New prenylated dihydrochalcones from the leaves of Artocarpus elasticus

The leaves of Artocarpus elasticus collected in Thailand were investigated for chemical constituents. Four new prenylated dihydrochalcones named elastichalcones C, D, E, F (1, 3, 5, 6) together with elastichalcone B (2) and artocarpanone (4) were isolated. Their structures were determined from analysis of spectroscopic data. Elastichalcone C (1) exhibited good antibacterial activity and cytotoxicity.     

Geranylated phenolic constituents from the fruits of Artocarpus nobilis

Chemical investigation of the combined dichloromethane and ethyl acetate extracts of the fruits of Artocarpus nobilis, furnished four new geranylated phenolic constituents, 2,4,4'-trihydroxy-3-[(2E)-5-methoxy-3,7-dimethylocta-2,6-dienyl]chalcone (4), 1-(3,4-dihydro-3,5-dihydroxy-2-methyl-2-(3-methyl-2-butenyl)-2H-1-benzopyran-6-yl-3-(4-hydroxyphenyl)-2(E)-propen-1-one (5), 8-geranyl-3',4',7-trihydroxyflavone (8), 3'-geranyl-4',5,7-trihydroxyflavanone (9), together with known related compounds, xanthoangelol (1), xanthoangelol B (2), 3-geranyl-2,3',4,4'-tetrahydroxychalcone (3), lespeol (6), 8-geranyl-4',7-dihydroxyflavanone (7), and isonymphaeol-B (10). Compounds 3, 8 and 10 showed strong antioxidant activity against DPPH radical by spectrophotometric method.     

Geranyl flavonoids from the leaves of Artocarpus altilis

Five geranyl dihydrochalcones, 1-(2,4-dihydroxyphenyl)-3-{4-hydroxy-6,6,9-trimethyl-6a,7,8,10a-tetrahydro-6H-dibenzo[b,d]pyran-5-yl}-1-propanone (2), 1-(2,4-dihydroxyphenyl)-3-[3,4-dihydro-3,8-dihydroxy-2-methyl-2-(4-methyl-3-pentenyl)-2H-1-benzopyran-5-yl]-1-propanone (4), 1-(2,4-dihydroxyphenyl)-3-[8-hydroxy-2-methyl-2-(3,4-epoxy-4-methyl-1-pentenyl)-2H-1-benzopyran-5-yl]-1-propanone (5), 1-(2,4-dihydroxyphenyl)-3-[8-hydroxy-2-methyl-2-(4-hydroxy-4-methyl-2-pentenyl)-2H-1-benzopyran-5-yl]-1-propanone (8), and 2-[6-hydroxy-3,7-dimethylocta-2(E),7-dienyl]-2',3,4,4'-tetrahydroxydihydrochalcone (9), along with four known geranyl flavonoids (1, 3, 6, 7), were isolated from the leaves of Artocarpus altilis. Their structures were established by spectroscopic means and by comparison with the literature values. Compounds 2, 4, and 9 exhibited moderate cytotoxicity against SPC-A-1, SW-480, and SMMC-7721 human cancer cells.     

Two New Isoprenylated Stilbenes from Artocarpus chama

Two new stllbenes with two Isoprenoid groups, namely artostllbenes A （compound 1） and B （compound 2）, were Isolated from the stems of Arfocarpus chama Buch.-Ham. by repeated column chromatography. The＆ structures were elucldated as （E）-4-[2-（7-meth-xy-2-2-d-methy-6-（3-methy-but-2-eny-）-2H-1-benz-pyran-5-y-）v-ny-]benzene-1- 2-dlol （compound 1） and （Z）-4-[2-（7-meth-xy-2-2-dimethy--6-（3-methy-but-2-eny-）-2H-1-benz-pyran-5-y-）v-ny-]ben- zene-l,2-dlol （compound 2） by spectroscopic methods, mainly by 1D-, 2D-NMR and MS spectra. Compounds 1 and 2 are two cls- and trans-lsomers and compound 2 is the flrst cis-stllbene isolated from Moraceous plants.     

Antiplatelet prenylflavonoids from Artocarpus communis

Four flavonoids, dihydroartomunoxanthone (1), artomunoisoxanthone (2), cyclocomunomethonol (3) and artomunoflavanone (4), together with three known compounds, artochamins B (5), D and artocommunol CC (6) were isolated from the cortex of the roots of Artocarpus communis. The structures of 1-4 were determined by spectroscopic methods. The antiplatelet effects of the flavonoids, 1-3, 5 and 6 on human platelet-rich plasma (PRP) were evaluated. Of the compounds tested in human PRP, compounds 1, 5 and 6 showed significant inhibition of secondary aggregation induced by adrenaline. It is concluded that the antiplatelet effect of 1, 5 and 6 is mainly owing to an inhibitory effect on thromboxane formation.     

New antioxidant polyphenols from the medicinal mushroom Inonotus obliquus

The fruiting body of Inonotus obliquus, a medicinal mushroom called chaga, has been used as a traditional medicine for cancer treatment. Although this mushroom has been known to exhibit potent antioxidant activity, the mechanisms responsible for this activity remain unknown. In our investigation for free radical scavengers from the methanolic extract of this mushroom, inonoblins A (1), B (2), and C (3) were isolated along with the known compounds, phelligridins D (4), E (5), and G (6). Their structures were established by extensive spectroscopic analyses. These compounds exhibited significant scavenging activity against the ABTS radical cation and DPPH radical, and showed moderate activity against the superoxide radical anion.     

尼日利亚螫毛果(Cnestis ferruginca)中一种具有清除自由基的活性化合物的分离鉴定

用二苯基苦基苯肼自由基薄层实验法（DPPH-TLC-ASSAY）,从尼日利亚螫毛果（Cnestis ferruginca)植物的甲醇提取物中发现了一种具有很强的清除自由基活性的物质;用柱色谱及反相制备柱色谱（RP-LPPLC）,制备出了该活性物质的纯品;用质谱（HR ESI-MS）,核磁共振氢谱（^1H0,碳谱（^13C,DEPT)。紫外光谱及化学方法对该物质进行了结构鉴定,鉴定结果为对苯酚基-6-O-反式咖啡酸基-β-D-吡喃葡萄糖甙。     

Geranyl chalcone derivatives with antifungal and radical scavenging properties from the leaves of Artocarpus nobilis

Antifungal activity guided fractionation of the n-butanol extract from the methanol extract of the leaves of Artocarpus nobilis furnished 2',4',4-trihydroxy-3'-geranylchalcone (1), 2 ',4',4-trihydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (2), 2',4',4-trihydroxy-3'-[2-hydroxy-7-methyl-3-methylene-6-octaenyl]chalcone (3), 2',3,4,4'-tetrahydroxy-3'-geranylchalcone (4), 2',3,4,4'-tetrahydroxy-3'-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]chalcone (5). The chalcones 3 and 5 are new natural products whereas 1 and 2 are reported first time from the family Moraceae. All these compounds showed good fungicidal activity against Cladosporium cladosporioides and high radical scavenging activity towards the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical in TLC bio-autography method.     

尼日利亚螫毛果(Cnestis ferruginca)中一种具有清除自由基的活性化合物的分离鉴定

用二苯基苦基苯肼自由基薄层实验法(DPPH-TLC-ASSAY),从尼日利亚螫毛果(Cnestisferruginca)植物的甲醇提取物中发现了一种具有很强的清除自由基活性的物质;用柱色谱及反相制备柱色谱(RP-LPPLC),制备出了该活性物质的纯品;用质谱(HRESI-MS)、核磁共振氢谱(¹H)、碳谱(¹³C、DEPT)、紫外光谱及化学方法对该物质进行了结构鉴定,鉴定结果为对苯酚基-6-O-反式咖啡酸基-β-D-吡喃葡萄糖甙.     

Melatonin: New Places in Therapy

The fact that the full extent of the function of the pineal gland has not yet been elucidated, has stimulated melatonin research worldwide. This review introduces melatonin’s mechanism of action, direct and indirect antioxidant actions as well as the antioxidant properties of its metabolites, 6-hydroxymelatonin (6-OHM) and N-acetyl-N-formyl-5-methoxykynurenamine (AFMK). At present the mechanism of action is proposed to be receptor-, protein- and nonprotein-mediated. From its popular role in the treatment of jetlag, melatonin is now implicated in the reduction of oxidative stess, both as a free radical scavenger and antioxidant. Melatonin’s direct scavenging action in respect of the following will be discussed: superoxide anions, hydrogen peroxide, hydroxyl radicals, singlet oxygen, peroxy radicals and nitric oxide/peroxy nitrite anions. In addition melatonin also possesses indirect antioxidant activity and the role of its metabolites, AFMK and 6-OHM will be presented. It is these free radical scavenging and antioxidant properties of melatonin that has shifted the focus from that of merely strengthening circadian rhythms to that of neuroprotectant: a new place in therapy.     

海藻中清除氧自由基的物质

新鲜海藻的提取液含有超氧物歧化酶（SOD）活性物质,能清除超氧自由基（O2-）。海藻的SOD活性通常为60—280Ug-1FW,而在孔石莼（Ulvapertusa）、江蓠（Gracilariaverrucosa）和凤尾菜（G．eucheumoices）中活性较高,约为300Ug-1FW。一般来说,海藻的SOD活性和稳定性为：绿藻＞红藻＞褐藻。绿藻的SOD以CuZn-型为主,而蓝藻的SOD以Fe-型为主。以江蓠琼枝（Eucheumagelatinae）提取液作PAGE并SOD活性染色时,除了观察到SOD同工酶带之外,还发现在前沿指示剂附近有一区域,此区域与高效自由基清除剂SPD（Superphycodismutas）的电泳行为和对氮蓝四唑（NBT）负染色的抑制相同,可能两者为同一种物质。     

黑柄炭角菌产生的DPPH自由基捕捉成分

对黑柄炭角菌深层发酵制品中的DPPH自由基捕捉成分进行研究。经硅胶柱层析、中压液相色谱顺相和反相分离、制备型高压液相色谱分离等一系列步骤 ,共获得相对纯度在85%以上 ,收量在 2mg以上的自由基捕捉物质 2 0个 ,对其中的B4 1 6进行了质谱、1H NMR、13C NMR、1H 13CHMBC、红外光谱等的测定 ,测得分子式为C10 H10 O4 ,推断它为 5,8二羟基 3 甲基 3,4二氢异香豆素。在 2 0 μmol L时 ,它的DPPH自由基捕捉活性为维生素C的 1 67倍 ,维生素E的 2 1倍。     

Antioxidant activity of a new C-glycosylflavone from the leaves of Ficus microcarpa

By bioactive-guided fractionation of methanol extract of the Ficus microcarpa leaves, one new C-glucosylflavone, ficuflavoside (1), one new megastigmane glycoside, ficumegasoside (8), and twelve known compounds including flavonoids (2-6), phenylpropanoids (7), megastigmanes (9-11) and sterol derivatives (12-14) were isolated. Their chemical structures were elucidated by mass, 1D, and 2D NMR spectroscopies. The antioxidant activities of these compounds were measured using the oxygen radical absorbance capacity methods. Compounds 1-6 exhibited potent antioxidant activities of 6.6-9.5 μM Trolox equivalents at the concentration of 2.0 μM. The results indicated 2, 3, and 5 having meaningful reducing capacity of copper (I) ions concentration of 6.1-8.4 μM.     

Effect of gamma sterilization on microhardness of the cortical bone tissue of bovine femur in presence of N-Acetyl-L-Cysteine free radical scavenger

Gamma sterilization is usually used to minimize the risk of infection transmission through bone allografts. However, it is believed that gamma irradiation affects the mechanical properties of allografts and free radical scavengers can be used to alleviate the radiation-induced degradation of these properties. The aim of this study was to investigate the radioprotective effects of N-Acetyl-L-Cysteine (NAC) free radical scavenger on the material properties of sterilized bovine cortical bone at microstructure level. Forty-two cortical tissue specimens were excised from three bovine femurs and irradiated to 35 and 70 kGy gamma rays in the presence of 5, 50, and 100 mM concentrations of NAC. The localized variations in microhardness were evaluated via indentation in the radial and longitudinal directions to examine different regions of the microstructures of the specimens, including the osteonal and interstitial tissues. A significant increase was observed in the hardness of osteonal, interstitial, and longitudinal combined microstructures exposed to 35 and 70 kGy radiations (P < 0.05), whereas a relative reduction of the hardness was observed in the radial direction. Furthermore, it was found that the application of 50 and 100 mM NAC during gamma irradiation significantly subsided the hardening in longitudinal combined microstructure. Moreover, the reduction of hardness in radial direction was suppressed in the presence of 100 mM of NAC. In conclusion, the results indicated that NAC free radical scavenger can protect the cortical bone against deteriorative effects of ionizing radiation and can be used to improve the material properties of sterilized allografts.     

Synthesis and antioxidant evaluation of (S,S)- and (R,R)-secoisolariciresinol diglucosides (SDGs)

Secoisolariciresinol diglucosides (SDGs) (S,S)-SDG-1 (major isomer in flaxseed) and (R,R)-SDG-2 (minor isomer in flaxseed) were synthesized from vanillin via secoisolariciresinol (6) and glucosyl donor 7 through a concise route that involved chromatographic separation of diastereomeric diglucoside derivatives (S,S)-8 and (R,R)-9. Synthetic (S,S)-SDG-1 and (R,R)-SDG-2 exhibited potent antioxidant properties (EC₅₀ = 292.17 ± 27.71 μM and 331.94 ± 21.21 μM, respectively), which compared well with that of natural (S,S)-SDG-1 (EC₅₀ = 275.24 ± 13.15 μM). These values are significantly lower than those of ascorbic acid (EC₅₀ = 1129.32 ± 88.79 μM) and α-tocopherol (EC₅₀ = 944.62 ± 148.00 μM). Compounds (S,S)-SDG-1 and (R,R)-SDG-2 also demonstrated powerful scavenging activities against hydroxyl [natural (S,S)-SDG-1: 3.68 ± 0.27; synthetic (S,S)-SDG-1: 2.09 ± 0.16; synthetic (R,R)-SDG-2: 1.96 ± 0.27], peroxyl [natural (S,S)-SDG-1: 2.55 ± 0.11; synthetic (S,S)-SDG-1: 2.20 ± 0.10; synthetic (R,R)-SDG-2: 3.03 ± 0.04] and DPPH [natural (S,S)-SDG-1: EC₅₀ = 83.94 ± 2.80 μM; synthetic (S,S)-SDG-1: EC₅₀ = 157.54 ± 21.30 μM; synthetic (R,R)-SDG-2: EC₅₀ = 123.63 ± 8.67 μM] radicals. These results confirm previous studies with naturally occurring (S,S)-SDG-1 and establish both (S,S)-SDG-1 and (R,R)-SDG-2 as potent antioxidants and free radical scavengers for potential in vivo use.     

Three new geranyl aurones from the leaves of Artocarpus altilis

From the MeOH extract of the leaves of Artocarpus altilis (Moraceae), three new aurones, altilisin H (1), I (2), and J (3), have been isolated together with two known flavonoids. Their structures were elucidated on the basis of spectroscopic data. All compounds possessed tyrosinase inhibitory activity with IC₅₀ values less than 100 μM, while compounds 1–3 displayed potent α-glucosidase inhibitory activity with IC₅₀ values ranging from 4.9 to 5.4 μM.     

Artoindonesianins Q-T,four isoprenylated flavones from Artocarpus champeden Spreng. (Moraceae)

Four isoprenylated flavones, artoindonesianins Q-T, were isolated from the heartwood of Artocarpus champeden Roxb. The structures of these compounds were elucidated on the basis of their spectroscopic data.     

Cyathuscavins A, B, and C, new free radical scavengers with DNA protection activity from the Basidiomycete Cyathus stercoreus

Three new polyketides, cyathuscavins A (1), B (2), and C (3) were isolated from the mycelium culture of Cyathus stercoreus. The structures of the compounds were elucidated on the basis of NMR and mass spectroscopic data. Antioxidant activities of the compounds were evaluated by the scavenging ability against ABTS⁺, DPPH, and superoxide anion radicals. Cyathuscavins A–C showed significant antioxidant activity comparable to those of reference antioxidants, BHA and Trolox. Cyathuscavins A–C protected supercoiled plasmid DNA from Fe²⁺/H₂O₂-induced breakage.     

Oxyradicals and multivitamin tablets

Ingestion of a single multivitamin tablet leads to hydroxyl radical production equivalent to a radiation dose rate of 53 Gy/h.