bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical studies of carbohydrates (II) On the mechanism of the conversion of a glucose derivative into a pyridazine compound
Authors: Smit P. , Stork G. A. , Van Der Plas H. C. 
Published: April 2009

AbstractThe formation of 3‐(2′,2′‐dimethyl‐1′,3′‐dioxolan‐4′‐yl)pyridazine (4) by reacting 1,2:5,6‐di‐O‐isopropylidene‐3‐O‐(p‐tolylsulfonyl)‐α‐D‐glucofuranose (1) with hydrazine hydrate via the intermediate 3‐deoxy‐1,2:5,6‐di‐O‐isopropylidene‐α‐D‐erythro‐hex‐3‐enofuranose (3) is explained by a mechanism, involving an initial attack of the hydrazine molecule at position 4 in compound 3, a subsequent ring opening by fission of the C4O bond and a ring closure by formation of a NC1 bond.
The reaction of α‐haloketones with N‐alkyl benzothiazolium salts
Authors: Van Allan J. A. , Mee John D. , Maggiulli C. A. , Henion R. S. 
Published: April 2009

AbstractPhenacyl chloride (1a) reacts with the 3‐methylbenzothiazolium quaternary salt (2) to give 4‐methyl‐2‐benzoyl‐4H‐1,4‐benzothiazine (4a). A mechanism is discussed. Secondary α‐haloketones give benzothiazolines. Merocyanine dyes are formed by the reaction of 2 with carbanions. It is shown that 2 functions as a hydride ion abstractor in the formation of merocyanine dyes.
Further investigations of the interaction of trimethylsilyl azide with substituted maleic anhydrides. Synthesis of 4‐ and 5‐aryl substituted 1,3‐(3H)oxazine‐2,6‐diones
Authors: MacMillan John H. , Washburne Stephen S. 
Published: April 2009

AbstractThe reactions of phenyl‐, o‐chlorophenyl‐, p‐chlorophenyl‐, 3,4‐dichlorophenyl‐, p‐fluoro‐ and p‐anisylmaleic anhydrides with trimethylsilyl azide are described. In all cases mixtures of isomeric 4‐ and 5‐aryl‐2H‐1,3‐(3H)oxazine‐2,6‐diones are obtained after hydrolysis with the 4‐isomer predominating. The yield of 5‐isomer is greatest for o‐chlorophenyl maleic anhydride, and substantial for other arylmaleic anhydrides, indicating increased importance of steric effects in these reactions, in contrast to previously reported syntheses of methyl and halo‐substituted oxazine‐diones, where electronic factors appeared dominant.
The stobbe condensation with dimethyl homophthalate. II
Authors: El‐Rayyes N. R. , Ali A. H. A. 
Published: April 2009

AbstractThe condensation of some heterocyclic aldehydes with dimethyl homophthalate in the presence of either sodium hydride or potassium t‐butoxide as condensing agents gave either the (E)‐or the (Z)‐half‐ester (1b) as the predominant product. The structure and configuration of the products has been established by both chemical and spectroscopic tools.
Reaction of Sulfene wild Heterocyclic N,N‐Disubstituted α‐Aminomethylene Ketones IV. Synthesis of 3,4‐Dihydro‐5H‐[1]benzothiopyratio [3,4‐e]‐1,2‐oxathiin and 2,3,6,7‐Tetrahydro‐5H‐thiopyrano[3,4‐e]‐1,2‐oxathiin Derivatives
Authors: Schenone Pietro , Mosti Luisa , Bignardi Gaetano 
Published: April 2009

AbstractThe reaction of sulfene with N,N‐disubstituted 3‐aminomethylene‐2,3‐dihydro‐4‐thiochromanones and‐2,3,5,6‐tetrahydro‐4‐thiopyranones gave 1,4‐cycloadducts which are derivatives of new heterocyclic systems, namely 3,4‐dihydro‐5H‐[1]benzothiopyrano[3,4‐e]‐1,2‐oxathiin and 3,4,7,8‐tetrahydro‐5H‐thiopyrano[3,4‐e]‐1,2‐oxathiin, respectively. Furthermore, some pyrazole derivatives VII and VIII were prepared from 3‐hydroxymethylene‐2,3‐dihydro‐4‐thiochromanone or 2,3,5,6‐tetrahydro‐4‐thiopyranone and hydrazines.
Mononuclear heterocyclic rearrangement. Note I. Kinetic study of the rearrangement of the phenylhydrazone of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole into 2,5‐diphenyl‐4‐benzoylamino‐1,2,3‐triazole
Authors: Spinelli Domenico , Corrao Anlonino , Frenna Vincenzo , Vivona NicolÒ , Ruccia Michele , Cusmano Giuseppe 
Published: April 2009

AbstractThe rates of the mononuclear heterocyclic rearrangement of the phenylhydrazone of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole (1) into 2,5‐diphenyl‐4‐benzoylamino‐1,2,3‐triazole (II) have heen measured in dioxane/water (50:50, v:v) in the range of pS+ 3.8–12.2 at various temperatures and the activation parameters determined. On the basis of the results obtained, we present evidence for the occurrence of two different types of reaction: the first, base‐catalyzed; the second, pS+ ‐independent. In the base‐catalyzed range the catalysis is of the general type.
Condensation de la base de mannich de l'hydroxy‐3 pyridine avec les ethers vinyliques: Accés aux alcoxy‐2 aza‐5 chromannes
Authors: Sliwa H. , Blondeau D. 
Published: April 2009

AbstractLa condensation thermique de la base de Mannich de l'hydroxy‐3 pyridine avec les éthers vinyliques conduit aux alcoxy‐2 aza‐5 chromannes; la condensation avec l'α‐pyranne fournit le cis hexahydro‐5,6,7,8,8a,10a oxa‐5 aza‐1 xanthène.
The preparation of heterocyclic materials from 2‐isocyanatobenzoyl chloride and difunctional nucleophiles
Authors: Beam Charles F. , Heindel Ned D. , Chun Maria , Stefanski Anthony 
Published: April 2009

Abstract2‐Isocyanatobenzoyl chloride was treated with difunctional nucleophiles such as o‐phenylenediamine, 1,8‐diaminonaphthalene, o‐aminothiophenol, and thioacetamide. The diaminonucleophiles gave intermediates which were thermally cyclized, and the other nucleophilic reagents gave heterocyclic materials directly.
Reactions of pyranylidenemethylpyrylium salts with ammonia and amines
Authors: Van Allan J. A. , Reynolds G. A. 
Published: April 2009

AbstractPyranylidenemethylpyrylium salts (1) react with ammonia to give pyranylidenepyridines as a result of the replacement of one of the oxygen atoms of 1 by nitrogen. Aliphatic primary amines react with 1 by replacing both of the oxygen atoms by nitrogens. Aniline and 1 give the monoreplacement product. Pyranylidenemethylthiopyrylium salts have only the oxygen atom replaced by reaction with primary aliphatic amines.
A heterocyclic arene oxide. 5,6‐Diphenylbenz[c]acridine 5,6‐oxide
Authors: Avnir David , Blum Jochanan 
Published: April 2009

AbstractThe first synthesis of a benz[c]acridine 5,6‐oxide is described. Treatment of 5,6‐benz[c]‐acridinequinone with phenylmagnesium bromide results in the formation of a trans‐diol, which gives the title compound upon dehydration with dimethylformamide dimethylacetal. In sulfuric acid, the epoxide rearranges mainly into 6,6‐diphenyl‐5‐benz[c]acridone.
Some ring expansion and related reactions of the phosphindole system
Authors: Hughes Alan N. , Amornraksa Kitti , Phisithkul Siriporn , Reutrakul Vichai 
Published: April 2009

Abstract3‐Butyl‐1,2‐diphenylphosphindole reacts smoothly with ethyl propiolate and water and with benzoyl chloride and water to give ring expanded products. The second of these products is further expanded to a seven‐membered system by treatment with sodium hydride. With diiodo‐methane followed by hydroxide ion, cleavage of the phosphorus‐containing ring occurs. The nmr and mass spectral data are analyzed in detail and the results are discussed in the context of related studies with simple phospholes and dibenzophospholes. Some of the results further illustrate that predictions regarding the types of reaction entered into by phosphorus heterocycles must be made with caution.
Photochemistry of methylenenitrones and related compounds. A study of oxaziridine and nitrene formation
Authors: Druelinger Melvin L. , Shelton Robert W. , Lammert Steven R. 
Published: April 2009

AbstractA series of N‐alkylmethylenenitrones has been prepared and can be irradiated cleanly to simple N‐alkyloxaziridines. Further irradiations of these systems lead to N‐alkylformamides via a singlet state rearrangement process. Triplet state fragmentation to give amines, presumably via alkyl nitrenes, has been observed but with very low efficiency. Only N‐aryl systems appear to lead to significant nitrene formation.
Synthetic studies of the antitumor antibiotic streptonigrin. I. Synthesis of the A‐B ring portion of streptonigrin
Authors: Liao T. K. , Nyberg Wayne H. , Cheng C. C. 
Published: April 2009

AbstractBromination of 6‐methoxy‐5,8‐quinolinedione gave the 7‐bromo derivative in quantitative yield. Treatment of the bromo compound with sodium azide followed by hydrogenation yielded 7‐amino‐6‐methoxy‐5,8‐quinolinedione, the A‐B ring portion of the antitumor antibiotic strep tonigrin. The corresponding 2‐methyl homolog was prepared in a similar manner from 6‐methoxy‐2‐methyl‐8‐nitroquinoline, which in turn, was obtained by a Skraup synthesis from 2‐nitro‐anisidine and crotonaldehyde.
Isothiazoles VI: 4,5‐dihaloisothiazolidin‐3‐one 1‐Oxides
Authors: Weiler Ernest D. , Miller George A. 
Published: April 2009

AbstractA useful and facile procedure for preparing 4,5‐dihaloisothiazolidin‐3‐one 1‐oxides is reported. Chlorination or bromination of various 4‐isothiazolin‐3‐one 1‐oxides yielded the title compounds.
Oxidation of methylbenzimidazoles with ceric ammonium nitrate
Authors: Talaty C. N. , Zenker N. , Callery P. S. 
Published: April 2009

AbstractA convenient method for the preparation of benzimidazole carboxaldehydes by the oxidation of methylbenzimidazoles with cerie ammonium nitrate is described. A series of methyl, dimethyl, and trimethylbenzimidazoles was treated with ceric ammonium nitrate in sulfuric acid, and the major ethyl acetate soluble products were characterized. In addition to carboxaldehyde products, side reactions yielding benzimidazolediones and nitrobenzimidazoles were also observed.
Synthesis and michael reaction of 3,4‐dimethylpyrrole
Authors: Cheng D. O. , Bowman T. L. , Legoff E. 
Published: April 2009

AbstractA two step synthesis of 3,4‐dimethylpyrrole via the reduction of 3‐carboethoxy‐4‐methyl‐pyrrole is described. Michael addition of methyl vinyl ketone and butyn‐2‐one to 3,4‐dimethylpyrrole gives the bisadducts, 2,5‐bis(3‐oxobutyl)‐3,4‐dimethylpyrrole and 2,5‐bis(3‐oxobutenyl)‐3,4‐dimethylpyrrole, respectively, while ethyl propiolate affords only the monoadduct, ethyl 3‐(3,4‐dimethylpyrrol‐2‐yl)propenoate. Catalytic reduction of the latter ester gives ethyl 3‐(3,4‐dimethylpyrrol‐2‐yl)propanoate which with ethyl propiolate gives ethyl 3‐(5‐carbethoxyethyl‐3,4‐dimethyl‐2‐yl)propenoate.
Rearrangement of 1,4‐benzodiazepin‐2,4‐diones to 3,l‐benzoxazin‐4‐ones
Authors: Anhydride Acetic , Kim Dong Han 
Published: April 2009

AbstractTreatment of 7‐chloro‐3,4‐dihydro‐1H‐1,4‐benzodiazepin‐2,5‐dione (Ia) with refluxing acetic anhydride in the presence of pyridine afforded 6‐chloro‐2‐methyl‐4H‐3,1‐benzoxazin‐4‐one (IIa). A plausible reaction path for this novel rearrangement reaction is described: Ia → 4‐acetyl‐7‐chloro‐3,4‐dihydro‐lH‐1,4‐benzodiazepin‐2,5‐dione → 7‐chloro‐1,4‐diacetyl‐3,4‐dihydro‐lH‐1,4‐benzodiazepin‐2,4‐dione → IIa. When 7‐chloro‐3,4‐dihydro‐4‐methyl‐lH‐1,4‐benzodiazepin‐2,5‐dione (Ib), 3,4‐dihydro‐4‐methyl‐1H‐1,4‐benzodiazepin‐2,5‐dione (Id) and 3,4‐dihydro‐1‐methyl‐1H‐1,4‐benzodiazepin‐2,5‐dione (Ie) were allowed to react with acetic anhydride under conditions similar to those used for the rearrangement reaction, only acetylation occurred.
Reaction of dichloroketene and sulfenc with N,N‐disubstituted 2‐aminomethylene‐1 ‐indanones. Synthesis of indeno[ 1,2‐b ] pyran and lndeno[2,l‐e] ‐1,2‐oxathiin derivatives
Authors: Mosti Luisa , Kvangelisti Filippo , Bignardi Caetano , Schenone Pietro 
Published: April 2009

AbstractThe 1,4‐cycloaddition of dichloroketene to N,N‐disubstituted 2‐aminomethylcnc‐l‐indanones afforded N,N‐disubstituted 4‐ainino‐3,3‐dichloro‐3,4‐dihydro‐2‐oxoindeno[1,2‐b ]pyrans only in the case of full or partial aromatic N‐substitution. The diphenylamino adduct gave 3‐chloro‐4‐diphenylamino‐2‐oxoindeno[ 1,2‐b]pyran by dehydrochlorination with DBN. The 1,4‐cycloaddition with sulfene occurred only in the case of 2‐diethylaininomethylene‐1‐indanone to give 4‐diethylamino‐3,4‐dihydroindeno[2, 1‐e]‐1,2‐oxathiin 2,2‐dioxide, a derivative of a new hetero‐cyclic system.
Synthesis of the 13,14‐diazasteroid ring system
Authors: Prickett J. E. , Gillis B. T. 
Published: April 2009

Abstractl‐Vinyl‐6‐methoxy‐3,4‐dihydronaphthalene (1) reacted with azo dienophiles to form cyclo‐adducts II, III, IV, and V. The reaction of adduct II with bromine resulted in the aromatization of the B ring to form the cycloadduct VIII.
The synthesis of 5‐amino‐v‐triazolo[4,5‐b] pyridin‐7‐one (l‐deaza‐8‐azaguanine) and 5‐amino‐3‐(β‐D‐ribofuranosyl)‐v‐triazolo[4,5‐b] pyridin‐7‐one (1‐deaza‐8‐azaguanosine)
Authors: Cline Barry L. , Panzica Raymond P. , Townsend Leroy B. 
Published: April 2009

AbstractThe synthesis of l‐deaza‐8‐azaguanine has been accomplished via a facile route from pyridine precursors. The site of rihosylation and anomeric configuration of l‐deaza‐8‐azaguanosine and several closely related derivatives was accomplished by cmr and pmr, respectively.
Micropreparative fractionation of the complexome by blue native continuous elution electrophoresis
Authors: Huang Kuan Yen , Filarsky Michael , Padula Matthew P. , Raftery Mark J. , Herbert Ben R. , Wilkins Marc R. 
Published: April 2009

AbstractThe large‐scale analysis of protein complexes is an emerging challenge in the field of proteomics. Currently, there are few methods available for the fractionation of protein complexes that are compatible with downstream proteomic techniques. Here, we describe the technique of blue native continuous elution electrophoresis (BN‐CEE). It combines the features of blue native PAGE (BN‐PAGE) and continuous elution electrophoresis (CEE), generating liquid‐phase fractions of protein complexes of up to 800 kDa. The resulting complexes can be further analysed by BN‐PAGE, by SDS‐PAGE and/or by MS. This can help define the constituent proteins of many complexes and their stoichiometry. As BN‐CEE is also micropreparative, with a capacity to separate milligram quantities of protein complexes, it will assist the study of proteins of lower abundance. In this regard, the acrylamide concentration and elution rate during separation can be controlled to help ‘zoom in’ on particular high mass regions and thus complexes of interest. We illustrate the utility of the technique in the analysis of Saccharomyces cerevisiae cellular lysate.
Epithelium‐derived chemokines induce airway smooth muscle cell migration
Authors: Takeda N. , Sumi Y. , Préfontaine D. , Al Abri J. , Al Heialy N. , Al‐Ramli W. , Michoud M‐C , Martin J. G. , Hamid Q. 
Published: April 2009

SummaryBackground
The remodelling of airway smooth muscle (ASM) associated with asthma severity may involve the migration of ASM cells towards the epithelium. However, little is known about the mechanisms of cell migration and the effect of epithelial‐derived mediators on this process.Objective
The main objective of the current study is to assess the effects of epithelial‐derived chemokines on ASM cell migration.Methods
Normal human ASM cells were incubated with supernatants from cells of the bronchial epithelial cell line BEAS‐2B and normal human bronchial epithelial (NHBE) cells. To induce chemokine production, epithelial cells were treated with TNF‐α. Chemokine expression by epithelial cells was evaluated by quantitative real‐time PCR, ELISA and membrane antibody array. To identify the role of individual chemokines in ASM cell migration, we performed migration assays with a modified Boyden chamber using specific neutralizing antibodies to block chemokine effects.Results
Supernatants from BEAS‐2B cells treated with TNF‐α increased ASM cell migration; migration was increased 1.6 and 2.5‐fold by supernatant from BEAS‐2B cells treated with 10 and 100 ng/mL TNF‐α, respectively. Protein levels in supernatants and mRNA expression by BEAS‐2B cells of regulated on activation, normal T cell expressed and secreted (RANTES) and IL‐8 were significantly increased by 100 ng/mL TNF‐α treatment. The incubation of supernatant with antibodies to RANTES or IL‐8 significantly reduced ASM cell migration, and the combined antibodies further inhibited the cell migration. The migratory effects of supernatants and inhibiting effects of RANTES and/or IL‐8 were confirmed also using NHBE cells.Conclusion
The results show that chemokines from airway epithelial cells cause ASM cell migration and might potentially play a role in the process of airway remodelling in asthma.
Cell‐specific mechanisms and systemic signalling as emerging themes in light acclimation of C3 plants
Authors: KANGASJÄRVI SAIJALIISA , NURMI MARKUS , TIKKANEN MIKKO , ARO EVA‐MARI 
Published: April 2009

ABSTRACTChloroplasts perform essential signalling functions in light acclimation and various stress responses in plants. Research on chloroplast signalling has provided fundamental information concerning the diversity of cellular responses to changing environmental conditions. Evidence has also accumulated indicating that different cell types possess specialized roles in regulation of leaf development and stress acclimation when challenged by environmental cues. Leaf veins are flanked by a layer of elongated chloroplast‐containing bundle sheath cells, which due to their central position hold the potential to control the flux of information inside the leaves. Indeed, a specific role for bundle sheath cells in plant acclimation to various light regimes is currently emerging. Moreover, perception of light stress initiates systemic signals that spread through the vasculature to confer stress resistance in non‐exposed parts of the plant. Such long‐distance signalling functions are related to unique characteristics of reactive oxygen species and their detoxification in bundle sheath cells. Novel techniques for analysis of distinct tissue types, together with Arabidopsis thaliana mutants with vasculature‐specific phenotypes, have proven instrumental in dissection of structural hierarchy among regulatory processes in leaves. This review emphasizes the current knowledge concerning the role of vascular bundle sheath cells in light‐dependent acclimation processes of C3 plants.
The impact of caesarean delivery and type of feeding on cow’s milk allergy in infants and subsequent development of allergic march in childhood
Authors: Sánchez‐Valverde F. , Gil F. , Martinez D. , Fernandez B. , Aznal E. , Oscoz M. , Olivera J. E. 
Published: April 2009

Background:  The incidence of IgE‐mediated cow’s milk allergy (CMA) has increased over the last few years. There are several genetic and environmental risk factors that may be related to this allergy and the subsequent allergic march (AM).Methods:  A prospective, cohort study was conducted in patients recruited into the study between 1998 and 2002. Information on clinical variables and complementary tests, perinatal and obstetric factors and the type of hydrolysed formula used was recorded. A cross sectional study on the prevalence of allergic diseases in this cohort was performed in 2004.Results:  We compared IgE‐mediated CMA patients with non‐IgE‐mediated CMA patients and found that IgE‐mediated CMA is associated with caesarean delivery (OR = 2.14 95% CI: 1.02–4.49), duration of breast feeding (>2 months, OR = 4.14; 95% CI: 2.17–7.89) and the use of supplementary artificial formula whilst breast feeding (OR = 2.86; 95% CI: 1.33–6.13). The factors associated with AM in IgE‐mediated CMA patients were caesarean delivery (OR = 0.42; 95% CI: 0.19–0.92) and the use of more extensively hydrolysed high grade hydrolysates (+EH/HGH) (OR = 0.44; 95% CI: 0.20–0.98), both as protective factors.Conclusions:  Caesarean delivery is demonstrated as being a risk factor for IgE‐mediated CMA, but it does not increase the risk of AM in these infants. The use of +EH/HGH appears to protect IgE‐mediated CMA patients from eventually developing AM.
PARTIAL PRIVATIZATION IN A MIXED DUOPOLY WITH AN R&D RIVALRY
Authors: Heywood John S. , Ye Guangliang 
Published: April 2009

ABSTRACTThis paper is the first to examine the incentive for partial privatization in a mixed duopoly with R&D rivalry. We show that because mixed duopolies engage in more R&D, the optimal extent of privatization is unambiguously reduced. Yet, this reduction is often very modest. Adopting the extent of privatization that would be optimal if one ignored the R&D rivalry routinely results in greater welfare than retaining a fully public firm and ignoring partial privatization. Only when R&D has an extremely low cost would it be preferable to ignore partial privatization.
A RULE FOR AGGREGATING INDIVIDUAL WELFARE MEASURES
Authors: Pench Alberto 
Published: April 2009

ABSTRACTIt is common, but often incorrect, practice in most applied works, especially in the field of applied general equilibrium models, to evaluate the overall impact of alternative policy changes by means of the sum of equivalent variations of (different classes of) individual consumers. This note proposes to use these same equivalent variations in a different way, namely, to aggregate them by the Borda rule.
Design and Use of a Quantitative Scale for Measuring Presyncope
Authors: SHELDON ROBERT S. , AMUAH JOSEPH E. , CONNOLLY STUART J. , ROSE SARAH , MORILLO CARLOS A. , TALAJIC MARIO , KUS TERESA , FOUAD‐TARAZI FETNAT , KLINGENHEBEN THOMAS , KRAHN ANDREW D. , SHELDON AARON , KOSHMAN MARY‐LOU , RITCHIE DEBBIE 
Published: April 2009

Introduction: Vasovagal syncope is common and distressing. One important symptom is presyncope, but there are no clinimetric measures of this. We developed the Calgary Presyncope Form (CPF) and used it to test whether metoprolol reduces presyncope in a randomized trial. Methods: The CPF captures the frequency, duration, and severity of presyncope. We administered it to participants in the Prevention of Syncope Trial (POST), a randomized clinical trial that tested the hypothesis that metoprolol reduces syncope and presyncope in adult patients with vasovagal syncope. Results: The CPF was completed by 44 patients on metoprolol and 39 patients on placebo, of a total of 208 subjects. Completion of the CPF for each of the threedimensions was 84–87% in the 83 respondents. Results were centrally distributed in duration and severity dimensions, but not in frequency. Patients had a median of 1.2 presyncopal spells per day, with a median moderate severity, lasting a median 10 minutes. The 3 scales were statistically independent of each other. These results were independent of subject age, and results in all 3 dimensions were stable over the observation period. There was no significant difference between patients on metoprolol and placebo in any dimension. Conclusion: The 3‐dimensional CPF is simple, easy to use, stable over time, measures 3 independent variables, and documents that metoprolol does not reduce presyncope.
Diabetic foot ulcers and ethnicity in Tanzania: a contrast between African and Asian populations
Authors: Abbas Zulfiqarali G. , Lutale Janet K. , Archibald Lennox K. 
Published: April 2009

ABSTRACTTo characterise the role of ethnicity in the occurrence of foot ulcer disease in persons with diabetes, we analysed prospectively collected data for persons attending the diabetes clinic at Muhimbili National Hospital (MNH), Dar es Salaam, Tanzania. A case was defined as any adult presenting to MNH with an ulcer at or below the ankle joint during July 1998–June 2005. We documented clinical and epidemiologic characteristics, progress, interventions and outcome. Seven hundred and eight persons met the case definition – 570 (80%) ethnic Africans and 138 (20%) Asian Indians. Ethnic Africans were more likely to present with gangrene (P < 0.01); Indians were more likely to be obese (P < 0.001) or have large vessel disease (P < 0.001). For Africans, intrinsic complications (neuro‐ischaemia or macrovascular disease) delayed ulcer healing; for Asian Indians, mode of intervention (e.g. sloughectomy or glycaemic control with insulin or oral agents) determined the same outcome. Indigenous ethnic African and Asian Indian populations with diabetes display contrasting foot ulcer epidemiology. Peripheral vascular disease and gangrene are playing a larger role in ulcer pathogenesis and outcomes for both ethnic groups than was previously thought. Preventive efforts and interventions should be tailored to the two ethnic groups to achieve complete ulcer healing.