工布乌头中生物碱成分研究

从工布乌头 (AconitumkongboenseLauener)的块根中分得 9个已知的C19 二萜生物碱 :塔拉萨敏 (talatisamine) 1,黄草乌碱丁 (sachaconitine) 2 ,大渡乌碱 (franchetine) 3,vilmorrisine 4 ,滇乌碱 (yunaconi tine) 5 ,印乌碱 (indaconitine) 6 ,查斯曼宁 (chasmanine) 7,伪乌头宁 (pseudaconine) 8和 8 去乙酰滇乌碱 (8 deacetyl yunaconitine) 9。并用光谱法和与已知品TLC对照 ,鉴定了所有化合物的结构。     

Alkaloidal Constituents of the Root of Aeonitum pseudogeniculatum

From the root of Aconitum pseudogeniculatum W. T. Wang, collected from the west of Sichuan province, six diterpenoid alkaloids were isolated and identified as denudatine ( Ⅰ ), chasmanine ( Ⅱ ), talatisamine (Ⅲ), yunaconitine (Ⅳ), crassicauline Ⅰ (Ⅴ) and vilmorrinianine C (Ⅵ). Yunaconitine, the major alkaloid of the plant, and its chemically transformed products pseudaconine and tetraacetylpseudaconine, showed antiinflammatory activities.     

Properties of 2,3-Butanediol Dehydrogenases from Lactococcus lactis subsp. lactis in Relation to Citrate Fermentation

Two 2,3-butanediol dehydrogenases (enzymes 1 and 2; molecular weight of each, 170,000) have been partially purified from Lactococcus lactis subsp. lactis (Streptococcus diacetylactis) D10 and shown to have reductase activity with either diacetyl or acetoin as the substrate. However, the reductase activity with 10 mM diacetyl was far greater for both enzymes (7.0- and 4.7-fold for enzymes 1 and 2, respectively) than with 10 mM acetoin as the substrate. In contrast, when acetoin and diacetyl were present together, acetoin was the preferred substrate for both enzymes, with enzyme 1 showing the more marked preference for acetoin. meso-2,3-Butanediol was the only isomeric product, with enzyme 1 independent of the substrate combinations. For enzyme 2, both the meso and optical isomers of 2,3-butanediol were formed with acetoin as the substrate, but only the optical isomers were produced with diacetyl as the substrate. With batch cultures of strain D10 at or near the point of citrate exhaustion, the main isomers of 2,3-butanediol present were the optical forms. If the pH was sufficiently high (>pH 5), acetoin reduction occurred over time and was followed by diacetyl reduction, and meso-2,3-butanediol became the predominant isomer. Interconversion of the optical isomers into the meso isomer did occur. The properties of 2,3-butanediol dehydrogenases are consistent with diacetyl and acetoin removal and the appearance of the isomers of 2,3-butanediol.     

Purification and Properties of a Diacetyl Reductase from Escherichia coli

A reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductase with the ability to reduce diacetyl has been isolated from Escherichia coli and has been purified 800-fold to near homogeneity. The product of the reduction of diacetyl was shown to be acetoin. The enzyme proved to catalyze the oxidation of NADPH in the presence of both uncharged α- and β-dicarbonyl compounds. Even monocarbonyl compounds showed slight activity with the enzyme. On the basis of its substrate specificity, it is suggested that the enzyme functions as a diacetyl reductase. In contrast to other diacetyl reductases, the one reported here is specific for NADPH and does not possess acetoin reductase activity. The pH optimum of this enzyme was found to be between 6 and 7. The maximal velocity for the NADPH-dependent reduction of diacetyl was determined to be 9.5 μmol per min per mg of protein and the K_m values for diacetyl and NADPH were found to be 4.44 mM and 0.02 mM, respectively. The molecular weight was estimated by gel filtration on Sephadex G-100 to be approximately 10,000.     

Differences between Lactobacillus casei subsp. casei 2206 and Citrate-Positive Lactococcus lactis subsp. lactis 3022 in the Characteristics of Diacetyl Production

Lactobacillus casei subsp. casei 2206 exhibited much lower levels of diacetyl reductase activity than Citr⁺Lactococcus lactis subsp. lactis 3022 but two-, three-, and more than eightfold-higher levels of diacetyl synthase, lactate dehydrogenase, and NADH oxidase activities, respectively. A requirement for metal ions by the diacetyl synthases in both species was observed. The extracts of strain 2206 but not strain 3022 produced more diacetyl from pyruvate when the reaction for diacetyl synthase was aerated than when it was conducted statically.     

Diacetyl, Acetoin, and Acetaldehyde Production by Mixed-Species Lactic Starter Cultures

Citrate utilization and acetoin, diacetyl, acetaldehyde, and lactic acid production in milk at 21 C by five different mixed-strain starters, containing Streptococcus diacetilactis (D type), Leuconostoc (B type), and S. diacetilactis and Leuconostoc (BD type), were measured. BD and D cultures utilized citrate more rapidly and produced more diacetyl, acetoin, and acetaldehyde than B types. All cultures produced much more acetoin than diacetyl, with the BD and D cultures producing four to five times larger amounts of acetoin than the B cultures. Reduction of diacetyl and acetoin toward the end of the normal incubation period was characteristic of BD and D cultures, whereas a similar reduction of acetaldehyde was characteristic of BD and especially of B cultures. Continued incubation of B cultures beyond 17 h also resulted in reduction of diacetyl and acetoin. Addition of citrate to the milk retarded diacetyl and acetoin reduction. Mn²⁺ had no effect on diacetyl production by a BD culture but increased citrate utilization and, as a consequence, caused greater diacetyl destruction in one of the B cultures.     

Desmethoxyabresoline and 10-epi-desmethoxyabresoline,new ester alkaloids in Heimia salicifolia

Two new ester alkaloids, desmethoxyabresoline and 10-epi-desmethoxyabresoline, have been isolated from young seedlings of Heimia salicifolia and have been synthesized. Chemical and physical properties of the natural and synthetic isomers are in agreement. The presence of these alkaloids adds support to the postulate that the biphenyl system of the lythraceous alkaloids is derived from trans-cinnamate esters of phenylquinolizidinols.     

Therapeutic potential of indole alkaloids in respiratory diseases: A comprehensive review

BackgroundIndole alkaloids are very promising for potential therapeutic purposes and appear to be particularly effective against respiratory diseases. Several experimental studies have been performed, both in vivo and in vitro, to evaluate the effectiveness of indole alkaloids for the management of respiratory disorders, including asthma, emphysema, tuberculosis, cancer, and pulmonary fibrosis.PurposeThe fundamental objective of this review was to summarize the in-depth therapeutic potential of indole alkaloids against various respiratory disorders.Study designIn addition to describing the therapeutic potential, this review also evaluates the toxicity of these alkaloids, which have been utilized for therapeutic benefits but have demonstrated toxic consequences. Some indole alkaloids, including scholaricine, 19-epischolaricine, vallesamine, and picrinine, which are derived from the plant Alstonia scholaris, have shown toxic effects in non-rodent models.MethodsThis review also discusses clinical studies exploring the therapeutic efficacy of indole alkaloids, which have confirmed the promising benefits observed in vivo and in vitro.ResultsThe indole alkaloidal compounds have shown efficacy in subjects with respiratory diseases.ConclusionThe available data established both preclinical and clinical studies confirm the potential of indole alkaloids to treat the respiratory disorders.     

Medicinal history of North American Veratrum

Plants belonging to the genus Veratrum have been used throughout history for their medicinal properties. During the nineteenth and twentieth centuries, phytochemical investigations revealed a host of steroidal alkaloids in Veratrum species, some of which are potent bioactives. This review discusses Veratrum species that grow in North America with a focus on the medicinal history of these plants and the steroidal alkaloids they contain. While significant reviews have been devoted to singularly describing the plant species within the genus Veratrum (botany), the staggering breadth of alkaloids isolated from these and related plants (phytochemistry), and the intricacies of how the various alkaloids act on their biological targets (physiology and biochemistry), this review will straddle the margins of the aforementioned disciplines in an attempt to provide a unified, coherent picture of the Veratrum plants of North America and the medicinal uses of their bioactive steroidal alkaloids.     

Suppression of Microbial Metabolic Pathways Inhibits the Generation of the Human Body Odor Component Diacetyl by Staphylococcus spp

Diacetyl (2,3-butanedione) is a key contributor to unpleasant odors emanating from the axillae, feet, and head regions. To investigate the mechanism of diacetyl generation on human skin, resident skin bacteria were tested for the ability to produce diacetyl via metabolism of the main organic acids contained in human sweat. l-Lactate metabolism by Staphylococcus aureus and Staphylococcus epidermidis produced the highest amounts of diacetyl, as measured by high-performance liquid chromatography. Glycyrrhiza glabra root extract (GGR) and α-tocopheryl-l-ascorbate-2-O-phosphate diester potassium salt (EPC-K1), a phosphate diester of α-tocopherol and ascorbic acid, effectively inhibited diacetyl formation without bactericidal effects. Moreover, a metabolic flux analysis revealed that GGR and EPC-K1 suppressed diacetyl formation by inhibiting extracellular bacterial conversion of l-lactate to pyruvate or by altering intracellular metabolic flow into the citrate cycle, respectively, highlighting fundamentally distinct mechanisms by GGR and EPC-K1 to suppress diacetyl formation. These results provide new insight into diacetyl metabolism by human skin bacteria and identify a regulatory mechanism of diacetyl formation that can facilitate the development of effective deodorant agents.     

Alstrostines in Rubiaceae: Alstrostine A from Chassalia curviflora var. ophioxyloides and a novel derivative,rudgeifoline from Rudgea cornifolia

Monoterpenoid indole alkaloids have frequently been isolated from the species-rich Psychotria alliance (Rubiaceae), a complex group including several tribes and genera. In our aim of understanding the chemical diversification within this remarkably heterogeneous group, members of two genera of the tribe Palicoureeae have been studied. Alstrostine A was isolated from Chassalia curviflora var. ophioxyloides, and a novel derivative, rudgeifoline from Rudgea cornifolia, respectively. Alstrostines, an unusual class of alkaloids comprising one tryptamine and two iridoid units, have recently been discovered in Alstonia rostrata (Apocynaceae). The presence of alstrostines in two rubiaceous species is remarkable but not unexpected as both families share similar biosynthetic pathways and are capable of synthesizing related alkaloids.     

β-Phenethylamine,tetrahydroisoquinoline and indole Alkaloids of Desmodium tiliaefolium

Ten alkaloids (I-X), five β-phenethylamines, two tetrahydroisoquinolines, and three indole-3-alkylamines, have been isolated from Desmodium tiliaefolium. Chemical transformations, spectral (UV,IR, NMR, MS) evidence, and in most cases comparison with reference materials established their identity as tyramine (I), hordenine (II), 3,4-dimethoxy-β-phenethylamine (III), N,N- dimethyl-3,4-dimethoxyphenethylamine (IV), N-methyl-3,4-dimethoxy-β-hydroxyphenethylamine (V), salsoline (V1), salsolidine (VII), tryptamine (VIII), abrine (IX), and hypahorine (X). Alkaloid (V) is a new naturally occurring compound, while no tetrahydroisoquinoline alkaloid has been encountered before in this genus. This is the first time that three different types of alkaloids have been reported in a single legume species. In addition to the above alkaloids, four quaternary β-phenethylamines and tetrahydroisoquinoline alkaloids have been detected, and choline and betaine have been isolated from the water-soluble alkaloid fraction of the roots.     

Biodiversity of Convolvulaceous species that contain ergot alkaloids,indole diterpene alkaloids,and swainsonine

Convolvulaceous species have been reported to contain several bioactive principles thought to be toxic to livestock including the calystegines, swainsonine, ergot alkaloids, and indole diterpene alkaloids. Swainsonine, ergot alkaloids, and indole diterpene alkaloids are produced by seed transmitted fungal symbionts associated with their respective plant host, while the calystegines are produced by the plant. To date, Ipomoea asarifolia and Ipomoea muelleri represent the only Ipomoea species and members of the Convolvulaceae known to contain indole diterpene alkaloids, however several other Convolvulaceous species are reported to contain ergot alkaloids. To further explore the biodiversity of species that may contain indole diterpenes, we analyzed several Convolvulaceous species (n = 30) for indole diterpene alkaloids, representing four genera, Argyreia, Ipomoea, Stictocardia, and Turbina, that had been previously reported to contain ergot alkaloids. These species were also verified to contain ergot alkaloids and subsequently analyzed for swainsonine. Ergot alkaloids were detected in 18 species representing all four genera screened, indole diterpenes were detected in two Argyreia species and eight Ipomoea species of the 18 that contained ergot alkaloids, and swainsonine was detected in two Ipomoea species. The data suggest a strong association exists between the relationship of the Periglandula species associated with each host and the occurrence of the ergot alkaloids and/or the indole diterpenes reported here. Likewise there appears to be an association between the occurrence of the respective bioactive principle and the genetic relatedness of the respective host plant species.     

Alkaloid distribution in some new world Lupinus species

Alkaloidal profiles of 21 Lupinus species indigenous to North and South America have been determined. Nineteen quinolizidine alkaloids were identified, including aphyllidine and N-methylcytisine, which have not previously been found in the genus. Two dipiperidine alkaloids were also detected. The pattern of alkaloidal distribution is related to a taxonomic classification of the genus.     

Antimicrobially active alkaloids from Tabernaemontana pachysiphon

Twenty-three alkaloids and five steroids and triterpenes have been isolated and identified from the root bark and stem bark of a Nigerian Tabernaemontana pachysiphon. The following bases have not previously been obtained from this species: isositsirikine, 16-epiisositsirikine, normacusine B, 16-epiaffinine, anhydrovobasindiol, tubotaiwine, ibogaline, isovoacangine, voacamine, lochnericine, 3R-hydroxyconopharyngine, 3S-hydroxyconopharyngine and 11-demethylconoduramine, the last three being new alkaloids. The dimeric indole alkaloids and 3R/S-hydroxyconopharyngine were shown to possess strong antibacterial activity against Gram-positive bacteria and the dimers against Gram-negative bacteria also.     

Glucosyloxy alkaloids from Pancratium biflorum

From fluids of flower stems and bulbs, and from extracts of roots of Pancratium biflorum, collected at different stages of growth, three new glucosyloxy alkaloids, viz. hordenine-4-O-β-d-glucoside, lycorine-1-O-β-d-glucoside and pseudolycorine-1-O-β-d-glucoside, have been isolated and characterized. Additionally, three proto alkaloids, β-phenethylamine, tyramine and hordenine, together with four true alkaloids, lycorine, pseudolycorine, pretazettine and tazettine, encountered before in other memebrs of the Amaryllidaceae, have now been isolated also from this species. Ontogenic variations of alkaloidal constituents have been observed. The ability of the alkaloidal constituents to complex with divalent metal ions and phytosterols has been examined with a view to evaluating their significance in plant biochemistry.     

Alcaloïdes d'Alstonia vitiensis var. Novo ebudica monachino

Five alkaloids have been isolated from Alstonia vitiensis: pleïocarpamine, vincorine, cabucraline, alstovine (11-methoxycompactinervine) and quaternoxine; the latter two are new alkaloids.     

Acetoin Fermentation by Citrate-Positive Lactococcus lactis subsp. lactis 3022 Grown Aerobically in the Presence of Hemin or Cu2+

Citr⁺Lactococcus lactis subsp. lactis 3022 produced more biomass and converted most of the glucose substrate to diacetyl and acetoin when grown aerobically with hemin and Cu²⁺. The activity of diacetyl synthase was greatly stimulated by the addition of hemin or Cu²⁺, and the activity of NAD-dependent diacetyl reductase was very high. Hemin did not affect the activities of NADH oxidase and lactate dehydrogenase. These results indicated that the pyruvate formed via glycolysis would be rapidly converted to diacetyl and that the diacetyl would then be converted to acetoin by the NAD-dependent diacetyl reductase to reoxidize NADH when the cells were grown aerobically with hemin or Cu²⁺. On the other hand, the Y_Glu value for the hemincontaining culture was lower than for the culture without hemin, because acetate production was repressed when an excess of glucose was present. However, in the presence of lipoic acid, an essential cofactor of the dihydrolipoamide acetyltransferase part of the pyruvate dehydrogenase complex, hemin or Cu²⁺ enhanced acetate production and then repressed diacetyl and acetoin production. The activity of diacetyl synthase was lowered by the addition of lipoic acid. These results indicate that hemin or Cu²⁺ stimulates acetyl coenzyme A (acetyl-CoA) formation from pyruvate and that lipoic acid inhibits the condensation of acetyl-CoA with hydroxyethylthiamine PP_i. In addition, it appears that acetyl-CoA not used for diacetyl synthesis is converted to acetate.     

Peptide and tetrahydroisoquinoline alkaloids from Euonymus europaeus

Three p-aryloxy macrocyclic peptide alkaloids frangulanine, franganine and frangufoline together with the 1-benzyltetrahydroisoquinoline alkaloid armepavine have been isolated from Euonymus europaeus native to Poland. These types of alkaloids are new to the Celastraceae and are of chemotaxonomic interest.     

Alkaloids of turkish papaver tauricola

The major alkaloids of Papaver tauricola collected in three different parts of Anatolia have proved to be of the rhoeadine type. The three collections possessed different major alkaloids and the existence of chemical strains containing rhoeadine-type alkaloids, is indicated. In addition to the rhoeadine-type alkaloids (rhoeagenine, rhoeadine, oreogenine, oreodine, glaucamine, glaudine and epiglaudine), tetrahydroprotoberberine-(sinactine, scoulerine) and isopavine- (amurensinine) type alkaloids have been isolated as minor products. These findings contrast with the previous literature in which 1-benzyltetrahydroisoquinoline- and proaporphine types were reported to be the major alkaloids.