Medicinal applications of heavy-metal compounds

A brief summary of the key role for certain heavy-metal compounds in medicine is discussed, with a special focus on very recent findings in the following four topics: platinum anti-tumor compounds (novel mononuclear compounds, dinuclear compounds and trinuclear compounds with promising activity); ruthenium anti-tumor compounds (the first clinical trial for a Ru compound has begun); gadolinium NMR-imaging compounds (association with biomacromolecules is now possible); technetium compounds (the use of organometallic precursors opens a plethora of new species and enables the labeling of, for example, neurotransmitter molecules).     

Stimulating Effects of Organic Solvents on the Mutagenicities of Sugar-degradation Compounds

Most of the organic solvents tested were found to stimulate the mutagenicities of some mutagenic compounds. These stimulated compounds were restricted to the sugar-degradation products among various mutagenic compounds. From reduction of Nitro Blue tetrazolium (NBT), it can be said that all of the sugar-degradation compounds tested formed oxygen radicals in alkali conditions by autoxidation, and it was confirmed that the rates of the reducion of NBT by these compounds were greatly stimulated by various organic solvents. Further, the depolymerization of DNA by sugar-degradation compounds was found to stimulated by organic solvents. These results demonstrate that organic solvents enhance the oxygen radical formation of these sugar-degradation compounds, which leads to the stimulation of their mutagenicity.     

Detection of organic compounds on Mars]

McKay et al. detected polycyclic aromatic hydrocarbons (PAHs) in Martian meteorite ALH 84001 by two-step laser mass spectrometry. From the presence of PAHs, together with other results, they concluded that there were past life of Mars. On the other hands, no organisms nor organic compounds were detected in Martian regolith in Viking experiments in 1976. In order to obtain solid evidence for organisms or bioorganic compounds compounds on Mars, further analyses of Martian samples are required. There may be four classes of organic compounds on Mars, which are (i) organic compounds abiotically formed from primitive Mars atmosphere, (ii) Organic compounds delivered out of Mars, (iii) Organic compounds biotically formed by Mars organisms, and (iv) Organic compounds abiotically formed from the present Mars atmosphere. Possible organic compounds on Mars and analytical methods for them are discussed.     

Gas Chromatographic and Mass Spectral Analyses of Heated Flavor Compounds of Beef Fats

The volatile compounds from beef fats heated under the cooking condition-145°C, l0 min-were isolated, and nonacidic compounds separated from them were further fractionated into five fractions by silicic acid column chromatography. The odor of nonacidic compounds significantly resembled the heated flavor of beef fats. Several carbonyl compounds, hydrocarbons, alcohols, lactones and pyrazine compounds in the fractionated compounds were identified with the techniques of gas chromatography and gas chromatography-mass spectrometry. Their possible contribution to the heated beef fat flavor was discussed. The typical heated flavor could probably be ascribed to a proper combination of aldehydes, ketones, esters and sulfur-containing compounds.     

Flavonoids as chemosystematic markers in the tribe Cichorieae of the Asteraceae

This review summarizes reports on flavonoids from the Cichorieae (Lactuceae) tribe of the Asteraceae family. A total of 135 different compounds have been reported from 354 taxa belonging to 299 species, including many cultivars of common vegetables like chicory and lettuce. The reported compounds encompass flavanones (11 compounds), flavanonols (2 compounds), flavones (72 compounds), flavonols (35 compounds), anthocyanidins (9 compounds), isoflavonoids (2 compounds), chalcones (3 compounds), and an aurone. So far only 43 of the approximately 100 currently recognized genera of the tribe Cichorieae have been investigated for the occurrence of flavonoids. The distribution of the various classes of flavonoids is analyzed with regards to data from the current molecular-based reassessment of the systematics of the tribe.     

Microbial degradation of pollutants at high salt concentrations

Though our knowledge on microbial degradation of organic pollutants at high salt concentrations is still limited, the list of toxic compounds shown to be degraded or transformed in media of high salinity is growing. Compounds transformed aerobically include saturated and aromatic hydrocarbons (by certain archaeobacteria), certain aromatic compounds, organophosphorus compounds, and formaldehyde (by halotolerant eubacteria). Anaerobic microbial transformations of toxic compounds occurring at high salt concentrations include reduction of nitroaromatic compounds, and possibly transformation of chlorinated aromatic compounds.     

Effect of Glucose on the Interaction of Hydrophobic Compounds with the Alanine Receptor Field of Bacillus subtilis Spores during Initiation of Germination

Glucose interfered with the inhibitory action of hydrophobic compounds, such as n-octanol, diphenylamine and 2-tert-butylphenol, during L-alanine-initiated germination of Bacillus subtilis spores. The action of glucose on the action of the hydrophobic compounds was not competitive, and the binding affinity of glucose was not essentially affected by the hydrophobic compounds, indicating the presence of separate binding sites for glucose and the hydrophobic compounds. The binding affinity of D-alanine, a competitive inhibitor of L-alanine, was not affected by the hydrophobic compounds, indicating separate binding sites for D-alanine and the hydrophobic compounds. A possible arrangement of the binding sites for glucose and for the hydrophobic compounds in relation to those for L- and D-alanine on the spores is discussed.     

Identification of autotoxic compounds from fibrous roots of Panax quinquefolium L.

Panax quinquefolium (American ginseng) is a perennial understory herb that has been widely used as a medicinal plant in China and other countries. Autotoxicity has been reported to be one of the major problems hindering the consecutive cultivation of American ginseng. However, the potential autotoxic compounds produced by the root of American ginseng are less well known. Here, we report the isolation and characterization of five groups of autotoxic compounds from aqueous extracts of the fibrous roots of American ginseng. Ether extracts of the water-soluble compounds were further analyzed and separated into seven fractions. Among them, the most autotoxic fraction (Fraction V) was subjected to GC/MS analysis, and 44 compounds were identified. Based on literature information, 14 individual compounds were selected and their autotoxic effects on seedling growth were further tested. The results revealed that, of these 14 compounds, 9 phenolic compounds significantly reduced the growth of seedlings in a concentration-dependent manner, while 5 aliphatic compounds showed modest inhibition at all three concentrations tested. Furthermore, we verified the existence of the autotoxic compounds in the plow layer soil of commercially cultivated American ginseng fields, and the concentration of these compounds as determined by HPLC analysis was in line with the concentration determined to be bioactive. Taken together, our study established a functional link between the compounds produced by American ginseng and their autotoxic effects.     

Studies on the Flavors of Roast Barley (Mugi-Cha)

Five weakly acidic carbonyl compounds and two neutral carbonyl compounds were newly isolated as their 2,4-dinitrophenylhydrazones besides the previously reported compounds by using column and thin-layer chromatographies.

These compounds were characterized and identified by their IR, UV and MS spectra and the mixed melting points test.

The newly isolated and identified compounds were as follows; weakly acidic carbonyl compounds: 2-pyrrolealdehyde, vanillin, p-hydroxybenzaldehyde, syringaldehyde, proto-catechuic aldehyde, neutral carbonyl compounds: glyoxal, 5-hydroxymethylfurfural.

These compounds, particularly vanillin, protocatechuic aldehyde, 2-pyrrolealdehyde and 5-hydroxymethylfurfural, appeared to be concerned with the flavor of roast barley (Mugi-Cha).     

Effect of water and temperature stress on the content of active constituents of Hypericum brasiliense Choisy.

Hypericum brasiliense is a medicinal herb containing several compounds with important pharmacological activity. In this study, we investigated the effects of water stress (waterlogging and drought) and temperature (low and high, constant and alternate) on the content of betulinic acid and phenolic compounds (quercetin, rutin, 1,5-dihydroxyxanthone, isouliginosin B) in this species. In general, the water stress increased the levels of all of the compounds analyzed, particularly some of the phenolic compounds. On the other hand, the responses to alternating temperatures varied according to the compound. The results for plants kept in growth chambers indicated that low light intensity might have influenced the levels of the compounds. There was also a reallocation of carbon, with water-stressed plants showing a reduction in growth while the levels of the compounds increased. In the temperature treatments, such an increase was evident only for the phenolic compounds.     

Desmutagenic effect of alpha-dicarbonyl and alpha-hydroxycarbonyl compounds against mutagenic heterocyclic amines

The desmutagenic effects of alpha-hydroxycarbonyl compounds, such as glyceraldehyde, glycolaldehyde, dihydroxyacetone, furfural, 5-hydroxymethylfurfural, maltol, acetol and acetoin and alpha-dicarbonyl compounds, such as diacetyl, glyoxal, methyl glyoxal and 2,3-pentanedione were investigated against the mutagenic heterocyclic amines, such as Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 and IQ. Most of the carbonyl compounds suppressed the mutagenicity of heterocyclic amines for S. typhimurium TA98, alpha-dicarbonyl compounds showing a higher desmutagenic effect than alpha-hydroxycarbonyl compounds. Among the alpha-hydroxycarbonyl compounds, glyceraldehyde, glycolaldehyde and dihydroxyacetone showed more effective desmutagenicity, and diacetyl among the alpha-dicarbonyl compounds had the highest desmutagenic effect. These carbonyl compounds alone also showed mutagenicity to S. typhimurium TA100 without S9 mix. The reaction of carbonyl compounds with mutagenic heterocyclic amines also eliminated the mutagenicity of the former for S. typhimurium TA100.     

Structural specificity of aromatic compounds with special reference to mutagenic activity in Salmonella typhimurium--a series of chloro- or fluoro-nitrobenzene derivatives

The mutagenicity of 21 chloro- or fluoronitrobenzene compounds and 9 chloro- or fluorobenzene compounds in Salmonella typhimurium (strains TA98, TA1538, TA1537, TA100 and TA1535) was examined. The tests were carried out under the conditions of absence and presence of liver microsomal activation. 15 nitro-group compounds had mutagenic activity; above all, compounds of fluoronitrobenzene were mutagenic for both types of strain. On the other hand, chloronitrobenzene compounds were mutagenic for base-pair substitution strains only. Mutagenic activity was exhibited by all compounds having a chloro or fluoro substituent at the para and ortho position in the nitrobenzene nucleus. All compounds without a nitro substituent showed no mutagenic activity.     

Phytodegradation of organic compounds

The phytodegradation of organic compounds can take place inside the plant or within the rhizosphere of the plant. Many different compounds and classes of compounds can be removed from the environment by this method, including solvents in groundwater, petroleum and aromatic compounds in soils, and volatile compounds in the air. Although still a relatively new area of research, there are many laboratories studying the underlying science necessary for a wide range of applications for plant-based remediation of organic contaminants.     

Quantification of noncyclooxygenase derived prostanoids as a marker of oxidative stress

Recently, we discovered there is a unique class of prostaglandin F2-like compounds that are formed in vitro from arachidonoyl-containing lipids in plasma by a free radical-catalyzed mechanism. More recent studies have elucidated that these prostanoids are also produced in vivo in humans by a similar noncyclooxygenase mechanism. Levels of these PGF2 compounds detected by a mass spectrometric assay in normal human plasma and urine range from approximately 5-50 pg/mL and 500-3000 pg/mg creatinine, respectively. Circulating levels of the compounds were shown to increase by as much as 200-fold in animal models of free radical-induced lipid peroxidation. These results suggest that quantification of these prostanoids may provide a new approach to assess oxidative stress in vivo in humans. Potential advantages of this approach are that the mass spectrometric assay has a high degree of sensitivity, accuracy, and specificity and the assay can be used to quantitate these compounds in a variety of biological fluids. In addition, quantification of these compounds is of interest because these compounds possess biological activity. Disadvantages of the assay are the potential of ex vivo formation of these compounds in biological fluids containing lipids and, further, these compounds must be differentiated from PGF2 compounds that are formed via the cyclooxygenase enzyme. In addition, because the levels of these compounds in normal human plasma and urine are relatively high, assaying these compounds in circulating plasma and urine may be somewhat insensitive for the detection of increased production at isolated sites of oxidant injury within the body, in which case sampling near localized sites of their formation may be required.(ABSTRACT TRUNCATED AT 250 WORDS)     

武夷岩茶炭焙工艺对肉桂乌龙茶挥发性组分的影响

以武夷岩茶当家茶树品种肉桂(Camellia sinensis ‘Rougui’)鲜叶制成的乌龙茶为试材,基于顶空固相微萃取法(HS-SPME)结合气相色谱-质谱联用技术(GC-MS),探讨武夷岩茶炭焙工艺对肉桂乌龙茶挥发性组分的影响。实验中共检测到样本挥发性成分443个,其中包括96个杂环化合物、81个酯类化合物、31个萜类化合物、42个芳香烃类化合物、55个酮类化合物、24个其他烃类化合物、35个醇类化合物、24个醛类化合物、15个酚类化合物、14个胺类化合物、10个酸类化合物、5个含氮化合物、3个含硫化合物等。经主成分分析及聚类分析显示,焙火工艺是影响乌龙茶挥发性成分含量的重要影响因子。随炭焙程度增加,不同类别物质中的多数挥发性成分含量随之显著升高,且以美拉德反应产物等具有茶叶烘炒香的吡嗪类、糠醛类衍生物、吡咯类等化合物最具代表性;同时,部分含量丰富且具有乌龙茶特殊花果香气的醇类、萜烯类物质如香叶醇、反式-橙花叔醇、植物醇、α-法尼烯等,及具清新花香的吲哚含量显著降低。然而,大多数挥发性差异代谢物随炭焙程度增加相对含量显著升高,并不代表茶叶中芳香物质总量增加。研究表明,乌龙茶精制烘焙过程中,香气物质的积累主要来自热作用下的美拉德反应及非酶促的降解和氧化,如黄酮苷类物质水解。     

Constituents of marsh grass: Survey of the essential oils in Juncus roemerianus

The essential oil of Juncus roemerianus was isolated by steam distillation with a yield of 0·01 % of the fresh grass. Analysis by combined GLC-MS gave evidence for the presence of 78 compounds. They included 13 benzene derivatives, 11 polycyclic (mostly naphthalene type) compounds, 8 cyclohexyl compounds, 32 acyclic compounds, 9 terpenoids, and 6 furan derivatives. In total, these compounds accounted for 46·6% of the oil. Due to the presence of tetrachlorobenzene and benzyl cyanide, other halogenated compounds and alkaloids can be anticipated.     

天然活性先导化合物生物转化研究进展

天然活性先导化合物生物转化是利用生物催化剂(如：酶、微生物、动植物细胞)将加入到生物反应系统中的天然活性先导化合物进行特异性的分子结构修饰以获得高效、低毒新化合物的方法。该方法可以有效地提高已知的天然活性先导化合物的活性、降低毒副作用、改善水溶性和生物利用度,也可以用来生产具有重要应用价值的微量天然活性先导化合物,同时可用于药物代谢机制的研究。国内外学者已经针对甾体、醌类、黄酮类、萜类等化合物开展了天然活性先导化合物生物转化研究,筛选出一批有重要应用价值的生物转化反应类型,但针对天然活性先导化合物生物转化的机制、生物转化过程工程以及生物转化产物活性等方面的研究较少。将现代生命科学技术(如：生物催化剂的定向改造、高通量筛选、组合生物转化、非水相生物转化)引入天然活性先导化合物生物转化研究中,必将推进天然活性先导化合物的快速发展。     

Differentiation of the drug-binding sites of calmodulin

Calmodulin contains several binding sites for hydrophobic compounds. The apparent specificity of various 'calmodulin antagonists' for these sites was investigated. The Ki values for the inhibition of calmodulin-activated cyclic-nucleotide phosphodiesterase and myosin light-chain kinase was determined. In addition, the Kd values of the same compounds for binding to calmodulin were measured. The compounds could be separated into four groups. Group I and II compounds inhibited competitively the activation of the phosphodiesterase and myosin light-chain kinase by calmodulin. Group I compounds inhibited the activation of the phosphodiesterase and myosin light-chain kinase at identical concentrations. In contrast, group II compounds inhibited the activation of the phosphodiesterase at 5-10-fold lower concentrations than that of myosin light-chain kinase. Group III compounds inhibited the activation of these enzymes by an uncompetitive mechanism. Group IV compounds inhibited the activation of the phosphodiesterase with Ki values above 10 microM and did not affect the activation of myosin light-chain kinase. Binding of [3H]bepridil to calmodulin under equilibrium conditions yielded one high-affinity site (apparent Kd 0.4 microM) and four low affinity sites (apparent Kd 44 microM). Group I compounds interfered with the binding of bepridil to the high and low-affinity sites in a competitive manner. Group II compounds interfered in a non-competitive manner with the high-affinity site and apparently competed only with one of the low-affinity sites. Group III compounds did not compete with any of the bepridil-binding sites. Nimodipine, a group III compound, bound to one site on calmodulin with a Kd value of 1.1 microM. Other dihydropyridines competed with [3H]nimodipine for this site. The group I and II compounds, trifluoperazine and prenylamine, did not affect the binding of [3H]nimodipine. These data show that 'calmodulin antagonists' can be differentiated into at least three distinct groups. Kinetic and binding data suggest that the three groups bind to at least three different sites on calmodulin. Selective occupation of these sites may inhibit specifically the activation of distinct enzymes.     

Biodegradation of central intermediate compounds produced from biodegradation of aromatic compounds

In this study I consider the incomplete biodegradation of aromatic compounds during the wastewater cycle between aerobic or anaerobic zones in biological nutrient removal processes, including aerobic biodegradation of compounds (such as cyclohex-1-ene-1-carboxyl-CoA) produced during the incomplete anaerobic biodegradation of aromatic compounds, and anaerobic biodegradation of compounds (such as catechol, protocatechuate, and gentisic acid) produced during the incomplete aerobic biodegradation of aromatic compounds. Anaerobic degradation of the aerobic central intermediates that result from the incomplete aerobic degradation of aromatic compounds usually leads to benzoyl-CoA. On the other hand, aerobic degradation of the anaerobic central intermediates that result from the incomplete anaerobic degradation of aromatic compounds usually leads to protocatechuate.     

四氢蒽醌类化合物结构及其生物活性研究进展

四氢蒽醌类化合物是一类比较少见的天然结构,以微生物次生代谢产物居多,少量来源于植物,具有细胞毒活性、抗菌活性、抗疟原虫等生物活性。本文主要从四氢蒽醌类化合物及其衍生物的结构和生物活性两方面来对天然四氢蒽醌化合物进行综述,共综述了54个四氢蒽醌类化合物,45个来源于微生物,9个来源于植物南山花的根中,其中altersolanol A具有很好的抗肿瘤活性,是一个有很大吸引力的抗癌先导化合物。通过对四氢蒽醌类化合物的综述,为四氢蒽醌类化合物的进一步研究和开发提供依据。