Screening of Plant Constituents for Effect on Glucose Transport Activity in Ehrlich Ascites Tumour Cells.

Murakami, Chikage; Myoga, Keiko; Kasai, Ryoji; Ohtani, Kazuhiro; Kurokáwa, Tomonori; Ishibashi, Shun; Dayrit, Fabian M; Padolina, William G.; Yamasaki, Kazuo

doi:10.1248/cpb.41.2129

Cited by 66 publications

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“…As the basis of the hypoglycemic action, the banaba extract is shown to increase the glucose uptake of 3T3-L1 adipocytes (2). In efforts to identify the active ingredients, Murakami et al isolated a triterpene, corosolic acid, from the methanol extract of the banaba leaves as an activator of glucose uptake of Ehrlich ascites tumor cells (3). The hypoglycemic effect of corosolic acid in experimental animals has also been reported (4).…”

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confidence: 99%

Activation of Insulin Receptors by Lagerstroemin

et al. 2003

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Abstract. Lagerstroemin, an ellagitannin isolated from the leaves of Lagerstroemia speciosa (L.) Pers. (Lythraceae), was examined for its biological activities. In rat adipocytes, the compound increased the rate of glucose uptake and decreased the isoproterenol-induced glycerol release. In Chinese hamster ovary cells expressing human insulin receptors, it increased the Erk activity. These insulin-like actions were accompanied by the increased tyrosine-phosphorylation of the b-subunit of the insulin receptors. Tryptic digestion of the extracellular sites of the insulin receptors markedly increased the effective concentrations of insulin without changing those of lagerstroemin. Thus lagerstroemin was considered to cause its insulin-like actions by a mechanism different from that employed by insulin.

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Section: Introductionmentioning

confidence: 99%

Activation of Insulin Receptors by Lagerstroemin

et al. 2003

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“…Compounds 3, 4, and 5 were identified with colosolic acid, 1) which has been already isolated from the title plant by Murakami et al, ursolic acid, and b-sitosterol glucoside, respectively, on the basis of various spectral and chemical data.…”

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A New Triterpenoid Isolated from Lagerstronemia speciosa (L.) PERS..

Okada

Omae

Okuyama

2003

CHEMICAL & PHARMACEUTICAL BULLETIN

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Lagerstronemia speciosa (L.) PERS. (Lythraceae) is a deciduous tree native to regions from India and southern China to tropical Australia. Murakami et al. 1) isolated two triterpenoids, colosolic acid and maslinic acid, from the leaves of this plant and colosolic acid was shown to be a glucose transport activator. Studies on tannin, 2,3) acetal, 4) ellagic acid derivatives, 5) alkaloids, 6) and sterol 2) have also been reported so far. Its leaves, locally called "banaba," are well-known as a popular home remedy for diabetes and other conditions. We began studies on the plant in order to isolate the active components and confirm their usefulness for treating diabetic complications.This paper describes the isolation of a new triterpene along with known compounds from the leaves of the plant.The leaves of L. speciosa were extracted with ethyl acetate, 50% acetone and then water, successively, to yield the corresponding extract. The ethyl acetate extract was separated and purified by using column chromatography and HPLC with silica gel and/or ODS to yield compounds 1, 2, 3, 4, and 5.Compound 1, a white powder, mp 245-247°C, demonstrated a fragment peak due to typical retro Diels-Alder cleavege at m/z 248 in its mass spectrum, suggesting the presence of a 12-en olean or ursan type triterpenoid. The high resolution-mass spectrum (HR-MS) gave an M ϩ ion peak at m/z 486.3341 to confirm the molecular formula for C 30 H 46 O 5 . All of the 13 C-NMR signals of 1 are shown in Table 1, which reveals the presence of six methyl, a carboxyl, and a carbonyl carbon. The 1 H-NMR (Table 2) gave six tertiary methyl signals, and a trisubstituted olefinic proton at d 5.50 ppm due to a C-12 double bond and a hydroxy methyl proton signal. The hydroxy methyl proton was suggested to be at C-23 or 24 by the analysis of 1 H-, 13 C-NMR, and heteronuclear multiple bond connectivity (HMBC) spectra. The location of the hydroxy methyl was confirmed by the different nuclear Overhauser effect (NOE) experiments. A different NOE was observed between the methyl proton at C-25 and the methyl proton at C-23 or C-24, suggesting that a methyl group was attached to the b position at C-4. The location of the b methyl group at C-4 assigned in the 13 C-NMR chemical shift value appeared at d 13.7 ppm. 7,8) Therefore, the hydroxy methyl group at C-4 was determined to be a, while the signal of C-24 was a b methyl group.The proton signal at d 4.55 ppm (1H, dd, Jϭ11.9, 4.9 Hz) had a correlation with the C-24 methyl carbon in the HMBC spectrum and had correlations with two protons at C-2 in 1 H-1 H correlation spectroscopy (COSY). It was therefore proved to be the C-3 proton and from the coupling constant and different NOE, the C-3 proton was determined to be a and the hydroxyl group was a b orientation, respectively. In the HMBC spectrum of 1, a carbon signal at d 213.1 ppm correlated with the C-25 methyl proton and with two proton signals at C-2. The C-2 and C-10 carbon signals shifted to a lower field for 18 ppm and 15 ppm, respectively, compared with oleanoli...

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“…Corosolic acid is a naturally occurring pentacyclic triterpene which is chemically 2 alpha-hydroxy ursolic acid, 2R, 3β-dihydroxyurs-12-en-28-oic acid. It displays a potential anti-diabetic activity [8], [9], [10], [11], [12], [13], [14], [15], [16] as well as anti-oxidant, anti-inflammation, and antihypertension properties [17].…”

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A Rapid Densitometric Comparison Method For The Quantification of Corosolic Acid In Lagerstroemia Speciosa Leaves Using HPTLC

Patel¹

2017

ijcrr

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Background:Banaba (Lagerstroemia speciosa, Lythraceae, Pride of India) is a medicinal plant that grows in the Philippines, Japan, India, Southeast Asia, etc. Traditionally, the leaves are used to treat diabetes and hyperglycemia. This effect is attributed to its chemical constituents belonging to the groups of terpenoids, tannins, and flavanoids. The objectives of this paper are to present a new method of identification and quantification of corosolic acid, a terpenoid, using HPTLC. Material and methods:The hydroalcoholic extract of leaves was chromatographed on aluminum plates coated with silica gel 60F254, with Toluene: Acetone: Formic acid (5:2:1 v/v) as the mobile phase. Densitometric quantification of corosolic acid was performed after derivatization with 10 % methanolic sulphuric acid in fluorescence mode at 366 nm. Results:Amounts of corosolic acid (at 366 nm, Rf value = 7.2) in the sample was calculated using regression equations (R 2 = 0.9959 (366 nm) of calibration plots, which showed there was a good polynomial relationship between peak area and amount of corosolic acid in the range 250-3000 ng/band. The limits of detection (LOD) and limits of quantitation (LOQ) were 70 and 245.6 ng/band, respectively. The method was validated for precision and accuracy. Recovery was determined by spiking the extract with corosolic acid standard and found to be in the range 94.4-96.5%. Conclusion:The corosolic acid content found in the leaves was 1.5% w/w at 366 nm.

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Screening of Plant Constituents for Effect on Glucose Transport Activity in Ehrlich Ascites Tumour Cells.

Cited by 66 publications

References 0 publications

Activation of Insulin Receptors by Lagerstroemin

Activation of Insulin Receptors by Lagerstroemin

A New Triterpenoid Isolated from Lagerstronemia speciosa (L.) PERS..

A Rapid Densitometric Comparison Method For The Quantification of Corosolic Acid In Lagerstroemia Speciosa Leaves Using HPTLC

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