperetin and naringenin in complex with methylated β-cyclodextrin

• Waratchada Sangpheak,
• Jintawee Kicuntod,
• Roswitha Schuster,
• Thanyada Rungrotmongkol,
• Peter Wolschann,
• Nawee Kungwan,
• Helmut Viernstein,
• Monika Mueller and
• Piamsook Pongsawasdi

Beilstein J. Org. Chem. 2015, 11, 2763–2773, doi:10.3762/bjoc.11.297

• three different cancer cell lines. The overall results suggested that solubilities and bioactivities of both flavanones were increased by complexation with methylated β-CDs. Keywords: binding energy; bioactivity; cyclodextrins; hesperetin; naringenin; Introduction Flavonoids are secondary metabolites

• found in fruits, vegetables, grains, roots, bark, stems, flowers, and especially in tea and wine [1]. More than 5,000 naturally occurring different flavonoids have been identified [2], including flavonols, flavones, flavanones, anthocyanidins, isoflavones, and dihydroflavonols. They possess many

• beneficial biological properties, i.e., free radical scavenging activity [3], cardioprotective action [4], antibacterial and antiviral activities [5]. Two flavonoids in the class of flavanones, hesperetin and naringenin (chemical structures in Figure 1), can be extracted from citrus fruits such as lemon

Genicunolide A, B and C: three new triterpenoids from Euphorbia geniculata

• Alia Farozi,
• Javid A. Banday and
• Shakeel A. Shah

Beilstein J. Org. Chem. 2015, 11, 2707–2712, doi:10.3762/bjoc.11.291

• inflammations. Previous phytochemical investigations have demonstrated that this plant contains flavonoids: kaempferol, quercetin and 3-rhamnosyl quercetin [28] and triterpenes β-amyrin acetate [29] and geniculatin [30]. Reinvestigation of chemistry of the plant led to isolation of three new triterpenoids