Neuroprotective constituents from Hedyotis diffusa

In a bioassay-guided search for neuroprotective compounds from medicinal plants, a MeOH extract of whole plants of Hedoytis diffusa yielded five flavonol glycosides, kaempferol 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (1), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-galactopyranoside (2), quercetin 3-O-[2-O-(6-O-E-feruloyl)-beta-D-glucopyranosyl]-beta-D-glucopyranoside (3), kaempferol 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (4), and quercetin 3-O-(2-O-beta-D-glucopyranosyl)-beta-D-galactopyranoside (5), and four O-acylated iridoid glycosides (6-9). Compounds 1 and 2 are previously unreported natural products, and all nine compounds exhibited significant neuroprotective activity in primary cultures of rat cortical cells damaged by L-glutamate.     

Neuroprotective limonoids of root bark of Dictamnus dasycarpus

A methanolic extract of Dictamnus dasycarpus root bark afforded four new degraded limonoids, 9alpha-hydroxyfraxinellone-9- O-beta- d-glucoside ( 1), dictamnusine ( 2), dictamdiol A ( 3), and dictamdiol B ( 4), together with eight known compounds, dictamdiol ( 5), fraxinellone ( 6), fraxinellonone ( 7), 9beta-hydroxyfraxinellone ( 8), calodendrolide ( 9), obacunone ( 10), limonin ( 11), and rutaevin ( 12). Compounds, 2, 3, 6, 9, 10, and 11 showed significant neuroprotective activity against glutamate-induced neurotoxicity in primary cultures of rat cortical cells at a concentration of 0.1 microM.     

Four new neuroprotective dihydropyranocoumarins from Angelica gigas

Four new dihydropyranocoumarins were isolated from Angelica gigas roots through neuroprotective activity-guided isolation and were characterized as decursinol derivatives 4"-hydroxytigloyldecursinol (1), 4"-hydroxydecursin (2), (2"S,3"S)-epoxyangeloyldecursinol (3), and (2"R,3"R)-epoxyangeloyldecursinol (4), respectively. All four new dihydropyranocoumarins and major coumarin derivatives of A. gigas, decursinol and decursin, exhibited significant protective activity against glutamate-induced neurotoxicity when added to primary cultures of rat cortical cells at concentrations ranging from 0.1 to 10 microM.     

Iridoid and phenylethanoid glucosides from Veronica lavaudiana

From an extract of Veronica (sect. Hebe) lavaudiana we have identified mannitol and isolated 11 iridoid glucosides, the carbohydrate ester hebitol II, and four phenylethanoid glycoside esters. Five of the iridoid glycosides are new; of these, lavaudiosides A, B, and C (2a, 3a, and 4) are 1-mannityl esters of 8-epiloganic acid, while 7e and 7f are 6'-O-caffeoyl derivatives of catalpol. The new phenylethanoid glycoside esters, heliosides A, B, and C (8b-d), are 6'-xylosyl derivatives of aragoside. The structures of the new compounds were elucidated mainly by spectroscopic analysis, but also by chemical degradation. We also demonstrated that the structures of the known glycosides globularitol and hebitols I and II should be revised. These compounds are derivatives of mannitol and not glucitol as previously believed.     

Glycosides from the root of Iodes cirrhosa

Seven new neolignan glycosides ( 1- 7), two arylglycerol glycosides ( 8, 9), and 18 known glycosides have been isolated from an ethanolic extract of the root of Iodes cirrhosa. Their structures including absolute configurations were determined by spectroscopic and chemical methods. Based on analysis of the NMR data of threo and erythro 8-4'-oxyneolignans and arylglycerols in different solvents, the validity of J 7,8 and Deltadelta C8-C7 values to distinguish threo and erythro derivatives was discussed. In the in vitro assays, compound 4 and liriodendrin ( 17) both showed activity against glutamate-induced PC12 cell damage at 10 (-5) M.     

Glycosides from the bark of Adina polycephala

Four new dimeric phenolic glycosides (1- 4), a new iridoid diglycoside (5), and 15 known glycosides have been isolated from an ethanolic extract of the bark of Adina polycephala. Their structures were determined by spectroscopic and chemical methods. Compounds 1, 3, and 5 showed in vitro inhibitory activity against the release of beta-glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor.     

An iridoid glucoside from Euphrasia pectinata

A new iridoid glucoside, 5beta,6beta-dihydroxyboschnaloside (1), was isolated from the aerial parts of Euphrasia pectinata. Five known iridoid glucosides, 6beta-hydroxyboschnaloside (2), aucubin, euphroside, plantarenaloside, and geniposidic acid, and two known phenylethanoid glycosides, verbascoside (= acteoside) and leucosceptoside A, were also obtained and characterized. The structure of compound 1 was established by spectroscopic evidence.     

Two new iridoids from hedyotis chrysotricha

Two new iridoid glycosides, asperulosidic acid ethyl ester (1) and 6'-acetyl deacetylasperuloside (2), were isolated from Hedyotis chrysotricha (Palib) Merr. Their structures were elucidated by spectroscopic means.     

Sulfur-containing bis-iridoid glucosides and iridoid glucosides from Saprosmas cortechinii

Six new sulfur-containing bis-iridoid glucosides, saprosmosides A-F (1-6), were isolated from the leaves of Saprosma scortechinii. From the stems of this same plant, two new iridoid glucosides, 3,4-dihydro-3-methoxypaederoside (8) and 10-O-benzoyldeacetylasperulosidic acid (12), were isolated. Their structures were elucidated by means of chemical, NMR, and mass spectroscopic methods. Additionally, 11 known iridoid glucosides were isolated and characterized as deacetylasperuloside, asperuloside, paederoside (7), deacetylasperulosidic acid (9), scandoside, asperulosidic acid, 10-acetylscandoside, paederosidic acid (10), 6-epi-paederosidic acid (11), methylpaederosidate, and monotropein. The structures of the new bis-iridoid glucosides were formed by intermolecular esterification between the glucose and carboxyl groups of three monomeric iridoid glucosides (7, 9, and 10).     

Resin glycosides from the roots of Ipomoea tyrianthina and their biological activity

Seven new tetrasaccharide glycosides, tyrianthins 1-7 (1-7), along with six known glycolipids were isolated from the roots of Ipomoea tyrianthina, and their structures were elucidated by spectroscopic and chemical methods. The content of resin glycosides in samples collected in three different regions was analyzed and compared, and the results showed that the flowering or dry season did not have any effect on the chemical composition for the same locality, but the growing location itself did affect the chemical composition of resin glycosides. Intraperitoneal administration to mice of tyrianthin 6 (6) resulted in antidepressant activity. Tyrianthin 6 (6), scammonin 1 (8), and scammonin 2 (9) exhibited dose-dependent protective effects against pentylenetetrazole-induced seizures. Also, tyrianthin 6 (6) and scammonin 2 (9) produced relaxant effects on spontaneous contractions in the isolated rat ileum.     

Iridoid glycosides of Leonurus persicus.

Two new iridoid glucosides, 6-O-acetylajugol (1) and 7, 8-epoxy-8-epi-loganic acid (2), together with five known iridoid glucosides, galiridoside (3), ajugoside (4), 10-deoxygeniposidic acid (5), 7-deoxy-8-epi-loganic acid (6), and 8-O-acetylharpagide (7), have been isolated from the aerial parts of Leonurus persicus. Leucosceptoside A (8), eugenyl beta-rutinoside (9), and kaempferol 3-O-glucoside (10) were also isolated. The structures of 1 and 2 were elucidated by extensive 1D- and 2D-NMR spectroscopy and molecular modeling. The structure of 3 was confirmed by single-crystal X-ray diffraction. Antimicrobial activity of compounds (1-10) was also evaluated against a panel of gram-positive and gram-negative bacteria and two strains of fungi.     

Iridoid glycosides from Globularia trichosantha

A new iridoid glycoside, deacetylalpinoside (2), was isolated from the aerial parts of Globularia trichosantha together with nine known iridoid glycosides: catalpol, 10-O-benzoyl-catalpol, aucubin, asperuloside, deacetylasperuloside, asperulosidic acid, scandoside, geniposidic acid, and alpinoside (1). From the underground parts of the same plant, two new bisiridoid glycosides, globulosides A (3) and B (4); a known iridoid glycoside, globularidin; a lignan glycoside, liriodendrin; and seven phenylethanoid glycosides, arenarioside, verbascoside (= acteoside), isoacteoside, crenatoside, isocrenatoside, and trichosanthosides A and B, were isolated. Compounds 2-4 are new iridoids containing an 8,9 double bond representing a rare carbon skeleton. Their structures were established by spectroscopic methods.     

Two new hepatoprotective stilbene glycosides from Acer mono leaves

Two new stilbene glycosides, 5-O-methyl-(E)-resveratrol 3-O-beta-d-glucopyranoside (1) and 5-O-methyl-(E)-resveratrol 3-O-beta-D-apiofuranosyl-(1-->6)-beta-d-glucopyranoside (2), were isolated from the leaves of Acer mono, along with seven known compounds. Among these compounds, 1, 2, and quercetin (3) showed significant hepatoprotective activities against H(2)O(2)-induced toxicity in primary cultures of rat hepatocytes.     

Neuroprotective 2-(2-phenylethyl)chromones of Imperata cylindrica

Bioactivity-guided fractionation of the methanolic extract of the rhizomes of Imperata cylindrica afforded a new compound, 5-hydroxy-2-(2-phenylethyl)chromone (1), together with three known compounds, 5-hydroxy-2-[2-(2-hydroxyphenyl)ethyl]chromone (2), flidersiachromone (3), and 5-hydroxy-2-styrylchromone (4). Among these four compounds, 1 and 2 showed significant neuroprotective activity against glutamate-induced neurotoxicity in primary cultures of rat cortical cells.     

Verbaspinoside, a new iridoid glycoside from Verbascum spinosum

A new iridoid glycoside, verbaspinoside (1), was isolated from the aerial parts of Verbascum spinosum. Its structure was elucidated on the basis of chemical and spectral data as 6-O-[(2' '-O-trans-cinnamoyl)-alpha-L-rhamnopyranosyl]-catalpol. Additionally, three known iridoids (aucubin, catalpol, and ajugol) and three phenylpropanoid glycosides [acteoside, angoroside A (2), and angoroside C (3)] were isolated and identified.     

钙调素拮抗剂E6对缺血性损伤神经细胞的保护作用

 目的:观察具有较强钙调素拮抗活性的双苄基异喹啉类化合物E6对缺血性神经细胞损伤的保护作用?方法:采用NaCN加缺糖引起肾上腺髓质瘤细胞(PC12细胞株)损伤和谷氨酸(glutamate,Glu)引起乳大鼠脑皮质神经细胞损伤模型?结果:E6对NaCN加缺糖损伤的PC12细胞保护作用较弱,而对Glu损伤的原代皮质细胞有较强的保护作用,并降低培养液中一氧化氮(NO)的含量?NO合成前体L-精氨酸(L-arginine,L-Arg)可减弱E6的保护作用?E6对硝普钠(sodium nitroprusside,SNP)损伤的原代神经细胞无保护作用?结论:E6可能是作用于Glu引起神经元损伤途径中NO生成之前的环节,从而表现出对缺血样损伤神经细胞的保护作用?     

7-O-6'-O-malonylcachinesidic acid, a new macrocyclic iridoid ester of malonic acid from the Tunisian plant Ajuga pseudoiva

A new iridoid glucoside, 7-O-6'-O-malonylcachinesidic acid (1), was isolated from the leaves of Ajuga pseudoiva and characterized as its triacetyl derivative (1a). Its structure was established by spectroscopic methods and showed an unusual feature, in which an alcoholic function of the iridoid moiety and the primary alcohol of a glucopyranose unit form a 13-membered heterocycle with malonic acid.     

Acylated iridoid and phenylethanoid glycosides from the aerial parts of Scrophularia nodosa.

From the aerial parts of Scrophularia nodosa L. (Scrophulariaceae), eighteen acylated iridoid glycosides and nine phenylethanoid glycosides were isolated. The structures of eight new iridoid and two new phenylethanoid glycosides were elucidated on the basis of chemical and spectroscopic evidences.     

缬草环烯醚萜抗肿瘤作用的实验研究

目的探索缬草环烯醚萜的抗肿瘤作用。方法对从缬草中提取分离的总环烯醚萜类物质及其中的环烯醚萜甙与环烯醚萜酯进行体内(小鼠移植性肿瘤)、体外(噻唑蓝染色法)抗肿瘤活性研究。结果缬草环烯醚萜甙与环烯醚萜酯对K562,HL60,U937,HepG2和Hale细胞株具有突出的细胞毒作用,对小鼠在体的EAC(腹水型)、S180(实体型)呈现出明显抑瘤作用;其抗癌活性强度为双烯键结构的环烯醚萜酯>单烯键结构的环烯醚萜酯>环烯醚萜甙。结论缬草环烯醚萜类物质具有显著的细胞毒与抗肿瘤作用,尤其是环烯醚萜酯。