Sesquiterpene lactones from Liatris acidota, L. Aspera and L. Mucronata

Examination of Liatris mucronata gave the known 15-hydroxylated heliangolides liscundin, liscunditrin, punctaliatrin and two new closely related heliangolides. Liatris acidota furnished six new similar but 15-deoxygenated heliangolides as well as euparin and 3β-acetoxytaraxaster-20-en-30-aldehyde. Liatris aspera gave a known glycosidic germacradienolide and a new germacradienolide as well as several known flavones and a known benzofuran. Structures were established by spectroscopic methods and chemical transformations.     

Bioassay of Entomophthora against the spotted alfalfa aphid Therioaphis trifolii f. maculata

A method for the bioassay of Enthomophthora spp. against aphids is described. Twenty-four isolates comprising five species of fungi were screened for activity against Therioaphis trifolii f. maculata. The only isolates with a high level of activity were those of E. sphaerosperma obtained from aphids. The initial bioassays with E. sphaerosperma indicated that aphids, starved for 24 hr during inoculation with E. sphaerosperma primary spores, were less susceptible than those removed from the plants, for just the period of exposure to the primary spore shower. Using the latter procedure, five assays of the most pathogenic isolate gave a mean LC₅₀ of 11.3 primary spores/mm² while bioassays of four other isolates gave LC₅₀ values ranging from 15.7 to 27.3 spores/mm². The potential of E. sphaerosperma as a microbial control agent for T. trifolii f. maculata in Australia is discussed.     

Further sesquiterpene lactones from Calea and Viguiera species

The aerial parts of Calea clematidea gave three new germacranolides, those of Viguiera procumbens two orizabin derivatives and those of V. linearis dihydrobudlein A. In addition to these lactones, several known ones were isolated.     

Sesquiterpenes and acetylenes from Argyranthemum adauctum ssp. jacobaeifolium

The roots of Argyranthemum adauctum ssp. jacobaeifolium, a rare endemic from Gran Canaria, afforded two new derivatives of the aromatic acetylene frutescin and 8-isovaleryloxymyrcene, while the aerial parts gave a new bisabolol derivative. Furthermore several known compounds were isolated. The structures were elucidated by high field ¹H NMR spectroscopy and a few chemical reactions.     

Stereochemistry of strictic acid and related furano-diterpenes from conyza japonica and grangea maderaspatana

Extraction of Conyza japonica gave strictic acid, ent-2β-hydroxy-15,16-epoxy-3,13(16),14-clerodatrien-18-oic acid and 5,7-dihydroxy-3,8,4′-trimethoxyflavone. Extraction of Grangea maderaspatana gave (-)-hardwickiic acid, ent-15,16-epoxy-1,3,13(16),14-clerodatetraen-18-oic acid and 3-hydroxy-8-acetoxypentadeca-1,9,14-trien-4,6-diyne. The structure of ent-2β-hydroxy-15,16-epoxy-3,13(16),14-cleroclatrien-18-oic acid was deduced by spectroscopic methods and by partial synthesis from (-)-hardwickiic acid and the stereochemistries of strictic acid and (ent-15,16-epoxy-1,3,13(16),14-clerodatraen-18-oic acid were established by correlation with ent-2β-hydroxy-15,16-epoxy-3,13(16),14-clerodatrien-18-oic acid.     

Ent-Labdanes from Baccharis Sternbergiana

The aerial parts of Baccharis sternbergiana afforded six new ent-labdane derivatives, while those of a Baccharis tricuneata subspecies gave 12-acetoxytremetone.     

Tetrahydrofuran-type terpenoids from Tanacetum vulgare

Investigation of a rare genotype of Tanacetum vulgare afforded a series of tetrahydrofuran-type terpenoids, whose pattern was different in flowers and leaves. The major constituent of the flowers was the trans Δ^3,4-hydroperoxide of davanone, whereas the leaves gave mostly a peroxyhemiketalic compound resulting from the intramolecular cyclization of the cis Δ^3,4-hydroperoxide of davanone. Structures were elucidated by spectral data and chemical reactions, including correlation with natural (+)-davanone. The peroxyhemiketalic compound upon acylation of its hydroxyl group gave an instantaneous complex reaction, resulting in the formation of a β-acyloxyenone and loss of one molecule of acetone. Among the minor constituents of the leaves, a C-10 carboxylic acid biogenetically related with davanone was isolated.     

Major xanthones from Garcinia quadrifaria and Garcinia staudtii stem barks

The stem bark of Garcinia quadrifaria has yielded the novel xanthone 1, 3, 5-trihydroxy-4, 8-di(3,3-dimethylallyl)xanthone and the biflavonoids O-methylfukugetin and morelloflavone. The seeds contained the biflavonoids but not the xanthone. G. staudtii stem bark gave rheediaxanthone-A and the polyisoprenylated benzophenone xanthochymol. .     

Ent-kauranes and other constituents of three Helianthus species

Aerial parts of Helianthus debilis subsp. cucumerifolius, H. occidentalis and H. simulans afforded a variety of known and some unknown ent-kauranoic acids. H. occidentalis gave, in addition, ciliaric acid and a new biogenetically related atisane derivative occidentalic acid. H. simulans gave the heliangolide leptocarpin and the flavone hymenoxin in addition to ent-kauranes. Several of the diterpenoids from these species inhibited larval growth of the sunflower moth.     

Biological implications of flavonoid chemistry in Baptisia and Thermopsis

An analysis of flavonoid distributional data from detailed biochemical systematic investigations of Baptisia and Thermopsis species supports the contention that the two genera are closely related with Baptisia being the more advanced evolutionarily and exhibiting greater evolutionary vigor. B. megacarpa may represent an ancestral complex which gave rise to several major Baptisia lines. Enzymes involved in methoxylation and 4′-glucosylation of flavonoids in Thermopsis have higher substrate specificities than those involved in 7-glucosylation.     

Septal pore complex morphology in the Agaricomycotina (Basidiomycota) with emphasis on the Cantharellales and Hymenochaetales

The ultrastructure of septa and septum-associated septal pore caps are important taxonomic markers in the Agaricomycotina (Basidiomycota, Fungi). The septal pore caps covering the typical basidiomycetous dolipore septum are divided into three main phenotypically recognized morphotypes: vesicular-tubular (including the vesicular, sacculate, tubular, ampulliform, and globular morphotypes), imperforate, and perforate. Until recently, the septal pore cap-type reflected the higher-order relationships within the Agaricomycotina. However, the new classification of Fungi resulted in many changes including revision of existing and addition of new orders. Therefore, the septal pore cap ultrastructure of more than 325 species as reported in literature was related to this new classification. In addition, the septal pore cap ultrastructures of Rickenella fibula and Cantharellus formosus were examined by transmission electron microscopy. Both fungi have dolipore septa associated with perforate septal pore caps. These results combined with data from the literature show that the septal pore cap-type within orders of the Agaricomycotina is generally monomorphic, except for the Cantharellales and Hymenochaetales.It appears from the fungal phylogeny combined with the septal pore cap ultrastructure that the vesicular-tubular and the imperforate type both may have arisen from endoplasmic reticulum. Thereafter, the imperforate type eventually gave rise to the perforate septal pore cap-type.     

Microbial oxygenation of dialkylbenzenes (I)

The use of the microorganism Sporotrichum sulfurescens (ATCC 7159) to oxygenate organic molecules has been extended to several dialkylbenzenes. Oxygenation of 1,4-di-t-butylbenzene (1) gave 4-t-butyl(1-hydroxy-2-methyl)isopropylbenzene (2) and 1,4-di-(1-hydroxy-2-methyl)isopropylbenzene (3); of 1,4-diisopropylbenzene (4) gave (R,R)-1,4-di-(1-hydroxy)isopropylbenzene (5); of 1,3-diisopropylbenzene (6) gave 1,3-di-(2-hydroxy)isopropylbenzene (7), 3-(1-hydroxy)isopropyl-(2-hydroxy)isopropylbenzene (8), and 1,3-di-(1-hydroxy)isopropylbenzene (9); and of p-isobutylisopropylbenzene (20) gave 1-(p-2-hydroxyisopropylphenyl)-2-methylpropan-2-ol (15) and 1-(p-1-hydroxyisopropylphenyl)-2-methylpropan-2-ol (16). Monohydroxydialkylbenzenes also served as useful substrates in this reaction as suggested by the fact that 2 is an intermediate in the formation of 3 from 1. Oxygenation of 1-(p-isopropylphenyl)-2-methylpropan-2-ol (14), conveniently prepared from 2-(p-isopropylphenyl)propene (12) via oxygenative isomerization with thallium trinitrate to 13 followed by addition of methyl magnesium bromide, gave 15 and 16. Oxygenation of 2-(p-isobutylphenyl)propan-2-ol (18) gave 15, 2-(p-isobutylphenyl)-propan-1,2-diol (21), and 1-(p-2-hydroxyisopropylphenyl)-2-methylpropan-3-ol (22). Compound 16, obtained from substrate 14, was converted to (2R)-2-[4-(2-hydroxy-2-methylpropyl)phenyl]propionic acid (11), the enantiomer of a metabolite of the antiinflammatory agent, 2-(4-i-butyl)phenylpropionic acid (10).     

Proacaciberin,A cyanogenic glycoside from Acacia sieberiana var. Woodii

A new cyanogenic glycoside isolated from pods of Acacia sieberiana var. woodii has been shown by chemical and spectroscopic methods to be (2S)-2-[(6-O-α-l-arabinopyranosyl-β-d-glucopyranosyl)oxy]-3-methylbut-3-enenitrileo. Acid-catalysed hydrolysis of the glycoside afforded arabinose and proacacipetalin, and base-catalysed double-bond migration gave 2- [(6-O-α-l-arabinopyranosyl-β- d-glucopyranosyl)oxy ]-3-methylbut-2-enenitrile.     

Glaucolide-like sesquiterpene lactones from Cotula cinerea

The aerial parts of Cotula cinerea gave, in addition to widespread compounds, a characteristic diacetylenic spiroketal enolether and several sesquiterpene lactones, three of them being glaucolide-like lactones. The structures were elucidated by highfield ¹H NMR spectroscopy.     

Aroma volatiles of Cynara scolymus and Helianthus tuberosus

Samples of the aroma volatiles of globe artichoke and Jerusalem artichoke were obtained by well established methods and were analysed by routine GC and GC/MS. Eight sesquiterpene hydrocarbons afforded the major group of components (over 42%) in globe artichoke samples, with β-selinene (ca 32%) as the main constituent. Previously reported caryophyllene could not be detected. α-Cedrene was found to have globe artichoke aroma characteristics on odour evaluation of separated components at an odour port at the exit of the GC column. Jerusalem artichoke samples contained one major component (β-bisabolene, ca 51%) and a range of saturated long-chain hydrocarbons (ca 22%). The sesquiterpene presumably contributes appreciably to the characteristic flavour of Jerusalem artichoke. Both types of artichoke gave a low concentration of total volatiles.     

Laboratory and field evaluations of industrial formulations of Bacillus thuringiensis serovar. israelensis against some mosquito species of central Italy

Two wettable powder formulations (Bactimos and Vectobac) and a flowable concentrate (Teknar) formulation of Bacillus thuringiensis serovar. israelensis were evaluated as larvicides of Culex pipiens, Aedes caspius, and Aedes detritus. In the laboratory, the levels of susceptibility of these species to the test formulations were essentially similar and corresponded to their relative potencies; the LC₉₀ values ranged from 0.042 to 0.37 ppm. C. pipiens, A. caspius, and A. detritus, in that order, were susceptible to the biocide. Under field conditions in central Italy. Bactimos at 0.5 kg/ha gave 98% control of C. pipiens in an irrigation canal. Teknar at 1.25 liters/ha gave 86–100%, and at 2.5 liters/ha gave 90–100% control of C. pipiens in two natural ponds. Against A. caspius in salt marsh habitats, Bactimos at 0.5 kg/ha and Teknar at 2.5 liters/ha yielded complete control of the larvae, while a lower rate (0.2 kg/ha) of Bactimos, and Vectobac at 0.5 kg/ha resulted in 82–94% and 67–91% control, respectively. Higher rates (0.75 and 1.0 kg/ha) of Vectobac gave 76–100% and 98–100% control of A. caspius. Bactimos at 0.15 kg/ha gave 93–98% control of A. detritus in two salt marsh ponds. B. thuringiensis serovar. israelensis is practically economical for the control of C. pipiens, A. caspius, and A. detritus in the various biotopes in central Italy.     

Properties of hydroxycinnamate: CoA ligase from stems of Salix babylonica cultured in vitro

Hydroxycinnamate: CoA ligase was extracted from stems of in vitro willow cultures and characterized. One peak of activity was obtained after column chromatography on Sephadex G 100 or DEAE Sephacel. p-Coumaric acid gave the highest V_max among the cinnamates examined. The K_mvalues for p-coumaric, caffeic and ferulic acid were 31.0, 4.7 and 46 μM, respectively. The MW of the CoA ligase was 57 000 and the pH optimum was 7.0. The characteristics of the enzyme correspond to its physiological role in lignin biosynthesis.     

Chemical markers in Veronica sect. Hebe. II

In a continued chemosystematic investigation of the water-soluble compounds in Veronica sect. Hebe, four additional species were investigated. In comparison to other, Northern Hemisphere (NH) species of Veronica, those belonging to the New Zealand species in sect. Hebe are apparently more variable in chemical content. In addition to the compounds characteristic for NH Veronica, namely mannitol, aucubin, catalpol and 6-O-esters of catalpol as well as some caffeoyl phenylethanoid glucosides (CGPs), Veronica topiaria (syn. Hebe topiaria) also gave an unusual 6-O-ester of aucubin named topiarioside. The former Hebe species Veronica cupressoides and Veronica stenophylla each provided one of the two previously undescribed disaccharide esters named hebitol I and II, respectively, and the former plant also provided a CPG named cuproside, a 6-O-β-glucopyranosyl derivative of the known hebeoside. The last species, namely Veronica hulkeana (syn. Heliohebe hulkeana) only contained compounds common to other species of Veronica. The taxonomic results are discussed and it is concluded that carbohydrate esters are common in sect. Hebe. The data so far obtained indicate that the occurrences of esters of 6-O-rhamnopyranosylcatalpol are confined to the most derived species in the section.     

Expression of maize prolamins in Escherichia coli

We have constructed a cDNA expression library of developing corn (Zea mays L.) endosperm using plasmid pUC8 as vector and Escherichia coli strain DH1 as host. The expression library was screened with non-radioactive immunological probes to detect the expression of gamma-zein and alpha-zein. When anti-gamma-zein antibody was used as the probe, 23 colonies gave positive reactions. The lengths of cDNA inserts of the 23 colonies were found to be 250–900 base pairs. When anti-alpha zein antibody was used, however, fewer colonies gave positive reactions. The library was also screened by colony-hybridization with ³²P-labeled DNA probes. Based on immunological and hybridization screening of the library and other evidence, we conclude that alpha-zein was either toxic to E. coli cells or rapidly degraded whereas gamma-zein and its fragments were readily expressed.     

New chromenochalcones from Flemingia

2-Methyl-2-(4′-methylpent-3′-enyl)-5,8-dihydroxy-6-(4-hydroxycinnamoyl)-chromene (flemingin-D) has been isolated from inflorescences of Flemingia congesta, together with the known flemingin-C and two other chalcones. These (flemingin-E and -F) are allylic alcohols which differ from flemingin-D by an additional OH group in the side chain. Photooxidation of model 2-methyl-2-(4′-methylpent-3′-enyl)-chromenes gave pairs of allylic alcohols with the same structural feature. The known flemingin-A, -B, -C and homoflemingins have been isolated from F. grahamiana, and another new chalcone from F. bracteata.