[On the phytochemistry of Leonurus quinquelobatus Gilib].
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Choline↗
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The potency and phytochemistry of Indian squill soft extract.
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Animals↗
Cloning, heterologous expression, and functional characterization of 5-epi-aristolochene-1,3-dihydroxylase from tobacco (Nicotiana tabacum).
Capsidiol is a bicyclic, dihydroxylated sesquiterpene produced by several solanaceous species in response to a variety of environmental stimuli. It is the primary antimicrobial compound produced by Nicotiana tabacum in response to fungal elicitation, and it is formed via the isoprenoid pathway from 5-epi-aristolochene. Much of the biosynthetic pathway for the formation of this compound has been elucidated, except for the enzyme(s) responsible for the conversion of 5-epi-aristolochene to its dihydroxylated form, capsidiol. Biochemical evidence from previous studies with N. tabacum (Whitehead, I. M., Threlfall, D. R., and Ewing, D. F., 1989, Phytochemistry 28, 775-779) and Capsicum annuum Hoshino, T., Yamaura, T., Imaishi, H., Chida, M., Yoshizawa, Y., Higashi, K., Ohkawa, H., Mizutani, J., 1995, Phytochemistry 38, 609-613. suggested that the oxidation of 5-epi-aristolochene to capsidiol was mediated by at least one elicitor-inducible cytochrome P450 hydroxylase. In extending these observations, we developed an in vivo assay for 5-epi-aristolochene hydroxylase activity and used it to demonstrate a dose-dependent inhibition of activity by ancymidol and ketoconazole, two well characterized inhibitors of cytochrome P450 enzymes. Using degenerate oligonucleotide primers designed to the well conserved domains found within most P450 enzymes, including the heme binding domain, cDNA fragments representing four distinct P450 families (CYP71, CYP73, CYP82, and CYP92) were amplified from a cDNA library prepared against mRNA from elicitor-treated cells using PCR. The PCR fragments were subsequently used to isolate full-length cDNAs (CYP71D20 and D21, CYP73A27 and A28, CYP82E1 and CYP92A5), and these in turn were used to demonstrate that the corresponding mRNAs were all induced in elicitor-treated cells, albeit with different induction patterns. Representative, full-length cDNAs for each of the P450s were engineered into a yeast expression system, and the recombinant yeast assessed for functional expression of P450 protein by measuring the CO difference spectra of the yeast microsomes. Only microsomal preparations from yeast expressing the CYP71D20 and CYP92A5 cDNAs exhibited significant CO difference absorbance spectra at 450 nm and were thus tested for their ability to hydroxylate 5-epi-aristolochene and 1-deoxycapsidiol, a putative mono-hydroxylated intermediate in capsidiol biosynthesis. Interestingly, the CYP71D20-encoded enzyme activity was capable of converting both 5-epi-aristolochene and 1-deoxycapsidiol to capsidiol in vitro, consistent with the notion that this P450 enzyme catalyzes both hydroxylations of its hydrocarbon substrate.
Amino Acid Sequence↗
Iridoids from Scrophularia genus.
We report here an updated summary about iridoid composition of a series from the genus Scrophularia which have been investigated until now from a phytochemistry point of view. In addition a list is included about iridoids isolated in our laboratory from different plant parts of Scrophularia scorodonia L., which are compared with iridoids from some species of the Scrophularia genus. The present study may serve as a current information to researchers working on phytochemistry and pharmacological aspects from the Scrophularia genus and possibly to serve as a new starting point for future investigations.
Asteraceae↗
[Potential effects of elevated carbon dioxide on forest leaf-feeding insects].
Elevated atmospheric CO2 concentration may result in a decline of leaf nutritional quality (especially N) and an increase in some kinds of defensive secondary components such as phenolic compounds. The changes in tree phytochemistry, combined with the effects of elevated CO2 per se, have a potential impact on leaf-feeding insects. This paper reviewed the effects of elevated CO2 on the performance of leaf-feeding forest insects at individual level and community level. The elevated CO2 per se had very little influence on the metabolism of insect. Over half of the tree-insect experimental system showed that under high CO2, the performance of individual insect became poorer, while the others showed that insect had little or no response to the treatments. The direction and magnitude of the changes in insect performance could be affected by various factors, and the effects of treatments were strongly species-dependant. The magnitude of the changes in phytochemistry, the sensitivity and adaptive capacity of insect to poorer leaf quality, the differences in plant growth conditions and experimental methods, and the mediated effects of other environment factors, e. g., soil NO3-, light, temperature, and O3, were all closely related to the final performance of insect. But, the larvae's consumption usually increased under enriched CO2 treatment, which was widely thought to be a compensatory response for poorer plant quality. The experiments on forest community level found identically a reduction in herbivory, which was contrary to the results from small-scale experiments. The change of insect population and the true response of consumption by leaf-feeding forest insects under CO2 enrichment environment remain unclear, and more field-based experiments need to be conducted.
Animals↗
[Not Available].
From the beginning, next to their essential function of preparing drugs pharmacies also served as educational institutions, in particular for the instruction of their own rising generation. Especially between 1750 and 1850 pharmacies in addition were engaged in scientific research. It were basically experimental-analytic chemistry and after 1800 mainly phytochemistry which inspired numerous apothecaries to do corresponding work in their laboratories. For many of those scientifically ambitious pharmacists, however, pharmacies were merely a starting point in their professional career. More or less rapidly, they turned to other places of activity which were organizationally, socially, and intellectually of higher standards (e.g. academies or universities). There, they were better able to realize their research interests frequently roused and shaped in the pharmacies. When around 1850 chemistry as an autonomous discipline definitely was established at the universities and competition became increasingly apparent through the rising chemical industry, the former meaning and function of pharmacies as places of scientific research disappeared more and more and was completely lost about 1900.
Chemistry, Pharmaceutical↗
Antioxidant activity of five vegetables traditionally consumed by South-Asian migrants in Bradford, Yorkshire, UK.
Five vegetables traditionally consumed among South-Asian migrants in Bradford (Yorkshire, UK) were tested for their free radical scavenging activity (FRSA) in the DPPH (1,1-diphenyl-2-picrylhydrazil radical) screening assay (using extracts prepared both by cold maceration and also by boiling the plant in the solvent under reflux) and for their in vitro non-enzymatic inhibition of bovine brain lipid peroxidation. In both antioxidant assays a strong activity was shown by extracts derived from okra (Abelmoschus esculentus, Malvaceae) fruits and charungli (Caralluma edulis, Asclepiadaceae) aerial parts. Extracts from bitter melon (Momordica charantia, Cucurbitaceae) and angular loofah (Luffa acutangula) showed a significant difference in the FRSA between the extract obtained by using cold maceration and that prepared by boiling the plant in the solvent under reflux, suggesting the chemical composition of the plant changed during the heating process, leading to an increase in the amount of antioxidant components. These findings confirm the great interest of the nutraceutical sciences in extracts of Caralluma edulis, whose phytochemistry and phytopharmacology should be investigated further in order to detect possible phytotherapeutic uses in the prevention of ageing related diseases (ARDs) and Alzheimer disease (AD).
Animals↗
The antimycobacterial constituents of dill (Anethum graveolens).
As part of a project to characterize selected members of the Kuwaiti flora for their phytochemistry and antimycobacterial activity, a new furanocoumarin, 5-[4''-hydroxy-3''-methyl-2''-butenyloxy]-6,7-furocoumarin (3), was isolated from the whole herb of Anethum graveolens. The known compounds oxypeucedanin (1), oxypeucedanin hydrate (2) and falcarindiol (4) were also isolated from this plant. The structure of each compound was determined by interpretation of NMR and mass spectrometric data. The three known compounds exhibited antibacterial activity against a panel of rapidly growing mycobacteria with minimum inhibitory concentration (MIC) values in the range 2-128 microg/mL.
Anethum graveolens↗
Functional analysis of members of the isoflavone and isoflavanone O-methyltransferase enzyme families from the model legume Medicago truncatula.
Previous studies have identified two distinct O-methyltransferases (OMTs) implicated in isoflavonoid biosynthesis in Medicago species, a 7-OMT methylating the A-ring 7-hydroxyl of the isoflavone daidzein and a 4'-OMT methylating the B-ring 4'-hydroxyl of 2,7,4'-trihydroxyisoflavanone. Genes related to these OMTs from the model legume Medicago truncatula cluster as separate branches of the type I plant small molecule OMT family. To better understand the possible functions of these related OMTs in secondary metabolism in M. truncatula, seven of the OMTs were expressed in E. coli, purified, and their in vitro substrate preferences determined. Many of the enzymes display promiscuous activities, and some exhibit dual regio-specificity for the 4' and 7-hydroxyl moieties of the isoflavonoid nucleus. Protein structure homology modeling was used to help rationalize these catalytic activities. Transcripts encoding the different OMT genes exhibited differential tissue-specific and infection- or elicitor-induced expression, but not always in parallel with changes in expression of confirmed genes of the isoflavonoid pathway. The results are discussed in relation to the potential in vivo functions of these OMTs based on our current understanding of the phytochemistry of M. truncatula, and the difficulties associated with gene annotation in plant secondary metabolism.
Chromatography, High Pressure Liquid↗
Metabolic pathways as enzyme complexes: evidence for the synthesis of phenylpropanoids and flavonoids on membrane associated enzyme complexes.
In earlier studies [G. Hrazdina, G. J. Wagner, and H. W. Siegelman (1978) Phytochemistry 17, 53-56; G. J. Wagner and G. Hrazdina (1984) Plant Physiol. 74, 901-906], evidence was obtained suggesting that the endoplasmic reticulum was a site for phenylpropanoid and flavonoid metabolism in petal tissue, and that (a) multienzyme complex(es) might be involved in this metabolism. Now, the possible role of membrane-bound multienzyme complexes in phenylpropanoid and flavonoid metabolism in three tissues has been investigated by (1) correlating enzyme induction kinetics and rates, (2) examining the molecular weight of putative complexes, (3) channeling of substrates, (4) determining the susceptibility of bound activities to trypsin digestion, and (5) investigating the structurally linked latency of bound activities. Results suggest that at least a part--and possibly the entire pathway--from phenylalanine to flavonoids is membrane (endoplasmic reticulum) associated, and that this metabolism is facilitated by a multienzyme complex. Phenylalanine ammonia lyase, the first enzyme of the biosynthetic sequence, and a flavonoid glucosyltransferase, the last, appear to be located in the lumen of the membranes. Cinnamate 4-hydroxylase is membrane embedded, while other enzyme activities appear to be weakly associated with the cytoplasmic face of endoplasmic reticulum membranes.
Anthocyanins↗
The occurrence of dihydrophytyl wax esters in bovine rumen liquor.
The purpose of this study was to examine the bovine rumen liquor wax esters and compare them with those of the dietary white clover leaf and stem tissues (Body, D.R. (1974) Phytochemistry 13, 1527-1530). The major fatty acid composition of the total bovine rumen liquor wax esters was made up of saturated fatty acids (62.1%) including palmitic (20.4%), stearic (16.2%) and other acids over the n-C19-n-C30 range (20.5%). However, 13.2% phytanic acid was also present. Of the two major fatty alcohol components, dihydrophytol (33.4%) and triacontanol (20.2%) were the principal contributors. Approximately 30% of the total intact rumen liquor wax esters was a series of dihydrophytyl wax esters. These represented 0.6% of the total rumen liquor lipid extract. Individually they were comprised of dihydrophytyl palmitate (0.05%), dihydrophytyl phytanate (0.10%) and dihydrophytyl n-C18 fatty acids (0.45%). The appearance of saturated isoprenoid moieties was the most striking difference between the composition of rumen liquor and dietary white clover wax esters.
Animals↗
Levels of aminoacyl-tRNA synthetases, tRNA nucleotidyltransferase and ATP in germinating lupin seeds.
Transfer RNAs in dry lupin seeds are aminoacylated to a low extent (Kedzierski, W. and Pawełkiewicz, J. (1977) Phytochemistry 16, 503-504) and are partly degraded at the acceptor terminus (Dziegielewski, T. and Pawełkiewicz, J. (1977) Bull. Acad. Polon. Sci. Ser. Biol. 7, 4oo-435). Increase in the levels of tRNA aminoacylation and disappearance of defective tRNA molecules during seed germination are not accompanied by significant changes in the levels of phenylalanyl-, arginyl-, valyl-tRNA synthetases and tRNA nucleotidyltransferase. Additionally, no inhibitor of aminoacylation of valine tRNA has been detected in dry seeds. However, dry seeds contain very low ATP amounts, which increase dramatically during germination. The above results suggest that a very low ATP level is a factor limiting the aminoacylation and reparation of tRNA molecules at early stages of seed germination.
Adenosine Triphosphate↗
In vitro inhibition of animal and higher plants 2,3-oxidosqualene-sterol cyclases by 2-aza-2,3-dihydrosqualene and derivatives, and by other ammonium-containing molecules.
2-Aza-2,3-dihydrosqualene and related molecules, a series of new compounds designed as analogues of the transient carbocationic high energy intermediate, occurring in the oxirane ring opening during the cyclization of 2,3-oxidosqualene, were tested in vitro as inhibitors of the microsomal 2,3-oxidosqualene cyclase of animals (rat liver) and of higher plants (maize, pea). These molecules proved to be good and specific inhibitors for the cyclases of both phyla. The inhibition is due to positively charged species and is sensitive to the steric hindrance around the nitrogen-atom. 4,4,10 beta-Trimethyl-trans-decal-3 beta-ol and 4,10 beta-dimethyl-trans-decal-3 beta-ol, which have previously been described (J.A. Nelson et al., J. Am. chem. Soc. 100, 4900 (1978] as inhibitors of the 2,3-oxidosqualene cyclase of chinese hamster ovary cells, were found to be non-competitive inhibitors of the rat liver microsomal enzyme and presented no activity towards the higher plants cyclases. Aza derivatives of these decalines (A. Rahier et al., Phytochemistry, in press), which were aimed to mimic the C-8 carbocationic intermediate occurring during later steps of the 2,3-oxidosqualene cyclization did not inhibit the cyclases. This result underlines the theoretical limitations of the high energy analogues concept in designing enzyme inhibitors. Amongst other molecules tested, 2,3-epiminosqualene was found to be a reversible, non-competitive inhibitor of the cyclases; similarly U18666A was a very potent inhibitor of the microsomal cyclases. In contrast AMO 1618, a known anticholesterolemic agent reported previously to act at the level of the 2,3-oxidosqualene cyclization step, was not found per se to act on the cyclases.
Amines↗
Nucleotide sequence of a cDNA clone encoding a major allergenic protein in rice seeds. Homology of the deduced amino acid sequence with members of alpha-amylase/trypsin inhibitor family.
A cDNA clone of rice major allergenic protein (RAP) was isolated from a cDNA library of maturing rice seeds. The cDNA had an open reading frame (486 nucleotides) which coded a 162 amino acid residue polypeptide comprising a 27-residue signal peptide and a 135-residue mature protein of M(r) 14,764. The deduced amino acid sequence of RAP showed a considerable similarity to barley trypsin inhibitor [1983, J. Biol. Chem. 258, 7998-8003] and wheat alpha-amylase inhibitor [1981, Phytochemistry 20, 1781-1784].
Allergens↗
Studies on the N-acetyl-beta-D-hexosaminidase B from germinating Lupinus luteus L. seeds. I. Purification and characterization.
The N-acetyl-beta-D-hexosaminidase B of germinating Lupinus luteus L. seeds (McFarlane et al. (1984) Phytochemistry 23, 2431-2433) was partially purified with a six-step purification procedure following extraction. This enzyme consists of one protein chain (Mr 69,000, as determined by SDS-PAGE and 62,500, as obtained by gel filtration on Bio-Gel P-60 Gel) and has a neutral isoelectric point (pI = 7.05, as determined by chromatofocusing). Moreover, it was found to be very sensitive to low ionic strength, especially in the presence of different gels based on Sephadex. Considering the substrate specificity, the enzyme splits both p-nitrophenyl-2-acetamido-2-deoxy-beta-D-glucosaminide and -galactosaminide substrates, but lacks N,N'-diacetylchitobiase activity. A new mixed-substrate procedure was developed and is presented here to demonstrate that a common active site is responsible for the splitting of both synthetic substrates.
Acetylgalactosamine↗
The African Strychnos species and their alkaloids: a review.
A review of the phytochemistry of African Strychnos species and the biological activities of some species as well as of some individual alkaloids isolated from them is presented. Although pharmacological studies of 48 species showed that muscle-relaxant and/or convulsant properties were generally present, antimicrobial, cytotoxic and hypotensive properties among others have also been demonstrated by some of the species and/or alkaloids.
Africa↗
Fifteen years of study of psychoactive snuffs of South America: 1967-1982--a review.
Much has been learned concerning psychoactive snuffs in South America in the past 15 years since I delivered a review paper in the now famous symposium "Ethnopharmacologic Search for Psychoactive Drugs" held in San Francisco in 1967 (Efron et al., 1967; Schultes, 1967). There is still much to be investigated, but it seems that a recapitulation at this time may be warranted. The advances in our knowledge have come about as a result of field work as well as laboratory research and have been effected by investigators in several disciplines: archaeology, ethnobotany, ethnology and phytochemistry.
Psychotropic Drugs↗
Frequently used medicinal plants in Baja California Norte.
Herbalists in Baja California Norte, Mexico, were interviewed to determine the ailments and diseases most frequently treated with 22 commonly used medicinal plants. Those diseases which were most frequently mentioned by the herbalists provided the focus for initial assessments. The phytochemistry of the medicinal plants was determined from published research, and the likelihood of successful treatment of diseases was assessed by determining the known pharmacological actions of the plant constituents. Most of the plants contained substances which had recognized pharmacological effects in the treatment of the diseases being treated by the herbalists.
Humans↗