Antioxidant and free-radical scavenging activities of Allium roseum and Allium subhirsutum

This study was designed to examine the antioxidant and free-radical scavenging activities of two Allium species, Allium roseum and Allium subhirsutum. This study reports the results concerning bulb, stalk and leaf antioxidant enzyme activities (superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase), quantities of malonyldialdehyde, (*)OH and O(2) (*-) radicals and total antioxidant capacity determined by the FRAP method. Scavenging activities were determined by ESR method. The total antioxidant capacity was the highest in the leaves of Allium roseum. Among the investigated organs the leaves exhibited the highest antioxidant activities in all investigated Allium species. The highest ESR (84.61%) scavenger activity was observed in the leaves of Allium roseum.     

Evaluation of chemical constituents and free-radical scavenging activity of Swarnabhasma (gold ash), an ayurvedic drug

From ancient times, Swarnabhasma (gold ash) has been used in several clinical manifestations including loss of memory, defective eyesight, infertility, overall body weakness and incidence of early aging. Swarnabhasma has been used by Ayurvedic physicians to treat different diseases like bronchial asthma, rheumatoid arthritis, diabetes mellitus, nervous disorders, etc. In the present investigation, Swarnabhasma was prepared after proper purification and calcination as per Ayurvedic pharmacy which consisted of Realger (As₂S₂), Lead oxide (Pb₃O₄), Pure gold (Au) and Latex of Calotropis gigantea. Qualitative analyses indicated that Swarnabhasma contained not only gold but also several microelements (Fe, Al, Cu, Zn, Co, Mg, Ca, As, Pb, etc.). Infrared spectroscopy showed that the material was free from any organic compound. The metal content in the bhasma was determined by atomic absorption spectrometry. Acute oral administration of Swarnabhasma showed no mortality in mice (up to 1 ml /20 g b.w. of Swarnabhasma suspension containing 1mg of drug). Chronic administration of Swarnabhasma also showed no toxicity as judged by SGPT, SGOT, serum creatinine and serum urea level and histological studies. In an experimental animal model, chronic Swarnabhasma-treated animals showed significantly increased superoxide dismutase and catalase activity, two enzymes that reduce free radical concentrations in the body.     

Radical scavenging activity of Crocus sativus L. extract and its bioactive constituents

Radical scavenging activity is involved in aging processes, antiinflammatory, anticancer and wound healing activity. Hence, in the present study the DPPH radical scavenging activity of a natural product that possesses biological properties, an extract of Crocus sativus L. (saffron), grown in Crocos, Kozani (Greece), and some of its bioactive constituents (crocin, safranal) was studied.It was shown that a methanol extract of Crocus sativus exhibited high antioxidant activity, although it contains several active and inactive constituents. In trying to approximate a structure-activity relationship, two bioactive constituents of saffron extract were tested, namely crocin and safranal. Crocin showed high radical scavenging activity (50% and 65% for 500 and 1,000 ppm solution in methanol, respectively), followed by safranal (34% for 500 ppm solution). All the tested samples showed high radical scavenging activity, probably due to the ability to donate a hydrogen atom to the DPPH radical.Thus, saffron grown in Greece can be used promisingly in functional foods, drinks with antioxidant activity, in pharmaceutical and cosmetic preparations for their antioxidant activity and probably for their antiaging activity. Saffron can also be used internally in the form of powder or other pharmacotechnical formulae as a food supplement with antioxidant properties.     

Secoiridoid glucosides with free radical scavenging activity from the leaves of Syringa dilatata

Activity-guided fractionation of the EtOAc and MeOH extract of the leaves of Syringa dilatata NAKAI furnished one free radical scavenger, the secoiridoid glucoside oleuropein together with ligstroside and an iridoid glucoside, syringopicroside. Oleuropein interacted with the stable free radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and showed an IC(50) value of 40.4 microM. L-Ascorbic acid as a positive control showed an IC(50) value of 50.3 microM.     

Phenolic constituents and antioxidant activity of an extract of Anthuriumversicolor leaves

Fractionation of a methanolic extract of the leaves of Anthurium versicolor has resulted in the isolation of two main fractions, I and II. Both the extract and the fractions were assayed for their radical-scavenging activity by means of an in vitro test (bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical) and showed a significant radical-scavenging effect. Subsequent chromatographic fractionation of the most active fraction, II, has led to the isolation and characterization, as major constituents, of four new flavone glycosides, acacetin 6-C-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside] (1), acacetin 6-C-[beta-D-xylopyranosyl-(1-->6)-beta-D-glucopyranoside] (2), acacetin 6-C-[beta-D-apiofuranosyl-(1-->3)-beta-D-glucopyranoside] (3), and acacetin 8-C-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside] (4), as well as vitexin (apigenin-8-C-beta-D-glucopyranoside) and rosmarinic acid. The structures of 1-4 were determined using spectroscopic methods.     

Antioxidant and free radical scavenging activity of flavonol glycosides from different Aconitum species

Bioassay-guided fractionation by 1,1-diphenyl-2-dipicrylhydrazyl (DPPH) radical scavenging test of polar extracts of some Italian Aconitum species (A. napellus subsp. tauricum, A. napellus subsp. neomontanum, A. paniculatum, A. vulparia) led to the isolation of 13 flavonol glycosides: quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (1), kaempferol 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (2), quercetin 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (3), kaempferol 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (4), quercetin 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (5), kaempferol 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (6), kaempferol 7-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (7), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside (8), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (9), quercetin 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (10), quercetin 3,7-di-O-alpha-rhamnopyranoside (11), kaempferol 3,7-di-O-alpha-rhamnopyranoside (12) and quercetin 3-O-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (13). Their antioxidant activity (AA) was determined by measuring free radical scavenging activity by DPPH test and the coupled oxidation of beta-carotene and linoleic acid assay. The results showed that 5 is the most active compound in the DPPH free-radical scavenging test (IC(50) 1.9 microM) while in the coupled oxidation of beta-carotene and linoleic acid assay compound 1 has the highest inhibitory ratio after 1h (58.9%). Some structure-activity relationships on the AA were obtained.     

Active-oxygen scavenging activity of traditional nourishing-tonic herbal medicines and active constituents of Rhodiola sacra

The active-oxygen scavenging activity of 70 traditional herbal medicines used in China and Japan as nourishing tonics were evaluated by electron spin resonance (ESR) technique, in order to evaluate their effectiveness for anti-aging and to search for new active-oxygen scavengers from natural resources. Most of the 70 herbal medicines showed scavenging activity with various intensities. Areca catechu (methanol extract), Dendrobium plicatile (methanol extract), Juglans regia (water extract), Paeonia lactiflora (methanol extract), Psychotria serpens (water and methanol extracts), Rhodiola sacra (water and methanol extracts) and Uncaria rhynchophylla (water extract) especially showed strong scavenging activity against superoxide anion radical (*O2-), while J. regia (water and methanol extracts), Morus alba (water extract) and Schisandra chinensis (water extract) revealed strong scavenging activity against hydroxyl radical (HO*). In addition, the active-oxygen scavenging activities of 19 compounds isolated from R. sacra were also examined, and hydroquinone (1), caffeic acid (3), protocatechuic acid (6), gallic acid (7), (-)-epigallocatechin 3-O-gallate (8), 3-O-galloylepigallocatechin-(4beta-->8)-epigallocatechin+ ++ 3-O-gallate (10), heterodendrin (17) and gallic acid 4-O-beta-D-glucopyranoside (19) were found to show mild or strong inhibitory activity against superoxide anion radical (*O2-), while 4-hydroxybenzoic acid (2), 3, 4-hydroxycinnamic acid (4), 6-8 and 19 inhibited hydroxyl radical (OH*). These active-oxygen scavengers may contribute, to different extents, to their anti-aging action.     

Radical scavenging activity of Alkanna tinctoria root extracts and their main constituents, hydroxynaphthoquinones

Alkannin and shikonin (A[sol ]S) are pharmaceutical substances with a wide spectrum of biological properties. Radical scavenging activity is involved in aging processes, antiinssammatory, anticancer and wound healing activities. Hence, in the present study the DPPH radical scavenging activity of alkannin and shikonin, both monomeric and oligomeric, and extracts of Alkanna tinctoria roots were studied and a structure-activity relationship was approximated.It was shown that both monomeric and oligomeric alkannin and shikonin and also A[sol ]S esters exhibited extremely high radical scavenging activity. The presence of the naphthoquinone moiety seems to be essential for that activity, while the side chain of A[sol ]S possibly plays a minor role. Esterification of A[sol ]S on the side chain hydroxyl group does not affect radical scavenging activity. Organic solvents and olive oil (extracted at room temperature) extracts of Alkanna tinctoria roots, which contain as active ingredients A[sol ]S esters, exhibited very good antiradical activity.Alkannin and shikonin and their esters and also extracts of Alkanna tinctoria roots could be used promisingly in pharmaceutical and cosmetic preparations for their radical scavenging activity and probably for their antiaging activity.     

三春水柏枝化学成分的研究Ⅰ

目的：研究三春水柏枝的化学成分。方法：用硅胶柱色谱法分离,用理化性质及波谱方法鉴定结构。结果：从石油醚部位分离鉴定了4个化合物：3-羰基-14-taraxeren-28-醛(1),3-羰基-14-taraxeren-28-醇(2),表无羁萜醇(3),4-甲基-豆甾-7-烯-3-醇(4)；从醋酸乙酯部位分离鉴定了3个化合物：morelloflavone(5),3,5-二羟基-4-甲氧基-苯甲酸甲酯(6),3-羟基-4-甲氧基-反式桂皮酸(7)。结论：以上均为首次从该属植物中分离得到。     

山楂叶悬钩子根抗氧化活性成分研究

目的:研究山楂叶悬钩子根抗氧化活性成分.方法:综合利用硅胶减压柱色谱、凝胶柱色谱分离方法分离纯化山楂叶悬钩子根中化学成分,运用多种波谱技术(UV,1 H-NMR,13C-NMR,MS)鉴定化合物结构,进一步通过DPPH法评价各化合物的抗氧化活性.结果:从山楂叶悬钩子根中分离得到9个化合物,分别为蔷薇酸(1),山柰酚-3-O-β-D-吡喃半乳糖苷(2),吐曼酸(3),2α,19α,24-三羟基乌苏-12-烯-3-氧-28-酸(4),2α-羟基齐墩果酸(5),乌苏酸(6),胡萝卜苷(7),β-谷甾醇(8),白藜芦醇苷(9).抗氧化实验结果表明化合物2和9在50 mg·L-时对DPPH自由基清除能力分别为95.60％,75.23％.结论:化合物1～8为首次从该植物中分离得到,化合物2和9具有明显的抗氧化活性.     

栾树花化学成分研究

目的:对栾树花进行化学成分研究。方法:采用硅胶、聚酰胺柱层析进行分离纯化,根据理化性质和光谱分析鉴定化合物结构。结果:从栾树花乙酸乙酯部位中分离得到9个化合物,经鉴定分别为:胡萝卜苷(Ⅰ)、没食子酸(Ⅱ)、山柰酚(Ⅲ)、木犀草素(Ⅳ)、山柰素-3-O-(6″-乙酰基)-β-D-葡萄糖苷(Ⅴ)、2″-O-乙酰基金丝桃苷(Ⅵ)、2″-O-没食子酰基金丝桃苷(Ⅶ)、金丝桃苷(Ⅷ)、山柰酚-3-O-β-D-葡萄糖苷(Ⅸ)。结论:9个化合物均为首次从栾树花中分离得到;化合物Ⅳ、Ⅴ、Ⅵ和Ⅸ为首次从该属植物中分离得到。     

吴茱萸化学成分清除DPPH自由基的活性研究

[目的]研究吴茱萸中分离得到的17个化合物清除1,1-二苯基-2-三硝基苯肼(DPPH)自由基的活性。[方法]采用DPPH薄层生物自显影法(TLC-DPPH)快速筛选17个化合物的清除DPPH自由基活性,并采用微孔板定量法测定其中4个具有较强活性化合物清除50%DPPH自由基的浓度(IC50)。[结果]TLC-DPPH生物自显影法结果显示金丝桃苷、咖啡酸、儿茶酚、绿原酸具有较强的清除DPPH自由基的活性,其IC50值分别为(108.06±5.96),(248.18±0.72),(122.33±16.80),(156.28±0.93)μmol/L(DPPH终浓度0.19 mmol/L)。[结论]吴茱萸中金丝桃苷、咖啡酸、儿茶酚、绿原酸清除自由基的活性较强,为进一步的吴茱萸药效物质研究奠定了基础。     

银杏叶和山楂叶的抗氧化作用

 目的：研究银杏叶、山楂叶提取物的抗氧化作用。方法：采用荧光法测定过氧化作用的产物丙二醛含量；分光光度法测定银杏叶、山楂叶提取物对氧自由基(H₂O₂，O₂)的抑制作用。结果：银杏叶(G)、山楂叶(H)的提取物能抑制小鼠肝匀浆在37℃温育下生成的丙二醛，抑制率G为68.5%，H为76.9%。抑制由邻苯三酚在pH8.4自氧化产生的O₂(与对照组相比,G:P＜0.01、H:P＜0.05)，并能降低由H2O2所致的血红蛋白氧化和红细胞的溶血作用(溶血率H₂O₂为10.9%，经G和H抗氧化作用后分别为5.7%和9.2%)。结论：银杏叶、山楂叶提取物对氧自由基具有强的抑制作用。     

怀山药茎叶化学成分及抗癌活性筛选研究

目的研究怀山药Dioscoreaopposita地上茎叶的化学成分。方法利用大孔树脂、硅胶柱色谱、SephadexLH-20以及制备液相色谱分离纯化,并根据波谱数据以及化合物理化性质鉴定化合物结构,探讨得到的化合物对人乳腺癌MCF-7细胞和人肝癌HepG2细胞增殖的影响。结果从怀山药茎叶50%丙酮提取物中分离得到20个化合物,分别鉴定为1H-吲唑(1)、3-吲哚甲醛(2)、3-吲哚甲酸(3)、3-(2-羰基-丙基)-3-羟基-吲哚啉-2-酮(4)、胸腺嘧啶核苷(5)、尿嘧啶核苷(6)、3-hydroxy-3-(2-oxopropyl)-2,4-(1H,3H)-quinolinedione(7)、hematinic acid(8)、尿囊素(9)、2-乙基-3-甲基-马来酰亚胺-N-β-D-葡萄糖苷(10)、泡桐素(11)、(+)-8-羟基松脂素(12)、(+)-丁香树脂醇(13)、(-)-dihydrodehydrodiconiferyl alcohol(14)、(7R,8S)-二氢去氢二愈创木基醇-4-O-β-D-吡喃葡萄糖苷(15)、(2E,6S)-6,7-二羟基-3,7-二甲基-2-辛烯酸(16)、(2E,4S)-4-羟基-2-壬烯酸(17)、(2E,6S)-6-hydroxy-2,6-dimethyl-2,7-dienoicacid (18)、 amarantholidosideIV (19)、(9Z,11E)-13-methoxy-9,11-octadecadienoicacidmethylester(20)。化合物1、4、8、11～15、18、20在25μmol/L显著性抑制MCF-7细胞增殖,化合物1、4、8、12～14、18、20在25μmol/L显著性抑制HepG2细胞增殖。结论化合物1、3～5、10～12、15～20是首次从该植物中分离得到;化合物1、4、8、11～15、18、20在一定浓度显著抑制MCF-7和Hep G2细胞增殖,具有潜在抗癌活性。     

广金钱草种子的化学成分和DPPH自由基清除活性研究

目的 对广金钱草Desmodium styracifolium种子的化学成分及其清除DPPH自由基活性进行研究。方法 采用硅胶、聚酰胺、Sephadex LH-20凝胶柱色谱等色谱方法进行分离纯化,通过NMR、MS等波谱数据进行结构鉴定。比较不同极性提取物总黄酮的量及其对DPPH自由基的清除活性。结果 从广金钱草种子的不同极性萃取部位中分离得到10个化合物,分别鉴定为豆甾醇(1)、邻苯二甲酸二正丁酯(2)、儿茶素(3)、苯甲酸(4)、麦芽酚(5)、3-O-乙酰基-(-)-表儿茶素(6)阿福豆苷(7)、3'-甲氧基-表儿茶素(8)、山柰酚-7-O-β-D-吡喃葡萄糖苷(9)、槲皮素-3-O-β-D-吡喃葡萄糖苷(10)。结论 其中化合物4～6、8为首次从山蚂蝗属植物中分离得到,化合物2、3、7、9为首次从广金钱草中分离得到。广金钱草种子的各段萃取物均表现出一定的DPPH自由基清除活性。     

华中枸骨叶的化学成分及其肿瘤细胞毒作用

目的:研究华中枸骨Ilex centrochinensis叶的化学成分及主要化合物抗肿瘤活性.方法:利用硅胶,sephadex LH-20,HPLC等各种色谱技术进行分离纯化,通过理化性质和NMR等波谱数据进行结构鉴定,采用MTT法对分离得到的主要单体化合物进行抗肿瘤活性评价.结果:从华中枸骨叶95％乙醇提取物的乙酸乙酯萃取物中分离得到10个化合物,分别鉴定为对苯二酚(1),(2S)-5,4’-二羟基-7,3’-二甲氧基黄烷(2),(2S)-5,4’-二羟基-7-甲氧基黄烷(3),山柰酚(4),槲皮素(5),柚皮素(6),熊果酸(7),熊果醇(8),齐墩果酸(9),β-谷甾醇(10);化合物2,3抑制人肝癌细胞系HuH7的半数有效浓度IC50分别为8.98,13.04 mg L-1,化合物7～9抑制Caco-2细胞的IC50分别为28.52,38.28,33.04 mg L-1.结论:1～5,7,8均为首次从该植物中分离获得,其中化合物1～3为首次从该属植物中分离得到.化合物2,3对人肝癌细胞HuH7具有较强的细胞毒活性,化合物7～9对Caco-2细胞有弱的细胞毒作用.     

三七叶的化学成分及其抗氧化活性研究

目的研究三七Panax notoginseng叶乙醇提取物的化学成分及抗氧化活性(ABTS和DPPH)。方法利用硅藻土、硅胶、MCI柱色谱、凝胶柱色谱、中压制备液相色谱和制备液相等色谱技术进行分离纯化,并应用质谱、核磁共振等波谱技术鉴定化合物结构。初步考察了这些化合物的抗氧化能力。结果从三七叶95%乙醇提取物的氯仿、丙酮-乙醇(4∶1)和丙酮-乙醇(1∶1)3个洗脱部位中分离鉴定了15个化合物,分别为falcarinol(1)、γ-tocopherol(2)、(5S)-3α-acetyl-2,3,5-trimethyl-7α-hydroxy-5-(4,8,12-trimethyltridecanyl)-1,3α,5,6,7,7α-hexahydro-4-oxainden-1-one(3)、picrionoside B(4)、linarionoside A(5)、viburnolide A(6)、槲皮素(7)、lilyn(8)、茵芋苷(9)、阿彼斯基姆素(10)、daphnin methylether(11)、20(S)-人参皂苷Rh2(12)、人参皂苷F2(13)、20(R)-人参皂苷Rh2(14)、异人参皂苷Rh3(15)。结论化合物3、6、9~11为首次从人参属植物中分离得到,化合物2、4为首次从该植物中分离得到。化合物2、4、7、8具有较强的抗氧化活性。     

Antioxidant and hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves

In present study, the hepatoprotective activity of ethanolic and aqueous extracts of Momordica dioica Roxb. leaves were evaluated against carbon tetrachloride (CCl4) induced hepatic damage in rats. The extracts at dose of 200mg/kg were administered orally once daily. The substantially elevated serum enzymatic levels of serum glutamate oxaloacetate transaminase (AST), serum glutamate pyruvate transaminase (ALT), serum alkaline phosphatase (SALP) and total bilirubin were restored towards normalization significantly by the extracts. Silymarin was used as standard reference and exhibited significant hepatoprotective activity against carbon tetrachloride induced haptotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that Momordica dioica Roxb. leaves have potent hepatoprotective action against carbon tetrachloride induced hepatic damage in rats. Ethanolic extract was found more potent hepatoprotective. Meanwhile, in vivo antioxidant and free radical scavenging activities were also screened which were positive for both ethanolic and aqueous extracts. This study suggests that possible mechanism of this activity may be due to free radical-scavenging and antioxidant activities which may be due to the presence of flavonoids in the extracts.     

New constituents of the leaves of Alpinia flabellata

Two new compounds were isolated from the leaves of Alpinia flabellata. The structures of these compounds were determined by a combination of NMR techniques and HREIMS as 4-hydroxy-2-(2,4,5-trimethoxyphenyl)-2E-butenal (1) and rel-labd-12-en-15(16)-olid-7-one-8R-spiro-1'-[2S-(2,4,5-trimethoxyphenyl)-3-cyclohexene] (2).     

无梗五加叶化学成分的研究

 目的:研究无梗五加叶的化学成分。方法:利用各种色谱技米进行分离纯化，根据理化常数和光语数据等进行结构鉴定。结果:从无梗五加叶中分得两种化合物，其结构分别鉴定为:I，(1R)-1,11α-二经基-3,4-开环-羽扇豆-4(23),20(29)-二烯-3, 28一二酸3,11-内酯28-氧-α-L- 吡喃鼠李糖基(1→　4)-β-D-吡喃蔺萄糖基((1→6)-β-D-吡喃葡 萄糖苷；Ⅱ，β-谷甾醇。结论:化合物I系首次从该植物中分出，并且为主要成分。