Dictyonamides A and B, new peptides from marine-derived fungus.
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Amino Acid Sequence↗
Biomedical subjects
H Shigemori
Publications and source records attributed to H Shigemori.
Pacovatinins A-C, new labdane diterpenoids from the seeds of Renealmia exaltata.
Three new labdane diterpenoids, pacovatinins A-C (1-3), were isolated from seeds of the Brazilian medicinal plant Renealmia exaltata ("Pacová-catinga"), and their structures including absolute configurations were elucidated by spectroscopic data and a modified Mosher method.
Animals↗
Porwenins A and B, new clerodane diterpenoids from Portulaca okinawensis.
Two new clerodane-type diterpenes, porwenins A (1) and B (2), were isolated from Portulaca okinawensis, and the structures were elucidated by spectroscopic data.
Diterpenes↗
Antimitotic activity of moroidin, a bicyclic peptide from the seeds of Celosia argentea.
A unique bicyclic peptide, moroidin (1), from the seeds of Celosia argentea (Amaranthaceae) strongly inhibited the polymerization of tubulin. The stereostructure of moroidin (1) was reinvestigated by spectroscopic data, chemical degradation, and molecular dynamics simulation.
Antineoplastic Agents↗
The diversity of chemical substances controlling the nyctinastic leaf-movement in plants.
Leaf-movement in nyctinastic plants has long been believed to be controlled by plant hormones that are common among all nyctinastic plants. We have identified several bioactive substances for nyctinasty, whose bioactivities were highly specific to the original plant, based on the bioassay using the original plant leaf, and have shown that nyctinastic leaf-movement is not regulated by plant hormones. Our present results are in accordance with Umrath et al. physiologically significant opinion.
Biological Assay↗
Coruscol A, a new metabolite from the marine-derived fungus penicillium species.
A new metabolite possessing a 1,3-dioxane ring, coruscol A (1), was isolated from the mycelium of the fungus Penicillium sp., which was separated from the Okinawan marine bivalve Mytilus coruscus, and the structure was elucidated by spectroscopic data.
Animals↗
Echinophyllins C-F, new nitrogen-containing clerodane diterpenoids from Echinodorus macrophyllus.
Four new nitrogen-containing clerodane diterpenoids, echinophyllins C-F (1-4), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus ("Chapéu-de-couro"), and their structures and relative stereochemistry were elucidated from their spectroscopic data. Compounds 1-4 possess an alpha,beta-unsaturated gamma-lactam ring consisting of a clerodane diterpene unit and an amine moiety.
Diterpenes↗
Sculezonones A and B, two metabolites possessing a phenalenone skeleton from a marine-derived fungus Penicillium species.
Two new metabolites possessing a phenalenone skeleton, sculezonones A (1) and B (2), were isolated from cultured broth of the fungus Penicillium sp., which was separated from the Okinawan marine bivalve Mytilus coruscus, and the structures were elucidated by spectroscopic data.
Molecular Structure↗
Chapecoderins A-C, new labdane-derived diterpenoids from Echinodorus macrophyllus.
A new seco-labdane-type diterpenoid, chapecoderin A (1), and two new rearranged labdane-type diterpenoids, chapecoderins B (2) and C (3), were isolated from the leaves of the Brazilian medicinal plant Echinodorus macrophyllus ("Chapéu-de-couro"), and their structures and relative stereochemistry were elucidated by spectroscopic data. Chapecoderins A-C (1-3) possess in common an alpha,beta-unsaturated gamma-lactone ring in the side chain.
Molecular Structure↗
Multidrug resistance reversal activity of taxoids from Taxus cuspidata in KB-C2 and 2780AD cells.
Some non-taxol-type taxoids having neither an oxetane ring at C-4 and C-5 nor an N-acylphenyl-isoserine group at C-13, such as taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J, which were isolated from the Japanese yew Taxus cuspidata, increased cellular accu-mulation of vincristine (VCR) in multidrug-resistant 2780AD cells as potently as verapamil, and efficiently inhibited [(3)H]azidopine photolabeling of P-glycoprotein (P-gp). Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J at 10 microM completely reversed the resistance to colchicine, VCR, and taxol in KB-C2 cells, which overexpress P-gp, while taxinine and taxinine M showed no effect. Taxuspine C, 2'-desacetoxyaustrospicatine, and 2-desacetoxytaxinine J may be candidate pharmaceuticals for reversing multidrug resistance (MDR) and also may be good modifiers of MDR in cancer chemotherapy.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
Modulation of multidrug resistance in tumor cells by taxinine derivatives.
Among a series of taxinine (1) and its designed derivatives (2-33), two taxoids (29 and 33) increased cellular accumulation of vincristine in multidrug-resistant tumor cells more potently than verapamil, while the activities of eight taxoids (11, 14-16, 22, and 30-32) were comparable with that of verapamil. These results reveal that some taxinine derivatives are good modifiers of multidrug resistance in tumor cells.
Animals↗
Palythoalones A and B, new ecdysteroids from the marine zoanthid palythoaaustraliae
Two new ecdysteroids, palythoalones A (1) and B (2), have been isolated from the marine zoanthid Palythoa australiae. The structures have been elucidated on the basis of spectroscopic data and by chemical means.
Journal Article↗
Brasilicardin A, a new terpenoid antibiotic from pathogenic Nocardia brasiliensis: fermentation, isolation and biological activity.
A novel tricyclic diterpenoid antibiotic, brasilicardin A, was isolated from the culture broth of Nocardia brasiliensis IFM 0406. The antibiotic exhibited immunosuppressive activity in a mouse mixed lymphocyte reaction (MLR) assay system and its IC50 value was 0.057 microg/ml. Although the inhibitory activity of cyclosporin A (CyA) against IL-2 production was confirmed in the MLR assay system, brasilicardin A did not have the activity. The results of in vitro toxicity testing of brasilicardin A against various human cell lines were compared with those of CyA.
Aminoglycosides↗
Modulation of multidrug resistance by taxuspine C and other taxoids from Japanese yew.
Taxuspine C (1), a new taxoid from the Japanese yew Taxus cuspidata, increasing the cellular accumulation of vincristine (VCR) in multidrug-resistant tumor cells as potent as verapamil enhanced the chemotherapeutic effect of VCR in P388/VCR-bearing mice. When taxuspine C (1) was given i.p. daily at 200 mg/kg with 0.2 mg/kg VCR for 5 days, a treated/control (T/C) value of 138% was obtained. The other new taxoids, taxezopidines G (8) and H (9), from the yew also increased the VCR accumulation as potent as verapamil. These results suggest that some taxoids may be useful for overcoming multidrug resistance in tumor cells.
Animals↗
Three new metabolites from the marine yeast aureobasidium pullulans
Two new diketopiperazines (1 and 2) with a d-cis-4-hydroxyproline residue, and orcinotriol (3), a new 1,3-dihydroxyphenol derivative, were isolated from cultured broth of the yeast Aureobasidium pullulans, which was isolated from an Okinawan marine sponge. The structures of the compounds, including their absolute stereochemistries, were determined by spectroscopic data and chemical means.
Journal Article↗
New cyclic polyketide peroxides from okinawan marine sponge plakortis sp
Three new cyclic peroxides (2-4) have been isolated from the Okinawan marine sponge Plakortis sp., and the structures were elucidated by extensive spectroscopic analyses. The absolute stereochemistries of 2 and 3 were determined by chemical conversion, whereas that of the dioxane ring of 4 was assigned by the modified Mosher's method.
Journal Article↗
Brasilinolide A, a new macrolide antibiotic produced by Nocardia brasiliensis: producing strain, isolation and biological activity.
A new 32-membered macrolide antibiotic, brasilinolide A was isolated from the fermentation broth of Nocardia sp. IFM 0406. The producer was identified as Nocardia brasiliensis. The antibiotic was only active against Aspergillus niger, but not active against other fungi including yeasts as well as other filamentous like fungi and bacteria. Brasilinolide A exerted an immunosuppressive activity in the assay system of a mixed lymphocyte reaction (MLR).
Animals↗
Gastric mucus generation in cirrhotic patients with portal hypertension. Effects of tetraprenylacetone.
We have evaluated gastric mucus generation (study 1) and the effects of tetraprenylacetone on gastric mucus generation (study 2) in cirrhotic patients with portal hypertension. Study 1: Included were 50 noncirrhotics (group A), 25 cirrhotics without portal hypertension (group B), and 25 cirrhotics with portal hypertension (group C). The antrum, corpus, and fundus mucus generation was assessed by hexosamine concentration using biopsy specimens. In groups A and B, the antrum hexosamine concentration was significantly higher compared with the corpus (P < 0.01, P < 0.01) and the fundus (P < 0.01). In contrast, the hexosamine concentration at each location was similar in group C. Furthermore, the antrum hexosamine concentration of group C was significantly lower compared with that of group A (P < 0.05). In study 2, a double-blind design, 300 mg of tetraprenylacetone was administered for four weeks in 10 cirrhotics with portal hypertension and placebo in 10. The regional hexosamine concentrations were measured before and after drug administration. Placebo administration did not change hexosamine concentration at each location. In contrast, tetraprenylacetone increased the antrum and corpus hexosamine concentration (P < 0.01, P < 0.05), although the fundus concentration did not change. These data suggest that cirrhotics with portal hypertension have reduced gastric antral mucus generation and tetraprenylacetone normalizes this.
Anti-Ulcer Agents↗