Flavonoid Aglycones from Some Canary Islands Species of Sideritis (original) (raw)

New flavanones from the seeds of Rumex vesicarius L

Natural Products: An Indian Journal, 2014

Rumex vesicarius L. (Polygonaceae) is an annual, monoecious glabrous, pale green herb cultivated as a leafy vegetable in many parts of India. The seeds are utilized as a refrigerant, to cure dysentery and as an antidote for scorpion venom. The seed powder is taken orally to treat liver diseases and as a laxative. Phytochemical investigation of themethanolic extract of seeds of R. vesicarius resulted in the isolation of two new flavanones characterized as 5,7,3'-trihydroxy-4'-methoxy-8-(3''-methyl-5''-methylene)hexenyl flavanone (vesicariaflavanoneA, 4) and 5,7,3',4'-tetrahydroxy-6-methoxy-8- (3''-methylene)-hexenylflavanone (vesicariaflavoneB, 5) alongwith the fatty acid glycerides identified as glyceryl-1-octadec-9'-enoate-3-phosphate (1), glyceryl-1,2-bis-hexadecanoate-3-phosphate (2) and glyceryl-1-octadec-9'- enoate-2-octahexanoate-3-phosphate (3). The structures of all the isolated phytoconstituents have been estabilished on the b...

Introduction and Interpretation of Flavonoids

Advanced Science, Engineering and Medicine Vol. 6, 1–16, 2014, 2014

An introduction to flavone, c-glucosyl flavones, flavone glycosides, acylated flavone glucosides, prenylated flavones, flavonoid sulfates, flavonoid glucuronides, a methylene dioxy flavonol, dihydroflavonols, acyl glucosylated flavonols, flavonol glycosides, flavanones, c-methylflavonoids, isoflavone, isoflavone glycosides, homoisolfavonoids, diprenyl isoflavones, isoflavanones, biflavones, biflavanone, chalcone, bicholcone, dihydrochalcone, enolchalcone, pyrano chalcones, oleanane triterpenoids and triterpene saponins. Their spectroscopic techniques, UV, IR, 1H-NMR, 13C-NMR and mass spectroscopy have been used in the identification and structure elucidation of the products isolated from different plants.

Biological Properties and Absolute Configuration of Flavanones From Calceolariathyrsiflora Graham

Frontiers in Pharmacology, 2020

Flavanones (-)-(2S)-5,4'-dihydroxy-7-methoxyflavanone (1) and (-)-(2S)-5,3',4'trihydroxy-7-methoxyflavanone (2) were isolated from the extracts of Calceolaria thyrsiflora Graham, an endemic perennial small shrub growing in the central zone of Chile. The absolute configuration of these compounds was resolved by optical rotation experiments and in silico calculations. Three analogs (3, 4, and 5) were synthesized to do structure-activity relationships with the biological assays studied. Biological tests revealed that only flavanone 2 exhibited a moderate inhibitory activity against the methicillinresistant strain S. aureus MRSA 97-77 (MIC value of 50 µg/ml). In addition, flavanone 2 showed a potent, selective, and competitive inhibition of 5-hLOX, which supports the traditional use of this plant as an anti-inflammatory in diseases of the respiratory tract. Also, 2 exhibited cytotoxic and selective effects against B16-F10 (8.07 ± 1.61 µM) but 4.6and 17-fold lesser activity than etoposide and taxol.

Some Flavonoids and the Diterpene Borjatriol from some Spanish Siden'tis Species

An HPLC and TLC analysis of the vacuolar and epicuticular flavonoids from Spanish Sideritis species has been carried out, and the distribution of these compounds has been used as a chemotaxonomic approach to the systematic problems of this genus. Generally, a correlation between the flavonoid patterns and the morphological and genetic data has been found. Epicuticular flavonoids accumulate in the phyletically more advanced species while the primitive species were devoid of external flavonoids. Excretory flavonoids also seem to increase in species growing in semi-arid habitats.

Characteristics of Flavanones from the Genus Artocarpus

2020

All patterns of order that exist in nature, have been listed in the scriptures. One such order can be seen in the secondary metabolite compounds of the genus Artocarpus. Some species of genus Artocarpus have been investigated the contained secondary metabolites. Flavonoid group is the most found from Artocarpus plant. One of flavonoid derivatives which is successfully isolated from Artocarpus plant is flavanon. The oxygenation pattern of flavanones in ring B was trioxygenation at position 2', 4 ', 6', or dioxygenation 2', 4 ' ', or monohydroxide 4. The pattern did not follow the shikimic acid and acetic malonate biogenesis pathways. The structures were determinated besed on IR and NMR spectroscopic data.

Prenylated flavanones from Derris reticulata

Phytochemistry, 1997

Two new pyranoflavanones, 2'",3"-epoxylupinifolin and dereticulatin, together with the known flavonoid lupinifolin, were identified from the stems of Derris reticulata. The structures and NMR spectral data were assigned by the use of 2D NMR technology and chemical transformations. All of the isolates showed cytotoxic activity in the P-388 cell line.

Flavones and New Isoflavone Derivatives from Microorganisms: Isolation and Structure Elucidation

Zeitschrift fur Naturforschung B

In the course of our chemical screening of actinomycetes and other bacteria from terrestrial and marine sources, several extracts showed colourless middle polar bands with strong UV absorption at 254 nm and brown to grey colouration with anisaldehyde/sulphuric acid. Working-up of such strains led to the isolation of a number of isoflavonoids. Daidzein (1a) and genistein (1b) are very wide-spread, however, compounds like kakkatin (2b, Streptomyces sp. GW39/1530) were known only from plant sources. Additionally, three new isoflavonoids were obtained, namely 4',7bis-(β -cymaropyranosyl)-genistein (1e) and 4'-hydroxy-6,7-methoxyisoflavone (2c) from the actinomycete isolate HKI 129-L, and genistein-4'-(6"-methyl)-salicylate (1d) from Streptomyces sp. isolate GW27/2506. 1d is the first natural 4'-ester of an isoflavonoid and an aromatic acid. For the first time, also two flavonoids were isolated from bacteria, apigenin (5a) and luteolin-3'-methyl ether (5b).

Flavanones from Vernonia diffusa

Journal of the Brazilian Chemical Society, 1999

Isolaram-se do extrato metanólico da madeira de Vernonia diffusa duas flavanonas: hesperidina e a nova flavanona, 3'-metilhesperetina (homoesperetina) e sacarose que foi identificada como derivado acetilado. A homoesperetina foi identificada como a aglicona obtida da hidrólise do novo glicosidio natural 7-rutinosilhomoesperetina. Do extrato em diclorometano foi identificada a mistura de sistosterol e estigmasterol. Foi preparado o novo derivado octaacetilhesperidina. As determinações estruturais foram realizadas através da análise dos dados espectrométricos de RMN de 1 H e 13 C incluindo experiências de DEPT, 1 Hx 1 H-COSY, 1 Hx 13 C-COSY e NOEDIFF. From the methanolic extract of the wood of Vernonia diffusa two flavanones were isolated and identified: hesperidin and a new flavanone, 3'-methylhesperetin (homoesperetin) and sucrose, which was identified as its acetyl derivative. The homoesperetin was identified as the aglicone obtained in the hydrolysis of the new natural flavanone glycoside, homoesperetin-7-O-rutinoside. From the dichloromethane extract, a mixture of sitosterol and stigmasterol was isolated together with a mixture of aliphatic acids. The new octaacetylhesperidin derivative was also prepared. Structural determination was made by 1 H and 13 C-NMR spectrometric data including DEPT, 1 Hx 1 H-COSY, and 1 Hx 13 C-COSY and NOEDIFF techniques.