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In garlic (Allium sativum L.) the enzyme alliin lyase catalyzes the cleavage of alliin into allicin which reacts further to furnish ajoene. A simultaneous determination of allicin and ajoene is introduced which, in contrast to the determination of alliin only, allows for the testing of the activity of alliin lyase. It can be demonstrated that at a pH value of less than 3 the enzyme produces only small amounts of allicin. For this reason preparations from garlic should be administered only as enteric-coated formulations.

A concentration dependent inhibition of 3-hydroxy-3-methylglutaryl CoA (HMG CoA) reductase was found on preincubation of microsomal preparations with diallyl disulfide, a component of garlic oil. This inhibited state was only partially reversed even with high concentrations of DTT. Glutathione, a naturally occurring reducing thiol agent, was ineffective. The substrate, HMG CoA, but not NADPH, was able to give partial protection for the DTT-dependent, but not glutathione-dependent activity. The garlic-derived diallyl disulfide is the most effective among the sulfides tested for inhibition of HMG CoA reductase. Formation of protein internal disulfides, inaccessible for reduction by thiol agents, but not of protein dimer, is likely to be the cause of this inactivation.

Organosulfur compounds of garlic have been shown to inhibit growth of animal tumors and to modulate the activity of diverse chemical carcinogens. There is also evidence that garlic may modulate antitumor immunity. In this study, we determined the effects of an aqueous garlic extract and a protein fraction isolated from the extract on the chemiluminescent oxidative burst of the murine J774 macrophage cell line and thioglycollate-elicited peritoneal macrophages obtained from BALB/c mice. T-lymphocyte activity was determined using mouse splenocytes incubated with phytohemagglutinin, labeled with [3H]-thymidine and assayed for lymphoproliferation. Significant dose-related augmentation of oxidative burst was observed with garlic extract and the protein fraction. The protein fraction also enhanced the T-lymphocyte blastogenesis. The data suggest that garlic compounds may serve as biological response modifiers by augmenting macrophage and T-lymphocyte functions.

This study evaluated the effect of a dried garlic powder preparation, standardised to 1.3% alliin, on the composition of plasma lipoproteins and erythrocyte membranes. Forty volunteers, aged 70 years and over, took 600 mg of garlic powder per day for three months. In participants with initially normal plasma cholesterol levels (CH less than 200 mg/dl; n = 11) after three months of garlic tablet administration, little or no change in CH values was registered, as for most of the other parameters. In contrast, in volunteers with initially elevated CH levels (CH greater than 200 mg/dl, n = 29), the CH levels were reduced by -7.7% (p less than 0.001). This reduction took place primarily in the esterified cholesterol fraction (-12%, p less than 0.001), whereas free cholesterol concentrations were not altered significantly. Triglycerides (-15.9%, p less than 0.05) and plasma choline phospholipids (-4.6%, p less than 0.01) were also reduced. No change of the plasma LDL-CH to HDL-CH ratio was observed in this group. Based on the weight of lyophilised, haemoglobin-free erythrocytes, the mean membrane concentration of phospholipids and cholesterol in the total cohort (n = 40) increased by 5.7% (p less than 0.001) and 6.1% (p less than 0.01), respectively. These increases were more pronounced the lower the body mass indices (kg/m2) were, and the longer the duration of garlic administration was. The molar ratio of membrane phospholipids to cholesterol remained unchanged. The results are discussed with regard to a possible role of the garlic-induced membrane effects in the plasma lipid-lowering potency of garlic and preparations made from it.

Garlic (Allium sativum) has had an important dietary and medicinal role for centuries. It is now known that garlic contains chemical constituents with antibiotic, lipid-lowering, detoxification, and other medicinal effects in the body. This article reviews some of the physiological characteristics of garlic and examines the relationship between garlic and cancer prevention and treatment. Hypotheses regarding the possible role of garlic in modulating mechanisms that may alter the carcinogenic process are discussed.

We have identified three main antiplatelet constituents, namely adenosine, allicin and paraffinic polysulfides in both garlic and onion. Adenosine and allicin both inhibited platelet aggregation without affecting cyclooxygenase and lipoxygenase metabolites of arachidonic acid. The trisulfides inhibited platelet aggregation as well as thromboxane synthesis along with induction of new lipoxygenase metabolites. The data indicate that the observed in vivo antiplatelet effects of ingesting onion and garlic are attributable more to the adenosine than to the allicin and paraffinic polysulfide constituents.

However great the success in the therapy of hypertension, atherosclerosis and ischemic heart disease has been gained today by recent efficient drugs, the definite healing of patients is not yet attained. The late discovery of reserpine, such an efficient drug of plant origin against hypertension, convinced so far reluctant scientists to consider the chemical compounds of the plant world. With respect to this traditional medical knowledge, it seems necessary to define more accurately the specificity of these healings-sometimes recommended unspecifically for a whole branch of medicine. This experimental verification should not use inconsiderately the present-day classification of diseases; there should be an awareness that conventional experimental methods in pharmacology are often unsuitable for revealing the real biological activity of one or another medicinal plant. The interest in the millennial empirical field of health care is acknowledged by the World Health Organization which promotes research and development of traditional medicine, along with investigations into its psychosocial and ethnographic aspects. These studies cover a number of plants growing in Bulgaria that have a healing effect in hypertension, atherosclerosis and ischemic heart disease according to the data of traditional medicine. Using screening methods, extracts and chemically pure substances were investigated; extraction was done with solvents such as water, ether, chloroform, dichloretan, ethanol, methanol, and acetone. Most of the experiments were carried out on anesthetized cats, rabbits and dogs. The substances tested were applied mainly intravenously, and in some experiments orally. Chronic experiments were also carried out on wakeful dogs with induced hypertension, on animals fed on an atherogenic diet, and on animals with induced arrhythmia and coronary spasm. Data are presented of clinical examination of some plants or of active substances isolated from them. Major results of these studies are presented for the following plants: Garlic, Geranium; Hellebore; Mistletoe; Olive; Valerian; Hawthorn; Pseucedanum arenarium; Periwinkle; Fumitory. For another 50 plants growing in Bulgaria and in other countries the author presents his and other investigators' experimental and clinical data about hypotensive, antiatheromatous and coronarodilatating action.

Garlic bulbs (Allium sativum) were extracted with distilled water or ethanol. The extracts were then incubated with Ehrlich ascites carcinoma cells at 37 degrees C for 1 h. These pretreated cells were injected into swiss albino mice which survived over 12 weeks. To the contrary, tumor cells which were pretreated with garlic extracts, produced ascites tumor in all mice that died 2 or 4 weeks after intraperitoneal injection. When mice were treated twice at intervals of 7 days with freshly prepared tumor cells exposed to watery or ethanolic extracts of fresh garlic, they acquired resistance against a challenge with Ehrlich ascites tumor cells. Administration of garlic extracts to mice for at least 2 weeks before tumor transplantation, caused a slight delay of 10-20 days in tumor growth and animal death. Generally, the ethanolic extract of garlic gave more pronounced effect as tumor inhibitor as well as immunity induction than watery extract. No change in serum electrophoretic pattern was detected in mice, whether the tumor cells injected were incubated or not with garlic extract. In animals treated with unincubated tumor cells, albumin and globulin percentages as well as albumin: globulin ratios (A/G) were decreased as compared to normal mice. A/G ratio was also decreased in immunized mice, pretreated with garlic extract, due to the increase of gamma globulin and unchanging of albumin.

Ethanol-insoluble components were extracted from fresh garlic with 0.9% NaCl solution containing streptomycin and penicillin. This extract, containing approximately 10% sugar, 0.3% nitrogen, and 0.4% ash, was termed garlic sugar solution. This garlic sugar solution (Medium 1) was used as the suspending medium for Ehrlich ascites tumor cells attenuated with allicin, the main principle of garlic, and 0.9% NaCl solution containing streptomycin and penicillin (Medium 2) was also used as the suspending medium. Mice of DDD strain were immunized with the attenuated tumor cells suspended in Medium 1 or 2. After immunization, the immunized and control mice were challenged intraperitoneally with viable Ehrlich ascites tumorcells. Animals immunized with the attenuated tumor cells suspended in Medium 1 acquired significantly stronger resistance against the tumor cells than animals immunized with those suspended in Medium 2.

Alliums have been grown for many centuries for their characteristic, pungent flavor and medicinal properties. The present review, which includes references published up to the middle of 1984, is primarily concerned with the chemical composition, flavor, and physiological properties of these crops, their extracts, and processed products. Special emphasis is placed upon the relationship between the organoleptically and biologically active components of onion and garlic. Following a brief historical introduction, current production of commercially important alliums is described and their botanical origins and interrelationships are explained. Following consideration of the major economic diseases and pests of alliums, the agronomic, husbandry, and practices associated with their cultivation are described, particular emphasis being placed upon the storage and processing of onion and garlic. The detailed, overall chemical composition and nutritional value of members of the genus Allium are presented in Section 7; after an outline of the origin and nature of flavor components and precursors, the flavor volatiles of individual members are presented. The effects of agronomic, environmental, and processing practices on chemical and flavor content and quality are considered in Section 9. The following section deals critically with the human and animal studies which have been conducted into the medical and therapeutic properties of alliums, emphasis being placed upon the studies into the antiatherosclerotic effect of onion and garlic and their essential oils. After a study of antimicrobial properties of alliums and their effects on insects and animals, an overview is presented which highlights unexplored or inadequately studied areas and suggests rewarding areas for future research.

Hot-water extraction of defatted garlic-bulbs yielded a mixture of polysaccharides containing a D-galactan, a D-galacturonan, an L-arabinan, a D-glucan, and a D-fructan. A trace of L-rhamnose was also detected in the polysaccharide hydrolyzate. The pectic acid was partially removed by precipitation with aqueous calcium chloride; from the remaining polysaccharide mixture, a pure D-galactan containing 97.3% of D-galactose was isolated by fractional precipitation and repeated chromatography through a column of DEAE-cellulose. Methanolysis and hydrolysis of the permethylated D-galactan yielded 2,3,4,6-tetra-, 2,3,6-tri-, and 2,3,di-O-methyl-D-galactose in the molar proportions of 1:2:1. On periodate oxidation, the D-galactan reduced 1.18 molar equivalents of the oxidant per D-galactosyl residue, and liberated one molar equivalent of formic acid per 4.13 D-galactosyl residues. Smith degradation of the D-galactan was also conducted. From these results, a structure has been assigned to the repeating unit of the D-galactan.

Adenosine (1), guanosine (2), and tryptophan (3), as well as beta-sitosterol beta-D-glucoside (4) were isolated from the n-butanol-soluble fraction of Xiebai, the tuber of Allium bakeri Reg., which was recognized to have an anti-platelet aggregation effect. Moreover, 1 and 2 were also isolated from the n-butanol-soluble fraction of Dasuan, the tuber of A. sativum L. Compound 1 showed a significant inhibitory activity against both the primary and secondary wave aggregation of human platelet induced by 2 microM ADP, whereas compounds 2-4 showed no or very low inhibitory effects. The structure-activity relationships on human platelet aggregation with regard to 1, 2 and their derivatives, adenosine 2'-monophosphate (5), adenosine 5'-monophosphate (6), adenosine triphosphate (7), guanosine 3'-monophosphate (8), and guanosine 5'-monophosphate (9), and guanylyl(3'----5')adenosine (10) are discussed. Compounds 5-7 and 10 also inhibited the primary and secondary wave aggregation with a dose-dependent response.

The feeding of a high fat-high cholesterol (HF-HC) diet to normal rats for 1 month increased the lipid components cholesterol and triglyceride in serum, liver and kidneys and decreased the serum albumin very significantly. Administration of garlic oil (100 mg/kg b. wt/day) for 1 month together with the HF-HC diet to another group almost nullified the lipid-increasing and albumin-decreasing effects of that diet. The reduction in total lipids, cholesterol and triglycerides and the restoration to normal level of serum albumin were highly significant in the garlic oil group. Adipose tissue triglyceride lipase activity was significantly increased in both the above groups with a much greater rise in the oil group.

Green leaves of leek and chive mainly contain kaempferol glycosides, with mono- and di-glycosides dominating in leek and di- and tri-glycosides in chive. In leek glucose is dominant as sugar component compared to xylose; in chive we found glucose and galactose. Kaempferol-3-beta-D-glucoside and kaempferol-3-xylosyl-beta-D-glucoside were isolated from leek and the 3-beta-D-glucosides of kaempferol, quercetin and isorhamnetin as by-glycosides from chive. In leek traces of quercetin-3-glucoside were identified by tlc, but no spiraeoside (quercetin-4'-glucoside) could be detected in the two species. The bulbs of garlic and leek contain only few milligram of glycosides of kaempferol and quercetin per kg fresh weight.

While fish chemotherapy is not a common practice in México, folk medicine is usually well accepted by fish farmers. Empirical knowledge suggested that garlic should have anthelmintic properties. Various trials were carried out in Cyprinus carpio infested with Capillaria sp., using minced garlic and its extracts. An empirical concentration of 200 mg/l of minced garlic showed the greatest activity against the above mentioned worms (100%). The hexane extract in equivalent amounts showed a 75% effectiveness while the aqueous extract showed no anthelmintic effect. The addition of ammonium-potassium tartrate to the tanks (1.5 mg/l) gave a 86% anthelmintic effectiveness.

It has been found by Cavallito (1944) that garlic (Allium sativum L.) has a strong antibacterial activity and the active principle of garlic is named "Allicin" and it has been confirmed by Stoll et al. (1948) that the allicin is derived from the alliin-alliinase system. Nevertheless, one worker in Japan (1951) stands on another view point which the effective component of garlic is some sugar-proteim because he could not find alliin in the native garlic. We intend to make sure that the alliin is contained in the native garlic, by using Hitachi Amino acid Analyser with Fraction Collecter and compared with garlic of other countrys' production. As the result of examinations, we found that the good amounts of alliin is contained in the native garlic also. The contents of alliin in garlic is varied by the species, the cultivation mode, and the district of production. The form of alliin in the tissue is a free style, and thereupon it is easy to change its chemical conformation by the method of extraction. We compared the relative capacity between 1 allicin unit by Klein (1954) and 1 cup unit by Schmidt et al. (1947). Furthermore we tested the antibiotic spectrum, using the pure crystallized alliin with the sufficient amount of raw alliinase gained by the isoelectric point precipitation and checked upon wide spectrum for Mycobacterium tuberculosis, Gram-positive and negative bacteria, and some fungi.

Effects of aqueous extract of garlic, of materials extracted in two organic solvents, viz., ether and chloroform in succession, and of some fractions obtained after TLC of the aqueous extract were examined on platelet aggregation induced by several aggregating agents. Their effects were also investigated on the formation of thromboxane and lipoxygenase products from endogenous arachidonic acid in intact platelets. The aqueous extract inhibited aggregation induced by all aggregating agents and so did the materials extracted in two organic solvents. Only two fractions obtained from TLC of the aqueous garlic extract were examined for effects on epinephrine- and arachidonic acid (AA)-induced aggregation; they were found to be antiaggregatory. The material extracted in ether (MEE) inhibited the incorporation of labelled AA into platelets in platelet-rich plasma. Garlic extracts (MEE and material extracted in chloroform, MEC) at higher dosage inhibited the degradation of platelet phospholipids and reduced the formation of thromboxane (TxB2) and lipoxygenase-derived products from labelled platelets. The two organic extracts at low dosage, while not affecting the degradation of platelet phospholipids, inhibited the cyclooxygenase and lipoxygenase enzymes. A concomitant increase in the amount of released AA was observed in the treated platelets. Similar effects in relation to dosage were observed with the aqueous extract of garlic.

An indirect method for the determination of trace bound selenomethionine (SeMet) has been developed. SeMet reacts with cyanogen bromide (CNBr) quantitatively in the presence of SnCl2 to form CH3SeCN, and after extraction with CHCl3 is acid-digested to form Se(IV). Selenium(IV) reacts with 4-nitro-o-phenylenediamine reagent to form 5-NO2-piazselenol which is then determined by gas chromatography equipped with electron capture detector. The sensitivity of this method (CNBr-piazselenol-GC method) is 6 ng SeMet/g of sample. Trace-bound SeMet in plants and some biological materials has been successfully determined by this method and its content has been compared with the total selenium in the sample.

This study was carried out to understand the antibacterial properties of some spice plants before and after heat treatment in boiling water. The samples included the core and the outer layers of onion, the white and the green parts of green onion, garlic bulb, ginger, ginger root, sweet pepper, chili pepper, brown pepper, and mustard. The test microorganisms included Escherichia coli, Salmonella typhimurium, Vibrio parahaemolyticus, Pseudomonas aeruginosa, Proteus vulgaris, Staphylococcus aureus, Mycobacterium phlei, Streptococcus faecalis, Bacillus cereus, and Micrococcus luteus. Raw garlic bulb could inhibit all of the test strains. The antibacterial activities of green onion are slightly weak than that of onion. However, green onion could inhibit P. aeruginosa and M. luteus, but onion could inhibit E. coli, P. vulgaris, S. faecalis, and B. cereus. Ginger and ginger root could only inhibit M. luteus. Chili pepper could inhibit V. parahaemolyticus and P. vulgaris. Brown pepper could also inhibit P. vulgaris. Sweet pepper and mustard showed no antibacterial activity to all of the test strains. In general, antibacterial components in the spice plants were heat labile. All the spices tested lost their antibacterial activities within 20 min at 100 degrees C.

When added to platelet-rich plasma, aqueous extracts of garlic inhibited platelet aggregation and the release reaction. Subsequent experiments designed to characterize the inhibitory component revealed that the inhibitory activity was i) associated with small molecular-weight components, ii) the inhibitory component possessed the typical garlic odor and contained an abundance of sulfur, iii) the inhibitory activity could be extracted with organic solvents, and iv) temperatures above 56 degrees C and alkaline pH above 8.5 quickly destroyed the inhibitory activity. The Rf value of the major inhibitory component after thin-layer chromatographic separation was similar to that of allicin, an unique thiosulfinate in garlic previously shown to possess strong antibiotic and antifungal properties. Allicin was synthesized. On thin-layer chromatographic plates, allicin co-migrated with the inhibitory component in garlic. At 10 microM concentration, allicin inhibited completely platelet aggregation and the release reaction. Comparative studies suggest that the major platelet aggregation and release inhibitor in garlic may be allicin.

Garlic extract, the ethanol-soluble fraction of garlic, prevented formation of thiobarbituric-acid-reactive substances and fluorescent substances during lipid peroxidation of rat liver microsomes. Lipid peroxidation increased the fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene labelled to the microsomes while this increase was prevented by the garlic extract. It thus seems probable that the garlic extract serves to maintain membrane fluidity. These effects were dependent on its concentration and particularly prominent on exceeding a certain concentration of garlic extract. These results suggest its possible role of protecting the membranes from lipid peroxidation.

A critical review of the analytical methods employed for the determination of the relevant components of seasonings is presented. Where the available methods were inadequate, new ones have been devised. Particular emphasis has been placed on those methods of analysis that provide a rapid and sufficiently accurate appraisal of seasoning extracts and essential oils from seasonings under routine control laboratory conditions. At the same time, the margin of error of these methods has been determined. The individual seasoning extracts were assessed according to the following criteria: (1) essential oil--cardamom, laurel leaves, cloves, origanum (marjoram), sage, and thyme; (2) essential oil and nonvolatile lipids--dillseed, coriander, caraway, mace, nutmeg, pimento (allspice), and celery seed; (3) essential oil and/or pungent ingredients--capsicum, ginger, and pepper; (4) essential oil and/or coloring matter--turmeric (curcuma) and paprika; (5) essential oil and other components--garlic, onion, and cinnamon.

Ajoene, the major antiplatelet compound derived from garlic, synergistically potentiates the antiaggregatory action of prostacyclin, forskolin, indomethacin and dypiridamole. For collagen-induced platelet aggregation in human PRP, the ID50 for ajoene is 95 +/- 5 microM. However, in the presence of the antiaggregatory drugs mentioned above, the ID50 for ajoene decreases more than what would be predicted on the basis of simple additive effects. Similarly, the ID50 for prostacyclin decreases from 1 nM to 0.15 nM in the presence of 80 microM ajoene. Isobolic curves for the various combinations of ajoene with prostacyclin or indomethacin exhibit departure from linearity, as predicted for a potentiated synergism between ajoene and these drugs. Dypiridamole, which in PRP has very little effect on the dose-response curve for ajoene, when assayed in whole blood decreases the ID50 for ajoene by a factor of four. These results demonstrate that the antithrombotic potential of ajoene is substantially increased in the presence of physiologically and pharmacologically active antiplatelet agents.

The aim of the study was to determine the composition of flavour isolates from garlic and horse-radish, prepared by dichlorodifluoromethane extraction. Gas chromatography, with olfactory determination of the flavour of the resolved components, and gas chromatography combined with mass spectrometry were used. In the garlic extract 19 components comprising mono-, di-, and trisulphides and thiophene derivatives were detected. In the horse-radish extract 14 components including isothiocyanates, thiocyanates and cyanides were identified.

Garlic (Allium sativum L.) water- and ethanol-soluble extracts were prepared and purified by column chromatography. They were tested on garlic-sensitive patients and showed that the allergenic fraction was well located in a few column chromatography fractions. Guinea-pigs were sensitized with garlic water-soluble extracts and tested (open epicutaneous tests) with several fractions. The presence of diallyldisulfide was detected in the sensitizing chromatographic fractions. Guinea-pigs were successfully sensitized to this product and cross-reacted to garlic; animals sensitized to garlic extracts cross-reacted to diallyldisulfide. Both groups reacted to allicin, an oxidized derivative of diallyldisulfide present in garlic. Garlic-sensitive patients showed positive tests to diallyldisulfide, allylpropyldisulfide, allylmercaptan and allicin.

The optimal conditions have been developed for garlic preservation by its treatment with a mixture of food paraffin and monoglyceride in the ratio of 95:5 at 80 degrees C, followed by the storage at 0-1 degrees C, and relative humidity 65-75%. When garlic is treated with plasticized paraffin, the main hydrocarbon components of paraffin - n-alkanes C20-C31 are accumulated in its pulp. Monocyclic aromatic hydrocarbons are practically absent in food paraffin and paraffined garlic. The quantitative parameters of the paraffined garlic characterizing high technological and economic effectiveness of the method, as well as insignificant increase in the p-alkanes content (1%) in the daily ration for humans, that contains paraffined garlic, have permitted the authors to recommend this method of garlic storage for using under industrial conditions, the technological regulations should be strictly kept to.

Crude juices of garlic (Allium sativum), onion (Allium cepa) and shallots (Allium ascalonicum) were tested in an agar diffusion test for their growth inhibitory effect on five gram negative and three gram positive bacterial species and two yeast species. All test organisms were inhibited by garlic juice, whilst onion and shallot juice showed no effect upon gram negative bacteria. Garlic juice was investigated in more detail. Addition of complex-forming agents and organic matter to the crude juice reduced its activity on all test organisms. Volatile substances showed a strong inhibitory activity after exposure for 8 hours or longer at 23 degrees C or 37 degrees C. Minimal inhibition concentrations determined in a dilution test were found to be high for gram negative bacteria and low for both yeast species. The D-values of the different test organisms in undiluted garlic juice were calculated. P. aeruginosa had a very low D-value, whilst the bacteriostatic concentration was high. This indicates a large concentration exponent of crude garlic juice for this organism. The opposite was found for S. aureus. In view of the strong antibiotic properties and the complete absence of development of resistance further investigation upon the principles of the antimicrobial activity of juices from Allium species merits consideration.

The effect of aqueous garlic extract on the macromolecular synthesis of Candida albicans was studied. Protein and nucleic acid syntheses were inhibited to the same extent as growth, but lipid synthesis was completely arrested. Blockage of lipid synthesis is likely an important component of the anticandidal activity of garlic.

Onion and garlic essential oils were previously shown to inhibit mouse skin tumor promotion, as were the enzymes, lipoxygenase, and cyclooxygenase. In the present study, the inhibition of soybean lipoxygenase (EC 1.13.11.12) by onion and garlic components and related compounds was investigated. The IC50 values as well as the kinetic inhibition constants were determined for the most active compounds. Di-(1-propenyl) sulfide, an analog of the substrate moiety required for oxygenase action, was the only irreversible inhibitor observed with Ki = 59 microM and k3 = 0.53/min. Inhibition in the presence of substrate was uncompetitive at 88 and 132 microM linoleic acid with Ki = 129 microM. At 173 microM linoleic acid, however, inhibition was competitive with Ki = 66 microM. Dially trisulfide, allyl methyl trisulfide, and diallyl disulfide were competitive inhibitors, while 1-propenylpropyl sulfide and (E, Z)-4,5,9-trithiadodeca-1,6,11-triene 9-oxide (ajoene) were mixed inhibitors. Nordihydroguaiaretic acid (NDGA), the most potent lipoxygenase inhibitor, was a competitive inhibitor with Ki = 0.29 microM. The results indicate a relative potency of inhibition for structural features in the following order: di(1-propenyl) sulfide greater than an alkenyl trisulfide greater than an alkenyl disulfide. Di(n-propyl) disulfide, a major onion oil component, inhibited neither lipoxygenase nor promotion. Di(1-propenyl) sulfide and ajoene inhibited both. This suggests that the inhibition of lipoxygenase may be involved in antipromotion.

Allium is a genus of some 500 species belonging to the family Liliaceae. However only a few of these are important as food plants, notably onion, garlic, chive, leek, and rakkyo. Such plants have been used for many centuries for the pungency and flavoring value, for their medicinal properties, and, in some parts of the world, their use also has religious connotations. The flavors of members of the genus Alliums, in addition to having certain characteristics, are also complex, being derived enzymically from a number of involatile precursors. In addition to there being variation of flavor between different alliums, there are also considerable changes that occur as a result of cooking and processing. Of course, these are of importance to the consumer and food technologist-processor. The review will introduce the subject by an historical perspective and will set this against data on the present cultivation and usage of commercially cultivated alliums. The chemical composition of these plants will be discussed, emphasis being given to nonvolatile constituents which are, perhaps, less often considered. Discussion of the volatile constituents, which will include mention of the methods currently used for their analysis and for the determination of "flavor strength", will be mainly concerned with literature taken from the last 5 years. In considering the extent and nature of allium cultivation and processing, factors affecting the nutritional value and quality will be highlighted. The medicinal properties of garlic and onion oils have been much studied over the last decade and the review will include critical assessment of this area and also will touch on the more general properties (antimicrobial, antifungal, antibacterial, and insecticidal) of these oils. Finally mention will be made of the antinutritional, toxic, or otherwise undesirable effects of alliums, for example, as inadvertent components of animal diets, tainting of milk and other food products. It is our intention to review the literature up to mid-1984.

A liquid chromatographic (LC) method is proposed for the determination of alliin in garlic and garlic products. The method involves heating of the sample with water in a bath of boiling water followed by homogenization and centrifugation. Interfering components are eliminated by use of a Sep-Pak C18 cartridge as a clean up step before injection. The LC system with ultraviolet detection at 210 nm consists of a separation on a Zorbax TMS column and isocratic elution with water as a mobile phase. Fluorometric determination by ion-pairing chromatography with tetra-n-butylammonium bromide on a Nucleosil 5C18 column is also described. The overall recoveries of alliin added to garlic products were greater than 90%. Thin-layer chromatography and enzymatic degradation of alliin were performed for the confirmation of alliin detected in garlic products.

The larvicidal principles of garlic, Allium sativum L.,have been isolated and identified as diallyl disulfide and diallyl trisulfide. Both natural and synthetic samples of these larvicides are fatal at 5 parts per million to Culex pipiens quinquefasciatus Say.