Diterpene acids from Helianthus species and their microbiological conversion by Gibberella fujikuroi, mutant B1-41a

The diterpene acid content in 10 species of Helianthus has been investigated. Ent-12,16-cyclokauranoic acid, isolated from H. annuus, is converted into a series of 12,16-cyclogibberellins by cultures of Gibberella fujikuroi, mutant B1-41a, and 12,16-cyclogibberellins A₉, and A₁₂ have been isolated. Ent-12β-acetoxykaurenoic acid and ent-13(S)-angeloxyatisenoic acid have been isolated from H. decapetalus; the metabolism of ent-13(S)-hydroxyatisenoic acid and atisenoic acid by B1-41a is also described.     

Biotechnological production of caffeic acid derivatives from cell and organ cultures of Echinacea species

Caffeic acid derivatives (CADs) are a group of bioactive compounds which are produced in Echinacea species especially Echinacea purpurea, Echinacea angustifolia, and Echinacea pallida. Echinacea is a popular herbal medicine used in the treatment of common cold and it is also a prominent dietary supplement used throughout the world. Caffeic acid, chlorogenic acid (5-O-caffeoylquinic acid), caftaric acid (2-O-caffeoyltartaric acid), cichoric acid (2, 3-O-dicaffeoyltartaric acid), cynarin, and echinacoside are some of the important CADs which have varied pharmacological activities. The concentrations of these bioactive compounds are species specific and also they vary considerably with the cultivated Echinacea species due to geographical location, stage of development, time of harvest, and growth conditions. Due to these reasons, plant cell and organ cultures have become attractive alternative for the production of biomass and caffeic acid derivatives. Adventitious and hairy roots have been induced in E. pupurea and E. angustifolia, and suspension cultures have been established from flask to bioreactor scale for the production of biomass and CADs. Tremendous progress has been made in this area; various bioprocess methods and strategies have been developed for constant high-quality productivity of biomass and secondary products. This review is aimed to discuss biotechnological methods and approaches employed for the sustainable production of CADs.     

Azetidine-2-carboxylic acid derivatives from seeds of Fagus silvatica L. and a revised structure for nicotianamine

2(S),3′(S)-N-(3-Amino-3-carboxypropyl)azetidine-2-carboxylic acid and 2(S),3′(S),3″(S)-N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid have been isolated from seeds of Fagus silvatica L. (beechnuts). The structures have been established by PMR- and ¹³C-NMR-spectroscopy and by synthesis from l-azetidine-2-carboxylic acid. The second of the new amino acids is identical with nicotianamine. previously isolated from Nicotiana tabacum but assigned a different formula. The ring opening reactions of azetidine-2-carboxylic acid in neutral solution have been studied and the chemical and possibly biochemical precursor role of this amino acid for various amino acids including the two new ones described here, nicotianine [N-(3-amino-3-carboxypropyl)nicotinic acid] and methionine is discussed.     

Terpenoid and biflavonoid constituents of Calophyllum calaba and Garcinia spicata from Sri Lanka

A new bark acid, isochapelieric acid (cis-chapelieric acid), chapelieric acid, friedelin, friedelan-3β-ol, canophyllal, canophyllol, friedelan-3β,28-diol, canophyllic acid and amentoflavone have been isolated and characterized from leaf extractives of Calophyllum calaba. ¹³CNMR spectra of methyl chapelierate and methyl isochapelierate have been recorded and interpreted. Leaf extractives of Garcinia spicata afforded an unidentified long chain carboxylic acid, friedelin, friedelan-3β-ol, sitosterol and the biflavanones GB-1, GB-1a, GB-2a and morelloflavone. Chemotaxonomic significance of the occurrence of some of the above foliar constituents in Calophyllum and Garcinia species is discussed.     

Triterpenoid taxonomic markers for Stemonoporus and other genera of the dipterocarpaceae

The bark and/or timber extracts of Stemonoporus affinis, S. cordifolius, S. elegans, S. lancifolius, S. oblongifolius and S. petiolaris have been studied. The following compounds have been isolated: α-amyrin, δ-amyrenone, ursolic acid, sitosterol, sitosteryl-o-methoxybenzoate, ursonic acid, acetylursolic acid, 4-hydroxybenzaldehyde, methyl 2,4-dihydroxybenzoate, 2α-hydroxyursolic acid and bergenin. TLC examination of extracts of S. petiolaris, S. canaliculatus and S. reticulatus is reported. Triterpenoid taxonomic markers are summarized for Dipterocarpus, Doona, Shorea and Stemonoporus.     

Phenolic acids in the genus Lycopodium

The dihydric phenolics from the leaves of 170 Ecuadorian Lycopodium specimens representing 49 species and varieties have been examined as semiquinones by EPR spectroscopy. An ester of dihydrocaffeic acid was observed in 137 extractors of specimens all confined to the subgenus Urostachya. The ester was not present in the subgenera Lycopodium and Lycopodiella, where the dominant phenolic acid was chlorogenic acid. The concentrations of the “Urostachyaester” were found to increase with increasing altitude. Hydroquinone and protochatechuic acid have been observed in a few specimens.     

Alkaloids of ethiopian Calpurnia aurea subsp. aurea

Two novel alkaloids 3β,4α,13α-trihydroxylupanine and 3β,4α-dihydroxy 13α-O-(2'-pyrrolylcarbonyl)-lupanine (calpaurine) have been isolated from the leaves of Ethiopian Calpurnia aurea subsp. aurea. In addition, lupinine and epilupinine (both new for the genus), calpurmenine and calpurmenine pyrrolecarboxylic acid ester (previously found in subsp. sylvatica but not in subsp. aruea) have been isolated together with 13-hydroxylupanine, its tiglate and pyrrolecarboxylic acid esters (calpumine), virgiline and virgiline pyrrolecarboxylic acid ester, alkaloids which have been reported previously from subsp. aruea.     

Amino acids and low-molecular-weight carbohydrates of some marine red algae

Amino acids and low-MW carbohydrates of 18 red algae have been analyzed. Several non-protein amino acids have been identified, including pyrrolidine-2,5-dicarboxylic acid (3c) and N-methylmethionine sulfoxide (5), new natural products, and 13 known compounds, citrulline, β-alanine, γ-aminobutyric acid, baikiain (1), pipecolic acid (2), domoic acid (3a), kainic acid (3b), azetidine-2-carboxylic acid (4), methionine sulfoxide taurine, N-methyltaurine, N,N-dimethyltaurine and N,N,N-trimethyltaurine. Sugars present were mainly floridoside, isofloridoside and mannoglyceric acid. Details of the structural elucidation of new compounds are also given.     

The biosynthesis of dicoumarol

Micro-organisms have been isolated that can utilize o-coumaric acid as a sole carbon source with the subsequent production of 4-hydroxycoumarin and dicoumarol. One of these organisms, Penicillium jenseni, has been used to examine the biosynthesis of dicoumarol. Certain thermophilic fungi have also been found that can convert o-coumaric acid into dicoumarol.     

Acid-catalyzed transformation of 13(S)-hydroperoxylinoleic acid into epoxyhydroxyoctadecenoic and trihydroxyoctadecenoic acids

Acid treatment of (13S)-(9Z,11E)-13-hydroperoxy-9,11-octadecadienoic acid in tetrahydrofuran-water solvent afforded mainly (11R,12R,13S)-(Z)-12,13-epoxy-11-hydroxy-9-octadecenoic acid, diastereomeric (Z)-11,12,13-trihydroxy-9-octadecenoic acids and four isomers of (E)-9,12,13(9,10,13)-trihydroxy-10(11)-octadecenoic acid. Other minor products were oxooctadecadienoic, (E)-9(13)-hydroxy-13(9)-oxo-10(11)-octadecenoic and (E)-12-oxo-10-dodecenoic acids. A heterolytic mechanism for acid catalysis was indicated, even though most of the products characterized also have been observed as a result of homolytic decomposition of the hydroperoxide via an oxy radical. Most of the products found in this study have been observed as metabolites of (13S)-(9Z,11E)-13-hydroperoxy-9,11-octadecadenoic acid in biological systems, and analogous compounds have been reported as metabolites of (12S)-(5Z,8Z,10E, 14Z)-12-hydroperoxy-5,8,10,14-hydroperoxy-5,8,10,14-eicosatetraenoic acid in either blood platelets or lung tissue.     

Triterpene acids from Salvia and Teucrium species

The pentacyclic triterpene acids ursolic acid, oleanolic acid, micromeric acid, maslinic acid and 3-epi-maslinic acid have been isolated from several Salvia and Teucrium species.     

The oxidative cleavage of folates. A critical study

Alkaline permanganate oxidation has been used to determine the chain length of naturally occurring pteroylpolyglutamates on the assumption that all forms of folates cleave at the C⁹N¹⁰ bond to produce the corresponding p-aminobenzoyl-polyglutamates. The chain length of the latter could be determined by cochromatography with synthetic markers. The products of alkalinc (ammonium bicarbonate buffer, pH 9.0) permanganate oxidation of a number of reduced and oxidized, one-carbon-substituted and unsubstituted folic acid derivatives have been identified, and their yields and stability to the oxidative treatment have been determined. Unsubstituted, oxidized and reduced folic acid and N⁵-formyl-tetrahydrofolic acid are cleaved at the C⁹N¹⁰ bond to produce p-aminobenzoylglutamic acid. N⁵, N¹⁰-methenyl-tetrahydrofolic acid, N⁵,N¹⁰-methylene-tetrahydrofolic acid, and N¹⁰-formyl-tetrahydrofolic acid are not cleaved but are oxidized to N¹⁰-formyl-folic acid which is completely stable to the oxidative treatment employed. N⁵-methyl-tetrahydrofolic acid is not cleaved either but is oxidized to N⁵-methyl-dihydrofolic acid which upon continued oxidation decomposes slowly to unidentified products. The γ-glutamyl peptide linkage is completely stable to oxidation. Using p-amino-[3,5-³H]benzoylglutamic acid, it is also shown that this product, previously thought to be stable to the oxidative treatment is decomposed by it. The significance of these findings in terms of the errors that may have been introduced in prior estimations of the chain length and pool sizes of the naturally occurring pteroylpolyglutamates is discussed. The possibility of developing a method for the chain length determination of noncleavable pools of one-carbon-substituted folates using [2-¹⁴C]folic acid to label the folates in vivo is presented.     

Free amino acids and γ-glutamyl peptides in fagaceae

Amino acids have been investigated in seeds and fresh parts of members of the Fagaceae. Seeds from the genus Fagus contain willardiine, 5-hydroxy-6-methylpipecolic acids, N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid and γ-glutamyl peptides, mainly γ-glutamylphenylalanine. These compounds are nearly or totally absent from leaves of F. silvatica and from seedlings and immature seeds of F. silvatica var. purpurea; instead, the seedlings contain large amounts of γ-l-glutamyl-l-isoleucine and γ-l-glutamyl-l-leucine. γ-l-Glutamyl-l-tryptophan and γ-l-glutamyl-γ-l-glutamyl-l-phenylalanine, not previously known from nature, have been isolated from seeds of F. silvatica var. purpurea. The structures have been confirmed by syntheses. 4-Hydroxypipecolic acid (with trans-configuration) has been identified in seeds of F. japonica Maxim. and F. sieboldii Endl. None of the above compounds was found in Quercus or Castanea species whereas argininosuccinic acid was identified in Castanea sativa.     

Acidic metabolites of benzyl alcohol in greenbug resistant barley

(¹⁴C-Carbinol)benzyl alcohol taken up through the roots of greenbug (Schizaphis graminum) resistant barley is metabolized into a large number of radioactive compounds which have been separated by ion exchange chromatography. Two of these acidic metabolites have been identified as O-benzoyl-l-malic acid and N-benzoylaspartic acid; these identifications were confirmed by synthesis.     

Triterpenoid,coumarin and quinone constituents of eleven Diospyros species (Ebenaceae)

From the bark and/or timber extracts of Diospyros hirsuta, D. moonii, D. quaesita, D. spinescens, D. thwaitesii and D. walkeri, the following compounds have been isolated; lupeol, betulin, betulinic acid sitosterol, taraxerol, taraxerone, ursolic acid, oleanolic acid scopoletin, plumbagin, elliptinone, diospyrin and diosindigo A. TLC examination of the bark and timber extract of D. acuta, D. chaetocarpa, D. oblongifolia, D. oppositifolia and D. rheophytica is reported. Lupeol betulin, oleanolic acid and sitosterol have been isolated from the fruit of D. oblongfolia.     

ψ-esters of depsidones with a lactole ring

The reaction of stictic, norstictic and salazinic acids with methanol, ethanol and tert-butanol has been investigated. 8′-O-Methylstictic acid is identical with methylstictic acid from Lobaria oregana. Ingolfdottir's vesuvianic acid from Stereocaulon vesuvianum and Handong's cetrariastrumin from Cetrariastrum nepalensis have been shown to be 8′-O-ethylstictic acid and 8′,9′-di-O-ethylsalazinic acid, respectively, by reaction of stictic and salazinic acids with ethanol.     

Isolation and Characterization of Rifampin-Resistant and Streptolydigin-Resistant Mutants of Bacillus subtilis with Altered Sporulation Properties

Mutants of Bacillus subtilis with altered deoxyribonucleic-dependent ribonucleic acid polymerase activity have been isolated and characterized. These mutants, selected as strains resistant to rifampin or streptolydigin, demonstrate drug-resistant in vitro ribonucleic acid synthesis. Sporeforming ability and support of phage infection are altered in many of the mutants. Mutations to rifampin and streptolydigin resistance have been located on the B. subtilis chromosome and ordered relative to the markers cysA14 and str.     

Saccharopine and 2-aminoadipic acid in Reseda odorata

2(S),2′(S)-N⁶-(2′-Glutaryl)lysine (l-saccharopine) and 2(S)-2-aminoadipic acid have been isolated from Reseda odorata. When traditional isolation procedures are used l-pyrosaccharopine (5(S),5′(S)-N-(5′-amino-5′-carboxy-pentyl)-2-pyrrolidone-5-carboxylic acid) is formed from l-saccharopine by lactamisation. The degree of lactamisation during various isolation steps has been studied, The amino acids were identified by IR and PMR spectroscopy and the configurations established by enzymic and polarimetric analyses. The contents of saccharopine and 2-amino-adipic acid have been determined relative to the total nitrogen content at various stages in the growth cycle of R. odorata.     

Comparative studies on human carboxypeptidases B and N

A series of dicarboxylic acid bi-product analogs of lysine and arginine have been tested as competitive inhibitors of human pancreatic carboxypeptidase B and human plasma carboxypeptidase N. The most effective derivative was guanidinoethylmercaptosuccinic acid with K_is of 0.5 and 1.0 × 10^?6m for Carboxypeptidases B and N, respectively. Values for the all-carbon guanidinopropylsuccinic acid were similar. In addition the kinetic parameters, K_m and $\text{k}{}_{\mathrm{<mtext>cat</mtext>}}\text{K}{}_{\mathrm{m}}$, have been determined for the hydrolysis of benzoyl-alanyl-lysine and benzoylalanyl-arginine by human Carboxypeptidases B and N. These substrates have been proposed for use in improved spectrophotometric assays. An enhanced affinity of these substrates versus benzoyl-glycyl-lysine or benzoyl-glycyl-arginine indicates a significant participation of the penultimate amino acid in catalysis of substrate.     

Saccharomycopsis fibuligera and its applications in biotechnology

Saccharomycopsis fibuligera is found to actively accumulate trehalose from starch and the gene responsible for biosynthesis of trehalose has been cloned and its expression has been characterized. This yeast is also found to secrete a large amount of amylases, acid protease and β-glucosidase which have highly potential applications in fermentation industry. The genes encoding amylases, acid protease and β-glucosidase in S. fibuligera have been cloned and characterized. It is also used to produce ethanol from starch, especially cassava starch by co-cultures of Saccharomyces cereviase or Zymomonas mobilis.