A smelling trip into the past: the influence of synthetic materials on the history of perfumery

Contemporary perfumery has its roots in the work of the past, and many of the perfumes from this time have long since disappeared. What follows is a short account of some of the most famous perfumes from the past which have been inspired by the novel synthetic materials of the time. These important creations include, ‘Fougère Royale’ by Houbigant (1884) containing coumarin ( 1 ), ‘Jicky’ by Guerlain (1889) containing vanillin ( 2 ) and linalool ( 3 ), ‘Vera Violetta’ by Roger & Gallet (1892) containing α‐ and β‐ionone ( 4 and 5 , resp.), ‘Trèfle Incarnat’ by Piver (1898) containing isoamyl salicylate ( 6 ), ‘La Rose Jacqueminot’ of Coty (1904) containing Rhodinol ( 7 ), ‘Après l'Ondée’ by Guerlain (1906) containing para‐anisaldehyde ( 8 ), ‘Quelques Fleurs’ by Houbigant (1912) containing hydroxycitronellal ( 9 ), ‘N°5’ by Chanel (1921) containing the aldehydes C‐10 ( 10 ), C‐110 ( 11 ), and C‐12 ( 12 ), ‘Nuit De Noël’ by Caron (1922) containing 6‐isobutylquinoline ( 14 ), and ‘Femme’ by Rochas (1944) containing the so‐called ‘aldehyde C‐14’ ( 15 , γ‐undecalactone). The Osmotheque, the International Conservatory of Perfumes, was launched in 1990 and is regarded as a primary source of knowledge for the history of perfumery. Its vocation is to compile an amazing collection of 1700 perfumes (400 of them almost forgotten fragrances) – jewels of perfumery.     

Effects of single and dual species herbivory on the behavioral responses of three thrips species to cotton seedlings

This study investigated the olfactory responses of 3 thrips species [Frankliniella schultzei Trybom, F. occidentalis Pergrande and Thrips tabaci Lindeman (Thysanoptera: Thripidae)] to cotton seedlings [Gossypium hirsutum L. (Malvales: Malvaceae)] simultaneously damaged by different combinations of herbivores. Cotton seedlings were damaged by foliar feeding Tetranychus urticae Koch (Trombidiforms: Tetranychidae), Helicoverpa armigera Hübner (Lepidoptera: Noctuidae), Aphis gossypii Glover (Hemiptera: Aphididae) or root feeding Tenebrio molitor L. (Coleoptera: Tenebrionidae). Thrips responses to plants simultaneously damaged by 2 species of herbivore were additive and equivalent to the sum of the responses of thrips to plants damaged by single herbivore species feeding alone. For example, F. occidentalis was attracted to T. urticae damaged plants but more attracted to undamaged plants than to plants damaged by H. armigera. Plants simultaneously damaged by low densities of T. urticae and H. armigera repelled F. occidentalis but as T. urticae density increased relative to H. armigera density, F. occidentalis attraction to coinfested plants increased proportionally. Thrips tabaci did not discriminate between undamaged plants and plants damaged by H. armigera but were attracted to plants damaged by T. urticae alone or simultaneously damaged by T. urticae and H. armigera. Olfactometer assays showed that simultaneous feeding by 2 herbivores on a plant can affect predator–prey interactions. Attraction of F. occidentalis to plants damaged by its T. urticae prey was reduced when the plant was simultaneously damaged by H. armigera, T. molitor, or A. gossypii and F. schultzei was more attracted to plants simultaneously damaged by T. urticae and H. armigera than to plants damaged by T. urticae alone. We conclude that plant responses to feeding by 1 species of herbivore are affected by responses to feeding by other herbivores. These plant‐mediated interactions between herbivore complexes affect the behavioral responses of thrips which vary between species and are highly context dependent.     

Isolation and spectral characterization of thermally generated multi-Z-isomers of lycopene and the theoretically preferred pathway to di-Z-isomers

Lycopene has a large number of geometric isomers caused by E/Z isomerization at arbitrary sites within the 11 conjugated double bonds, offering varying characteristics related to features such as antioxidant capacity and bioavailability. However, the geometric structures of only a few lycopene Z-isomers have been thoroughly identified from natural sources. In this study, seven multi-Z-isomers of lycopene, (9Z,13′Z)-, (5Z,13Z,9′Z)-, (9Z,9′Z)-, (5Z,13′Z)-, (5Z,9′Z)-, (5Z,9Z,5′Z)-, and (5Z,9Z)-lycopene, were obtained from tomato samples by thermal isomerization, and then isolated by elaborate chromatography, and fully assigned using proton nuclear magnetic resonance. Moreover, the theoretically preferred pathway from (all-E)-lycopene to di-Z-isomers was examined with a computational approach using a Gaussian program. Fine-tuning of the HPLC separation conditions led to the discovery of novel multi-Z-isomers, and whose formation was supported by advanced theoretical calculations.     

Physiological relevance of successive hydroxylations of toluene by toluene para-monooxygenase of Ralstonia pickettii PKO1

We have recently found that toluene para-monooxygenase (TpMO) of Ralstonia pickettii PKO1 (encoded by tbuA1UBVA2C) performs successive hydroxylations of benzene (Appl. Environ. Microbiol. 70: 3814, 2004) as well as hydroxylates toluene to a mixture of 90% p-cresol and 10% m-cresol which are then further oxidized to 100% 4-methylcatechol (J. Bacteriol. 186: 3117, 2004) whereas it was thought previously that TpMO forms 100% m-cresol and is not capable of successive hydroxylations. Here we propose a modification of the degradation pathway originally described by Olsen et al. (J. Bacteriol. 176: 3749, 1994) that now relies primarily on TpMO for conversion of toluene to 4-methylcatechol (instead of m-cresol) since both m-cresol and p-cresol are shown here to be good substrates for Escherichia coli expressing TpMO (V_max/K_m=0.046, 0.036, and 0.055 mL min^?1 mg^?1 protein for the oxidation of toluene, m-cresol, and p-cresol, respectively). In light of the broader activity of TpMO, phenol hydroxylase (encoded by tbuD) appears to facilitate conversion of any m-cresol or p-cresol formed from toluene oxidation by TpMO to 4-methylcatechol; hence, the cell has a redundant method for making this important intermediate 4-methylcatechol. Further, it is suggested that the physiological relevance of the 10% m-cresol formed from toluene oxidation by TpMO is needed for induction of the meta cleavage operon tbuWEFGKIHJ to enable full metabolism of toluene since p-cresol (and o-cresol) do not induce the meta-cleavage pathway. Therefore both the successive hydroxylation of toluene by TpMO and the product distribution are of physiological relevance to the cell.     

Chemotaxonomy of the genus Talaromyces

Species of the ascomycetous genus Talaromyces have been examined for profiles of secondary metabolites on TLC. The greatest number of specific metabolites were produced on oatmeal-, malt extract- and yeast-extract sucrose agars. Profiles of intracellular secondary metabolites produced on oatmeal agar were specific for each species and provided a means of simple differentiation of the taxa. Examination of the most important species using high performence liquid chromatography (HPLC) allowed to solve some taxonomic problems. Known mycotoxins are produced by T. stipitatus (duclauxin, talaromycins, botryodiploidin), T. stipitatus chemotype II (emodin), T. panasenkoi (spiculisporic acid), T. trachyspermus (spiculisporic acid), T. trac macrosporus (duclauxin) and T. wortmannii (rugulosin). Wortmannin is produced by an atypical strain of T. flavus but not T. wortmannii. Several other secondary metabolites were discovered for the first time in the following species: Glauconic acid is produced by T. panasenkoi, T. ohiensis and T. trachyspermus; vermiculine by T. ohiensis; duclauxin by T. flavus var. macrosporus and the mitorubrins by T. flavus and T. udagawae. The profiles of secondary metabolites support the established taxonomy of the species based on morphology, showing the genetic stability of profiles of secondary metabolites in Talaromyces. Two new taxa are proposed: T. macrosporus comb. nov. (stat. anam. Penicillium macrosporum stat. nov.), and Penicillium vonarxii, sp. nov. for the anamorph of T. luteus.     

Construction of a fusion flagellin complex and evaluation of the protective immunity of it in red snapper (Lutjanus sanguineus)

Aims: The main aims of this study were to construct a bivalent subunit vaccine containing flagellin flaA gene and flagellin flaB gene from Vibrio alginolyticus strain HY9901 and to explore the potential application of the fusion protein FlaA‐(G₄S)₃‐FlaB as a vaccine candidate for red snapper (Lutjanus sanguineus). Methods and Results: Flagellin gene flaA and flaB of V. alginolyticus were linked by gene SOEing (gene splicing by overlap extension) technology. The expression of the fusion gene flaA‐(G₄S)₃‐flaB in Escherichia coli BL21(DE3) was confirmed by SDS‐PAGE. Western blot analysis showed that the fusion protein FlaA‐(G₄S)₃‐FlaB, which was purified by affinity chromatography on Ni‐NTA resin, had positive reaction with mouse anti‐FlaA serum and mouse anti‐FlaB serum, respectively. The immunoprotection of FlaA‐(G₄S)₃‐FlaB as a bivalent subunit vaccine was investigated in red snapper model by enzyme‐linked immunosorbent assay (ELISA) and challenge test. Red snapper vaccinated with FlaA‐(G₄S)₃‐FlaB produced specific antibodies and were highly resistant to infection by virulent V. alginolyticus. Conclusions: The fusion gene flaA‐(G₄S)₃‐flaB from V. alginolyticus strain HY9901 was cloned by gene SOEing and was expressed in E. coli. This fusion protein FlaA‐(G₄S)₃‐FlaB is a good protective antigen of V. alginolyticus and should be considered as an effective vaccine candidate against infection by V. alginolyticus in red snapper. Significance and Impact of the Study: Two flagellin genes, flaA and flaB, which are independent in structure and function, were first linked together by gene SOEing technology. The finding that red snapper did adequately respond to the fusion protein FlaA‐(G₄S)₃‐FlaB injection made it a promising candidate for vaccine treatment. To develop effective vaccine candidates against V. alginolyticus, more attention should be given to these immunogenic flagellins.     

Synthesis of enantiomers of exo‐2‐norbornyl‐N‐n‐butylcarbamate and endo‐2‐norbornyl‐N‐n‐butylcarbamate for stereoselective inhibition of acetylcholinesterase

The acetylcholinesterase inhibition by enantiomers of exo‐ and endo‐2‐norbornyl‐N‐n‐butylcarbamates shows high stereoselelectivity. For the acetylcholinesterase inhibitions by (R)‐(+)‐ and (S)‐(?)‐exo‐2‐norbornyl‐N‐n‐butylcarbamates, the R‐enantiomer is more potent than the S‐enantiomer. But, for the acetylcholinesterase inhibitions by (R)‐(+)‐ and (S)‐(?)‐endo‐2‐norbornyl‐N‐n‐butylcarbamates, the S‐enantiomer is more potent than the R‐enantiomer. Optically pure (R)‐(+)‐exo‐, (S)‐(?)‐exo‐, (R)‐(+)‐endo‐, and (S)‐(?)‐endo‐2‐norbornyl‐N‐n‐butylcarbamates are synthesized from condensations of optically pure (R)‐(+)‐exo‐, (S)‐(?)‐exo‐, (R)‐(+)‐endo‐, and (S)‐(?)‐endo‐2‐norborneols with n‐butyl isocyanate, respectively. Optically pure norborneols are obtained from kinetic resolutions of their racemic esters by lipase catalysis in organic solvent. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

Trichoderma species for biocontrol of soil-borne plant pathogens of pasture species

Soil-borne plant pathogens such as Rhizoctonia solani (Kuhn), Pythium ultimum (Trow) and Sclerotinia trifoliorum (Eriks) can reduce grass and forage legume establishment. The potential for biocontrol of these pathogens by Trichoderma fungi was evaluated. Following dual culture assays, nine Trichoderma isolates (five of Trichoderma atroviride and one each of Trichoderma hamatum, Trichoderma koningiopsis, Trichoderma viride and Trichoderma virens) were chosen for assessment in pot experiments. In the presence of R. solani, perennial ryegrass (Lolium perenne L.) emergence was increased by 60–150% by two isolates of T. atroviride and by 35–212% by the isolate of T. virens, with the increase depending on growing medium and amount of pathogen inoculum. Red clover (Trifolium pratense L.) emergence in the presence of S. trifoliorum was significantly increased by two T. atroviride isolates and the T. hamatum isolate. In the presence of P. ultimum, white clover (Trifolium repens L.) emergence was increased by 25–42% by one isolate of T. atroviride and the T. hamatum isolate. However, for all three pasture species, some Trichoderma isolates reduced seedling emergence. Seedling growth (shoot and root fresh weight/plant) of the three pasture species was significantly increased by one or more T. atroviride isolates. On the basis of these results for both disease reduction and growth promotion, four T. atroviride isolates were selected for field assessment as biocontrol agents of soil-borne pathogens of pasture species.     

Isolation of nematophagous fungi from eggs and females of Meloidogyne spp. and evaluation of their biological control potential

Fungi were isolated from Meloidogyne spp. eggs and females on 102 field-collected root samples in China. Of the 235 fungi isolated (representing 18 genera and 26 species), the predominant fungi were Fusarium spp. (42.1% of the isolates collected), Fusarium oxysporum (13.2%), Paecilomyces lilacinus (12.8%), and Pochonia chlamydosporia (8.5%). The isolates were screened for their ability to parasitise Meloidogyne incognita eggs in 24-well tissue culture plates in two different tests. The percentage of eggs parasitised by the fungi, the numbers of unhatched eggs and alive and dead juveniles were counted at 4 and 7 days after inoculation. The most promising fungi included five Paecilomyces isolates, 10 Fusarium isolates, 10 Pochonia isolates and one Acremonium isolate in test 1 or test 2. Paecilomyces lilacinus YES-2 and P. chlamydosporia HDZ-9 selected from the in vitro tests were formulated in alginate pellets and evaluated for M. incognita control on tomato in a greenhouse by adding them into a soil with sand mixture at rates of 0.2, 0.4, 0.8 and 1.6% (w/w). P. lilacinus pellets at the highest rate (1.6%) reduced root galling by 66.7%. P. chlamydosporia pellets at the highest rate reduced the final nematode density by 90%. The results indicate that P. lilacinus and P. chlamydosporia as pellet formulation can effectively control root-knot nematodes.     

Synthesis of stereoisomers of antithrombotic nipecotamides

The stereoisomers of α,α′-bis[3-(N,N-diethylcarbamoyl)-piperidino]-p-xylene ( 1 ) were synthesized. Rac ethyl nipecotate was resolved by diastereomeric (-)-D - and (+)-L-tartrate salt formation. The enantiomeric esters were hydrolyzed to the corresponding nipecotic acids, which were then converted into t-BOC derivatives. Treatment of the latter with diethylamine/isobutyl chloroformate and removal of the t-BOC protecting group afforded (R)- and (S)-N,N-diethylnipecotamides. Condensation of the latter with α,α′-dibromo-p-xylene gave (R,R)- and (S,S)- 1 . The meso-diastereomer was obtained by stereospecific synthesis in addition to our earlier procedure involving fractional crystallization of the diastereomeric mixture obtained by synthesis. The latter was resolved earlier into 1A , 1B , and 1C using chiral high-performance liquid chromatography (HPLC). Based on the stereospecific synthesis now achieved, 1A and 1B are assigned the configurations, (R,R) and (S,S) respectively, and 1C is assigned the meso configuration. The (R,S) structure of the latter is also confirmed by X-ray crystallography. © 1995 Wiley-Liss, Inc.     

Activation and inhibition of mitochondrial adenosine triphosphatase by various anions and other agents

The activating or inhibiting actions of a variety of anion species and of oligomycin, aurovertin and Dio-9 on the ATPase of a sonic particle preparation of rat liver mitochondria have been characterized by measurements of the relevantV _max,K _i andK _m values.The normalV _max was increased by a factor near 7 by the anions: dichromate, chromate, pyrophosphate, orthophosphate, orthoarsenate and sulphate. The fully activating concentration varied from about 2 mM for dichromate to 150 mM for sulphate. The increase inV _max was accompanied by a time-dependent decrease in (K _i)ADP, but there was no change in (K _m)ATP. The increase inV _max by the activating anions was abolished by aurovertin; but in presence of oligomycin, the lowV _max was increased by the activating anions by the same factor as theV _max in absence of oligomycin.Certain anions, notably azide, decreasedV _max, but did not affect (K _i)ADP or (K _m)ATP. The decrease inV _max by azide and oligomycin were approximately additive. Even at high concentration, Dio-9 was without detectable effect on the ATPase, but it had a gramicidinlike effect on the intact mitochondria.The specificity of the ATPase for ATP relative to GTP was found to be attributable to the high value of (V _max)ATP compared with (V _max)GTP. The values of (K _m)ATP and (K _m)GTP were virtually the same.Some rationalization of these and other supporting observations is attempted in terms of present knowledge of the constitution of the ATPase complex.     

Synthesis of Streptovitacin-C2 Isomers

(2R*,4S*,6S*,αS*)- and (2R,4R,6R,αS)-Streptovitacin-C₂ (STV-C₂) (1a and 1b) were synthesized by an aldol condensation of (2R*,4S*)- or (2R,4R)-2,4-dimethyl-2-trimethylsiloxy-1-cyclohexanone (15a or 15b) with 4-(2-oxoethyl)-2,6-piperidinedione (16), which was followed by desilylation of the products. The stereochemistry of the synthesized STV-C₂ isomers (1a and 1b) was elucidated by NMR. STV-C₂ isomers (1a and 1b) did not show strong antimicrobial activity against Saccharomyces cerevisiae and Pyricularia oryzae.     

Incrimination of the mosquito,Aedes taeniorhynchus,as the primary vector of heartworm,Dirofilaria immitis,in coastal Yucatan,Mexico

Mosquito collections were carried out on microfilaraemic dogs, positive for Dirofilaria sp., for 18 consecutive nights in the coastal town of Celestún, Yucatan, southeast Mexico, during the rainy season (August) of 2007. A total of 292 female mosquitoes representing 12 species of dipteran Culicidae were collected: Anopheles albimanus (Wiedemann); Anopheles crucians (Wiedemann); Anopheles pseudopunctipennis (Theobald); Culex coronator (Dyar & Knab); Culex interrogator (Dyar & Knab); Culex nigripalpus (Theobald); Culex quinquefasciatus (Say); Culex salinarius (Coquillett); Aedes aegypti (Linnaeus); Aedes scapularis (Rondani); Aedes sollicitans (Walker), and Aedes taeniorhynchus (Wiedemann). Aedes taeniorhynchus and Cx. quinquefasciatus were the species found most commonly feeding on the dogs. Filarial nematodes were observed by microscopy in nine of the mosquito species collected; however, third‐instar larvae were only observed in Ae. taeniorhynchus and An. crucians. Of 76 Ae. taeniorhynchus specimens found positive for Dirofilaria sp. by dissection, 14 were confirmed to be positive for Dirofilaria immitis (Leidy) by polymerase chain reaction (PCR). The resulting infection rate for D. immitis confirmed by PCR (6.2%) is higher than any infection rate for Ae. taeniorhynchus previously reported from the Americas.     

Effects of Canavalia ensiformis and Mucuna pruriens intercrops on Pratylenchus zeae damage and yield of maize in subsistence agriculture

Host status of four leguminous cover crops [Canavalia ensiformis (L.) DC. (Jack bean), Crotalaria ochroleuca G. Don (Sunnhemp), Lablab purpureus L. (Hyacinth bean) and Mucuna pruriens (L.) DC. (velvet bean)] to Pratylenchus zeae Filipjev and effects of intercropping C. ensiformis and M. pruriens with Pan5195, H627 and Emap11 maize cultivars on P. zeae population and disease severity on maize were determined in greenhouse and field tests. Pratylenchus zeae significantly (P<0.05) reduced growth of C. ochroleuca by 36% but had no effect on C. ensiformis, M. pruriens and L. purpureus. While C. ensiformis, M. pruriens and L. purpureus reduced P. zeae population, C. ochroleuca increased it. In the greenhouse test, intercropping maize with C. ensiformis significantly (P<0.05) improved maize growth by up to 34%, Nematode populations in the roots of maize intercropped with either C. ensiformis or M. pruriens were significantly (P<0.05) reduced by up to 32% while nematode disease severity in these intercropping systems was reduced by up to 26%. In the field test, intercropping Emap11, Pan5195 and H627 with C. ensiformis significantly (P<0.05) increased maize grain yield by 190, 29 and 22%, respectively. Intercropping H627 with M. pruriens significantly (P<0.05) increased maize grain yield by 12%, but grain yields of Pan5195 and Emap11 declined by 79 and 40%, respectively. Root necrosis and soil nematode populations in the C. ensiformis–maize intercrop declined by up to 50 and 30%, respectively. Under pure maize stands, soil nematode populations increased by up to 35% in 90 days relative to the initial nematode population of three nematodes g⁻¹ of fresh soil. Section Editor: P. A. M. Bakker     

Distribution of the HLA-DRB1 Specificities in Populations of the Volga–Ural Region

Polymorphism at the HLA-DRB1 locus in six Turkic (Bashkirs, Tatars, and Chuvashes) and Finno-Ugric (Udmurts, Maris, and Komis) populations of the Volga–Ural region was studied by PCR. A total of 12 DRB1 specificities displaying population-specific frequency distribution patterns were described. The most frequently observed specificities in Bashkirs and Udmurts were DRB1*07 (25 and 34%, respectively) and *15 (by 15%). In Tatars the prevalence of *04 (18%), *01 (17%), *07 (16%), and *15 (13%) specificities was observed, while in Chuvashes these were *04 (28%), *11 (18%), *01 (16%), and *07 (16%). High frequencies of *11 (21%),*04 (17%), *01 (13%), and *07 (13%) specificities were characteristic of Komis, whereas Maris were distinguished by high frequencies of *01 (23%), *11 (14%), *07 (13%), and *04 (11%). In general, the pattern of DRB1 allelic polymorphism in populations of the Volga–Ural region, occupying the intermediate position between the Caucasoid- and Mongoloid-specific allelic frequency distribution patterns, was consistent with their anthropological type rather than with their linguistic affiliation.     

Enzymatic resolution of rac-1,1-dimethyl-1-sila-cyclohexan-2-ol by ester hydrolysis or transesterification using a crude lipase preparation of Candida cylindracea

Summary rac-2-Acetoxy-1,1-dimethyl-1-sila-cyclohexane (rac-2) was synthesized by esterification of rac-1,1-dimethyl-1-sila-cyclohexan-2-ol (rac-1) with acetic anhydride. Enantioselective hydrolysis of rac-2 in aqueous solution, catalysed by a crude lipase preparation of Candida cylindracea (EC 3.1.1.3), led to the formation of (S)-1 (95% ee). Enantioselective transesterification of rac-1 with triacetin in isooctane, catalysed by the same enzyme preparation, yielded (S)-2 (95% ee), which was separated by chromatography from non-reacted (R)-1 (96% ee). Recrystallization led to an improvement of the enantiomeric purity of (R)-1 and (S)-1 up to >98% ee. Thus the enantiomers of rac-1 were prepared (100 mg scale) with high enantiomeric purities by the use of two different types of enzyme-catalysed reaction.     

Volatile Methyl Esters of Medium Chain Length from the Bacterium Chitinophaga Fx7914

The analysis of the volatiles released by the novel bacterial isolate Chitinophaga Fx7914 revealed the presence of ca. 200 compounds including different methyl esters. These esters comprise monomethyl‐ and dimethyl‐branched, saturated, and unsaturated fatty acid methyl esters that have not been described as bacterial volatiles before. More than 30 esters of medium C‐chain length were identified, which belong to five main classes, methyl (S)‐2‐methylalkanoates (class A), methyl (S)‐2,(ω?1)‐dimethylalkanoates (class B), methyl 2,(ω?2)‐dimethylalkanoates (class C), methyl (E)‐2‐methylalk‐2‐enoates (class D), and methyl (E)‐2,(ω?1)‐dimethylalk‐2‐enoates (class E). The structures of the compounds were verified by GC/MS analysis and synthesis of the target compounds as methyl (S)‐2‐methyloctanoate ( 28 ), methyl (S)‐2,7‐dimethyloctanoate ((S)‐ 43 ), methyl 2,6‐dimethyloctanoate ( 49 ), methyl (E)‐2‐methylnon‐2‐enoate ( 20a ), and methyl (E)‐2,7‐dimethyloct‐2‐enoate ( 41a ). Furthermore, the natural saturated 2‐methyl‐branched methyl esters showed (S)‐configuration as confirmed by GC/MS experiments using chiral phases. Additionally, the biosynthetic pathway leading to the methyl esters was investigated by feeding experiments with labeled precursors. The Me group at C(2) is introduced by propanoate incorporation, while the methyl ester is formed from the respective carboxylic acid by a methyltransferase using S‐adenosylmethionine (SAM).     

Direct effect of biocontrol agents on wilt and root-rot diseases of sesame

In Egypt, sesame cultivation is subject to attack by wilt and root-rot diseases caused by Fusarium oxysporum f.sp. sesami (Zap) Cast. and Macrophomina phaseolina (Maubl) Ashby causing losses in quality and quantity of sesame seed yield. Bacillus subtilis and Trichoderma viride isolates which were isolated from sesame rhizosphere were the most effective to antagonise fungal pathogens, causing high reduction of hyphal fungal growth. Trichoderma viride was found to be mycoparasitic on Fusarium oxysporum f.sp. sesami and M. phaseolina causing morphological atternation of fungal cells and sclerotial formation. In general, Bacillus subtilis, T. viride, avirulent Fusarium oxysporum isolate and Glomus spp. (Amycorrhizae) significantly reduced wilt and root-rot incidence of sesame plants at artificially infested potted soil by each one or two pathogens. Data obtained indicate that Glomus spp significantly reduced wilt and disease severity development on sesame plants followed by T. viride. Meanwhile, avirulent Fusarium oxysporum isolate followed by Glomus spp. were effective against root-rot disease incidence caused by M. phaseolina. Glomus spp. followed by B. subtilis significantly reduced wilt and root-rot disease of sesame plants. All biotic agents significantly reduced F. oxysporum f.sp. sesami and M. phaseolina counts in sesame rhizosphere at the lowest level. Glomus spp. and the avirulent isolate of F. oxysporum eliminated M. phaseolina in sesame rhizosphere. Meanwhile T. viride was the best agent at reducing F. oxysporum at a lower level than other treatments. Application of VA mycorrhizae (Glomus spp.) in fields naturally infested by pathogens significantly reduced wilt and root-rot incidence and it significantly colonised sesame root systems and rhizospheres compared to untreated sesame transplantings.     

Effect of maize stunting mollicutes on survival and fecundity of Dalbulus leafhopper vectors

The effect of corn stunt spiroplasma (CSS) on survival and fecundity of three Dalbulus leafhopper species was determined. CSS significantly reduced the survival, as measured by the time to 50% (t₅₀) and 25% (t₂₅) survival, and by the scale parameter (b) of the Weibull model, for D. elimatus and D. gelbus. Fecundity of these two species, as measured by the net and gross reproductive rates, was also reduced by CSS. CSS did not significantly affect the corn leafhopper, D. maidis. In a separate experiment, maize bushy stunt mycoplasma (MBSM) reduced the survival and fecundity of D. maidis at temperatures from 20 to 29 °C. The effect of MBSM on D. maidis survival was less severe than CSS on D. elimatus and D. gelbus; t₂₅, but not t₅₀, was reduced by MBSM. Survival times and the cohort generation time generally declined with increasing temperature. Fecundity, however, generally increased with increasing temperature.     

Conformational change of the triple-helical structure. I. Synthesis of model peptides of collagen by the solid-phase method

As model peptides of collagen, (Pro-Pro-Gly)_n (n = 10, 12, 14, and 15) and (Pro-Pro-Gly)_n(Ala-Pro-Gly)_m(Pro-Pro-Gly)_n (2n + m = 15; m = 1, 3, and 5) were synthesized by the solid-phase method. The final products were pure when checked by high-voltage paper electrophoresis and by amino acid analysis. Elemental composition was also examined.