Theoretical evaluation of flotation performance of carboxyl hydroxamic acids with different number of polar groups on the surfaces of diaspore (010) and kaolinite (001)

The adsorption behaviors of three carboxyl hydroxamic acids on diaspore (010) and kaolinite (001) have been studied by density functional theory (DFT) and molecular dynamics (MD) method. The results indicated that carboxyl hydroxamic acids could adsorb on diaspore surface by ionic bonds and hydrogen bonds, and adsorb on kaolinite surface by hydrogen bonds. The models of carboxyl hydroxamic acids adsorbed on diaspore and kaolinite surfaces are proposed.

Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors

A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels.     

The two nitrogen mobilisation- and senescence-associated <Emphasis Type="Italic">GS1</Emphasis> and <Emphasis Type="Italic">GDH</Emphasis> genes are controlled by C and N metabolites

In tobacco, the two enzymes of nitrogen metabolism, cytosolic glutamine synthetase (GS1; E.C.6.3.1.2) and glutamate dehydrogenase (GDH; E.C.1.4.1.2), are induced during leaf senescence, whereas the chloroplastic glutamine synthetase (GS2; E.C.6.3.1.2) and nitrate reductase (NR; E.C.1.6.1.1) are repressed in the course of ageing. In this report, we showed in discs of fully expanded Nicotiana tabacum L. cv. Xanthi leaves that sucrose (Suc) and amino acids were involved in the regulation of the expression of GS1 and GDH genes. Suc induced the expression of GS1 and repressed that of GDH. Therefore, we concluded that in response to Suc, GS1 behaved as an early Senescence Associated Gene (SAG), whereas GDH behaved as a late SAG. Moreover, amino acids induced the expression of both genes. Among the amino acids tested as signal molecules, proline (Pro) and glutamate (Glu) were major inducers of GDH and GS1 expression, respectively. Interestingly, an opposite regulation of GS1 and GS2 by Pro and Glu was shown. The contrary effect of Suc on NIA (NR encoding gene) and GDH mRNA accumulation was also emphasized.     

Acyl Transfer Activity of an Amidase from Rhodococcus sp. Strain R312: Formation of a Wide Range of Hydroxamic Acids

The enantioselective amidase from Rhodococcus sp. strain R312 was produced in Escherichia coli and was purified in one chromatographic step. This enzyme was shown to catalyze the acyl transfer reaction to hydroxylamine from a wide range of amides. The optimum working pH values were 7 with neutral amides and 8 with α-aminoamides. The reaction occurred according to a Ping Pong Bi Bi mechanism. The kinetic constants demonstrated that the presence of a hydrophobic moiety in the carbon side chain considerably decreased the K_mamide values (e.g., K_mamide = 0.1 mM for butyramide, isobutyramide, valeramide, pivalamide, hexanoamide, and benzamide). Moreover, very high turnover numbers (k_cat) were obtained with linear aliphatic amides (e.g., k_cat = 333 s⁻¹ with hexanoamide), whereas branched-side-chain-, aromatic cycle- or heterocycle-containing amides were sterically hindered. Carboxylic acids, α-amino acids, and methyl esters were not acyl donors or were very bad acyl donors. Only amides and hydroxamic acids, both of which contained amide bonds, were determined to be efficient acyl donors. On the other hand, the highest affinities of the acyl-enzyme complexes for hydroxylamine were obtained with short, polar or unsaturated amides as acyl donors (e.g., K_mNH2OH = 20, 25, and 5 mM for acetyl-, alanyl-, and acryloyl-enzyme complexes, respectively). No acyl acceptors except water and hydroxylamine were found. Finally, the purified amidase was shown to be l-enantioselective towards α-hydroxy- and α-aminoamides.Many bacterial amidases (EC 3.5.1.4) have been described previously because of their amide hydrolysis activities. Wide-spectrum amidases from Rhodococcus sp. strain R312 (26) and Pseudomonas aeruginosa (1), which are very similar, hydrolyze only short-chain amides. These enzymes are made up of four and six identical subunits having molecular weights of about 45,000 and 35,000, respectively. Based on the results of experiments performed with inhibitors, they have been classified as belonging to a branch of sulfhydryl enzymes (1, 26). The other amidases, the enantioselective amidases from Pseudomonas chlororaphis B23 (5), Rhodococcus erythropolis MP50 (12, 27), Rhodococcus sp. strain R312 (20), Rhodococcus sp. strain N-774 (10), Rhodococcus sp. (21), and Rhodococcus rhodochrous J1 (14), belong to a group of amidases containing a GGSS signature in the amino acid sequence (4) and are made up of two (or eight) identical subunits. The corresponding genes are located in clusters containing genes encoding the two subunits of a nitrile hydratase (EC 4.2.1.84). These amidases were also previously classified as sulfhydryl enzymes (5, 15), but no active amino acid residue was identified in any of them. Recently, Kobayashi et al. (15) showed that the real active site residues of the amidase from R. rhodochrous J1 were Asp-191 and Ser-195 rather than the generally accepted Cys-203 residue. These authors showed that aspartic acid and serine residues of this enzyme were also present in the active site sequences of aspartic proteinases and suggested that there is an evolutionary relationship between amidases and aspartic proteinases.All of the different amidases also exhibit an acyl transfer activity in the presence of hydroxylamine: RCONH₂ + NH₂OH ↔ RCONHOH + NH₃. This kind of reaction was previously described for the wide-spectrum amidase from Rhodococcus sp. strain R312 (6), but there has been no detailed study examining the acyl transfer reaction of amidases belonging to the GGSS signature-containing group. The final reaction products (hydroxamic acids) are known to possess high chelating properties. Some of them (particularly α-aminohydroxamic acid derivatives) are potent inhibitors of matrix metalloproteases, a family of zinc endopeptidases involved in tissue remodelling (3). Some other hydroxamic acids (α-aminohydroxamic acids, synthetic siderophores, acetohydroxamic acid, etc.) have also been investigated as anti-human immunodeficiency virus agents or antimalarial agents or have been recommended for treatment of ureaplasma infections and anemia (2, 8, 13, 28). Moreover, some fatty hydroxamic acids have been studied as inhibitors of cylooxygenase and 5-lipooxygenase with potent antiinflammatory activity (9).Apart from these medical applications, some hydroxamic acids (particularly polymerizable unsaturated hydroxamic acids and mid-chain or long-chain hydroxamic acids) have also been extensively investigated in wastewater treatment and nuclear technology studies as a way to eliminate contaminating metal ions (11, 16, 18).In this paper we describe the formation of a wide range of hydroxamic acids with the enantioselective amidase (a 120,000-dalton homodimer) from Rhodococcus sp. strain R312, and we provide some additional information which enhanced our comprehension of the reaction mechanism of this amidase.     

Enhancement of Serum Lysozyme Activity by Injecting a Mixture of Chitosan Oligosaccharides Intravenously in Rabbits

Mycophenolic acid (MPA, 1), an inhibitor of IMP-dehydrogenase (IMPDH) and a latent PPARγ agonist, is used as an effective immunosuppressant for clinical transplantation and recently entered clinical trials in advanced multiple myeloma patients. On the other hand, suberoylanilide hydroxamic acid (SAHA), a non-specific histone deacetylase (HDAC) inhibitor, has been approved for treating cutaneous T-cell lymphoma. MPA seemed to bear a cap, a linker, and a weak metal-binding site as a latent inhibitor of HDAC. Therefore, the hydroxamic acid derivatives of mycophenolic acid having an effective metal-binding site, mycophenolic hydroxamic acid (MPHA, 2), 7-O-acetyl mycophenolic acid (7-O-Ac MPHA, 3), and 7-O-lauroyl mycophenolic hydroxamic acid (7-O-L MPHA, 4) were designed and synthesized. All these compounds inhibited histone deacetylase with IC₅₀ values of 1, 0.9 and 0.5 μM, and cell proliferation at concentrations of 2, 1.5 and 1 μM, respectively.     

Effects of Organic Solvents on Streptomyces griseus Protease I with Transfer Action

The protease I from Streptomyces griseus var. alcalophilus strongly catalyzed the transfer reaction forming hydroxamic acids of various amino acids, especially aromatic and hydrophobic amino acids. Dimethyl sulfoxide (DMSO), 1,4-butane diol, and glycerol protected this enzyme from heat denaturation. Moreover, only DMSO strongly activated the transfer action of protease I and the velocity of reaction was accelerated three times in the presence of 50% DMSO. The yield of transfer product strongly depended on reaction time and the concentrations of enzyme and substrates in the presence of DMSO. The velocity of the transfer reaction was faster than that of the hydrolysis reaction under the conditions of 0.1 M Phe-OEt, 0.75 M NH₂OH, and 50% DMSO.     

Lipase-catalyzed enantioselective hydrolysis of N-protected racemic non-protein amino acid esters

Porcine pancreatic lipase (PPL)-catalyzed enantioselective hydrolysis of N-benzyloxycarbonyl-dl-amino acid esters (Z-dl-AA-ORs) was studied for the optical resolution of a variety of non-protein amino acids. The ester moiety (R) of the substrate affected the rate of hydrolysis significantly. The glyceryl (Gl) and carbamoylmethyl (Cam) esters were found to be highly reactive substrates. The hydrolysis of the Gl esters (Z-dl-AA-OGls) of both aliphatic and aromatic amino acids was examined in acetonitrile containing 70% (v/v) of 0.02 M phosphate buffer (pH 7.0) at 30°C. With all amino acids tested, the corresponding l-enantiomers were hydrolyzed preferentially. PPL favored aromatic amino acids, such as phenylalanine and p-chlorophenylalanine, leading to completion of the hydrolysis within 20 min with excellent enantioselectivities (E>100). The PPL-catalyzed hydrolysis of the corresponding Cam esters (Z-dl-AA-OCams) was also examined under the same reaction conditions. Although the hydrolysis of the Cam esters was rapid, the l-enantioselectivities were rather poor with aromatic amino acids, such as 2-phenylglycine and homophenylalanine.     

Metal complexes of cyclic hydroxamates. Synthesis and crystal structures of 3-hydroxy-2-methyl-3H-quinazolin-4-one (ChaH) and of its Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes

The attempted acetylation of anthranilic hydroxamic acid (2-aminobenzohydroxamic acid) as a possible dual inhibitor of the catalytic sites in prostaglandin-H-synthase (PGHS) gave the cyclic hydroxamic acid 3-hydroxy-2-methyl-3H-quinazolin-4-one (ChaH) which was characterised by spectroscopy and X-ray crystallography. The length of the hydroxamic acid C-N bond, 1.3998(17) Å, in ChaH is longer than normal (∼1.33 Å) indicative of reduced delocalisation of the nitrogen lone pair of electrons into the hydroxamic acid π system. This is confirmed by the appearance of the ν(CO) band at a considerably higher wavenumber in the IR spectrum than normal. The complexes Fe(Cha)₂(Cl)(H₂O)·⁷/₂H₂O, Co(Cha)₂(EtOH)₂, Ni(Cha)₂(EtOH)₂, Cu(Cha)(H₂O)(Cl) and Zn(Cha)₂(H₂O), have been synthesised and their structures determined by X-ray crystallography. The X-ray data confirmed coordination by Cha^- through the carbonyl and deprotonated hydroxamate oxygen in all cases. The M-O (hydroxamate) bonds are shorter than the M-O (carbonyl) bonds by between 0.0930 Å for the Co(II) complex and 0.0448 Å for the Ni(II) complex. The geometries of all complexes conform to the coordination requirements of the particular metal ion involved. Speciation studies for ChaH and its complexes with Ni(II) and Zn(II) were carried out using pH-metric methods. The results show that ChaH is much more acidic than related acyclic hydroxamic acids and that its metal complexes are correspondingly less stable.     

Attraction ofCarpoglyphus lactis (Acarina: Acaridae) to selected organic compounds

Various chemicals commonly found in food (twelve monosaccharides, nine sugar alcohols, twenty triglycerides, eleven unsaturated fatty acids and nine saturated fatty acids) were tested in different concentrations for their ability to attract and sustain feeding by the dried-fruit mite,Carpoglyphus lactis (L.). Oleic acid, -d-glucose and some triglycerides act as phagoincitants and phagostimulants, whiled-fucose and trilaurin are phagodeterrents.     

Enrichment of γ-linolenic acid from fungal oil by lipase-catalysed reactions

Summary Various lipases have been evaluated as biocatalysts for the enrichment of -linolenic acid from a commercial fungal oil derived from Mucor sp. by selective esterification of the fungal oil fatty acids with n-butanol or by selective hydrolysis of the oil. Lipase from M. miehei (Lipozyme), as compared to lipases from Candida cylindracea, Penicillium cyclopium, and Rhizopus arrhizus, was found to be most effective in the enrichment of -linolenic acid in unesterified fatty acids upon esterification of the fungal oil fatty acids with n-butanol. Thus, the -linolenic acid content could be raised from 10.4% in the starting material to 68.8% in the unesterified fatty acids. Selective hydrolysis of the fungal oil triacyglycerols using Lipozyme resulted in about 1.5-fold enrichment of -linolenic acid in the unhydrolysed acylglycerols. Other lipases tested, such as those from P. cyclopium, C. cylindracea, R. arrhizus, Penicillium sp. (Lipase G), porcine pancreas and Chromobacterium viscosum, were also rather ineffective in the enrichment of -linolenic acid by selective hydrolysis of the fungal oil triacylglycerols. Offprint requests to: K. D. Mukherjee     

Urease Inhibition by Polymeric Substrate Analogues and Thiophosphamides

Inhibition of soybean urease by polymeric substrate analogues, urea and thiourea polydisulfides (PDSU and PDSTU, respectively); or three thiophosphoric acid amides (TPAA), tri-(N-3-hydroxyphenyl)thiophosphamide (1), tri-(N-4,4"-aminodiphenyl)thiophosphamide, and di-oxy-(N--piridyl)thiophosphamide (3) was studied in aqueous solutions at various pH values. The inhibitory effects of all these substances were reversible and competitive with the lowest inhibition constant K _i2.8 M for TPAA-1 at pH 3.85. Above and below this pH value, K _iincreased, reaching 24 M at pH 7.2. All test substances inhibited urease comparably with known inhibitors such as thiols (cysteamine, etc.) and hydroxamic acid derivatives, but were less efficient than phosphorodiamidates. Structural features of possible urease inhibitors of higher efficiency were proposed.     

Substrate selectivity in esterification of less common fatty acids catalysed by lipases from different sources

Lipases from microorganisms (Candida cylindracea, Rhizopus arrhizus and Rhizomucor miehei), animal tissue (porcine pancreas) and a higher plant (rape, Brassica napus) have been evaluated as biocatalysts in the esterifications with n-butanol with regard to their substrate specificity towards fatty acids having a cis-4 unsaturation, e.g. docosahexaenoic (n-3 22:6), cis-6 unsaturation, e.g. petroselinic (n-12-18:1), -linolenic (n-6 18:3) and stearidonic (n-3 18:4), as well as cis-8 unsaturation, e.g. dihomo--linolenic (n-6 20:3) acid, and fatty acids having unusual structures, e.g.cyclopentenyl (hydnocarpic and chaulmoogric), hydroxy (ricinoleic and 12-hydroxystearic) and epoxy (cis- and trans-9,10-epoxystearic) acids. A common feature of all the lipases tested is their ability to discriminate strongly against unsaturated fatty acids having a cis-4, cis-6 or a cis-8 unsaturation as substrates for esterification, whereas cyclopentenyl, hydrocy and epoxy acids are very well accepted as substrates. Esterification of the fatty acids of Hydnocarpus wightiana seed oil with n-butanol, catalysed by each of the above lipases, revealed that, as compared to the cyclopentenyl fatty acids having saturated alkyl chains, gorlic acid — a cyclopentenyl acid having a cis-6 unsaturation — is also strongly discriminated against as a substrate for esterification.This paper is Part of the doctoral thesis of Iván Jachmanián to be submitted to Facultad de Química, Universidad de la República, Montevideo, Uruguay     

N-(indol-3-ylacetyl)amino acids as sources of auxin in plant tissue culture

N-(Indol-3-ylacetyl) derivatives (IAA conjugates) of aliphatic amino acids with a two- to six-carbon backbone including -l-amino acids, (-amino acids, and the ,-diamino acids ornithine and lysine were prepared, chemically characterized, and tested as sources of auxin in plant tissue culture. Stimulation of unorganized growth in Solanum nigrum L. callus and callus induction and developmental effects in tomato (Lycopersicon esculentum Mill. cv. Marglobe) hypocotyl explants were studied systematically. Relative auxin activities were estimated by comparing physiologically equivalent concentrations, in the optimal and suboptimal range, of the individual IAA conjugates. While the growth-promoting properties of some of the conjugates were species-dependent, those containing straight-chain two- to four-carbon -l-amino acid moieties were generally up to 100 times more active than those of their five- to six-carbon homologues. Branching of the amino acid backbone at C- (norvaline vs. valine and norleucine vs. isoleucine) and C- (norleucine vs. leucine) had a minor effect, but substitution of H- by a methyl group (-amino-l-butyric vs. -aminoisobutyric acids) almost completely blocked growth-promoting activity. IAA conjugates of -amino acids were, in most cases, nearly as active as those of their -amino-l-isomers. Among the conjugates of ,-diamino acids N -(IAA) ornithine was less active than N -(IAA)lysine. The activity of N -(IAA)lysine was less than for the -(IAA) isomer, and that of N ,N -(IAA)₂-lysine was different in tomato and Solanum nigrum. The l-alanine and -lysine conjugates were also found to be useful for induction and development of Oenothera leaf callus and in tomato cell-suspension culture, two systems which require highly active sources of auxin.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indol-3-ylacetic acid the abbreviations for N-(indol-3-ylacetyl)amino acids are listed in Table 1.     

Reaction of Phosphinyl and Phosphinothioyl Disulfides with Diazomethane

Four kinds of 4-substituted phenyl diethoxyphosphinyl disulfide (substitueras: H, CH₃, C₂H₅, Cl) and phenyl diethoxyphosphinothioyl disulfide reacted readily with diazomethane. The phosphinyl disulfides produced diethyl (4-substituted phenylthio)methyl phosphorothionate and the isomer, diethyl S-(4-substituted phenylthio)methyl phosphorothiolate, as the main products, whereas the phosphinothioyl disulfide produced only diethyl S-(phenylthio)methyl phosphorodithioate.

The possible mechanism involved is as follows: the S-S bond in (EtO)₂P(X)-S-S-C₆H₄R (X = O or S) is cleaved by nucleophilic attack of diazomethane at the sulfur atom bonded to the phenyl group to produce and ^⊕ N₂CH₂–S–C₆H₄R; the latter reacts with the former with loss of nitrogen; therefore, when X is O, two compounds, (EtO)₂P(S)–O–CH₂–S–C₆H₄R and (EtO)₂P(O)–S–CH₂–S–C₆H₄R, are produced, when X is S, only (EtO)₂P(S)–S–CH₂ –S–C₆H₄R is obtained.     

The effect of copper toxicity on the contents of nitrogen compounds in Silene vulgaris (Moench) Garcke

The effect of copper on the uptake of nitrogen and the tissue contents of inorganic nitrogen, amino acids and proteins were studied in cooper-sensitive Silene vulgaris (Moench) Garcke, grown at different nitrogen sources (NH₄ ⁺ or NO₃ ^-). All the toxic copper levels tested, i.e. 4, 8, 16 M Cu²⁺, strongly inhibited the uptake of nitrogen, especially of NO₃ ^-, and decreased the content of NO₃ ^-, amino acids and proteins. Especially at 4 and 8 M Cu²⁺, NH₄ ⁺ accumulated in the plants, suggesting that the conversion of NH₄ ^- into amino acids was inhibited.     

Synthesis and biological evaluation of O-methyl and O-ethyl NSAID hydroxamic acids

This paper reports the synthesis of O-methyl and O-ethyl NSAID hydroxamic acids, their antimicrobial activities, and their ability to inhibit urease and soybean lipoxygenase activities. Ibuprofen and fenoprofen hydroxamic acids with free hydroxy groups present the highest antimicrobial activity, while indomethacin and diclofenac analogs show significantly lower antimicrobial activity. Diclofenac hydroxamic acid 4e exerts the highest anti-urease activity. Indomethacin O-ethyl hydroxamic acid 3h and ibuprofen O-benzyl hydroxamic acid 4b exert significant inhibitory activities on soybean lipoxygenase. Fenoprofen and indomethacin O-ethyl hydroxamic acids 3b and 3h and diclofenac and indomethacin O-benzyl analogs 4g and 4i highly inhibit lipid peroxidation. The highest antioxidant activity was shown by fenoprofen derivative 3b.     

A comparison between the amino acid composition of an egg parasitoid wasp and some of its hosts

Amino acid compositions of the eggs of five lepidopteran hosts for Trichogramma minutum were compared with each other and with a non-host species, Rhodnius prolixus, in which T. minutum oviposits but does not develop. Host eggs are quite homogeneous, particularly when compared according to groupings of potentially interconvertible amino acids. Combined mole percent values for glycine, serine and alanine were higher in hosts (27.5–29.2 mole%) than in R. prolixus eggs (21.5 mole%), in bovine serum albumin (14.9%), which has been used as a protein source in artificial diets for T. minutum, or in many of the mixtures used in published diets for this species. Since these three amino acids make up 26.3 mole% of the adult amino acid content of T. minutum, their deficiency in diets could require metabolic compensation detrimental to development.Adult T. minutum arising from eggs of Manduca sexta, Choristoneura fumiferana, and Sitotroga cerealella are similar in amino acid composition to each other and, in general, to their hosts. Variability appears greater in hosts than in adult wasp composition, suggesting some interconversion of host amino acids to accommodate inflexible nutritional requirements of T. minutum.In the three host species tested, free amino acids constituted 15.8–19.3% by weight of the amino acid in egg contents. In M. sexta eggs, glycine, serine and alanine together make up 28.4% by weight of the total free amino acid, a much higher proportion than in many published diets. The four free amino acids (isoleucine, leucine, phenylalanine and histidine) reported to be oviposition stimulants in experiments on encapsulated diets are present in sufficient concentrations to induce oviposition in the host species tested and in R. prolixus. S. cerealella egg contents having approximately 1.8 g amino acid, yield one or rarely two adult T. minutum (1g amino acid/insect). In contrast, M. sexta eggs with 94 g amino acid each yield an average of 10–12 adults (8.2g amino acid/insect). This suggests that small hosts are allocated few eggs which can only develop into small adults because of nutrient supply (parasitoid size in metabolically restricted), whereas much larger hosts are allocated proportionately fewer eggs than the former resulting in larger, and presumably more viable and fecund, adults (parasitoid size is established behaviourally).     

Activity of yeast d-amino acid oxidase on aromatic unnatural amino acids

d-Amino acid oxidase is a FAD-dependent enzyme that catalyses the conversion of the d-enantiomer of amino acids into the corresponding α-keto acid. Substrate specificity of the enzyme from the yeast Rhodotorula gracilis was investigated towards aromatic amino acids, and particularly synthetic α-amino acids.A significant improvement of the activity (V_max,app) and of the specificity constant (the V_max,app/K_m,app ratio) on a number of the substrates tested was obtained using a single-point mutant enzyme designed by a rational approach. With R. gracilis d-amino acid oxidase the complete resolution of d,l-homo-phenylalanine was obtained with the aim to produce the corresponding pure l-isomer and to use the corresponding α-keto acid as a precursor of the amino acid in the l-form.     

Production of arachidonic acid by Mortierella fungi

Summary Various Mortierella fungi were assayed for their productivity of arachidonic acid (ARA). Only strains belonging to the subgenus Mortierella accumulated detectable amounts of ARA together with dihomo--linolenic acid. None of the strains belonging to the subgenus Micromucor tested accumulated these C-20 fatty acids, although they produced a C-18 fatty acid, -linolenic enic acid. A soil isolate, M. alpina 1S-4, was found to grow well in a liquid medium containing glucose and yeast extract as carbon and nitrogen sources, respectively. Addition of several natural oils such as olive and soybean oils to the medium increased the accumulation of ARA. Under optimal culture conditions in a 5-1 bench-scale fermentor, the fungus produced 3.6 g/l of ARA in 7 days. On cultivation for 10 days at 28°C in a 2000-1 fermentor, the same fungus produced 22.5 kg/kl mycelia (dry weight) containing 9.9 kg lipids, in which ARA comprised 31.0% of the total fatty acids. On standing the harvested mycelia for a further 6 days, major mycelial fatty acids (i.e. palmitic acid, oleic acid, linoleic acid, etc.) other than ARA rapidly decomposed and the ARA content of the total fatty acids reached nearly 70%.