A new prenylated flavone from Artocarpus champeden inhibits the K(+)-dependent amino acid transport in Bombyx mori midgut

A New Isoprenylated Chalcone, Artoindonesianin J, from the Root and Tree Bark of Artocarpus Bracteata

A new prenylated chalcone artoindonesianin J, the structure of which was determined on the basis of spectroscopic evidence, was isolated from the root and tree bark of Artocarpus bracteata Hook, together with three known flavonoids, kanzonol, 6-(3-methylbut-2-enyl)-apigenin and carpachromene.

Diastereoselective synthesis of novel spiro indanone fused pyrano[3,2-c]chromene derivatives following hetero-Diels–Alder reaction andin vitroanticancer studies

Synthesis of novel spiro indanone fused pyrano[3,2-c]chromene derivatives following hetero-Diels–Alder reaction has been demonstrated and evaluated for theirin vitroanticancer activity.

Differential response in foliar chemistry of three ash species to emerald ash borer adult feeding

The emerald ash borer (EAB; Agrilus planipennis Fairmaire; Coleoptera: Buprestidae), is an exotic wood-boring beetle that has been threatening North American ash (Fraxinus spp.) resources since its discovery in Michigan and Ontario in 2002. In this study, we investigated the phytochemical responses of the three most common North American ash species (black, green, and white ash) in northeastern USA to EAB adult feeding. Black ash was the least responsive to EAB adult feeding in terms of the induction of volatile compounds, and levels of only two (indole and benzyl cyanide) of the 11 compounds studied increased. In green ash, levels of two [(E)-β-ocimene and indole] of the 11 volatile compounds studied were elevated, while the levels of two green leaf volatiles [hexanal and (E)-2-hexenal] decreased. White ash showed the greatest response with an increase in levels of seven of the 11 compounds studied. Qualitative differences among ash species were detected. Among the phenolic compounds detected, ligustroside was the only one detected in all three species. Oleuropein aglycone and 2 unidentified compounds were found only in black ash; coumaroylquinic acid and feruloylquinic acid were detected only in green ash; and verbascoside hexoside was detected only in white ash. EAB adult feeding did not elicit or decrease concentrations of any selected individual phenolic compounds. However, although levels of total phenolics from black and green ash foliage were not affected by EAB adult feeding, they decreased significantly in white ash. EAB adult feeding elevated chymotrypsin inhibitors in black ash. The possible ecological implications of these findings are discussed.

Artin M: a rational substitution for the names artocarpin and KM+

The aim of the present letter is to propose a rational nomenclature for the d-mannose-binding lectin from seeds of Artocarpus integrifolia. It is justified by the existing confusion in the literature concerning the trivial names used until now to designate the lectin and by the increasing interest in its biomedical applications, specially those concerning the immunomodulation activity exerted by the lectin, triggered by the recognition of glycoconjugates on the surface of cells of the innate immunity. The new nomenclature proposed for the lectin refers to both its origin and its specificity on sugar recognition.

Prenylated flavonoids and related compounds of the Indonesian Artocarpus (Moraceae)

Several species of the genus Artocarpus (Moraceae) have been investigated in our laboratories during the last decade. Over 60 phenolic constituents have been discovered and characterized, including 27 new compounds from 13 Indonesian taxa of Artocarpus, namely A. champeden, A. lanceifolius, A. teysmanii, A. scortechinii, A. rotunda, A. maingayi, A. kemando, A. bracteata, A. altilis, A. fretessi, A. gomezianus, A. reticulatus and A. glaucus. The principal and the most pronounced features of these phenolic constituents are the assembly of an isoprenyl substituent at C-3 of a flavone skeleton by closure of an ether bridge or a carbon-carbon linkage with the B ring of the skeleton, which may further rearrange into xanthone to produce various classes of natural products. The structures of the new and unusual natural products are presented. Many of the metabolites also exhibit cytotoxic effect against murine leukemia P388 cells.

Molecular diversity of Artocarpus champeden (Moraceae): A species endemic to Indonesia

A summary of results obtained in the study of natural products isolated from a Moraceae species Artocarpus champeden is presented. The various classes of 3-prenylflavonoids isolated and the biogenetical correlation between the metabolites are discussed. Some of the flavonoids exhibited strong cytotoxicity against murine leukemia P388 cell lines, suggesting that flavonoids derived from moraceous plants represent a plausible unexplored resource of novel antitumor leads.

Changes in leucine transport activity in Chironomus riparius larvae after short-term exposure to potassium dichromate and fenitrothion

The effect of sublethal concentrations of potassium dichromate and fenitrothion on sodium-leucine cotransport in brush border membrane vesicles from Chironomus riparius larvae has been investigated. Exposure to potassium dichromate and fenitrothion caused a dose- and time-dependent inhibition of leucine uptake. Transport inhibition is easily detectable at doses 100-fold lower than LD50. Kinetic experiments showed that inhibition was mainly caused by a decrease of the Vmax (680 +/- 53 vs. 382 +/- 23 and 555 +/- 27 nmol/15s/mg protein in control and exposed larvae to K2Cr2O7 and fenitrothion, respectively). Inhibition is possibly related to a variation of sodium ions permeability as evidenced by increased membrane lipid peroxidation. Appropriate control experiments ruled out that the observed differences could be due to changes in general features of membrane preparations. Transport inhibition observed in larvae exposed to potassium dichromate was accompanied by changes in ascorbate peroxidase and dehydroascorbate reductase activities, whereas those exposed to fenitrothion displayed an increase in transaminase activity. The possible value of leucine uptake as biochemical biomarker is briefly discussed. Arch. Insect Biochem. Physiol. 55:90-101, 2004.

Bioactive prenylated flavonoids from the stem bark of Artocarpus kemando

Four known prenylated flavonoids, artonins E (1) and O (2), artobiloxanthone (3), and cycloartobiloxanthone (4), were isolated from the stem bark of Artocarpus kemando by bioassay-guided fractionation using the DNA strand-scission and the KB cytotoxicity assays as monitors. Compounds 1 and 3 exhibited strong DNA strand-scission activity, and all four compounds were found to be cytotoxic.

Artoindonesianins Q-T, four isoprenylated flavones from Artocarpus champeden Spreng. (Moraceae)

Four isoprenylated flavones, artoindonesianins Q-T, were isolated from the heartwood of Artocarpus champeden Roxb. The structures of these compounds were elucidated on the basis of their spectroscopic data.

The biochemistry and medical significance of the flavonoids

Flavonoids are plant pigments that are synthesised from phenylalanine, generally display marvelous colors known from flower petals, mostly emit brilliant fluorescence when they are excited by UV light, and are ubiquitous to green plant cells. The flavonoids are used by botanists for taxonomical classification. They regulate plant growth by inhibition of the exocytosis of the auxin indolyl acetic acid, as well as by induction of gene expression, and they influence other biological cells in numerous ways. Flavonoids inhibit or kill many bacterial strains, inhibit important viral enzymes, such as reverse transcriptase and protease, and destroy some pathogenic protozoans. Yet, their toxicity to animal cells is low. Flavonoids are major functional components of many herbal and insect preparations for medical use, e.g., propolis (bee's glue) and honey, which have been used since ancient times. The daily intake of flavonoids with normal food, especially fruit and vegetables, is 1-2 g. Modern authorised physicians are increasing their use of pure flavonoids to treat many important common diseases, due to their proven ability to inhibit specific enzymes, to simulate some hormones and neurotransmitters, and to scavenge free radicals.

Artoindonesianin L, a new prenylated flavone with cytotoxic activity from Artocarpus rotunda

A new prenylated flavone, named artoindonesianin L (1), was isolated from Artocarpus rotunda (Hout) Panzer (Moraceae). Its structure was elucidated as on the basis of spectroscopic evidence. Along with this new compound, four known phenolic compounds were also isolated from this plant and identified as artonins M (2) and E (3), cycloartobiloxanthone (4) and artonin O (5). All these compounds showed significant cytotoxicity against murine P388 leukemia cells.

Artoindonesianins G-I, three new isoprenylated flavones from Artocarpus lanceifolius

Three new isoprenylated flavones, artoindonesianins G-I (1-3), together with the two known flavones artelastofuran (4) and artelasticin (5), have been isolated from the heartwood of Artocarpus lanceifoliu. The structures of the new compounds were determined on the basis of spectroscopic data. Compounds 1-3 and 5 showed strong cytotoxicity against P-388 cells.

A geranylated chalcone with 5alpha-reductase inhibitory properties from Artocarpus incisus

A geranylated chalcone was isolated from leaves of Artocarpus incisus and it showed potent 5alpha-reductase inhibitory activity.

Substrate specificity of the brush border K+-leucine symport of Bombyx mori larval midgut

L-leucine uptake into membrane vesicles from Bombyx mori larval midgut was tested for inhibition by 55 compounds, which included sugars, N-methylated, alpha-, beta-, gamma-, delta-, epsilon-amino acids, primary amines, alpha-amino alcohols, monocarboxylic organic acids and alpha-ketoacids. Based on cis-inhibition experiments performed at the high pH (10.8) characteristic of the midgut luminal content in vivo, we find that the carrier binding site interacts with molecules which possess a well-defined set of structural features. Amino acids are preferentially accepted as anions and the ideal inhibitor must have an hydrophobic region and a polar head constituted by a chiral carbon atom bearing two hydrophilic groups, a deprotonated amino-group and a dissociated carboxylic group. Binding is reduced if one of the two hydrophilic groups is removed. Lowering the pH to less alkaline value (8.8) only affects the affinity of delta- and epsilon-amino acids, which are excluded from binding because of their positively charged side-chain. Modifications of the potassium electrochemical gradient increased the affinity constant values of the molecules, but have little effect on the rank of specificity. Physiological implications of the data reported are discussed.

Amino acid transport in insects

Most insect cell membranes seem to contain uniporters that facilitate the diffusion of amino acids into and out of the cells. In addition to these passive diffusion systems, all but one of the insect tissues studied to date seem to contain at least one amino acid-cation symport system that allows their cells to accumulate certain amino acids from the extracellular medium. cDNAs encoding three such symporters have very recently been cloned and sequenced. The deduced amino acid sequence of each insect symporter was determined to be homologous to that of symporters mediating the transport of the same or related substrates in mammalian tissues.

Artoindonesianins A and B, two new prenylated flavones from the root of Artocarpus champeden

Two new prenylated flavones, named artoindonesianin A (1) and artoindonesianin B (2), were isolated from the root of Artocarpus champeden, together with a known prenylated flavone, artonin A. The structures of artoindonesianins A and B were determined on the basis of spectral evidence (MS, 1H and 13C NMR) and by comparison with known related compounds. Compounds 1 and 2 exhibited cytotoxic activity against murine leukemia (P-388) cells.