New neolignans that inhibit DNA polymerase beta lyase

Bioassay-directed fractionation of a methyl ethyl ketone extract of the roots of Endlicheria aff. resulted in the isolation of four new neolignans (1-4) and eight known compounds, namely, canellin A (5), canellin C (6), 3'-methoxyguianin (7), (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',6'-dihydroxy-5'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan (8), armenin-B (9), dillapiole (10), 1-allyl-2,6-dimethoxy-3,4-methylenedioxybenzene (11), and omega-hydroxyisodillapiole (12). The structures of the new compounds (1-4) were established as (7S,8R,1'S,5'S,6'R)-Delta(2',8')-5',6'-dihydroxy-3'-methoxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, (7S,8R,1'S,5'S,6'R)-Delta(2',8')-3',5',6'-trihydroxy-3,4-methylenedioxy-4'-oxo-8.1',7.5'-neolignan, 2,4-dimethoxy-5,6-methylenedioxy-1-(2-propenyl)benzene, and 2,6-dimethoxy-3,4-methylenedioxycinnamyl alcohol, respectively, on the basis of spectroscopic interpretation.     

Carotenoids of tunicates. III. The structural elucidation of two new marine carotenoids, amarouciaxanthin A and B

The structure of two new marine carotenoids, isolated from the tunicate, Amaroucium pliciferum, and designated as amarouciaxanthin A and B, were determined on the basis of chemical and spectral data. Amarouciaxanthin A was determined as (6S, 3'S, 5'R,6'R)- 6,3',5'-trihydroxy-4,5,6',7'-tetradehydro-7,8,5',6'-tetrahydro-beta, beta-carotene-3,8-dione, and Amarouciaxanthin B was determined as (6S,3'R)-6,3'-dihydroxy-4,5,7',8'-tetradehydro-7,8-dihydro-beta,beta- carotene-3,8-dione. These two compounds are also presumed to be new metabolic products of a typical marine carotenoid, fucoxanthin.     

Salmoxanthin, deepoxysalmoxanthin, and 7,8-didehydrodeepoxysalmoxanthin from the Salmon Oncorhynchus keta

The absolute configuration of salmoxanthin (5,6-epoxy-5,6-dihydro-beta,epsilon-carotene-3,3',6'-triol) (1) first isolated from the salmon Oncorhynchus keta was determined to be 3S, 5R, 6S, 3'S, 6'R. Furthermore, two minor carotenoids, deepoxysalmoxanthin (2) and 7,8-didehydrodeepoxysalmoxanthin (3), were isolated, and their structures were determined to be (3R,3'S,6'R)-beta,epsilon-carotene-3,3',6'-triol and (3R,3'S,6'R)-7,8-didehydro-beta,epsilon-carotene-3,3',6'-triol by (1)H NMR and CD spectroscopy.     

Inhibition of the superoxide anion release and hydrogen peroxide formation in PMNLs by flavonolignans.

The mixture of flavonolignans [Legalon: silybin (2a), isosilybin (3), silydianin (4) and silychristin (5)] and derivatives of silybin (2b-d) were assessed for their inhibitory activity on the oxidative burst of PMA-stimulated human PMNLs. The inhibitory effect of flavonolignans on O(2)(-) release were compared with that of vitamin E (1). The flavonolignans tested exhibited the following order in inhibition of O(2)(-) release by PMA-stimulated PMNLs: 5,7,4"- trimethylsilybin (2c) approximately vitamin E (1) > Legalon >or= peracetylsilybin (2b) > silybin (2a) > peracetyl-5,7,4"-trimethylsilybin (2d). The flavonolignans inhibited not only the O(2)(-) release, but also the H(2)O(2) formation in PMA-stimulated PMNLs. The inhibitory capacity of flavonolignans on H(2)O(2) formation was similar to their inhibitory capacity on O(2)(-) release. These data suggest that the flavonolignans have antioxidant properties on the PMNL oxidative burst. The fact that the trimethyl derivative of silybin (2c) has a greater inhibitory effect than silybin itself suggests that the efficacy of the antioxidant properties is dependent on the lipophilicity of the molecules. This is underlined by the fact that peracetylation of all of the hydroxyl groups in silybin resulted in a total loss of the antioxidant activity of the molecule. In summary, flavonolignans inhibit the oxidative burst of PMNLs, and this inhibitory effect depends on the chemical structure of the flavonolignans.     

Phytochemical studies on Stemona plants: isolation of stemofoline alkaloids

Six new stemofoline alkaloids, (2'R)-hydroxystemofoline (5), (3'R)-stemofolenol (6), (3'S)-stemofolenol (7), 1',2'-didehydrostemofoline-N-oxide (8), the first C(19) stemofoline alkaloid, methylstemofoline (9), and the first glycosidated Stemona alkaloid, stemofolinoside (10), and three known alkaloids, (2'S)-hydroxystemofoline (2), (11Z)-1',2'-didehydrostemofoline (3), and (11E)-1',2'-didehydrostemofoline (4), have been isolated from a root extract of an unidentified Stemona species. The structure and relative configuration of these new alkaloids have been determined by spectral data interpretation and from semisynthetic studies.     

Terpenylated coumarins as SIRT1 activators isolated from Ailanthus altissima

Four new terpenylated coumarins (1-4) were isolated from the stem bark of Ailanthus altissima by bioactivity-guided fractionation using an in vitro SIRT1 deacetylation assay. Their structures were identified as (2'R,3'R)-7-(2',3'-dihydroxy-3',7'-dimethylocta-6'-enyloxy)-6,8-dimethoxycoumarin (1), 6,8-dimethoxy-7-(3',7'-dimethylocta-2',6'-dienyloxy)coumarin (2), (2'R,3'R,6'R)-7-(2',3'-dihydroxy-6',7'-epoxy-3',7'-dimethyloctaoxy)-6,8-dimethoxycoumarin (3), and (2'R,3'R,4'S,5'S)-6,8-dimethoxy-7-(3',7'-dimethyl-4',5'-epoxy-2'-hydroxyocta-6'-enyloxy)coumarin (4). Compounds 1-4 strongly enhanced SIRT1 activity in an in vitro SIRT1-NAD/NADH assay and an in vivo SIRT1-p53 luciferase assay. These compounds also increased the NAD-to-NADH ratio in HEK293 cells. The present results suggest that terpenylated coumarins from A. altissima have a direct stimulatory effect on SIRT1 deacetylation activity and may serve as lead molecules for the treatment of some age-related disorders.     

苍耳子中苯丙素类化学成分的研究

目的 研究菊科植物苍耳(Xanthium sibiricum Patrin ex Widder)的干燥成熟带总苞的果实(苍耳子)中苯丙素类化学成分。方法 采用正相硅胶柱色谱、反相十八烷基硅烷键合硅胶(ODS)柱色谱、Sephadex LH-20凝胶柱色谱和半制备高效液相色谱(HPLC)等色谱方法进行分离纯化,并结合高分辨质谱(HR-ESI-MS)、核磁共振(NMR)对分离得到的化合物进行结构鉴定。采用脂多糖(LPS)诱导的巨噬细胞RAW 264.7为筛选模型评价分离得到化合物的抗炎活性。结果 从苍耳子体积分数95%乙醇提取物的乙酸乙酯萃取物中分离并鉴定了24个苯丙素类化合物,分别为c-藜芦酰乙二醇(1)、3,4'-二羟基-3'-甲氧基苯丙酮(2)、阿魏醛(3)、丁香脂素(4)、蛇菰宁(5)、落叶松脂醇(6)、愈创木基甘油(7)、3-hydroxy-l-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone(8)、salicifoliol(9)、6-(4-hydroxy-3-methoxyphenyl)-3,7-dioxabicyclo[3.3.0]octan-2-ol(10)、榕醛(11)、jatrointelignan D(12)、icariol A₂(13)、异落叶松脂素(14)、ehletianol C(15)、(7R,7'R,7”S,7‴S,8S,8'S,8”S,8‴S)-4”,4‴-dihydroxy-3,3',3”,3‴,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8”;4',8‴-bisoxy-8,8'-dineolignan-7”,7‴,9”,9‴-tetraol(16)、(7R,7'R,7”R,7‴S,8S,8'S,8”S,8‴S)-4”,4‴-dihydroxy-3,3',3”,3‴,5,5'-hexamethoxy-7,9';7',9-diepoxy-4,8”;4',8‴-bisoxy-8,8'-dineolignan-7”,7‴,9”,9‴-tetraol(17)、2-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)-propan-1,3-diol(18)、2,3-bis-(4-hydroxy-3-methoxyphenyl)-3-methoxypropanol(19)、楝叶吴萸素B(20)、threo-guaiacylglycerol-8-vanillin ether(21)、erythro-guaiacylglycerol-8-vanillin ether(22)、黄花菜木脂素B(23)和27-对香豆酰氧基熊果酸(24)。结论 化合物6~24为首次从苍耳中分离得到。对分离得到的24个化合物进行抗炎活性筛选,其中,化合物14、21和23具有抗炎活性,其IC₅₀值分别为(28.14±1.89),(16.78±0.68)和(38.42±2.15)μmol·L^-1。     

Coumarins from the fruits of Seseli devenyense

Eight new coumarins were isolated from the fruits of Seseli devenyense Simonkai. Their structures were established from NMR and mass data and their absolute configurations from chemical degradation correlation reactions. The new structures are the decanoic and dodecanoic esters of (+)-lomatin (3, 4), the decanoates of (+)-cis-khellactone at positions 4' (5) and 3' (6) as well as the 2'S epimer of 8-(2,3-dihydroxy-3-methylbutyl)-7-hydroxychromen-2-one (7) named devenyol, its two O-monoglucosides at positions 3' and 7 named devenyosides A (8) and B (9), and the corresponding 3'- and 7-O-diglucoside named devenyoside C (10). This plant is an interesting example of stereochemical diversity based on biodiversity given that other members of the Apiaceae family produce exclusively the 2'R epimers of compounds 7-9.     

瑶山润楠根的化学成分研究

对樟科润楠属植物瑶山润楠Machilus yaoshansis根乙醇提取物的化学成分进行研究。利用多种色谱技术从瑶山润楠的醋酸乙酯萃取物中分离得到15个化合物;通过理化性质和波谱数据鉴定其结构为12个木脂素类(+)-愈创木素(1),kadsuralignan C(2),(+)-异落叶松脂素(3),(+)-5’-甲氧基异落叶松脂素(4),南烛木树脂酚(5),内消旋-裂环异落叶松树脂酚(6),异落叶松脂素-9’-O-β-D-吡喃木糖苷(7),5’-甲氧基-异落叶松脂素-9’-O-β-D-吡喃木糖苷(8),南烛木树脂酚9’-O-β-D-吡喃木糖苷(9),(2R,3R)-2,3-二氢-2-(4-羟基-3-甲氧基苯基)-7-甲氧基-3-甲基-5-(E)-丙烯基苯并呋喃(10),3,5’-二甲氧基-4’,7-环氧-8,3’-新木脂素-4,9,9’-三醇(11),甘密树皮素B(12),和3个黄烷类(+)-儿茶素(13),(-)-表儿茶素(14),bis-8,8’-catechinylmethane(15)。化合物1～15均为首次从该植物中分离得到。     

Structures of carotenoids with 5,6-dihydro-beta-end groups from the spindle shell Fusinus perplexus

A series of pirardixanthin derivatives, 1, 2, 3, 4, and 5, possessing the 5,6-dihydro-beta-end group were isolated from the spindle shell Fusinus perplexus.(1,2) Their structures and absolute configurations were determined by modern spectroscopic analysis to be (4S,5S,6S,4'S,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-4,4'-diol (1), (3S,4R,5S,6S,4'S,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-3,4,4'-triol (2), (3S,4R,5S,6S,3'S,4'R,5'S,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-3,4,3',4'-tetrol (3), (5S,6S,4'S,5'S,6'S)-4'-hydroxy-5,6,5',6'-tetrahydro-beta,beta-caroten-4-one (4), and (4'S,5'S,6'S)-4'-hydroxy-5',6'-dihydro-beta,beta-caroten-4-one (5).