3-Hydroxyisoflavanones from the stem bark of Dalbergia melanoxylon: Isolation,antimycobacterial evaluation and molecular docking studies

Two new 3-hydroxyisoflavanones, (S)-3,4′,5-trihydroxy-2′,7-dimethoxy-3′-prenylisoflavanone (trivial name kenusanone F 7-methyl ether) and (S)-3,5-dihydroxy-2′,7-dimethoxy-2″,2″-dimethylpyrano[5″,6″:3′,4′]isoflavanone (trivial name sophoronol-7-methyl ether) along with two known compounds (dalbergin and formononetin) were isolated from the stem bark of Dalbergia melanoxylon. The structures were elucidated using spectroscopic techniques. Kenusanone F 7-methyl ether showed activity against Mycobacterium tuberculosis, whereas both of the new compounds were inactive against the malaria parasite Plasmodium falciparum at 10 μg/ml. Docking studies showed that the new compounds kenusanone F 7-methyl ether and sophoronol-7-methyl ether have high affinity for the M. tuberculosis drug target INHA.     

Photodynamic activity of anthraquinones isolated from Heterophyllaea pustulata Hook f. (Rubiaceae) on MCF-7c3 breast cancer cells

Searching for agents that could be effective in the treatment of cancer, special highlight has focused on the study of numerous plant-derived compounds. We previously demonstrated that anthraquinones (AQs) isolated from a vegetal species: Heterophyllaea pustulata Hook f. (Rubiaceae), such as rubiadin, rubiadin-1-methyl ether, soranjidiol, soranjidiol-1-methyl ether exhibit photosensitizing properties without antecedents as photodynamic agents in malignant cells. In the present study, we investigated the potential role of these AQs as a phototoxic agent against human breast carcinoma using MCF-7c3 cells. All AQs exhibited significant photocytotoxicity on cancer cells at the concentration of 100 μM with 1 J/cm² light dose, resulting soranjidiol-1-methyl ether in complete cell destruction. The observed cellular killing by photoactivated AQs exhibited close relation with singlet oxygen production, except for soranjidiol-1-methyl ether, where cell viability decrease is in relation to uptake by tumor cells.     

Bacteriostatic heterocycles from Euodia lunu-ankenda

A new constituent characterized as 8-acetyl-3,4-dihydroxy-5,7-dimethoxy-2,2-dimethylchroman has been isolated together with alloevodionol-7-methyl ether, 4-methoxy-1-methyl-2(1H)quinolinone, evolitrine, isoevodionol and its methyl ether from the aerial parts of Euodia lunu-ankenda. Its structure was confirmed by its transformation to alloevodionol-7-methyl ether. 4-Methoxy-1-methyl-2(1H)quinolinone and its isomer were synthesized by a modified procedure.     

New sesquiterpenoids of Bombax malabaricum

Hemigossypol-6-methyl ether, reported to be present in the root bark of Bombax malabaricum, has been shown to be isohemigossypol-1-methyl ether. Isohemigossypol-1,2-dimethyl ether, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthaquinone, 7-hydroxycadalene and an unidentified phenolic compound have also been isolated. Long range couplings in the ¹H NMR spectrum of isohemigossypol-1-methyl ether have been established by decoupling experiments.     

Flavonoids from Wyethia glabra

Ten flavonoid compounds, including three new natural products, were isolated from a dichloromethane extract of Wyethia glabra. The known compounds are: orobol 7-methyl ether, orobol 3′-methyl ether, naringenin 7-methyl ether, eriodictyol, 8-C-prenyleriodictyol, 6-C-prenyleriodictyol and 8-C-prenylnaringenin. Eriodictyol 7-methyl ether, 2′,4′,6′-trihydroxy-4-methoxychalcone and 6-C-prenylnaringenin are new natural products. An additional prenylated flavanone was isolated and partially characterized.     

Coumarins in artemisia caruifolia

Isolation of daphnethin 7-methyl ether, daphnetin dimethyl ether, daphnetin methylene ether, daphnetin 7-methyl-8(3,3-dimethylallyl) ether and 3,4-dimethoxy-2-hydroxycinnamic acid from Artemisia caruifolia is reported.     

Synthesis of the 3- and 4-methyl, 3,4-dimethyl, and 3,4,6-trimethyl ethers of methyl 2-acetamido-2-deoxy-alpha-D-mannopyranoside

The methyl ethers of 2-amino-2-deoxy-D-mannose are reference compounds in studies, by the methylation procedure, of the chemical structure of polysaccharides containing 2-amino-2-deoxy-D-mannose and 2-amino-2-deoxy-D-mannuronic acid residues. Methylation of methyl 2-acetamido-2-deoxy-α-D-mannopyranoside (1) gave the 3,4,6-trimethyl ether. Methylation of the 6-trityl ether of 1, followed by detritylation, gave the 3,4-dimethyl ether of 1. Methylation of the 4,6-O-benzylidene derivative (6) of 1, followed by removal of the benzylidene group, gave the 3-methyl ether of 1. Benzoylation of 6, followed by removal of the benzylidene group and monobenzoylation, gave the 3,6-dibenzoate of 1, which was methylated, and the product saponified, to give the 4-methyl ether of 1; the latter compound was also obtained by a similar route via the 3-O-acetyl-6-O-benzoyl derivative.     

6-Hydroxy- and 6-methoxyflavonoids from Neurolaena lobata and N. macrocephala

Twelve flavonoids including one new sulfate were isolated from Neurolaena lobata, and six known flavonoids were obtained from N. macrocephala. The new compound isolated from N. lobata is 6-hydroxykaempferol 3-methyl ether 7-sulfate, and the known flavonoids are 6-hydroxykaempferol 3,7-di-dimethyl ether, 6-hydroxykaempferol, 3-methyl ether 7-glucoside, 6-hydroxykaempferol 7-glucoside, quercetagetin and its 7-glucoside, quercetagetin 3,6- and 3,7-dimethyl ethers, quercetagetin 3-methyl ether 7-glucoside and 7-sulfate, 6-hydroxyluteolin 3′-methyl ether and 6-hydroxyluteolin 7-glucoside. The known flavonoids identified from N. macrocephala are quercetagetin 3,6- and 3, 7-dimethyl ethers, quercetagetin 6-methyl ether 7-glucoside, quercetagetin 3,6-dimethyl ether 7-glucoside, quercetagetin 7-glucoside and quercetagetin 3-methyl ether 7-sulfate.     

New 6-hydroxyflavonoids and their methyl ethers and glycosides from Neurolaena oaxacana

Six new and nine known flavonoids were obtained from Neurolaena oaxacana. The known flavonoids are 6-hydroxykaempferol 3,7-dimethyl ether, quercetagetin 3,7-dimethyl ether, quercetin 3-methyl ether, axillarin, nodifloretin, 6-hydroxyluteolin 7-glucoside, kaempferol 3-glucoside, quercetagetin 7-glucoside and patulitrin. The new compounds are 6-hydroxykaempferol 3-methyl ether, quercetagetin 3,7-dimethyl ether 6-galactoside, quercetagetin 3-methyl ether 7-glucoside, the 6- and 7-glucosides of 6-hydroxykaempferol 3-methyl ether and quercetagetin 3-methyl ether 7-sulfate.     

6-methoxyflavonoids from Brickellia laciniata (compositae)

One new and fourteen known flavonoids, including thirteen containing 6-methoxy groups, were isolated from Brickellia laciniata. The new flavonol is quercetagetin 6,4′-dimethyl ether. Among the known compounds identified were the 4′-methyl and 7,4′-dimethyl ethers of eupafolin and luteolin 4′-methyl ether, and the flavonols: patuletin, spinacetin, eupatolitin, eupatin, centaureidin, casticin, patuletin 3-glucoside and 3-galactoside, eupatolitin 3-galactoside, patuletin 3-SO₃K and eupatin 3-SO₃Ca_1/2.     

Isoflavones from Dipteryx odorata

Five isoflavones have been isolated from the heartwood of Dipteryx odorata: retusin, retusin 8-methyl ether, 3′-hydroxyretusin 8-methyl ether, odoratin (7,3′-dihydroxy-6,4′-dimethoxyisoflavone) and dipteryxin (7,8-dihydroxy-6,4′-dimethoxyisoflavone).     

Caulobacter zeae sp. nov. and Caulobacter radicis sp. nov., novel endophytic bacteria isolated from maize root (Zea mays L.)

Four bacterial strains designated 410^T, 441, 695^T and 736 were isolated from maize root in Beijing, P. R. China. Based on 16S rRNA gene phylogeny, the four strains formed two clusters in the genus Caulobacter. Since strain 441 was a clonal variety of strain 410^T, only three strains were selected for further taxonomic studies. The whole genome average nucleotide identity (ANI) value between strains 410^T and 695^T was 94.65%, and both strains shared less than 92.10% ANI values with their close phylogenetic neighbors Caulobacter vibrioides DSM 9893^T, Caulobacter segnis ATCC 21756^T and Caulobacter flavus CGMCC 1.15093^T. Strains 410^T and 695^T contained Q-10 as the sole ubiquinone and their major fatty acids were C_{16:0, 11-methyl C18:1ω 0}, 11-methyl C_{18: 1}ω7c, summed feature 3 (C_{16:1ω7c and/or C16:1ω 1}ω7c and/or C_{16: 1}ω6c) and summed feature 8 (C_{18:1ω7c and/or C18:1ω 1}ω7c and/or C_{18: 1}ω6c). Their major polar lipids consisted of glycolipids and phosphatidylglycerol, and phenotypic tests differentiated them from their closest phylogenetic neighbors. Based on the results obtained, it is proposed that the three strains represent two novel species, for which the names Caulobacter zeae sp. nov. (type strain 410^T = CGMCC 1.15991 = DSM 104304) and Caulobacter radicis sp. nov. (type strain 695^T = CGMCC 1.16556 = DSM 106792) are proposed.     

Structure and biosynthesis of a new anthraquinone from Streptocarpus dunnii

A new anthraquinone (1-hydroxy-2-hydroxymethylanthraquinone has been isolated from the title plant. The structure was determined by spectroscopy and synthesis. Investigation on the biosynthesis showed that this quinone is formed via o-succinoylbenzoic acid.     

Metabolism of radioactive 17 beta-estradiol 3-methyl ether by humans.

A mixture of 2-3H and 4-14C-17beta-estradiol 3-methyl ether was administered orally to a man and to a woman. 34 and 35 percent of the 3H was liberated into the body water of the man and of the woman, respectively, reflecting reactions involving position 2. The metabolism of estradiol methyl ether was qualitatively similar to that observed previously for radioactive estradiol administered intravenously to the same subjects, as judged by the measurement of various urinary metabolites by reverse isotope dilution. Evidence was obtained for hydroxylation at position 2 without demethylation by the isolation of urinary 2-hydroxyestrone 3-methyl ether which retained 33% of the original 3H. This 3H was presumably at position 1, resulted from an NIH shift which does not occur during hydroxylation of estrone or estradiol. This was confirmed by subsequent administration of a mixture of 4-14C and 3H-(methoxyl)-estradiol 3-methyl ether to the man. There was no evidence (by reverse isotope dilution) for 1-hydroxyestrone, 1-hydroxyestrone 3-methyl ether, 4-hydroxyestrone 3-methyl ether or 4-hydroxyestradiol 3-methyl ether as urinary metabolites of estradiol 3-methyl ether.     

Flavonoids of Wyethia angustifolia and W. helenioides

Seventeen flavonoids, including seven new natural products, were isolated from a dichloromethane extract of Wyethia angustifolia. Known compounds are:8-C-prenyleriodictyol, 6-C-prenyleriodictyol, 8-C-prenylnaringenin, 6-C-prenylnaringenin, orobol 7-methyl ether, orobol 3′-methyl ether, naringenin 4′-methyl ether, orobol, eriodictyol and naringenin. The new compounds are 6-C-prenylorobol, 6-C-prenylorobol 3′-methyl ether, orobol 7,3′-dimethyl ether, 8-C-prenyldihydroisorhamnetin, 7,8-dihydrooxepinocriodictyol, 7,8-dihydrooxepinodihydroquercetin and 3′,4′-dihydrooxepino-6′-hydroxybutein. A dichloromethane extract of Wyethia heleniodes yielded eleven compounds only five of which were previously reported from the species. All these compounds appear to occur on the leaf surface.     

Role of porcine endometrial estrogen sulfotransferase in progesterone mediated downregulation of estrogen receptor

Estrogen sulfotransferase (EST) is a progesterone (Pg) induced secretory endometrial enzyme which may effect estrogen receptor levels by esterifying estradiol-17 beta (E2) to an inactive, sulfate form. The effects of this enzyme were studied using specific inhibitors of EST that do not bind to estrogen receptor (ER): 4-nitroestrone 3-methyl ether and 4-fluoroestrone 3-methyl ether. A 1 h pulse with 4 nM E2 caused ERn (i.e. E2-bound, chromatin-bound receptor) to increase 40% in incubations of proliferative gilt endometrium (no EST activity), while the same E2 treatment of secretory endometrium (high EST activity) caused no increase in ERn. ERn accumulation was completely restored in these experiments by preincubating secretory endometrium with 4 microM 4-fluoroestrone 3-methyl ether. Gilt endometrial explants cultured 7 days with 1 nM E2 plus 1 microM Pg (which induced EST activity) possessed half the ERn as explants devoid of EST activity which were cultured in E2 alone. The addition of 10 microM 4-nitroestrone 3-methyl ester to the cultures of secretory endometrium restored ERn to the levels seen in minces cultured with E2 alone. Furthermore, ovariectomized gilts injected daily with 250 micrograms E2 plus 25 mg Pg had much lower ERn (0.06 fmol/micrograms DNA) than gilts injected with E2 only (0.21 fmol/microgram DNA). ERn was restored completely by supplementing the E2 plus Pg injections with 0.5 g 4-nitroestrone 3-methyl ether administered by vaginal suppositories.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chemotaxonomic value of flavonoids in Chromolaena congesta (Asteraceae)

The phytochemical investigation on the aerial parts of Chromolaena congesta led to the isolation of nine flavonoids, known in the literature as genkwanin (1) kumatakenin (2) acacetin (3), kaempferol 3-methyl ether (4), apigenin (5), apigenin 5,7-dimethyl ether (6), apigenin 5-methyl ether (7), luteolin (8) and kaempferol (9). The chemical structures were established on the basis of spectral evidence. All the compounds were isolated from this species for the first time. The results from the present study provide further information about the flavonoids as taxonomic marker of the genus Chromolaena, and the chemotaxonomic significance of these compounds were also summarized.     

Polyphenols from Achyrocline satureioides

Galangin, galangin 3-methyl ether, querectin, querectin 3-methyl ether, caffeic acid and two esters of calleryanin (3,4-dihydroxybenzylalcohol 4-glucoside), with caffeic acid and protocatechuic acid, have been isolated from aerial parts of Achyrocline satureioides.     

Naphthaquinones in Lomatia species

Lomatiol, juglone, β-hydrojuglone and naphthazarin have been found distributed in various parts of six Lomatia spp. Three others contained no quinonoid pigments but the leaves of L. dentata yielded kaempferol-3-methyl ether and quercetin-3-methyl ether.     

Flavone 5-O-glucosides from Daphne sericea

The aerial parts of Daphne sericea yielded two new flavonoids, luteolin 7-methyl ether 5-β-d-glucoside and luteolin 7,3′-dimethyl ether 5-β-d-glucoside, as well as luteolin 7-methyl ether, isovitexin, apigenin and its 7-β-d-glucoside.