Tetramethoxyflavone Research Articles

Radical scavenging potential of compounds isolated from Vitex agnus-castus

Nine secondary metabolites-artemetin (1), casticin (2), 3-hydroxy-5,6,7,4'-tetramethoxy flavone U(3), penduletin (4), p-hydroxybenzoic acid (5), methyl 3,4-dihydroxybenzoate (6), methyl isovanillate (7), vanillic acid (8), and 3,4-dihydroxybenzoic acid (9)-were isolated from a folkloric medicinal plant, Vitex agnus-castus. The structures of compounds 1-9 were identified using spectroscopic techniques. Compound 7 was isolated for the first time from this plant. These compounds were screened for their antioxidant activity. Compounds 6 and 9 exhibited significant activity against the DPPH free radical.

Simultaneous Quantification of Sinensetin and Tetramethoxyflavone in Misai Kucing Capsules using TLC-UV Densitometric Technique

Thin-layer chromatographic (TLC)-UV densitometric method is developed for simultaneous quantification of sinensetin and 5-hydroxy--6,7,3', 4'-tetramethoxyflavone (TMF) in Misai kucing capsules (Orthosiphon stamineus). Sinensetin and TMF are isolated from the leaves of local Orthosiphon stamineus. The TLC-UV desitometric quantification is performed by external standard method on silica gel plates using chloroform-ethyl acetate (60:40) as developing solvent and UV detection at 365 nm.The TLC densitometer, although yields slightly higher values than the other analytical methods, is preferred due to its simplicity, easy and low cost. Keywords: Orthosiphon stamineus; Lamiaceae; Local medicinal plant; HPTLC; Quantification; Densitometer. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2300

Sinensetin, rutin, 3′-hydroxy-5, 6, 7, 4′-tetramethoxyflavone and rosmarinic acid contents and antioxidative effect of the skin of apple fruit

A GC–MS method was developed for the separation and quantifiation of three flavones: sinensetin (SEN), rutin (RU) and 3′-hydroxy-5, 6, 7, 4′-tetramethoxyflavone (TMF) and rosmarinic acid (RA), a caffeic acid derivative, in the skin of apple fruit collected from different local markets of Bangladesh. The results showed significant variation in the amount of these markers in methanolic extracts of skin samples from different markets of Bangladesh, even though the values were almost identical for most of the cases. A variation in antioxidant activities, ranging from 62.82 to 92.34%, and variations in total phenolics, ranging from 6.69 to 10.20 mg caffeic acid/g dry weight of the methanol extracts, were observed. Antioxidative potency of the methanolic extracts was comparable to that of pure quercetin and the synthetic antioxidant butylated hydroxylanisole (BHA).

HPTLC Densitometric Analysis of Orthosiphon stamineus. Leaf Extracts and Inhibitory Effect on Xanthine Oxidase Activity

ABSTRACTOrthosiphon stamineus. Benth. was cultivated at different locations in Malaysia to compare the xanthine oxidase inhibitory potential of the methanol extracts of the leaf. The extracts showed superoxide scavenging and xanthine oxidase inhibitory activities using in vitro. methods. By means of HPTLC densitometric technique and UV-Vis spectra, sinensetin (SEN) and 3′-hydroxy-5,6,7,4′-tetramethoxyflavone (TMF) concentrations in the extracts were found to vary from 0.09% to 0.36% and 0.02% to 0.10% of the day weight, respectively. The study provided evidence that the leaf of the plant can be useful for studying its anti-gout action.

Tanacetamide C: One New Ceramide from Tanacetum artemisioides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Sinensetin, eupatorin, 3 ′-hydroxy-5, 6, 7, 4 ′-tetramethoxyflavone and rosmarinic acid contents and antioxidative effect of Orthosiphon stamineus from Malaysia

An HPLC method was developed for the separation and determination of three methoxylated flavones:sinensetin (SEN), eupatorin (EUP) and 3 ′-hydroxy-5,6,7,4 ′-tetramethoxyflavone (TMF) and rosmarinic acid (RA), a caffeic acid derivative in Orthosiphon stamineus (OS). All the compounds were separated using a reversed phase C18, Lichrosorb column with the mobile phase of methanol-water-tetrahydrofuran (45:50:5 v/v). The HPLC method was applied for the quantification SEN, EUP, TMF and RA in OS from different places in Malaysia. The results showed significant variation in the amounts of these markers in methanolic extracts of leaf samples from different parts of Malaysia. A variation in antioxidant activities, ranging from 55.5% to 84.2% and variations in total phenolics, ranging from 6.7 to 10.1 mg caffeic acid/g dry weight of the methanol extracts, were observed. Antioxidative potency of the methanol extracts was comparable to that of pure quercetin and the synthetic antioxidant butylated hydroxylanisole (BHA).

Antithrombotic activity of ternatin, a tetramethoxy flavone from Egletes viscosa less

AbstractTernatin, a tetramethoxy flavone isolated from Egletes viscosa Less. was evaluated for a possible antithrombotic acitivity on in vitro platelet aggregation induced by ADP and in vivo mouse model of tail thrombosis induced by kappa‐carrageenan (KC). ADP‐induced platelet aggegation was inhibited by ternatin in a concentration‐dependent manner with an IC50 of 390 μM. It also provided marked protection of mice from thrombotic challenge with KC. Tail thrombosis was totally prevented in mice that received ternatin prophylactically (1 h prior to KC injection) whereas therapeutically (4 h after KC injection) administered ternatin effectively reduced the length of the thrombosed/infarcted part of the tail. The observations suggest an antithrombotic action of ternatin.

Flavonoids from Three Ethiopian Species of Premna

Two novel hepta-oxygenated flavonols have been isolated from the aerial parts of Premna oligotricha and identified, primarily on the basis of N M R spectroscopy, as 3,5,5'-trihydroxy- 6,7,3',4'-tetram ethoxyflavone (2) and 3,5,7,5'-tetrahydroxy-6,3',4'-trim ethoxyflavone (3). Known flavonoids, with lower levels of oxygenation were obtained from two other Premna species, P. schimperi and P. recinosa.

Fungistatic constituents in citrus varieties resistant to the mal-secco disease

The resistance mechanism of mandarin varieties towards Deuterophoma tracheiphila Petri, the causal agent of Mal-secco, (a citrus disease) has been investigated. From two mandarin varieties, Cleopatra and Avana, five flavones were isolated, identified and tested for their fungistatic activity. Four of the flavones were found potent, one of which 5, 4′-dihydroxy-6, 7, 8, 3′-tetramethoxy flavone, is a new compound, while a second, 5, 4′-dihydroxy 6, 7, 8-trimethoxy flavone, is reported for the first time to occur in citrus.

Rearrangement in the demethylation of 2′-methoxyflavones. Part II. Further experiments and the determination of the composition of lotoflavin

Both 5 : 8 : 2' trimethoxyflavone (I ; R = Me) and the 2' : 3' : 6'- isomer(II; R = Me) yield 5 : 6 : 2' - trihydroflavone (IV : R = H) on demethylaction by hydridic acid. This result confirms previous views (see Gallagher et., al., J., 1953, 3770) that the diketone produced by decyclisation, e.g., (III) is intermediate in the rearrangement of both 5 : 8-dihydroxy- and 2' hydroxy- flavones. The presence of hydrogen ion is necessary for 5 : 8 → 5 : 6 rearrangement of flavones. Experiments related to the structure of lotoflavin, which Dunstan and Henry (Phil, Trans., 1901, 194, B, 515) thought to be 5 : 7 : 2' : 4' - tetra-hydroxyflavone (VI : R = H) have shown that 7 : 2' : 4' : 6'-tetramethoxy flavone (VI : R = Me) rearranges to form (V : R = H) on treatment with hydriodic acid. Lotoflavin as represented by the samples available is now found to be quercetin containing some kaempferol.

Pigments of cotton flowers

The constitution of Herbacitrin is established as the 7-glucoside of Herbacetin by methylating the glucoside through the acetyl derivative and isolating 7-hydroxy-3: 5: 8: 4'tetramethoxy flavone from the hydrolysis of the methylated glucoside. Similarly, the constitution of Quercimeritrin is confirmed as the 7-glucoside of Quercetin.

Pigments of cotton flowers

The constitution of Herbacitrin is established as the 7-glucoside of Herbacetin by methylating the glucoside through the acetyl derivative and isolating 7-hydroxy-3: 5: 8: 4′tetramethoxy flavone from the hydrolysis of the methylated glucoside. Similarly, the constitution of Quercimeritrin is confirmed as the 7-glucoside of Quercetin.