December 1971
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5 Reads
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12 Citations
Tetrahedron
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December 1971
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5 Reads
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12 Citations
Tetrahedron
December 1971
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9 Reads
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55 Citations
Tetrahedron
Moarelloflavone (BGH-II) and a new biflavonyl, BGH-111 along with optically active amentoflavone and podocarpusflavone A have been isolated from the phenolic extractives ofheartwood, bark and leaves of Garcinia livingstonii. Two members of a new series of 3,8-linked biflavones have been produced from BGH-II and BGH-111. Mass spectral and NMR studies including solvent dependent shifts ofOMe resonances are used for structure elucidation. An anomaly in the method ofOMe proton shifts is pointed out.
August 1971
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3 Reads
Chemischer Informationsdienst Organische Chemie
Die 4′-Hydroxy- und T-Hydroxy-flavanone (I) und (IV) bzw. -chalkone (III) und (VI) liefern bei der Oxidation mit Kaliumhexacyanoferrat(III) in hohen Ausbeuten Flavone (II) bzw. Aurone (V) im Gegensatz zu den 3′-Hydroxy= Verbindungen, die undefinierte Produkte liefern.
July 1971
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4 Reads
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29 Citations
Phytochemistry
From the subterranean parts of Piper sanctum (Miq) Schlecht (Piperaceae), two new compounds, piperolid (III) and methylendioxypiperolid were isolated. Piperolid was shown to be 5-(γ-methoxy)-cinnamylidene-4-methoxybut-3-enolide, the first derivative of tetronic acid characterized from higher plants.
May 1971
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2 Reads
Chemischer Informationsdienst Organische Chemie
Aus Cupressus sempervirens und C. funebris wird optisch aktives Cupressu- flavon (+)-(Ia) isoliert.
April 1971
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23 Reads
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55 Citations
Phytochemistry
It is proposed that phenolic oxidation of a 4(2)-hydroxychalcone(4′[2′]-hydroxyflavanone) serves to initiate transformations to aurone, flavone, dihydroflavonol and isoflavone. Flavonols could be produced by phenolic oxidation of either a 4′-hydroxydihydroflavonol or a 4′-hydroxyflavone. The production of 4-hydroxyphenylcoumarins and derived products could follow a similar pathway from isoflavones. Simple model flavanones and chalcones have been synthesized and their oxidation by potassium ferricyanide studied. The 4′-hydroxy and 2′-hydroxy compounds rapidly give flavone or aurone in high yield, in sharp distinction to the 3′-hydroxy derivatives. The fully methylated flavanones or corresponding chalcones are not oxidized after long periods. The results provide excellent analogies for the proposed biosynthetic pathway. The hydroxyaurone is produced as a metal complex, in which form it is protected from further oxidation, a situation that may have biochemical analogies.
December 1970
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6 Reads
Chemischer Informationsdienst Organische Chemie
Die aus den oberirdischen Teilen von Gnaphalium obtusifolium (Compositae) isolierte, als Obtusifolin bezeichnete Verbindung wird spektroskopisch untersucht.
September 1970
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18 Reads
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25 Citations
Planta Medica
Aus den Früchten von Piper peepuloides wurden als Haupt–Flavonoidkomponenten isoliert: 5–Hydroxy–3',4',7–trimethoxyflavon und 5–Hydroxy–4',7–dimethoxyflavon. Während letzteres bereits aus Birkenknospen bekannt war, ist die erstere Verbindung erstmalig als Naturprodukt nachgewiesen.
August 1970
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13 Reads
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29 Citations
Phytochemistry
March 1970
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1 Read
Chemischer Informationsdienst Organische Chemie
Das durch Extraktion des Kernholzes von I. globiflora gewonnene, cromatographisch reine "Globiflorin" läßt sich durch Craig-Verteilung in 4 Fraktionen auftrennen (Globiflorin l-4), von denen Globiflorin 3 durch weitere Verteilung in 8 Fraktionen aufgetrennt wird.
... Perhaps the best known reagent for this transformation is DMSO. Johnson and Pelter [27] showed that DMSO at 150˚C oxidized 1-iodooctane rapidly to aldehyde in 74% yield. Lower yields were obtained with secondary iodides or primary chlorides. ...
January 1964
... 39,40 The biosynthetic pathway of isocoumarin derivates had been studied by Birch's group. 41,42 Their study investigated the biosynthesis of canescin from Penicillium canescens using stable isotopes ( 13 C labelled) and NMR spectroscopy to determine the sites of incorporation. They pointed out that the isocoumarin portion of the canescin molecule was generated through the acetate/malonate pathway. ...
September 1969
... [1-oxo-5(3,4-methyl-enedioxyphenyl)-2Z,4E-pentadienyl]pyrrolidineFig. (2). Alkaloids from roots of Piper nigrum[64][65][66]. ...
March 1968
Tetrahedron Letters
... Small and complex compounds, such as xanthones and xanthone derivatives, have been identified from numerous species of Garcinia throughout the past few years (Bennet and Lee, 1989;Minami et al., 1994). Several xanthones, biflavonoids, and benzophenones with antiparasitic, antiviral, antifungal, antibacterial, and cytotoxic activity have been found in previous chemical and pharmacological investigations on the root bark, leaves, and fruits of G. livingstonei (Pelter et al., 1971;Gustafson et al., 1992;Sordat-Diserens et al. 1992a, 1992bVerdi et al., 2004;Mbwambo et al., 2006;Kaikabo et al., 2009). In this review, the ethnobotanical applications, phytochemical compositions, pharmacological activities, and cytotoxicity of G. livingstonei will all be thoroughly summarized (Figs. 1 and 2). ...
December 1971
Tetrahedron
... There are many types of biflavonoids depending on position and type of linkage between the two flavonoids [30,31]. Reported biflavonoids in G. livingstonei are shown in Table 2. Morelloflavone type biflavonoids; namely morelloflavone was isolated from the heartwood and bark in India [32], fukugetin and fukugiside were isolated from the fruits in Florida [14,15]. Amentoflavone type namely, amentoflavone and podocarpusflavone A were isolated from the leaf extract in India [32]. ...
December 1971
Tetrahedron
... Early studies indicated that a strict requirement for oxidation of some chalcone derivatives by potassium ferricyanide is the presence of a hydroxyl group in the B-ring (Dean & Podimuang, 1965). Oxidation of various flavonoids with potassium ferricyanide (Pelter, Bradshaw, & Warren, 1971) further confirmed that only the B-ring is acted upon, and no reaction takes place if hydroxyl groups on the B-ring are methylated. These observations strongly indicate that modifications in the B-ring of the flavonoid skeleton are primarily involved in the oxidation mechanism. ...
April 1971
Phytochemistry
... It has been used in contemporary Chinese herbal formulations or dispensed as a medicine, such as Ce Bo San. Phytochemistry research found that flavonoids such as myricetrin, myricetin, quercitrin, quercetin, hinokiflavone, and amentoflavone are the main medicinal components of PC [3][4][5]. ...
August 1970
Phytochemistry
... Filtration of fractions 2-5 (combined after TLC analysis) yielded a colorless precipitate, that was re-crystallized from methanol/water (70:30) to afford purified 9, 10methylenedioxy-5, 6-Z-fadyenolide (1, 48 mg). The filtrate was further subjected to column chromatography over 500 ml reversed phase C-18 silica gel column and eluted with methanol/water (70:30) to afford 5, 6-Z-fadyenolide (2, 54 mg) (Lago et al., 2005) and piperolide (3, 12 mg) (Hänsel and Pelter, 1971), as determined by LR-LCMS, NMR and comparison to authenticated compounds. ...
July 1971
Phytochemistry
... Because of the medicinal importance of the core structural unit of flavenes, there has been significant interest in the development of methods for scaffold construction [3][4][5][6][7][8][9]. However, previous studies have revealed that the synthesis of a functionalized flavene skeleton is a challenging task [5]; hence, few methods have reported the efficient stereoselective synthesis of flavenes [14][15][16][17][18][19][20][21]. Clark-Lewis and Jemison [14] have reported the first synthesis of racemic 1 based on chalcone starting materials. ...
January 1967
Journal of the Chemical Society C Organic
... Perr. [63] Lonchocarpan L. laxiflorus (Fig. 6) ...
January 1969
Journal of the Chemical Society C Organic