Phytochemicals from Echinacea and Hypericum: A Direct Synthesis of Isoligularone

Reaction of trienes with α,β‐unsaturated aldehydes produces bicyclic products via a tandem Diels–Alder/ene reaction. The adduct from tiglic aldehyde was converted into isoligularone by conversion to a furan followed by benzylic oxidation.     

Synthesis and natural distribution of anti-inflammatory alkamides from Echinacea

The synthesis of the alkamides 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (1) and 2Z,4E-undeca-2,4-dien-8,10-diynoic acid isobutyl amide (5) was accomplished by organometallic coupling followed by introduction of the doubly unsaturated amide moiety. The distribution of these two amides in accessions of the nine species of Echinacea was determined.     

Phytochemicals Mediated Synthesis of AuNPs from Citrullus colocynthis and Their Characterization

Engineered nanoparticles that have distinctive targeted characteristics with high potency are modernistic technological innovations. In the modern era of research, nanotechnology has assumed critical importance due to its vast applications in all fields of science. Biologically synthesized nanoparticles using plants are an alternative to conventional methods. In the present study, Citrullus colocynthis (bitter apple) was used for the synthesis of gold nanoparticles (AuNPs). UV-Vis’s spectroscopy, XRD, SEM and FTIR were performed to confirm the formation of AuNPs. UV-Vis’s spectra showed a characteristic peak at the range of 531.5–541.5 nm. XRD peaks at 2 θ = 38°, 44°, 64° and 77°, corresponding to 111, 200, 220 and 311 planes, confirmed the crystalline nature of AuNPs. Spherical AuNPs ranged mostly between 7 and 33 nm, and were measured using SEM. The FTIR analysis confirmed the presence of phytochemicals on the surface of AuNPs. Successful synthesis of AuNPs by seed extract of Citrullus colocynthis (bitter apple) as a capping and reducing agent represents the novelty of the present study.     

The First Synthesis of a Diynone from Echinacea pallida

In order to provide an authentic standard and to generate pure material for biological testing, an efficient synthetic route to 1 was developed. This represents the first total synthesis of a major bioactive diynone from E. pallida.     

Synthesis and cannabinoid receptor activity of ketoalkenes from Echinacea pallida and nonnatural analogues

Despite its popularity and widespread use, the efficacy of Echinacea products remains unclear and controversial. Among the various compounds isolated from Echinacea, ketoalkenes and ketoalkenynes exclusively found in the pale purple coneflower (E. pallida) are major components of the extracts. In contrast to E. purpurea alkamides, these compounds have not been synthesized and studied for immunostimulatory effects. We present a practical and useful synthetic approach to the ketoalkenes using palladium-catalyzed cross-coupling reactions and the pharmaceutical results at the human cannabinoid receptors. The synthetic route developed provides overall good yields for the ketoalkenes and is applicable to other natural products with similar 1,4-diene motifs. No significant activity was observed at either receptor, indicating that the ketoalkenes from E. pallida are not responsible for immunomodulatory effects mediated via the cannabinergic system. However, newly synthesized non-natural analogues showed micro-molar potency at both cannabinoid receptors.     

A new isocoumarin from Hypericum annulatum

A new isocoumarin, annulatomarin (1), together with the known physcion and beta-sitosterol were isolated from the aerial parts of Hypericum annulatum. The structure of the new compound was established as 6,8-dihydroxy-7-methoxy-3-phenyl-3,4-dihydro-1H-isochromen-1-one on the basis of detailed spectroscopic analysis. Annulatomarin exhibited a modest growth-inhibitory activity in vitro against human chronic myeloid leukaemia LAMA-84 cells with an IC(50) = 111 microM.     

A Direct Synthesis of Vinylic Phosphonates from Vinylic Halides

Approaches to the formation of vinylic phosphonates through direct replacement of a vinylic halide by phosphorus have received considerable attention. With the exception of α,β-unsaturated systems^1,2 attempts involving simple Michaelis-Arbuzov reaction conditions (heating, trivalent phosphorus ester) have failed.^3–5 Other efforts involving transition metal salts as catalysts have found greater, but still quite limited success.^6–8     

A New Xanthone Derivative from Hypericum Erectum

A new xanthone,1,2-dihydro-3,6,8-trihydroxy-1,1-bis (3-methylbut-2-enyl)-5-(1,1-dimethylprop-2-enyl)-xanthen-2,9-dione(1),has been isolated from the aerial part of Hypericum erectum.     

A Direct Synthesis of Benzothiophene-3-Carboxylic Acid from Benzothiophene

The direct synthesis of benzothiophene-3-carboxylic acid from benzothiophene utilizing Friedel-Crafts acylation with trichloroacetyl chloride, followed by basic hydrolysis is presented.     

Direct Synthesis in the Undergraduate Laboratory: Synthesis of Copper Complexes from Zero-Valent Metals as a Demonstration of Base-Catalyzed Direct Synthesis

Direct synthesis is an important and active research field for scientists and technologists involved with the use of elemental metals. An undergraduate laboratory demonstration is presented that exposes students to this important synthetic technique. The direct synthesis of [Cu(NH₃)₄]²⁺ and [Cu(en)₂]²⁺ complexes in aqueous solution from zero-valent Cu metal is employed as an experiment illustrating the oxidizing properties of alkaline hydrogen peroxide solutions. The experiment also shows the decomposition of hydrogen peroxide catalyzed by the copper complexes. Finally, students can learn that the direct oxidation of metallic copper by alkaline hydrogen peroxide solution is an efficient and novel alternative approach to synthesize these and other copper complexes.     

A Direct Asymmetric Synthesis of Juglomycin A

Juglomycin A has been synthesized in four steps from 5-methoxy-1-naphthol.     

Conifers Phytochemicals: A Valuable Forest with Therapeutic Potential

Conifers have long been recognized for their therapeutic potential in different disorders. Alkaloids, terpenes and polyphenols are the most abundant naturally occurring phytochemicals in these plants. Here, we provide an overview of the phytochemistry and related commercial products obtained from conifers. The pharmacological actions of different phytochemicals present in conifers against bacterial and fungal infections, cancer, diabetes and cardiovascular diseases are also reviewed. Data obtained from experimental and clinical studies performed to date clearly underline that such compounds exert promising antioxidant effects, being able to inhibit cell damage, cancer growth, inflammation and the onset of neurodegenerative diseases. Therefore, an attempt has been made with the intent to highlight the importance of conifer-derived extracts for pharmacological purposes, with the support of relevant in vitro and in vivo experimental data. In short, this review comprehends the information published to date related to conifers’ phytochemicals and illustrates their potential role as drugs.     

Pyrohyperforin, A New Prenylated Phloroglucinol from Hypericum perforatum

The antidepressant activity of Hypericum perforatum extracts has sparked great interestin the chemistry and biochemistry of its constitUents, generating coverage also on themainstream press'. The major limitation to a rational exploitation of the medicinalpotential of this plant is our still incomplete knowledge of its active constitUents. In the1970s, Rusian workers described the isolation and characterization of one activeconstitUent named hyperforin (l) from Hypericum perforatum'". Then …     

CO_2和丙三醇直接合成碳酸甘油酯的新方法

报道了一种以CO_2和丙三醇为原料,Cs_2CO_3为碱,DMF为溶剂,bmimBF_4为增溶剂,直接合成碳酸甘油酯(GC)的新方法。在最优反应条件[丙三醇5 mmol,Cs_2CO_310 mmol,CH_2Cl_25 m L,bmimBF_41 m L,DMF 5 m L,P(CO_2)1 MPa,于100℃反应24 h]下,GC收率76%,其结构经1H NMR和ESI-MS确证。在最优条件下进行50倍放大实验,GC收率72%。     

Hyperinols A and B, chymotrypsin inhibiting triterpenes from Hypericum oblongifolium

Hyperinols A (1) and B (2) are new taraxastane type triterpenes which have been isolated from the chloroform soluble fraction of Hypericum oblongifolium and their structures elucidated on the basis of spectroscopic data. Both showed significant inhibitory activity against chymotrypsin enzyme.     

Hyperinoids A and B,two polycyclic meroterpenoids from Hypericum patulum

Hyperinoids A (1) and B (2), two prenylated acylphloroglucinol related meroterpenoids, were isolated from Hypericum patulum. Compound 1 incorporates an unprecedented 11,12-dioxatetracyclo[5.4.3.0^1,7.0^4,14]tetradecane system, while 2 possesses a unique 10,11-dioxatetracyclo[5.3.3.0^1,7.0^4,13]tridecane system. Their structures were established by spectroscopic analysis and X-ray crystallographic data. Compounds 1 and 2 were identified as potent NF-κB inhibitors and suppressed the LPS-induced inflammatory responses in RAW 246.7 macrophages and primary mouse BMDM cells     

Direct Synthesis of Phospholyl Lithium from White Phosphorus

The selective construction of P?C bonds directly from P₄ and nucleophiles is an ideal and step‐economical approach to utilizing elemental P₄ for the straightforward synthesis of organophosphorus compounds. In this work, a highly efficient one‐pot reaction between P₄ and 1,4‐dilithio‐1,3‐butadienes was realized, which quantitatively affords phospholyl lithium derivatives. DFT calculations indicate that the mechanism is significantly different from that of the well‐known stepwise cleavage of P?P bond in P₄ activation. Instead, a cooperative nucleophilic attack of two C Li bonds on P₄, leading to simultaneous cleavage of two P?P bonds, is favorable. This mechanistic information offers a new view on the mechanism of P₄ activation, as well as a reasonable explanation for the excellent yields and selectivity. This method could prove to be a useful route to P₄ activation and the subsequent production of organophosphorus compounds.     

Quantitative Analysis of Phytochemicals from Inula cappa Roots

JPC – Journal of Planar Chromatography – Modern TLC - Inula cappa (family Compositae) is used in the Ayurvedic medicinal system for the treatment of bronchitis, diabetes, fever,...