- A NEW TRITERPENE GLYCOSIDE FROM THE STEM OF ICHNOCARPUS FRUTESCENS
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Key Word Index: Ichnocarpus frutescens; Apocynaceae; α-L-rhamnopyranosyl-(1->4)-β-D-glucopyranosyl-(1->3)-α-amyrin.
- Minocha, P. K.,Tandon, R. N.
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- Synthesis of novel triterpene and N-allylated/N-alkylated niacin hybrids as α-glucosidase inhibitors
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Diabetes mellitus is a metabolic disorder characterized by chronic hyperglycemia. α-Glucosidase (EC 3.2.1.20) inhibitors interfere with enzymatic action to slow down the liberation of d-glucose from oligosaccharides and disaccharides, resulting in delayed glucose absorption and decreased postprandial plasma glucose levels. In continuation of our drug discovery program on antidiabetic agents, we synthesized novel N-allylated/N-alkylated niacin and α-amyrin (4-9) and lupeol (12-16) hybrids and tested for their α-glucosidase inhibiting activity. Compounds 4-9 showed better activity profile than the marketed α-glucosidase inhibitor i.e. acarbose. Compound 4 possess the highest inhibitory action with IC50 of 5 μM. Kinetic and CD studies revealed that 4 inhibited the α-glucosidase in a noncompetitive manner and caused conformational changes in secondary structure of the enzyme protein.
- Narender, Tadigoppula,Madhur, Gaurav,Jaiswal, Natasha,Agrawal, Manali,Maurya, Chandan K.,Rahuja, Neha,Srivastava, Arvind K.,Tamrakar, Akhilesh K.
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- Are Isoursenol and γ-Amyrin Rare Triterpenes in Nature or Simply Overlooked by Usual Analytical Methods?
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Among pentacyclic triterpenes commonly found in plants, γ-amyrin and isoursenol are seldom reported and considered rare in nature. It was hypothesized that these triterpenes are instead routinely overlooked due to inadequate spectral characterization. γ-Amyrin was prepared by HCOOH isomerization of α-amyrin, and isoursenol was isolated from products of a heterologously expressed oxidosqualene cyclase. With precise NMR and GC-MS data, a metabolomics strategy was used to identify isoursenol and γ-amyrin in a wide range of plants.
- Shan, Hui,Wilson, William K.,Castillo, Dorianne A.,Matsuda, Seiichi P.T.
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- An improved scalable synthesis of α- and β-amyrin
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The synthesis of α- and β-amyrin was accomplished starting from easily accessible starting materials, oleanolic, and ursolic acid. The procedures allow the preparation of β-amyrin in an exceptionally short scalable manner via selective iodation and reduction. For α-amyrin, a different synthetic approach had to be chosen providing access to α-amyrin in medium-to-large scale.
- Serbian, Immo,Csuk, René
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- Two triterpenyl fatty acid esters from fagonia cretica as lipoxygenase inhibitors
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Two triterpenyl fatty acid esters were isolated from the chloroform soluble fraction of Fagonia cretica and their structures elucidated as 3β-12-ursen-3yl-docosanoate (1) and 3β-12-ursen-3yl-nonacosanoate (2) by 1D-NMR, 2D-NMR, mass spectrometric and chemical analyses. Both new compounds were also evaluated for their lipoxygenase inhibitory potential using Baicalein as a standard.
- Nawaz, Zahid,Ahmed, Ejaz,Sharif, Ahsan,Sajid, Anam,Arshed, Faiza,Arshad, Muhammad,Anjum, Muhammad Imran,Razaq, Abdul
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p. 406 - 409
(2018/06/06)
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- Practical Synthesis of α-Amyrin, β-Amyrin, and Lupeol: The Potential Natural Inhibitors of Human Oxidosqualene Cyclase
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A practical synthesis of α-amyrin (1), β-amyrin (2), and lupeol (3) was accomplished in total yields of 32, 42, and 40% starting from easily available ursolic acid (4), oleanolic acid (5), and betulin (6), respectively. Remarkably, these three natural pentacyclic triterpenes exhibited potential inhibitory activity against human oxidosqualene cyclase.
- Chen, Dongyin,Xu, Fengguo,Zhang, Pu,Deng, Jie,Sun, Hongbin,Wen, Xiaoan,Liu, Jun
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- Triterpene esters: Natural products from dorstenia arifolia (moraceae)
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The phytochemical study of Dorstenia arifolia Lam. (Moraceae) has led to the identification of 18 triterpenes esterified by fatty acids, five triterpenes without esterification, 12 triterpenes esterified by acetic acid, together with a known furanocoumarin: α-amyrin (1), β-amyrin (2) α-amyrin acetate (3) β-amyrin acetate (4), α-amyrin octanoate (5), β-amyrin octanoate (6), α-amyrin decanoate (7), β-amyrin decanoate (8), α-amyrin dodecanoate (9), β-amyrin dodecanoate (10), α-amyrin tetradecanoate (11), β-amyrin tetradecanoate (12), α-amyrin hexadecanoate (13), β-amyrin hexadecanoate (14), glutinol (15), glutinyl acetate (16), 11-oxo-α-amyrin (17), 11-oxo-β-amyrin (18), 11-oxo-α-amyrin acetate (19), 11-oxo- β-amyrin acetate (20) 11-oxo-α-amyrin octanoate (21) 11-oxo-β-amyrin octanoate (22), 11-oxo-α-amyrin decanoate (23), 11-oxo-β-amyrin decanoate (24) 11-oxo-α-amyrin dodecanoate (25) 11-oxo-β-amyrin dodecanoate (26), ursa-9(11),12-dien-3-yl acetate (27), oleana-9(11),12-dien-3-yl acetate (28), ursa-9(11),12-dien-3-yl decanoate (29), oleana- 9(11),12-dien-3-yl decanoate (30), 12,13-epoxyolean-3-yl acetate (31), 12,13-epoxyolean- 9(11)en-3-yl acetate (32), taraxeryl acetate (33), lupenyl acetate (34), lanosta-8,24-dien-3- yl acetate (35) and psoralen (36). The identification of the triterpene compounds isolated as isomeric mixtures obtained from the hexane extract was based mainly in mass spectra and 13C-NMR data. The long-chain alkanoic acid esters of the triterpenes α- and β-amyrin; 11-oxo-α- and 11-oxo-β-amyrin; ursa- and olean-9(11),12-dien-3-yl; have not been reported before in the literature as constituents of the Dorstenia genus.
- Fingolo, Catharina E.,De S. Santos, Thabata,Filho, Marcelo D.M. Vianna,Kaplan, Maria Auxiliadora C.
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p. 4247 - 4256
(2013/06/05)
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- Synthesis of α-amyrin derivatives and their in vivo antihyperglycemic activity
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Ficus racemosa belongs to the family of Moraceae and is commonly known as 'Gular' in north India. Bio-activity guided isolation work on the fruits of F. racemosa resulted in the identification of antidiabetic active principle, α-amyrin acetate 7. Compound 7 lowered the blood glucose levels by 18.4 and 17.0% at 5 and 24 h, respectively, in sucrose challenged streptozotocin induced diabetic rat (STZ-S) model at the dose of 100 mg/kg body weight. Fifteen novel derivatives viz, 9-21, 24, 25 of α-amyrin 8 were prepared and their antihyperglycemic activity profile was assessed. The p-chlorobenzoic acid derivative 9 and nicotinic acid derivative 14 showed potent antihyperglycemic activity at 100 mg/kg body weight.
- Narender,Khaliq,Singh,Joshi,Mishra,Chaturvedi,Srivastava,Maurya,Agarwal
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experimental part
p. 1215 - 1222
(2009/09/30)
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- A short enantioselective total synthesis of the fundamental pentacyclic triterpene lupeol
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(Chemical Equation Presented) The first enantioselective synthesis of lupeol has been developed by applying two carefully crafted cation-π cyclization stages to generate the pentacyclic structure with complete stereocontrol. The synthesis (Scheme 1) is no
- Surendra, Karavadhi,Corey
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supporting information; experimental part
p. 13928 - 13929
(2009/12/25)
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- Aliphatics and triterpenoids from the heartwood of Dichrostachys cinerea
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Chemical investigation of combined pet ether and benzene solubles from the ethanolic extract of Dichrostachys cinerea (heartwood) afforded a new hydroxy ester, 6-hydroxypentacosyl pentanoate along with α-amyrin palmitate, n-triacontane, I-octyl docosonoate, ceryl cerotate, friedelin, stigmastanol, epifriedelinol, α-amyrin, γ-sitosterol, β-sitosterol and lacceric acid.
- Jain,Saxena
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p. 656 - 658
(2007/10/03)
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- New ursane-type triterpenic esters from the stem bark of Thevetia peruviana
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Phytochemical studies on the stem bark of Thevetia peruviana resulted in the isolation of six new ursane-type triterpenes, named peruvianursenyl acetate A, peruvianursenyl acetate B, isolupenyl acetate, peruvianursenyl acetate C, lupedienyl acetate and peruvianursenyl glucoside along with two known triterpenoids, namely α-amyrin acetate and lupeol acetate. The structures of the new phytoconstituents have been established as 23 - nor methyl urs-12-en-4α-ethylenic-18α-H-3β-yl acetate, urs-5.21-dien-18α-H- 3β-yl acetate, lup-20 (29)-en-3α-yl acetate, urs-12 en-18α- H-3β-yl acetate, lup-5,20 (29)-dien-3β-yl acetate, and urs-12-en-18α-H-3-O-β-D- glucopyranoside, respectively.
- Ali,Ravinder,Ramachandram
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p. 385 - 389
(2007/10/03)
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- TERPENOIDS OF CANARIUM ZEYLANICUM
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The following terpenoids were identified in the oleoresin, bark and timber of Canarium zeylanicum: 3β-hydroxyurs-12-en-11-one, 3β-hydroxyolean-12-en-11-one, olean-12-en-3,11-dione, urs-12-en-3,11-dione, α- and β-amyrin, α- and β-amyrenone, taraxerol, sitosterol, canaric acid, elemene, elemol, α-pinene, α- and β-phellandrene, limonene, terpineol, and cavrone. - Key Word Index - Canarium zeylanicum; Burseraceae; oleoresin; bark; timber; monoterpenoids; sesquiterpenoids; triterpenoids; 3β-hydroxyurs-12-en-11-one (neoilexonol); 3β-hydroxyolean-12-en-11-one; olean-12-en-3,11-dione; urs-12-en-3,11-dione; elemene; elemol; α-amyrine and β-amyrine; α- and β-amyrenone; canaric acid; taraxerol; sitosterol.
- Bandaranayake, Wickramasinghe M.
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p. 255 - 258
(2007/10/02)
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- INSECT GROWTH INHIBITOR FROM THE BARK OF SANTALUM ALBUM
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Key Word Index -- Santalum album; Santalaceae; bark; insect growth inhibitor; triterpene; urs-12-en-3β-yl palmitate
- Shankaranarayana, K. H.,Ayyar, K. S.,Rao, G. S. Krishna
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p. 1239 - 1240
(2007/10/02)
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