Novel Epicuticular Leaf Flavonoids from Kalmia and Gaidtheria (Ericaceae)

1984 ◽  
Vol 39 (7-8) ◽  
pp. 710-713 ◽  
Author(s):  
Eckhard Wollenweber ◽  
Gisela Kohorst
Keyword(s):  
Natural Products ◽  
Methyl Ether ◽  
The Other ◽  
Flavonoid Aglycones ◽  
Leaf Wax ◽  
Kalmia Angustifolia ◽  
Epicuticular Layer ◽  
New Compounds ◽  
Gaultheria Procumbens ◽  
Derivatives Of

Abstract Leaves of a number of Ericaceous plants have a thin epicuticular layer that consists mostly of triterpenes. In Kalmia angustifolia, K. latifolia and K. polifolia as well as in Gaultheria procumbens and G. shallon this material also contains trace amounts of flavonoid aglycones. In Kalmia they are the 3-OMe-derivatives of four C-methyl flavones reported previously as the typical leaf-wax flavonoids of Eucalyptus. The new compounds, 5-OH-3,7,4′-triOMe-6,8-diCH3-flavone (kalmiatin), 5-OH-3,7,4′-triOMe-6-CH3-flavone (8-desmethyl-kalmiatin), 5,4′-diOH-3,7-diOMe-6,8-diCH3-flavone (latifolin) and 5,4′-diOH-3,7-diOMe-6-CH3-flavone (8-desmethyl-latifolin) are novel natural products. They could not be detected in eight species of Eucalyptus. A screening of 15 species of Ericaceae revealed that 8-desmethyl-sideroxylin and 8-desmethyl-latifolin are present also in the epicuticular layer on leaves of Gaultheria procumbens, while on G. shallon and on Andromeda polifolia traces of galangin-3-methyl ether were found. In the other species checked no external flavonoid aglycones could be detected.

scholarly journals Charge transfer control by substituents: Donor pyrroles and fluoro-anilines

2005 ◽  
Vol 7 (3) ◽  
pp. 121-124 ◽  
Author(s):  
Antje Neubauer ◽  
Sukumaran Murali ◽  
Wolfgang Rettig
Keyword(s):  
Charge Transfer ◽  
Benzene Ring ◽  
The Other ◽  
Substituted Benzenes ◽  
Other Hand ◽  
Alkane Solvents ◽  
New Compounds ◽  
Derivatives Of ◽  
Acceptor Moiety ◽  
Donor Substituent

Derivatives of N-phenyl pyrrole with a para-donor substituent on the acceptor benzene ring are compared. It is shown that by a suitable increase of the donor strength of the pyrrolo group, CT fluorescence can be achieved even for donor-donor substituted benzenes. On the other hand, introducing fluoro substituents into the acceptor moiety strongly enhances the CT formation tendency, and several new compounds with CT fluorescence even in alkane solvents are presented.

Secondary metabolites of the aspen fungus Stachybotrys cylindrospora

1993 ◽  
Vol 71 (4) ◽  
pp. 487-493 ◽  
Author(s):  
William A. Ayer ◽  
Shichang Miao
Keyword(s):  
Natural Products ◽  
Antifungal Activity ◽  
Secondary Metabolites ◽  
The Other ◽  
Spectroscopic Techniques ◽  
Blue Stain ◽  
New Compounds

The secondary metabolites produced by the fungus Stachybotrys cylindrospora, which is known to be strongly antagonistic to the blue-stain fungus Ceratocystiopsis crassivaginata, have been examined. The compounds responsible for the antifungal activity are trichodermin (5) and trichodermol (6), two previously known mycotoxins belonging to the trichothecene family. The other metabolites, stachybotrydial (1), stachybotramide (8), and 6,8-dihydroxy-3,5,7-trimethylisochroman (7), although not active against C. crassivaginata, are new natural products. The structures of the new compounds were established by spectroscopic techniques.

scholarly journals Flavonoid Aglycones and Glycosides from the Leaves of some Japanese Artemisia Species

2018 ◽  
Vol 13 (5) ◽  
pp. 1934578X1801300
Author(s):  
Ayumi Uehara ◽  
Kazuhide Shimoda ◽  
Yoshinori Murai ◽  
Tsukasa Iwashina
Keyword(s):  
Acid Hydrolysis ◽  
Methyl Ether ◽  
The Other ◽  
Flavonol Glycosides ◽  
Flavonoid Aglycones ◽  
Other Hand ◽  
Artemisia Species ◽  
C Nmr

Sixteen Japanese Artemisia taxa were surveyed for flavonoid aglycones and glycosides. The leaves were rinsed with acetone and then extracted with MeOH. Isolated flavonoids were identified by UV, LC-MS, acid hydrolysis, 1H and 13C NMR, and/or HPLC comparisons with authentic samples. Thus, nine flavone aglycones, apigenin (10), luteolin (5), chrysoeriol (11), hispidulin (6), jaseosidin (7), nepetin (15), sudachitin (8), luteolin 7-methyl ether (13) and eupatilin (14), three flavonol aglycones, axillarin (9), quercetin 3-methyl ether (16) and 5,7,4′-trihydroxy-3,6-dimethoxyflavone (12), one flavanone aglycone, pinocembrin (4), three dihydroflavonol aglycones, taxifolin (1), taxifolin 3-acetate (2) and padmatin (3) were found in their Artemisia taxa with the various combination. On the other hand, four flavonol glycosides, quercetin 3- O-rutinoside (17), quercetin 3- O-glucoside (18), patuletin 3- O-glucoside (19) and patuletin 3- O-rhamnosylglucoside (20), were isolated from a few Artemisia taxa.

Unusual Flavanones from a Rare American Fern

1981 ◽  
Vol 36 (7-8) ◽  
pp. 604-606 ◽  
Author(s):  
Eckhard Wollenweber
Keyword(s):  
Methyl Ether ◽  
Lower Surface ◽  
Typical Pattern ◽  
Flavonoid Aglycones ◽  
Waxy Material ◽  
Methyl Derivatives ◽  
Trace Constituents ◽  
Derivatives Of

Abstract Notholaena fendleri, Polypodiaceae, Farinose Exudate, Novel Flavanone Notholaena fendleri is a rare representative of the genus, growing mainly in Colorado/USA. The white farinose exudate on the lower surface of its pinnules is composed partly of waxy material and partly of flavonoid aglycones. The flavonoid moiety consists mainly of methyl derivatives of the flavanones naringenin and eriodictyol. The eriodictyol methyl ethers are rare compounds; eriodictyol-7 methyl ether is a novel natural flavanone. Three flavones and two flavonols are found as trace constituents only. — The farina flavonoids of N. fendleri form a very typical pattern that is characteristic for this species.

scholarly journals Synthesis and Characterization of New Compounds Derived from Pyrrolidine-2-One and Evaluation of their Biological Activities

2020 ◽  
Vol 23 (4) ◽  
pp. 5-12
Author(s):  
Nadia A. Betti ◽  
◽  
Redha Ib. Hussain ◽  
Sahar Ab. Kadhem ◽  
Abdul Jabar Kh. Atia ◽  
...  
Keyword(s):  
Biological Activity ◽  
Mass Spectrum ◽  
Biological Activities ◽  
The Other ◽  
Synthesis And Characterization ◽  
E Coli ◽  
Ft Ir ◽  
New Compounds ◽  
Derivatives Of

New derivatives of pyrrolidine-2-one have been prepared by lactamization of -butyrolactone GBL with hydrazine hydrate (NH2NH2(80%)) to afford (1-aminopyrrolidin-2-one) which undergo many reactions to prepare the other derivatives. The prepared derivatives were determined by utilizing their FT-IR,1H-NMR and some by Mass spectrum. These derivatives were evaluated biologically against (Staphylococcus aureusand E. coli).Some of these derivatives exhibited good biological activity against one or both kind of bacteria while some exhibited no biological activity at all.

Energy Approximation

2017 ◽  
Author(s):  
Philip Isett
Keyword(s):  
Main Lemma ◽  
The Other ◽  
Coarse Scale ◽  
Continuous Solutions ◽  
Material Derivative ◽  
Energy Variation ◽  
Energy Approximation ◽  
The Difference ◽  
Derivatives Of

This chapter presents the equations and calculations for energy approximation. It establishes the estimates (261) and (262) of the Main Lemma (10.1) for continuous solutions; these estimates state that we are able to accurately prescribe the energy that the correction adds to the solution, as well as bound the difference between the time derivatives of these two quantities. The chapter also introduces the proposition for prescribing energy, followed by the relevant computations. Each integral contributing to the other term can be estimated. Another proposition for estimating control over the rate of energy variation is given. Finally, the coarse scale material derivative is considered.

SOME DIRECTIONS IN THE MODIFICATION OF AZOLES

2020 ◽  
Vol 5 (443) ◽  
pp. 85-91
Author(s):  
Ibrayev M.K., ◽  
◽  
Takibayeva A.T., ◽  
Fazylov S.D., ◽  
Rakhimberlinova Zh.B., ◽  
...  
Keyword(s):  
13C Nmr Spectroscopy ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
Active Compounds ◽  
Synthesis Conditions ◽  
Alkaloid Cytisine ◽  
Azole Ring ◽  
Cyclic Compounds ◽  
New Compounds ◽  
Derivatives Of

This article presents studies on the targeted search for new derivatives of azoles, such as benzthiazole, 3,5-dimethylpyrazole, 1,3,4-oxadiazole-2-thione, 1,3,4-thiadiazole. The possibility of combining in one molecule of the azole ring with other cyclic compounds: the alkaloid cytisine, morpholine, furan and some arenes has been studied. To obtain new compounds, the reactions of bromination, acylation, and interaction with isothiocyanates were studied. Optimal synthesis conditions were studied for all reactions. It was found that the reaction of 4-bromo-3,5-dimethylpyrazole with isothiocyanates, in contrast to the previously written derivatives of anilines, takes a longer time and requires heating the reaction mixture. The combination of a pirasol fragment with halide substituents often results in an enhanced therapeutic effect. The synthesized 2-bromine-N-(6-rodanbenzo[d]thiazole-2-yl)acetamide, due to the alkylbromide group, is an important synth in the synthesis of new benzthiazole derivatives. Its derivatives combine in one molecule the rest of rhodanbenzthiazole with alkaloid cytisine and biogenic amine morpholine and are potentially biologically active compounds, since the molecule structure contains several pharmacophoric fragments: benzthiazole and alkaloid (amine) heterocycles, rhodane and urea groups. The mechanism of formation of 1,3,4-oxadiazole-2-tyons from hydrazides under action on them by carbon disulfide was studied and assumed. It was shown that dithiocarbamates in acidic medium decompose with the release of hydrogen sulfide and the formation of highly reactive isothiocyanate group. Then, intra-molecular cyclization occurs, with the formation of end products - 1,3,4-oxadiazole-2-thions. The structures of the synthesized compounds were studied by 1H and 13C NMR spectroscopy. All synthesized substances are potentially biologically active compounds, since they contain several pharmacophore fragments in their structure.

Synthesis and Antimicrobial activities of Some Polyphenol compounds by Nano ZnO-TBAB as a Heterogeneous Catalytic Media

2020 ◽  
Vol 17 ◽  
Author(s):  
Rahele Bargebid ◽  
Ali Khalafi-Nezhad ◽  
Kamiar Zomorodian ◽  
Leila Zamani ◽  
Ali Ahmadinejad ◽  
...  
Keyword(s):  
Antibacterial Activities ◽  
Antimicrobial Activities ◽  
Reusable Catalyst ◽  
Nano Zno ◽  
Antifungal Activities ◽  
Chemical Structures ◽  
Heterogeneous Catalytic ◽  
Solvent Free Conditions ◽  
New Compounds ◽  
Derivatives Of

Introduction: Mannich reaction is a typical example of a three-component condensation reaction and the chemistry of Mannich bases has been the matter of search by researchers. Here an efficient procedure for the synthesis of some new Mannich derivatives of simple phenols is described. Methods: In this procedure a microwave-assisted and solvent less condensation were done between different phenols, secondary amines and paraformaldehyde. The reactions proceed in the presence of catalytic amount of nano ZnO and tetrabutylammonium bromide (TBAB) in excellent yields. 10 new compounds were synthesized (A1-A10). Chemical structures of all new compounds were confirmed by different spectroscopic methods. We optimized the chemical reactions in different conditions. Optimization reactions were done in the presence of different mineral oxides, different amount of TBAB and also different solvents. Nano ZnO and TBAB in catalytic amounts and solvent free conditions were the best conditions. All the synthesized compounds were screened for their antimicrobial activities. Antifungal and antibacterial activities of the synthesized compounds were evaluated against some Candida, filaments fungi, gram positive and gram negative bacteria by broth micro dilution method as recommended by CLSI. Results: The result showed that compounds A2, A3 and A4 against most of the tested Candida species and compounds A5 and A7 against C. parapsilosis and C. tropicalis, exhibited considerable antifungal activities. Also Compounds A8 and A10 showed desirable antifungal activities against C. neoformance and C. parapsilosis, respectively. The antibacterial activities of the synthesized compounds were also evaluated. Compounds A6 - A10 against E. Fecalis and compounds A5, A7, A9 and A10 against P. aeruginosa showed desirable antibacterial activities. Discussion: We have synthesized some new Mannich adducts of poly-hydroxyl phenols in the presence of nano-ZnO as a reusable catalyst, with the hope of discovering new lead compounds serving as potent antimicrobial agents. The advantages of this method are generality, high yields with short reaction times, simplicity, low cost and matching with green chemistry protocols. The antimicriobial studies of Mannich derivatives of phenols showed desirable results in vitro.

scholarly journals Novel Derivatives of 4-Methyl-1,2,3-Thiadiazole-5-Carboxylic Acid Hydrazide: Synthesis, Lipophilicity, and In Vitro Antimicrobial Activity Screening

2021 ◽  
Vol 11 (3) ◽  
pp. 1180
Author(s):  
Kinga Paruch ◽  
Łukasz Popiołek ◽  
Anna Biernasiuk ◽  
Anna Berecka-Rycerz ◽  
Anna Malm ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Carboxylic Acid ◽  
Bacterial Infections ◽  
Acid Hydrazide ◽  
Antimicrobial Effect ◽  
In Vitro Antimicrobial Activity ◽  
Research Goal ◽  
New Compounds ◽  
Derivatives Of

Bacterial infections, especially those caused by strains resistant to commonly used antibiotics and chemotherapeutics, are still a current threat to public health. Therefore, the search for new molecules with potential antimicrobial activity is an important research goal. In this article, we present the synthesis and evaluation of the in vitro antimicrobial activity of a series of 15 new derivatives of 4-methyl-1,2,3-thiadiazole-5-carboxylic acid. The potential antimicrobial effect of the new compounds was observed mainly against Gram-positive bacteria. Compound 15, with the 5-nitro-2-furoyl moiety, showed the highest bioactivity: minimum inhibitory concentration (MIC) = 1.95–15.62 µg/mL and minimum bactericidal concentration (MBC)/MIC = 1–4 µg/mL.

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