Showing papers on "Indole alkaloid published in 1998"
TL;DR: Martefragin A (1), a novel indole alkaloid, showed inhibitory activity on NADPH-dependent lipid peroxidation in rat liver microsomes and the structure of 1 was elucidated on the basis of spectral analysis of its methyl ester.
Abstract: Martefragin A (1), a novel indole alkaloid, was isolated from a red alga, Martensia fragilis, by repeated column chromatography. The structure of 1 was elucidated on the basis of spectral analysis of its methyl ester (2), including 1H- and 13C-NMR, 1H-1H correlation spectroscopy (COSY), and 13-1H COSY. A single crystal X-ray analysis of the hydrochloride of 1 confirmed the assignment. Martefragin A (1) showed inhibitory activity on NADPH-dependent lipid peroxidation in rat liver microsomes. The IC50 values of 1, α-tocopherol and ascorbic acid were 2.8, 87 and 200 μM, respectively.
58 citations
TL;DR: In vitro cultures of hairy root derived from Catharanthus roseus accumulate higher levels of indole alkaloids than cell suspension cultures, and upon regeneration of the roots the alkaloid content regained its original level.
Abstract: In vitro cultures of hairy root derived from Catharanthus roseus accumulate higher levels of indole alkaloids than cell suspension cultures. Hairy roots were interconverted to undifferentiated cells by manipulation of the culture medium. When the concentration of micronutrients in the culture medium was five times that of Phillips and Collins (1979) medium, cell suspensions formed from the hairy roots. The alkaloid content was five times lower in the cell suspensions than in the control, but upon regeneration of the roots the alkaloid content regained its original level. The formation of cell suspensions from hairy roots was also accompanied by a reduction in tryptophan decarboxylase and the strictosidine synthase activity to less than 5% and 30%, respectively. 3-Hydroxymethylglutaryl coenzyme A reductase activity was the same in the cell suspension and in the regenerated line.
29 citations
01 Jan 1998
TL;DR: The use of secondary metabolites produced by organisms as systematic markers is as old as the use of morphological characters but has, until this century, been subjective as discussed by the authors, and has been subjective.
Abstract: The use of secondary metabolites produced by organisms as systematic markers is as old as the use of morphological characters but has, until this century, been subjective. For example, calling a plant aromatic was invariably an indication of the presence of volatile oils, whereas the sensation of “bitterness,” more often than not, denoted the presence of alkaloids.
22 citations
TL;DR: All strains tested were found to deglucosylate and rearrange the alkaloid to vallesiachotamine, thereby providing an example of how gene technology and microbial biotransformation can be combined for the biotechnological production of alkaloidal natural products.
22 citations
TL;DR: In this paper, 17 alkaloids were isolated from the air-dried leaves of Alstonia villosa and their structures characterized, including (19Z)-5α-methoxyrhazimine, having a 3, 4-dihydroquinoline nucleus.
Abstract: Seventeen alkaloids were isolated from the air-dried leaves of Alstonia villosa and their structures characterized. One of the seven new alkaloids was elucidated to be (19Z)-5α-methoxyrhazimine, having a 3, 4-dihydroquinoline nucleus.
21 citations
TL;DR: Preference tests indicated that tryptamine may act as an antiattractant or antifeedant in this species and provide a mechanism for reducing insect reproduction, which is potentially useful in protecting crop plants.
Abstract: The plant-produced indole alkaloid tryptamine is one of a large array of neuroactive substances that may affect insect behavior, development, and physiology. We tested the role of tryptamine on insect reproduction using the fruit fly, Drosophila melanogaster (Meigen), as a model system. Measurements were made of reproductive success, oviposition rate, and preadult survival of insects on artificial diets containing tryptamine, its precursor tryptophan, as well as glycine and serotonin (5-hydroxytryptamine). Drosophila reproduction was reduced to 15% of controls when adult insects mated and the young were allowed to develop on medium containing 75 mM tryptamine. Tryptamine-induced depression in reproductive success was due to decreased oviposition rate and preadult survival. Serotonin, but not tryptophan or glycine, also reduced oviposition rate. Preference tests indicated that tryptamine may act as an antiattractant or antifeedant in this species. The accumulation of the indole alkaloid tryptamine in plants may provide a mechanism for reducing insect reproduction, which is potentially useful in protecting crop plants.
19 citations
TL;DR: Three new bis-indole alkaloids, tabernaebovine and methylenebismehranine, have been isolated from the leaves and stems of Tabernaemontana bovina by NMR investigations.
14 citations
01 Jan 1998
TL;DR: In this paper, the structure of β-carboline (βC; 9H-pyrido[3,4-b] indole or harmala) is reviewed.
Abstract: Carbolines (pyrido-indoles) are relatively omnipresent indole alkaloid constituents in our ecosystem and most diets (Robinson, 1981). They are often present in α-, β-, γ-and δ-forms in pyrolyzed/broiled proteinaceous materials and foods, industrial wastes and various types of smoke, with the structurally “simple” β-carboline (βC; 9H-pyrido[3,4-b] indole or harmala) alkaloids represented mainly by norharman and human (Sugimura and Nagao, 1979; Felton and Knize, 1990). Furthermore, many plants and fungi, while containing the above-mentioned βC’s along with oxygenated harmala alkaloid constituents such as harmine, har-mol and harmaline (Allen and Holmstedt, 1980), are also a source of more complex, medicinally important βC-based alkaloids—for example, reserpine and yohimbine (Saxton, 1960). Ibogaine, another indole alkaloid of current topical interest in addiction research, is often pharmacologically associated with harmaline, but it is not in the carboline subclass. Figure 1 shows the structures of the aforementioned simple βC’s and several other natural derivatives that are the main focus of this review.
11 citations
TL;DR: A pentacyclic indole alkaloid, danuphylline, was obtained from the leaf extract of Kopsia dasyrachis and its structure elucidated by spectral analysis as discussed by the authors.
10 citations
9 citations
TL;DR: The structure of a new indole monoterpene alkaloid was elucidated by spectroscopic data (1H- and 13C-NMR, MS, IR, UV) from Hedyotis capitellata.
Abstract: A new indole monoterpene alkaloid, named capitelline (1), was isolated from Hedyotis capitellata (Rubiaceae). Its structure was elucidated by spectroscopic data (1H- and 13C-NMR, MS, IR, UV).
01 Jan 1998
TL;DR: Catharanthus roseus (family Apocynaceae) is grown as an ornamental plant in many countries, although it originated from Madagascar, and the most valuable being the dimeric alkaloids vinblastine and vincristine, which show antitumor activity.
Abstract: Catharanthus roseus (family Apocynaceae) is grown as an ornamental plant in many countries, although it originated from Madagascar. It is also known as Madagascar periwinkle or Cape periwinkle. This plant was used traditionally as a crude medicine for diabetes and other ailments. It has also been used as a substitute for hops in brewing beer. Now, however, C. roseus is most useful as a source of various alkaloids; approximately 90 indole alkaloids have been isolated from it, the most valuable being the dimeric alkaloids vinblastine and vincristine, which show antitumor activity. They are very similar in chemical structure, but their activity spectra and side effects are extremely different: vinblastine is effective against Hodgkin’s disease, choriocarcinoma, and the like, while vincristine is mainly employed to treat childhood acute leukemia. Vinblastin shows bone marrow toxicity, whereas vincristine is toxic to the nervous system. Due to the very low yields of these dimeric indole alkaloids in the plant (approx. 0.0005%), attempts have been made to produce alkaloid and other secondary metabolites in cell and tissue cultures. General reviews of work in this field have been published (see Heijden et al. 1989; David and Tempe 1993; Hirata et al. 1994; Sakurai and Fujioka 1996).
TL;DR: The chapter describes many successful results concerning monoterpenoid indole alkaloid syntheses performed in recent decades by utilizing a biomimetic reaction in a synthetically crucial step.
Abstract: Publisher Summary The chapter discusses monoterpenoid indole alkaloid syntheses utilizing biomimetic reactions and reviews the significant accomplishments concerning the biomimetic synthesis of secologanin-derived monoterpenoid indole alkaloids that have been reported in the past 10–15 years This chapter consists of five areas of research in the field: (1) biomimetic syntheses of Corynanthe-related alkaloids from secologanin, strictosidine, and their analogues, (2) syntheses of Aspidosperma and Iboga alkaloids via secodine or dehydrosecodine intermediates, (3) biomimetic skeletal rearrangement and fragmentation, (4) biomimetic syntheses in the Sarpagine family, and ( 5 ) biomimetic bisindole alkaloid syntheses The chapter describes many successful results concerning monoterpenoid indole alkaloid syntheses performed in recent decades by utilizing a biomimetic reaction in a synthetically crucial step Adopting this biomimetic strategy, a number of structurally complex and/or unusual alkaloids are synthesized efficiently in a regio- and stereoselective manner The biosynthesis by chemical means has led to the discovery of new synthetic methodology and reactions In some cases, biogenetically patterned synthesis supported (or provided proof of) the postulated biosynthetic pathway
TL;DR: In this paper, the spectral data of isomers 3 and 4 with those of 19-hydroxytacamine from Tabernaemontana eglandulosa confirms that isomer 3 represents the naturally occurring 19hydroxacamine.
TL;DR: In this paper, the uptake of a synthetic amine (methoxycarbonylethyl)- N -[2-(1 H -indol-3-yl)-ethyl]- β -methyl alaninate) by seedlings of C. roseus cultivated in vitro, and its effects on indole alkaloid accumulation were analyzed by HPLC and TLC.
TL;DR: In this article, strictosidine produced by heterologously expressed strictosidine synthase from Rauwolfia serpentina was used in biotransformation experiments with a series of 22 bacterial strains.
Abstract: 3 α ( S )-Strictosidine produced by heterologously expressed strictosidine synthase from Rauwolfia serpentina was used in biotransformation experiments with a series of 22 bacterial strains. All strains tested were found to deglucosylate and rearrange the alkaloid to vallesiachotamine, thereby providing an example of how gene technology and microbial biotransformation can be combined for the biotechnological production of alkaloidal natural products.
01 Jan 1998
TL;DR: Many alkaloids contain an indole nucleus as a part of their structure, and monoterpene-derived indole alkaloid compounds are the most important of these compounds, but several other significant types of indoles exist.
Abstract: Many alkaloids contain an indole nucleus as a part of their structure. Monoterpene-derived indole alkaloids (see Chapter 34) are the most important of these compounds, but several other significant types of indole alkaloids exist. Ergot alkaloids formed from tryptamine and a mevalonate-derived hemiterpene unit are of medical importance. Others, such as harmane alkaloids, physostigmine and a series of structurally similar alkaloids, Calycanthus alkaloids (Calycanthaceae) and related compounds (principally from the Rubiaceae), and relatively minor types of alkaloids from the Ascelpiadaceae, Sterculiaceae, and Verbenaceae are summarized in the present chapter.
TL;DR: A pentacyclic indole alkaloid, danuphylline, was obtained from the leaf extract of Kopsia dasyrachis and its structure elucidated by spectral analysis as discussed by the authors.
Abstract: A novel pentacyclic indole alkaloid, danuphylline, was obtained from the leaf-extract of Kopsia dasyrachis and its structure elucidated by spectral analysis.