Asitrilobins A and B: cytotoxic mono-THF annonaceous acetogenins from the seeds of Asimina triloba.

The seeds of Asimina triloba have yielded two novel cytotoxic mono-tetrahydrofuran (THF) Annonaceous acetogenins, asitrilobins A (1) and B (2). In addition, annonacin, asimin and asiminacin, which are known, and annomontacin and xylomaticin, which are known but are new in this species, were obtained. Compounds 1 and 2 have a relative stereochemical relationship of erythro/cis/threo across the mono-THF ring with its two flanking hydroxyls and they, thus, represent a new type of acetogenin. Their structures were established on the basis of chemical and spectral evidence. 1 and 2 showed potent bioactivities in the brine shrimp lethality test (BST) and among six human solid tumor cell lines with notable selectivity for the pancreatic cell line (MIA PaCa-2) at ten to one-hundred times the potency of adriamycin.     

Guaiacylglycerol-7'-O-methyl 8'-vanillic acid ether and related compounds from Boreava orientalis

The threo and erythro forms of guaiacylglycerol-7'-O-methyl 8'-vanillic acid ethers, threo and erythro guaiacylglycerol 8'-vanillin ethers, and threo guaiacylglycerol 8'-(4-hydroxymethyl-2-methoxyphenyl) ether have been isolated from fruits of Boreava orientalis. Structural determinations were made on the basis of UV, MS, 1H- and 13C-NMR spectral data, including two-dimensional shift correlation. The relative configurations were assigned on the basis of 1H-NMR chemical shifts.     

Synthesis of erythro and threo furanoid glycals from 1- and 2-phenylselenenyl-carbohydrate derivatives.

Differently protected erythro and threo furanoid glycals were synthesized by selenoxide elimination when phenyl 1-selenoglycosides were treated in oxidizing conditions (tBuOOH, Ti(O(i)Pr)(4), Et(2)(i)PrN). The phenyl 1-selenoglycosides were obtained from methyl 2-deoxy-D-erythro-pentofuranoside by protection of the primary hydroxyl or both hydroxyls and further reaction with PhSeH in the presence of BF(3).Et(2)O. Erythro and threo furanoid glycals were also prepared by treating 2-deoxy-2-phenylselenenyl-1,4-anhydrocyclitols under similar conditions. The 2-deoxy-2-phenylselenenyl-1,4-anhydrocyclitols were obtained from 4-pentene-1,2,3-triols by a 5-endo selenium electrophilic induced cyclization.     

Stereospecificity in enzymic and non-enzymic oxidation of beta-O-4 lignin model compounds

The degradation of the erythro and threo isomers of the non-phenolic lignin model compound 2-(2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)-1,3-propanediol was examined. Enzymic and non-enzymic oxidation of the diastereomers was performed with Trametes versicolor lignin peroxidase and cerium(IV) ammonium nitrate, respectively. Mixtures of approximately equal amounts of the diastereomers were partially degraded and subsequently analyzed with TLC and 1H-NMR. Analysis of reaction mixtures from enzymic as well as non-enzymic oxidation, revealed a preferential degradation of the threo form. Preliminary analyses of enzymic reaction mixtures of either the erythro or threo isomer suggest they yield in part different products. The observations made would have implications for the understanding of how enzymes attack lignins. They should also be taken into consideration in experiments where model compounds are being used to mimic native lignin.     

Structure–activity relationships of diverse annonaceous acetogenins against human tumor cells

Twelve annonaceous acetogenins (ACGs) with different stereochemical structures and configuration were selected to test for their inhibitions on the growth of Hela, SMMC-7541, SGC-7901, MCF-7 and A-5408 tumor cell lines using MTT method. This was the first to simultaneously investigate effects of structural factors of stereochemical structures and configuration on cytotoxicities with structure–activity relationship. The present study showed that cytotoxic selectivities of ACGs with threo/trans/threo/trans/erythro stereochemical arrangement were gently more active than those with threo/trans/threo/trans/threo stereochemical arrangement, and ACGs with cis THF ring partly produced notable cytotoxic selectivities. Furthermore, ACGs with S configuration at C-24 exhibited gently more cytotoxic selectivities potency than those with R configuration at C-24.     

Induction of Ganglioside Biosynthesis and Neurite Outgrowth of Primary Cultured Neurons by l-threo-1-Phenyl-2-Decanoylamino-3-Morpholino-1-Propanol

Abstract: We reported previously that stereoisomers of 1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), the d - threo and l - threo forms, exerted inhibitory and stimulatory effects on glycosphingolipid (GSL) biosynthesis in B16 melanoma cells, respectively. In the present study, the primary cultured rat neocortical explants were treated with l - or d - threo -PDMP. These isomers exhibited opposite effects on neurite outgrowth: d -PDMP was inhibitory at concentrations ranging from 5 to 20 µ M , whereas l -PDMP was stimulatory over the same concentration range, and the maximal effect was observed at 10–15 µ M . Rat neocortical explants were doubly labeled with [¹⁴C]serine and [³H]galactose at 15 µ M l - or d -PDMP. l -PDMP increased the incorporations of both labels into sphinganine, sphingosine, ceramide, sphingomyelin, neutral GSLs, and gangliosides, whereas d -PDMP inhibited the glucosylation of ceramide resulting in a reduction of ganglioside biosynthesis and accumulation of precursors of glucosylceramide, ceramide, and sphingomyelin. To clarify the stimulatory effect of l -PDMP on GSL biosynthesis, serine palmitoyltransferase, sphingosine N -acyltransferase, glucosylceramide synthase, lactosylceramide synthase, GM3 synthase, and GD3 synthase were quantified in cell lysates of explants pretreated with this agent. Serine palmitoyltransferase was fully activated up to 150% of the control. Furthermore, marked increases in the activities of lactosylceramide synthase (200%), GM3 synthase (240%), and GD3 synthase (300%) were observed. These results suggest that the neurotrophic action of l -PDMP may be ascribable to its stimulatory effect on the biosynthesis of GSLs, especially that of gangliosides.     

广东土牛膝的化学成分

广东土牛膝为菊科泽兰属植物华泽兰（Eupatorium chinense）的干燥根。从其甲醇提取物中共分离得到11个化合物,其中eupatorinA（1）为一新化合物,经波谱学方法鉴定为（threo）-3-O-acetyl-1-（4-hydroxy-3-methoxyphenyl）-2-[4-（3-hydroxy-1-（E）-propenyl）-2,6-dimethoxyphenoxy]propyl-β-D-glucopy-ranoside。已知化合物分别鉴定为（threo）-3-hydroxy-1-（4-hydroxy-3-methoxyphenyl）-2-[4-（3-hydroxy-1-（E）-propenyl）-2,6-dimethoxyphenox-y]-propyl-β-D-glucopyranoside（2）,ardisiacrispinA（3）,ardisiac-rispinB（4）,euparone（5）,3-（2,3-dihydroxy-isopen-tyl）-4-hydroxyacetophenone（6）,12,13-di-hydroxy-euparin（7）,gymnastone（8）,N-（2′-hydroxy-tetracosanosyl）-2-amino-1,3,4-trihydroxy-octa-dec-8-（E）-ene（9）,stigmasterol（10）和stigmasterol-3-O-β-D-glucopyranoside（11）。化合物2-4为首次从菊科植物,5-8为首次从泽兰属植物中分离得到。     

Chemical Constituents of Guangdong Tu Niu Xi (Eupatorium chinense,Compositae)

One new compound, namely eupatorin A (1), was isolated from the methanolic extract of Guangdong Tu Niu Xi, the dried roots of Eupatorium chinense (Compositae). Its structure was determined to be (threo) 3 O acetyl 1 (4 hydroxy 3 methoxyphenyl) 2 \[4 (3 hydroxy 1 (E) propenyl) 2, 6 dimethoxyphenoxy\]propyl β D gluco pyranoside on the basis of detailed spectroscopic analysis. In addition, ten known compounds, including (threo) 3 hydroxy 1 (4 hydroxy 3 methoxyphenyl) 2 \[4 (3 hydroxy 1 (E) propenyl) 2, 6 dimethoxyphenoxy\]propyl β D glucopyranoside (2), ardisiacrispin A (3), ardisiacrispin B (4), euparone (5), 3 (2, 3 dihydroxy isopentyl) 4 hydroxy acetophenone (6), 12,13 dihydroxy euparin (7), gymnastone (8), N (2′ hydroxy tetracosanosyl) 2 amino 1, 3, 4 trihydroxy octadec 8 (E) ene (9), stigmasterol (10) and stigmasterol 3 O β D glucopyranoside (11) were also obtained. This was the first time that compounds 2-4 were reported from Compositae family, while 5-8 were isolated from the genus Eupatorium.     

广东土牛膝的化学成分(英文)

广东土牛膝为菊科泽兰属植物华泽兰(Eupatorium chinense)的干燥根。从其甲醇提取物中共分离得到11个化合物,其中eupatorinA(1)为一新化合物,经波谱学方法鉴定为(threo)-3-O-acetyl-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy]propyl-β-D-glucopy-ranoside。已知化合物分别鉴定为(threo)-3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenox-y]-propyl-β-D-glucopyranoside(2),ardisiacrispinA(3),ardisiac-rispinB(4),euparone(5),3-(2,3-dihydroxy-isopen-tyl)-4-hydroxyacetophenone(6),12,13-di-hydroxy-euparin(7),gymnastone(8),N-(2′-hydroxy-tetracosanosyl)-2-amino-1,3,4-trihydroxy-octa-dec-8-(E)-ene(9),stigmasterol(10)和stigmasterol-3-O-β-D-glucopyranoside(11)。化合物2-4为首次从菊科植物,5-8为首次从泽兰属植物中分离得到。     

Schistosoma mansoni: Antischistosomal activity of the four optical isomers and the two racemates of mefloquine on schistosomula and adult worms in vitro and in vivo

Recent studies have shown that mefloquine (MQ) reveals interesting antischistosomal properties. We examined the antischistosomal activities of the erythro and threo isomers and racemates of MQ on newly transformed schistosomula (NTS) and adult Schistosoma mansoni in vitro and in mice harbouring adult S. mansoni. The in vitro effects in the presence and absence of haemin were monitored by means of microcalorimetry, scanning electron microscopy and phenotypic evaluation. Incubation of NTS with the erythro derivatives at concentrations of 3 μg/ml and above resulted in convulsions, granularity, decrease in heat flow, and death while NTS incubated with the threo derivatives were only affected at high concentrations (100 μg/ml). Extensive tegumental alterations, decrease in metabolic activity, viability, and death were observed when adult schistosomes had been exposed to 10 μg/ml of the erythro compounds. Moderate tegumental and viability changes but reduced heat production rates were observed with the threo derivatives at 10 μg/ml. In the presence of haemin, all MQ derivatives showed pronounced antischistosomal properties against adult S. mansoni in vitro. In vivo, MQ derivatives achieved statistically significant total and female worm burden reductions ranging between 65.4% and 100%. The highest total worm burden reductions of 93.4% and 90.2% were observed following treatment with the erythro and threo racemates, respectively. In conclusion, the optical isomers and racemates of MQ show only moderate stereoselectivity, in particular in vivo. Our results may enhance our understanding of the mechanism of action and therapeutic profile of MQ derivates on schistosomes.     

青霉属真菌Penicillium sp. CPCC 400786的抗病毒活性成分

采用抗艾滋病毒抑制剂筛选模型对一株青霉属真菌Penicillium sp. CPCC 400786发酵产物的乙酸乙酯提取物进行活性评价,结果显示,其对艾滋病毒有较强的抑制活性。采用正相硅胶柱、Sephadex LH-20凝胶柱和半制备HPLC等色谱技术对乙酸乙酯提取物进行分离纯化,从中分离得到8个化合物。通过波谱数据分析,分别鉴定为：oxalicine A（1）、oxalicine B（2）、cis-4,6-dihydroxymellein（3）、亚油酸（4）、十八烯酸（5）、肉豆蔻酸（6）、尿嘧啶（7）、胸腺嘧啶（8）。化合物1和2为杂萜类化合物。对化合物1-6进行了抗艾滋病毒（HIV-1）和抗甲型流感病毒（H1N1）的活性评价。结果显示,化合物1具有良好的抗H1N1活性,其IC₅₀值为38.5μmol/L,比阳性对照药利巴韦林稍弱（IC₅₀=20.5μmol/L）;化合物1和2具有抗HIV-1的活性,其IC₅₀值分别为22.4、67.8μmol/L;其他化合物未显示抗病毒活性。本研究为从青霉属中发现更多抗病毒活性杂萜分子提供了依据。     

Synthesis of novel deoxy lambda(5) phospha sugar nucleosides: 1,3-dipolar cycloaddition of an azidophospholane with alkynes.

Several novel phospha sugar nucleosides, analogs of normal sugar nucleosides, were synthesized from a phospholene 1-oxide derivative. Bromination of a phospholene precursor in aqueous organic medium gave regio diastereomers, the threo and erythro bromohydrins 3 (1-bromo-1,3,4-trideoxy-1,4-C-[(R,S)-phenylphosphinylidene]-glycero-tetrofuranose). Further substitution of the threo isomer 3a with sodium azide led to its corresponding azidophospholane 4 (1-azido-1,3,4-trideoxy-2-methyl-1,4-C-[(R)-phenylphosphinylidene]-beta-D-glycero-tetrofuranose). 1,3-Dipolar cycloaddition of 4 with various electron-deficient and electron-rich alkynes afforded triazole derivatives that are nucleoside analogues. The strong electron-withdrawing phosphoryl group in the hemiacetal ring exerted no effect over reaction regioselectivity of the 1,3-dipolar cycloaddition, but steric effects of the alkynes played a vital role on the selectivity, since the regioisomer ratios and the rates and yields of cycloadducts changed as the bulkiness of the substituents on the acetylene changes. Structures of all compounds were unequivocally confirmed by 1H, 13C, and 31P NMR and mass spectral studies. Single crystal X-ray crystallographic analysis of some derivatives allowed determination of configuration of the phospha sugar nucleosides.     

Effects of Chloramphenicol on the Circadian Rhythm of Neurospora crassa

Chloramphenicol, an inhibitor of mitochondrial protein synthesis, shortened the period length of the circadian rhythm in the Timex strain of Neurospora crassa by 2 hours. Both the l(+) threo and d(-) threo optical isomers had the same effect on the period of the rhythm, whereas only the d(-) threo isomer significantly inhibited mitochondrial protein synthesis. Tetracycline, another inhibitor of mitochondrial protein synthesis, did not change the period of the circadian rhythm. The effect of chloramphenicol on the circadian rhythm is, therefore, presumably not directly related to inhibition of mitochondrial protein synthesis, suggesting that chloramphenicol has other effects.     

Guanaconetins, new antitumoral acetogenins, mitochondrial complex I and tumor cell growth inhibitors

The antitumoral activity of a series of acetylated bis-tetrahydrofuranic acetogenins with a threo/trans/threo/trans/erythro relative configuration was characterized by four new natural and two semisynthetic, 15,24,30-trioxygenated acetogenins that were found to inhibit mitochondrial complex I enzyme as well as growth of several tumor cell lines. Placement of acetyl groups along the alkyl chain modulated the potency of the bis-tetrahydrofuranic acetogenins and could be important for future utilization of these compounds as chemotherapeutic agents.     

Synthesis of polydeoxygenated and iodinated disaccharides.]

3-Amino-polydeoxy disaccharides have been prepared by condensation of a glycal with methyl 2,3,6-trideoxy-alpha-L-erythro-(or threo)-hex-2-enopyranoside in the presence of N-iodosuccinimide. After acid hydrolysis of the glycoside, 1,4-addition of hydrazoic acid to the corresponding hex-2-enopyranose led to 3-azido-disaccharides which were acetylated. Reduction of the azido group gave 2,2'-dideoxy- or 2,2'-dideoxy-2'-iodo compounds. Condensation of O-(3,4-di-O-acetyl-2,6-dideoxy-2-iodo-alpha-L-manno-hexopy-rano syl)-(1----4)-1- O-acetyl-2,3,6-trideoxy-3-trifluoroacetamido-alpha-L-arabino-he xopyranose with daunomycinone, followed by 3',4'-O-deacetylation produced the new anthracycline, 7-O-[O-(2,6-dideoxy-2-iodo-alpha-L-manno-hexopyranosyl)-(1----4)-2,3,6- trideoxy-3-trifluoroacetamido-alpha-L-arabino-hexopyranosyl]-da uno-mycinone.     

Cytochrome P450/NADPH-dependent formation of trans epoxides from trans-arachidonic acids

Trans-arachidonic acids (trans-AA) are products of cis-trans isomerization of arachidonic acid by nitrogen dioxide radical (NO(2)), and occur in vivo, but their metabolism is unknown. We found that hepatic microsomes oxidized trans-AA via cytochrome P450/NADPH system to epoxides, which were hydrolyzed by epoxide hydrolase to diols (DiHETEs). 14,15-trans-AA produced one erythro diol and three threo diols each having one trans double bond.     

High performance liquid chromatography preparation of the molecular species of GM1 and GD1a gangliosides with homogeneous long chain base composition

A semi-preparative, analytical high performance liquid chromatographic (HPLC) procedure is described for the isolation of molecular species of GM1 and GD1a gangliosides containing a single long chain base, C18 or C20 sphingosine, C18 or C20 sphinganine, each in its natural erythro or unnatural threo form. The threo forms were obtained from 2,3-dichloro-5,6-dicyanobenzoquinone/NaBH4 -treated gangliosides. The ganglioside molecular species separated by HPLC were analyzed for carbohydrate, fatty acid, and long chain base composition. In particular, long chain bases were submitted to gas-liquid chromatographic-mass spectrometric analyses as their trimethylsilyl (TMS) or N-acetyl-TMS derivatives, and chain length, presence or absence of C4-C5 double bond, and C-3 steric configuration were ascertained. The final preparations of individual molecular species of GM1 and GD1a gangliosides were more than 99% homogeneous in their saccharide moiety, contained a single long chain base (homogeneity higher than 99%), and had a fatty acid composition primarily of stearic acid (92 to 97%). All the individual molecular species of GM1 and GD1a gangliosides were also prepared in radioactive form by selective tritiation at C-3 of the long chain base. Their specific radioactivity ranged from 1.3 to 1.45 Ci/mmol. The availability of these molecular species of gangliosides is expected to facilitate studies aimed at ascertaining the role played by the hydrophobic portion in the functional behavior of gangliosides.     

Synthesis and antidiabetic activity of some new chromonyl-2,4-thiazolidinediones

A series of chromonyl-2,4-thiazolidinediones/imidazolidinediones/2-thioxo-imidazolidine-4-ones (IIIa–i, IVa–i) was prepared by Knoevenagel reaction of 2,4-thiazolidinedione/2,4-imidazolidinedione/2-thioxo-imidazolidine-4-one (IIa–c) with 2/3-formyl chromone (Ia–b) and then alkylation with methyl/ethyl iodide. The prepared compounds were tested for their insulinotropic activities in INS-1 cells. Compounds ?Vb and ?Vc (at lower concentration, 1?μg/mL) were able to increase insulin release in the presence of 5.6?mmol/L glucose.” should be written as “Compounds IVb and IVc (at lower concentration, 1?µg/mL) and also IIId and IIIg (at higher concentration) were able to increase insulin release in the presence of 5.6?mmol/L glucose. Compounds ?Vb and ?Vc (at lower concentration, 1?μg/mL) were able to increase insulin release in the presence of 5.6?mmol/L glucose.     

Anti-HIV benzylisoquinoline alkaloids and flavonoids from the leaves of Nelumbo nucifera, and structure-activity correlations with related alkaloids

(+)-1(R)-Coclaurine (1) and (-)-1(S)-norcoclaurine (3), together with quercetin 3-O-beta-D-glucuronide (4), were isolated from the leaves of Nelumbo nucifera (Nymphaceae), and identified as anti-HIV principles. Compounds 1 and 3 demonstrated potent anti-HIV activity with EC50 values of 0.8 and <0.8 microg/mL, respectively, and therapeutic index (TI) values of >125 and >25, respectively. Compound 4 was less potent (EC50 2 microg/mL). In a structure-activity relationship study, other benzylisoquinoline, aporphine, and bisbenzylisoquinoline alkaloids, including liensinine (14), negferine (15), and isoliensinine (16), which were previously isolated from the leaves and embryo of Nelumbo nucifera, were evaluated for anti-HIV activity. Compounds 14-16 showed potent anti-HIV activities with EC50 values of <0.8 microg/mL and TI values of >9.9, >8.6, and >6.5, respectively. Nuciferine (12), an aporphine alkaloid, had an EC50 value of 0.8 microg/mL and TI of 36. In addition, synthetic coclaurine analogs were also evaluated. Compounds 1, 3, 12, and 14-16 can serve as new leads for further development of anti-AIDS agents.     

烟曲霉GZWMJZ-152茶粕发酵代谢产物

在茶粕培养基摇床培养条件下,烟曲霉GZWMJZ-152将茶粕中的山茶苷A (1)和山茶苷B (2)代谢为山奈酚-3-O-芸香糖苷(3);在茶粕培养基静置发酵条件下,从发酵提取物中分离得到5个化合物,分别为山奈酚(4)、(-)Chaetominine (5)、trypacidin (6)、1,2-seco-trypacidin (7)、(-)-丁香脂素(8)。测试了8个化合物的α-葡萄糖苷酶抑制活性和DPPH自由基清除活性,其中化合物1-3,5-8具有较好的α-葡萄糖苷酶抑制活性,IC₅₀值在133.9-308.6μg/mL;化合物1,4,8具有较好的自由基清除活性,IC₅₀值在0.43-5.06μg/mL。