Characterizations of Pneumocystis carinii and rat lung lipids: glyceryl ethers and fatty alcohols

Pneumocystis carinii carinii and rat lung phospholipids contained 3-6% 1-alkyl-2-acyl glycerols composed of the glyceryl ether species, 1-O-octadecyl glycerol (batyl alcohol), 1-O-octadec-9-enyl glycerol (selachyl alcohol), 1-O-hexadecyl glycerol (chimyl alcohol), and 1-O-hexadec-9-enyl glycerol. Of the major phospholipid classes, phosphatidylinositol (PI) and phosphatidylserine contained the highest percentage of alkyl acyl glycerols. Methylprednisolone treatment caused an increase in alkyl acyl PI of rat lung lipids from 12% to 45%. As the PI concentration in lung phospholipids increases in rats treated with methylprednisolone, the increase in alkyl acyl PI was substantial; the proportions of alkyl acyl phosphatidylethanolamine and alkyl acyl lyso phosphatidylcholine (PC) also increased. Pneumocystis phospholipids contained higher proportions of alkyl acyl PC than the phospholipids of the lungs from normal and immunosuppressed uninfected rats. The glyceryl ether compositions of P. carinii carinii PC and lyso PC were similar, which suggests that lyso PC in the organism is derived by phospholipase A2 action on PC. This was not the case for PC and lyso PC of the lung controls. Analysis of the free fatty alcohols, precursors of glyceryl ethers identified only saturated species in P. carinii carinii and rat lung controls. Thus, the introduction of a double bond in the alcohol moiety of glyceryl ethers occurs after formation of the ether linkage between fatty alcohol and the glyceryl backbone.     

Influence of a subinhibitory dose of antifungal fatty acids from Sporothrix flocculosa on cellular lipid composition in fungi

Antifungal fatty acids produced by the biocontrol fungus Sporothrix flocculosa were studied on the basis of their effect on growth and cellular lipid composition of three fungi, Cladosporium cucumerinum, Fusarium oxysporum, and S. flocculosa, whose growth was decreased by 51, 33, and 5%, respectively, when exposed to 0.4 mg fatty acid per ml. The sensitivity to fatty acid antibiotics from S. flocculosa was related to a high degree of unsaturation of phospholipid fatty acids and a low proportion of sterols. The major responses of sensitive fungi to sublethal doses of antifungal fatty acids from liquid culture of S. flocculosa were: (i) a decrease in total lipid; (ii) an increase in the degree of fatty acid unsaturation (18:1 > 18:2 > 18:3); (iii) an increase in free fatty acids and phosphatidic acid and a decrease in total phospholipids; and (iv) an increase in sterol/phospholipid ratio. These modifications in lipid composition led to an increase in membrane fluidity in sensitive fungi as demonstrated by assessment of fluoresence anisotropy using liposomes and 1,6-diphenyl-1,3,5-hexatriene probe. This alteration in the physical state of lipids appears to be responsible for the previously demonstrated alteration of membrane structure and function in fungi confronted to S. flocculosa.     

Fat-modified diets influence serum concentrations of cholesterol precursors and plant sterols in hypercholesterolemic subjects

Serum noncholesterol sterols, cholesterol precursors and plant sterols, are indicators of cholesterol absorption and synthesis. Serum plant sterol concentrations correlate positively with cholesterol absorption, but have also been found to correlate with dietary unsaturated to saturated fatty acid ratios. We studied the concentration of serum noncholesterol sterols during four different fat-modified diets, (1) high-fat, saturated fat-enriched (control), (2) reduced-fat, sunflower oil-enriched (SO-enriched), (3) rapeseed oil-enriched (RO-enriched), and (4) reduced-fat, saturated fat-enriched (reduced-fat), followed for 6 months in hypercholesterolemic subjects in a parallel design. The proportion of lathosterol (micrograms per 100 mg cholesterol), a precursor of cholesterol synthesis, increased significantly (P < .05) in both SO-enriched (mean +/- SD 147 +/- 57 v 167 +/- 76, 0 v 6 months) and RO-enriched (147 +/- 54 v 157 +/- 52) groups, where the reduction in low-density lipoprotein (LDL) cholesterol was also significant. The proportion of sitosterol, a plant sterol, decreased significantly in the control group (137 +/- 48 v 122 +/- 42), and the proportion of another plant sterol, campesterol, increased in the RO-enriched group (280 +/- 141 v 333 +/- 162), reflecting changes in the use of vegetable oils in these two groups rather than increased cholesterol absorption. In the whole study population, the proportion of linoleic and alpha-linolenic acid (a marker of the use of RO) in cholesterol esters (CEs) correlated (P < .001) with the proportion of sitosterol (r = .43) and campesterol (r = .36) in serum at the end of the study. In conclusion, serum cholesterol precursors were found to be useful indicators of cholesterol metabolism, but changes in serum plant sterols reflected dietary changes rather than cholesterol metabolism during long-term dietary intervention with fat-modified diets.     

Lipids of hamster cheek pouch epithelium

The hamster cheek pouch is a much used but incompletely understood experimental model. In particular, the cheek pouch epithelial lipids, which are important for permeability barrier function as well as other aspects of epithelial biology, have not been completely characterized. In the present study, the complete lipid class composition has been determined by thin-layer chromatography in conjunction with photodensitometry. The major lipid classes were phospholipids, free sterols, and ceramides. Minor amounts of monohexosylceramides, sterol esters, fatty acids, and triglycerides were also present. Significant amounts of covalently bound omega-hydroxyceramide was also detected. Transmission electron micrographs reveal extensive, largely paired, lipid bilayers in the intercellular spaces of the stratum corneum.     

Lipoproteins of the egg perivitelline fluid of Pomacea canaliculata snails (Mollusca: Gastropoda)

The lipid and protein composition of the perivitelline fluid of the eggs of Pomacea canaliculata was investigated. Two lipoproteins (PV 1 and PV 2) and one lipoprotein fraction (PV 3) were detected for the first time in gastropods. They represent 57.0, 7.5, and 35.5% of the egg total proteins, respectively. PV 1 is a glyco-carotene-protein complex with characteristics of a very high-density lipoprotein (VHDL). It has 0.33% lipids, mainly free sterols and phospholipids. The particle has a MW of 300 Kd and is composed of three subunits of 35, 32, and 28 Kd, respectively. PV 2 particle is a VHDL of 400 Kd and 3.75% lipids. The major lipid classes are free sterols and phospholipids and also have significant quantities of energy-providing triacylglycerides and free fatty acids. It is composed of two apoproteins of 67 and 31 Kd. PV 3 density corresponds to a high-density lipoprotein (HDL). It was fractionated into two subfractions "h" and "p". Fraction "h" contains 5.16% lipids, mainly free sterols, phospholipids, and free fatty acids, and two particles of 100 and 64 Kd. Dissociating electrophoresis showed two subunits of 34 and 29 Kd. Fraction "p" is composed of a single particle of 26 Kd that contains 9.5% lipids, which represents 30% of the total egg lipids. It has high levels of a carotenoid pigment. Besides it contains free fatty acids, hydrocarbons, sterified sterols, and triacylglycerides. These three fractions are probably the major supply of lipids and amino acids for the developing embryo.     

Studies on phospholipids of different mutants of Salmonella minnesota

Lipid composition of the cells of smooth (S form) and core-defective rough mutants (Ra, Rb & Re) of Salmonella minnesota has been studied. The readily-extractable lipids (RELs), acid-extractable lipids, and polar and nonpolar phospholipids have been analysed. Fatty acid composition of the different fractions containing phospholipids and other neutral lipids have been determined by GLC and GC-MS techniques. Phosphatidyl glycerol (PG), phosphatidylethanolamine (PE) and diphosphatidyl glycerol (DPG) were the major phospholipids present in all the strains. The major saturated fatty acid found was C16:0, and unsaturated fatty acids were, C16:1 and C18:1. Cyclopropane fatty acids, C17cy and C19cy, were also present in small amounts. Increased amounts of REL and unsaturated fatty acids were found in the mutants compared with the smooth strain. The amount of PG and PE decreased and DPG increased in the mutant strains.     

Ether lipid composition and molecular species alterations in carp brain (Cyprinus carpio L.) during normoxic temperature acclimation

Carp (Cyprinus carpio L.) whole brain was used to investigate the thermal acclimation changes under normoxic conditions of three-subclasses (alkenylacyl-, alkylacyl- and diacyl-subclasses) of choline glycerophospholipids (CGP), ethanolamine glycerophospholipids (EGP) and inositol glycerophospholipids (IGP) as well as their acyl chain profiles and molecular species composition. The alkenylacyl subclass of CGP and IGP and the alkylacyl subclass of CGP and EGP varied significantly during summer (25 degrees C) acclimation compared to winter (5 degrees C). The levels of alkenylacyl and alkylacyl-CGP, alkylacyl-EGP and alkenylacyl-IGP were 17.3-, 3.7-, 3.5- and 1.3-fold higher in the summer, respectively, while the alkenylacyl EGP was moderately lower. The levels of diacyl subclasses from CGP and IGP were considerably lower in the summer to compensate for the higher proportion of alkenylacyl and alkylacyl subclasses. Significant changes of ether phospholipids and the reorganization of the molecular species composition of all lipid subclasses may be associated with the "fine tuning" of the physical properties of the cellular membranes in carp brain due to temperature acclimation. The overall acyl chain profile of the three subclasses of carp brain phospholipids showed differences in composition depending upon the subclass of the individual phospholipid. Generally the polyunsaturated fatty acid (PUFA) chain composition increased relative to monounsaturated fatty acid (MUFA) and saturated fatty acids (SFA) during winter acclimation. Docosahexaenoic acid (DHA) was richer in the winter compared to summer. However, no DHA was found in ether-containing species of IGP from either winter or summer, except for 2% in alkylacyl-IGP during the summer. The above observations suggest that the content of ether phospholipids (alkenylacyl and alkylacyl) as well as the reorganization of the molecular species composition of all phospholipids may serve to maintain a functional fluid-crystalline state to preserve the signaling functions in carp brain.     

Composition of lipids and production of mucidin in a submerged culture of the basidiomycete Oudemansiella mucida

Mycelial lipids of the submerged culture of Oudemansiella mucida contain acylglycerols, free and esterified sterols. Free fatty acids are not present. Development of the culture is associated with an increased content of unsaturated fatty acids and, on the contrary, with a decreased content of saturated fatty acids. Content of total lipids depends on age of the culture and is inversely related with production of the antibiotic mucidin.     

Cholesterol and ergosterol superlattices in three-component liquid crystalline lipid bilayers as revealed by dehydroergosterol fluorescence

We have examined the fractional sterol concentration dependence of dehydroergosterol (DHE) fluorescence in DHE/cholesterol/dimyristoyl-L-alpha-phosphatidylcholine (DMPC), DHE/ergosterol/DMPC and DHE/cholesterol/dipalmitoyl-L-alpha-phosphatidylcholine (DPPC) liquid-crystalline bilayers. Fluorescence intensity and lifetime exhibit local minima (dips) whenever the total sterol mole fraction, irrespective of the DHE content, is near the critical mole fractions predicted for sterols being regularly distributed in hexagonal superlattices. This result provides evidence that all three of these naturally occurring sterols (e.g., cholesterol, ergosterol, and DHE) can be regularly distributed in the membrane and that the bulky tetracyclic ring of the sterols is the cause of regular distribution. Moreover, at the critical sterol mole fractions, the steady-state anisotropy of DHE fluorescence and the calculated rotational relaxation times exhibit distinct peaks, suggesting that membrane free volume reaches a local minimum at critical sterol mole fractions. This, combined with the well-known sterol condensing effect on lipid acyl chains, provides a new understanding of how variations in membrane sterol content change membrane free volume. In addition to the fluorescence dips/peaks corresponding to hexagonal superlattices, we have observed intermediate fluorescence dips/peaks at concentrations predicted by the centered rectangular superlattice model. However, the 22.2 mol% dip for centered rectangular superlattices in DHE/ergosterol/DMPC mixtures becomes diminished after long incubation (4 weeks), whereas on the same time frame the 22.2 mol% dip in DHE/cholesterol/DMPC mixtures remains discernible, suggesting that although all three of these sterols can be regularly distributed, subtle differences in sterol structure cause changes in lateral sterol organization in the membrane.     

Determination of fat in olestra-containing savory snack products by capillary gas chromatography

A quantitative method to determine fat in olestra-containing savory snack products was validated within the AOAC Peer-Verified Methods Program. The method may be used to demonstrate compliance with the guidelines of the U.S. Nutrition Labeling and Education Act for labeling products as "fat free" or "low fat." The method can measure total and saturated fat in savory snacks when present at levels of 0.2-10 g total fat and 0.1-3 g saturated fat per 30 g serving. The method is standardized to measure C6-C24 fatty acids. Extraction of olestra-containing savory snack samples with chloroform-methanol (modified AOAC Official Method 983.23) yields a lipid extract containing the total fat and olestra. The extracted lipid is hydrolyzed by lipase, yielding fatty acids and unreacted olestra. The fatty acids are precipitated as calcium soaps. Olestra is extracted from insoluble soaps with hexane and then discarded. The isolated soaps are converted back into fatty acids with hydrochloric acid and extracted with hexane. The isolated fatty acids are converted to methyl esters with boron trifluoride-methanol and quantitated by capillary gas chromatography using internal standard. Test samples were prepared by blending olestra-containing and full-fat (triglyceride) snacks to obtain 6 levels of spiking (0-10 g total fat added/30 g serving) in potato chips, potato crisps, cheese puffs, and nacho cheese-flavored corn chips. Results were linear (r2 > 0.997) between 0 and 10 g fat/30 g serving for each product matrix. Mean recovery was 101 +/- 6% standard deviation (SD) for total fat and 104 +/- 6% SD for saturated fat. Mean recovery by peer laboratory was 88 +/- 5% SD for total fat and 95 +/- 4% SD for saturated fat in potato chips (0-3 g total fat added/30 g serving). Two sets of 10 replicates of potato chips (0.5 g total fat/30 g serving and 0.16 g saturated fat/30 g serving) and potato crisps (0.5 g total fat/30 g serving and 0.16 g saturated fat/30 g serving) were analyzed by submitting and peer laboratories. Repeatability relative standard deviations ranged from 3.90 to 7.33% for total fat and from 4.01 to 11.53% for saturated fat. Reproducibility relative standard deviations were 7.33% (total fat, potato chips), 7.15% (total fat, potato crisps), 11.36% (saturated fat, potato chips), and 13.50% (saturated fat, potato crisps).     

Change in the composition of Candida albicans cells during development of resistance to polyene antibiotics

The composition of lipid and protein components of the membrane structures was studied in the strains of Candida albicans susceptible and resistant to polyene antibiotics. The content of sterols was lower and the content of free fatty acids was higher in the cells of resistant strains cf. susceptible strains. The composition of sterols was also different in the resistant strains: analysis of absorption spectra of sterol extracts in heptane in UV revealed complete absence of ergosterol, the main component of the susceptible strain, and appearance of a heterogenous peak at 215--240 nm.     

Plasma cholesteryl ester transfer activity is modulated by the phase transition of the lipoprotein core

Previous studies have shown that lipid transfer protein (LTP) activity is strongly temperature dependent, demonstrating a dramatic rise in activity near 37 degrees C. We have investigated the origin of this rapid rise in LTP activity. LTP-mediated transfers of radiolabeled cholesteryl ester (CE) from LDL to HDL, HDL to LDL, LDL to biotin-LDL, HDL to biotin-HDL, and between liposomes were determined as a function of assay temperature. Only assays containing LDL demonstrated this rapid rise in CE transfer activity. In contrast, TG transfer was almost linear with assay temperature. As human LDL CE undergoes a thermal phase transition near 37 degrees C, we investigated whether the rapid rise in CE transfer was dependent on this transition. Monkey LDL were isolated from animals consuming diets containing cholesterol and enriched in saturated, monounsaturated, or polyunsaturated fatty acids. With these LDL as substrate, the CE transfer between 21 degrees and 49 degrees C could be described by two straight lines, the intersection of which defined the inflection temperature. Among eight LDL samples, the inflection temperature was highly correlated with the CE phase transition determined by differential scanning calorimetry (r2 = 0.86). Both calorimetry and CE transfer activity inflection values were correlated with the saturated + monoene/polyene ratio of the LDL cholesteryl esters (r2 = 0.733 and 0.612, respectively). For LDL with inflection temperatures below 37 degrees C, CE transfer activity at 37 degrees C increased 10-14% for each 1 degree C decrease in the inflection temperature. We conclude that LTP activity is markedly affected by the physical state of the core CE. Diets rich in saturated fatty acids may result in LDL that are poor LTP substrates, which may hinder LTP's ability to promote normal lipoprotein remodeling.     

High pressure reverse phase liquid chromatography of fatty acid p-bromophenacyl esters

High pressure reverse phase liquid chromatography has been employed to rapidly separate saturated and unsaturated fatty acids as the corresponding p-bromophenacyl esters. Through the use of a highly efficient C18 reverse phase column packing, it has also been possible to distinguish among geometrical and positional isomers of the unsaturated acids. The use of ultroviolet-sensitive esters has permitted the detection of low (nanogram range) concentrations of fatty acids. The time required for analysis has been further reduced by employing a novel and rapid method for the preparation of the esters.     

Lipoproteins as a specific circulatory transport system

In accordance with the systemic approach, each circulatory transport system is highly specific and transports an elementary substance from cell to cell in the hydrated medium. In the author's opinion, the lipoprotein system has also a functional specificity and carries the elementary substance fatty acid in the blood stream. A great variety of fatty acids, the individuality of their physicochemical properties, great stereochemic differences of saturated and polyenic fatty acids make their transport virtually impossible. The steric individuality of fatty acids can be reduced if the acids are covalently bonded by a matrix as complex lipids. For formation of complex lipids, nature prefers esterification of fatty acids with alcohols which have a varying hydrophoby, such as glycerol, sphingosine, cholesterol, cetyl alcohol. The steric differences of saturated and polyenic fatty acids form a basis for their being structurized in different lipids. Triacyl glycerides are a transport form of saturated, monounsaturated fatty acids and their transforms and give rise to a crystalline phase. Phospholipids and cholesterol esters are a transport form of mainly polyunsaturated fatty acids in the polar phase in the former case and in the crystalline phase in the latter one. The individual apolipoproteins structure complex lipids into individual lipoprotein particles and transport them in the hydrated medium of blood flow. Saturated fatty acids chiefly transport lipoprotein particles formed by apoB-48- and apoB-100-isoproteins. Polyenic acids transport mainly high-density apoA-1-lipoprotein particles, which makes up a main physiological function of the latter. Cholesterol is nothing more than a matrix; it reesterifies polyenic fatty acids from the polar transport form of phospholipids into the unpolar transport form of cholesterol esters. Cholesterol esterification of polyenic fatty acids may structure complex lipid in the unpolar phase and transport it to the cells via apoB-100-ligand-receptor interaction, which is considered to be a key stage in the multistage process of active transport to the cells of polyenic fatty acids. However, the significant differences of active and inactive transport of polyenic fatty acids in the blood stream await a separate consideration.     

The influence of gastric juice acidity on the occurrence of esophageal reflux]

Protective properties of n-3 and n-6 polyunsaturated, monosaturated and saturated fatty acids (respectively, n-3 PUFA, n-6 PUFA, MUFA and SFA) against ethanol induced hemorrhagic gastric mucosal lesions were compared. Female Wistar rats (90-100 g) were fed to four weeks semisyntethic diets containing 9% butter (SFA-diet), 6% butter and 3% olive oil (MUFA-diet), 6% butter and 3% sunflower oil (n-6 PUFA-diet) or 6% butter and 3% concentrate of n-3 PUFA ethyl esters (n-3 PUFA-diet). One group of rats received a non-lipid diet. Under all types of lipid containing diets, development of ethanol-induced hemorrhagic gastric mucosal lesions was reduced in compared with non-lipid diet. Cytoprotective effect of n-3 PUFA-E was greater than MUFA and SFA, but smaller than n-6 PUFA.     

Sterol and steryl ester regulation of phospholipase A2 from the mosquito parasite Lagenidium giganteum

Lagenidium giganteum, a facultative parasite of mosquito larvae, cannot synthesize sterols, and requires an exogenous source of these lipids in order to enter its reproductive cycle. This parasite grows vegetatively in the absence of sterols, but requires cholesterol or structurally related compounds to produce motile zoospores, which are the only stage capable of infecting mosquitoes. Sterols structurally related to cholesterol and some steryl esters inhibited the activity of L. giganteum phospholipase A2 (PLA2), an enzyme that hydrolyzes fatty acids from the sn-2 position of glycerophospholipids. Sterols that induce reproduction inhibited L. giganteum PLA2 activity, while sterols and steroids that do not support sporulation had minimal effect. Most steryl esters had no effect on enzyme activity, but cholesteryl arachidonate (CA) was a potent inhibitor of parasite PLA2. Not all enzymes partly purified using a DEAE-Sephacel column were affected by these lipids, demonstrating selective inhibition of specific enzymes. Potency was enhanced by up to several orders of magnitude if epoxy fatty acids were esterified to the cholesterol nucleus. The steryl ester pool was dynamic during morphogenesis, and the fatty acid composition of the steryl esters did not mimic total cell or membrane (glycerophospholipid) fatty acid composition as L. giganteum proceeded through its growth cycle. Synthesis of CA and monoepoxy CA by the parasite was confirmed using electrospray mass spectrometry and collision-induced dissociation. Steryl derivatives selectively inhibited PLA2 enzymes from bovine pancreas, snake venom, and human cytoplasmic 85-kDa PLA2.     

Analgesic effect of antidepressant drugs

We have examined the association of 5-androsten-3beta-ol (androsterol) with saturated phosphatidylcholines (PCs), having symmetric acyl chains from 10 to 16 carbons in length, in both mono- and bilayer membranes. The emphasis of the study was to measure how hydrophobic mismatch (i.e. the difference in hydrophobic length of the interacting molecules) affected androsterol/PC interactions in model membranes. With monolayer membranes (33 mol% sterol, 20 mN/m, 25 degreesC), androsterol was found to be macroscopically miscible with all the tested PCs. Androsterol was observed to condense the lateral packing of di14 and di15 PCs (by 6 and 4.5 A2 per molecule, respectively), but failed to condense shorter (di10, di11, di12 and di13 PCs) or the longer chain di16PC. The rate of androsterol desorption from mixed monolayers to beta-cyclodextrin acceptors in the subphase was a clear function of the host PC acyl chain length. The slowest rate of androsterol desorption (i.e. best androsterol/PC interaction) was seen from a di14PC monolayer, whereas the desorption rate increased when the host PC had shorter or longer chains. When the cholesterol oxidase susceptibility of androsterol was determined in small unilamellar vesicles (SUV) containing PCs of different chain lengths (33 mol% androsterol), the slowest rate of oxidation was seen in di14PC vesicles, whereas higher rates were measured for shorter or longer chain PC vesicles, again suggesting that androsterol interacted more favorably with di14PC than with the other PCs. In conclusion, the hydrophobic mismatch between androsterol and different PCs appeared to greatly affect the intermolecular interactions, as determined from the condensation effect, from sterol desorption rates, and the oxidation susceptibility of androsterol. Although androsterol is not a physiological membrane component, the present model system clearly shows that hydrophobic mismatch has a great influence on how sterols and phosphatidylcholines interact in membranes.     

Which operations can be done without general anesthesia?

The fatty acid composition of erythrocytes, platelets, and serum lipids was compared between subjects who had been eating a strict uncooked vegan diet ("living food") for years and omnivore controls. The vegan diet contains equal amounts of fat but more monounsaturated and polyunsaturated and less saturated fatty acids than the mixed diet of the control group. In vegans, the proportion of linoleic acid was greater in all lipid fractions studied. Also, the levels of other n-6 fatty acids were greater, with the exception of arachidonic acid levels, which were similar in most fractions. In erythrocytes, platelets and serum phospholipid fractions, this increase was mainly at the expense of the n-3 fatty acids. The proportions of eicosapentaenoic and docosahexaenoic acid were only 29-36% and 49-52% of those in controls, respectively. In vegans the ratio of n-3 to n-6 fatty acids was only about half that in omnivores. In addition to the lower levels of n-3 fatty acids, the proportions of palmitic and stearic acids were lower in serum cholesteryl esters, triglycerides and free fatty acids of vegans. The proportion of oleic acid was slightly lower only in serum cholesteryl esters and erythrocyte phosphatidylserine. The results show that, in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of n-3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components of this diet.     

Carbohydrate and lipid components of hyphae and conidia of human pathogen Fonsecaea pedrosoi

The carbohydrate and lipid components of mycelium and conidia of Fonsecaea pedrosoi (Brumpt) were analysed by paper, thin-layer and gas-chromatography, mass spectrometry and ultraviolet spectroscopy. Glucose, mannose, galactofuranose, rhamnose and glucosamine were polysaccharide components identified in F. pedrosoi. Significant changes in the carbohydrate pattern occurred during the conversion of mycelium into conidia. Rhamnose was predominant in conidia whereas galactose was prominent in mycelium. Palmitic, stearic, oleic, linoleic, and arachidonic acids were the fatty acids identified in the total lipid fraction. Palmitic and oleic acids were major fatty acids. Marked alterations in the fatty acid constituents were observed between the cell types of F. pedrosoi. Arachidonic acid was detected only in conidia and linoleic acid was preferentially identified in mycelium. Differences in the sterol composition was also associated with morphogenesis in F. pedrosoi. Two main sterols, ergosterol and another less polar sterol, not fully characterized, were found in mycelium whereas in conidia only the latter sterol was present.