Lignan and norditerpene dilactone constituents of Podocarpus saligna

Thujaplicatin methyl ether and a new norditerpene dilactone named salignone I have been isolated from the roots of Podocarpus saligna and their structures determined by high field ¹H NMR and NOE difference spectroscopy.     

The cytotoxic norditerpene dilactones of Podocarpus milanjianus and Podocarpus sellowii

The cytotoxic norditerpene dilactones nagilactone F and its new congener nagilactone G have been isolated from the bark constituents of Podocarpus milanjianus and Podocarpus sellowii. The diterpenes totarol, 19-oxototarol and macrophyllic acid were also isolated.     

Diterpenes of Podocarpus ferrugineus bark

The following oxygenated diterpenes have been isolated from the bark of Podocarpus ferrugineus D. Don: isopimarol, isopimaric acid, sandaracopimaric acid, ferruginol, sugiol, sugiyl methyl ether, xanthoperol, royleanone, 6-dehydroroyleanone, cryptojaponol, 5β-hydroxy-6-oxasugiyl methyl ether, 2-ketoferruginol and 2β-acetoxysugiyl methyl ether.     

Isolation and identification of two new biologically active norditerpene dilactones from Aspergillus wentii

Two new biologically-active norditerpenoid dilactones were purified from culture extracts of Aspergillus wentii and assigned the trivial names wentilactone A and wentilactone B. The absolute chemical structure of wentilactone A was determined by single crystal X-ray diffraction and circular dichroism. The structure of wentilactone B was determined by ¹H and ¹³C NMR analyses. Wentilactone A had an ld₅₀ of 7.0 mg/kg when administered orally to 1-day-old chickens. Both metabolites inhibited growth in wheat coleoptile bioassays.     

Biflavanoids,norditerpenes and a nortriterpene from Podocarp us urbanii

The structures of a biflavanoid, two new norditerpenes, urbalactone and 2,3-dihydropodolide, an ecdysterol, as well as a known biflavanoid, nagilactone C and podolide from Podocarpus urbanii were elucidated.     

Infraspecific variation of foliage diterpenes of Dacrydium cupressinum

The unique diterpene lauren-1-ene has only been found in the foliage of Dacrydium cupressinum, the New Zealand rimu, but the levels of this and other diterpenes vary greatly from tree to tree. Diterpene levels are apparently under genetic control, as they are not affected by environmental factors. Male and female trees do not differ significantly, but juvenile trees have lower phyllocladene levels than do adult trees. Different regions of New Zealand contain different proportions of high-laurenene trees.     

7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucoside and other flavonoids from Podocarpus nivalis

In the course of a chemotaxonomic survey of New Zealand Podocarpus species, a number of new flavonoid glycosides have been isolated from P. nivalis. These are: luteolin 3′-O-β-D-xyloside, luteolin 7-O-β-D-glucoside-3′-O-β-D-xyloside, dihydroquercetin 7-O-β-D-glucoside, 7-O-methyl-(2R:3R)-dihydrokaempferol 5-O-β-D-glucopyranoside, 7-O-methyl-(2R:3R)-dihydroquercetin 5-O-β-D-glucopyranoside, 7-O-methylkaempferol 5-O-β-D-glucopyranoside and 7-O-methylquercetin 5-O-β-D-glucopyranoside. Diagnostically useful physical techniques for distinguishing substitution patterns in dihydroflavonols are discussed and summarized. Glucosylation of the 5-hydroxyl group in (+)-dihydroflavonols is shown to reverse the sign of rotation at 589 nm.     

Isocrotocaudin,A new norclerodane-type diterpene from Croton caudatus

Isocrotocaudin, a new furanoid norditerpene (norclerodane type), has been isolated from the petrol extract of the stem-bark of Croton caudatus (Eup     

New physalins from Physalis angulata and Physalis lancifolia. Structure and reactions of physalins D,I, G and K

The structures of physalins I, G and K are established respectively as 5,6-dihydro-5α-methoxy-6β-hydroxy, 4,5-dehydro-5,6-dihydro-4β-hydroxy and 5,6-dihydro-4α,5α-epoxy-6α-hydroxy derivatives of physalin B. The chemistry of physalin D, and the synthesis of physalins D and I from physalin F and physalin K from physalin G are described.     

New indanone compounds from Onychium japonicum

A new indanone glucoside pteroside M has been isolated from fronds of Onychium japonicumPteridaceae. The structure of its aglycone pterosin M has been established by ¹³C NMR, PMR spectra and degradation with nitric acid.     

Phylloflavan,a characteristic constituent of Phyllocladus species

Selective visualization of 2D TLC of extracts of Phyllocladus species with vanillin—hydrochloric acid showed a characteristic pattern of constituents attributable to catechin, epicatechin and phylloflavan, a new flavanoid compound. Optical rotation measurements showed that while catechin and epicatechin are of the normal type with the 2R configurations, the flavan moiety in phylloflavan is of the opposite 2S configuration. Spectroscopic data of the new compound and its hydrolysis products showed phylloflavan to be ent-epicatechin-3-δ-(3,4-dihydroxyphenyl)-β-hydroxypentanoate.     

The effects of a macrophage-derived cytotoxin on the growth and metabolism of target cells.

Peritoneal macrophages obtained from Sarcoma I (SaI)-immune CS7BL/6 mice release a heat-labile cytotoxin, specific macrophage cytotoxin (SMC), following a two hour interaction with appropriate target cells. Specific macrophage cytotoxin specifically inhibits A/Jax spleen cells from mitogenically responding to concanavalin A, whereas syngeneic CS7BL/6 spleen cells are unaffected. Treatment of target cells with SMC results in early alterations in RNA and DNA metabolism. The uptake and incorporation of ³H-uridine was found to be initially elevated while intracellular levels of ³H-thymidine became markedly reduced. Furthermore, the cytotoxic action of SMC was found to be rapidly accelerated and amplified by low levels of actinomycin-D.     

A cathepsin L-like protease from Strongylusvulgaris: An orthologue of Caenorhabditiselegans CPL-1

Cathespin L-like proteases (CPLs), characterized from a wide range of helminths, are significant in helminth biology. For example, in Caenorhabditiselegans CPL is essential for embryogenesis. Here, we report a cathepsin L-like gene from three species of strongyles that parasitize the horse, and describe the isolation of a cpl gene (Sv-cpl-1) from Strongylusvulgaris, the first such from equine strongyles. It encodes a protein of 354 amino acids with high similarity to other parasitic Strongylida (90-91%), and C.elegans CPL-1 (87%), a member of the same Clade. As S.vulgariscpl-1 rescued the embryonic lethal phenotype of the C.eleganscpl-1 mutant, these genes may be orthologues, sharing the same function in each species. Targeting Sv-CPL-1 might enable novel control strategies by decreasing parasite development and transmission.     

Analysis of membrane fractions from Mycoplasma gallisepticum

Membrane fractions have been isolated from Mycoplasma gallisepticum following a procedure derived from that described by Maniloff, J. and Quinlan, D.C. (J. Bacteriol. (1974) 120, 495–501). A light fraction F₁ was obtained which contained structures resembling the bleb-infrableb apparatus characteristic of M. gallisepticum. It was enriched in DNA and had an electrophoretic profile different from that of unfractionated membranes. Cholesterol-to-phospholipid ratios higher than two and elevated values of the ratio of saturated to unsaturated fatty acids were other characteristics of this fraction. The two other fractions isolated (F_II and F_IV) also differed from intact membranes by their cholesterol and phospholipid content as well as by their saturation ratios. The membrane fluidity of F_II and F_IV, estimated by fluorescence polarization, was similar to that of unfractionated membranes while a slight but significant difference was recorded for the light fraction. Possible relationships between the lateral heterogeneity of the M. gallisepticum membrane and the obtainment of fractions are discussed.     

Ent-labdanes from Mikania alvimii

The aerial parts of Mikania alvimii afforded in addition to known compounds seven new ent-labdane derivatives and a 15-nor compound. The struct     

The telocentric tandem repeat at the p-arm is not conserved in Mus musculus subspecies

Mouse chromosomes, with the exception of the Y chromosome, are telocentric. The telomere at the p-arm is separated from the centromere by the tL1 sequence and TLC tandem repeats. A previous report showed that the TLC array was also conserved in other strains of the subgenus Mus. These results suggest that the TLC arrays promote the stable evolutionary maintenance of a telocentric karyotype in the subgenus Mus. In this study, we investigated the degree of conservation of TLC arrays among a variety of wild-derived inbred strains, all of which are descendants of wild mice captured in several areas of the world. Genomic PCR analysis indicates that the sequential order of telomere-tL1 is highly conserved in all strains, whereas tL1-TLC is not. Next, Southern blot analysis of DNAs isolated from a panel of mouse subspecies showed both Mus musculus domesticus and Mus musculus castaneus subspecies possess TLC arrays. Unexpectedly, this repeat appears to be lost in almost all Mus musculus musculus and Mus musculus molossinus subspecies, which show a clear geographic divide. These results indicate that either other unknown sequences were replaced by the TLC repeat or almost all M. m. musculus and M. m. molossinus subspecies do not have any sequence between the telomere and minor satellites. Our observation suggests that the TLC array might be evolutionarily unstable and not essential for murine chromosomal conformation. This is the first example of the subspecies-specific large genome alterations in mice.