John Leffingwell

Leffingwell & Associates · Research

We look at how biotech routes have started to transform the making of flavours and fragrances. Recent years have seen progress in biotechnological manufacture of a number of important flavor and fragrance (F&F) ingredients. In this article, we discuss this progress with respect to the following : amino acid-derived flavour enhancers (umami - monoso...

The volatile constituents of Raw Pumpkin, (Cucurbita pepo L. subsp. pepo-Howden Pumpkin cultivar – a Connecticut Field type) were determined by dynamic headspace GC-MS analyses. In excess of 110 volatile constituents were identified. Analysis of the fibrous stringy and/or seedy portions gave primarily (Z)-3-hexenol and 1-hexanol while the " meat or...

This report provides the results of a capillary gas chromatography-mass spectrometry (GC-MS) study and identification of the volatiles from a commercial, partially denicotinized, supercritical CO2 Extract of Kentucky Dark Fire-Cured Tobacco. The results show that along with the expected tobacco constituents, among the major aroma volatiles, many ar...

The use of “purified” cooling agents in pharmaceutical and cosmetic preparations only dates back to the late 1880s with the commercial production of menthol from Japanese peppermint (Mentha arvensis) oil in Japan (1). The cultivation of peppermint in Japan before the Christian era appears to predate any other country, and menthol is reputed to have...

This review provides a history of the first important chiral drugs used in treating disease and a basis for understanding the importance of chirality on the bioactivity of pharmacologically active drugs.

Perfumer & Flavorist, Vol. 42, May 2017, pp. 26-30. This article addresses three prevalent industry themes. Firstly, we set into context the nature of the current peak of mergers and acquisitions (M&A) activity that analytically examine its empirical trend and impact on expected value. Secondly, we probe the differing strategic objectives of deal p...

(-)-Rotundone ((3S,5R,8S)-3,8-Dimethyl-5-prop-1-en-2-yl-3,4,5,6,7,8-hexahydro-2H-azulen-1-one) is an important odor active constituent of Agarwood (Oud), white & black peppercorns, patchouli oil, Cypriol oil (Cyperus scariosus) as well as various wines that exhibit peppery spicy notes. It also is reported as being important to oak aged spirits.

The compositions of volatile organic compounds (VOCs) emitted by Fusarium fungi (F. langsethiae, F. sibiricum, F. poae, and F. sporotrichioides) grown on two nutritive substrates: potato sucrose agar (PSA) and autoclaved wheat kernels (WK) were investigated. The culturing of fungi and study of their VOC emissions were performed in chromatographic v...

The main source of commercial pumpkin puree is from the Dickinson pumpkin cultivar of Cucurbita moschata ('Libby's Select') produced by the Nestlé Food Company. The town of Morton, near Peoria in central Illinois (USA), is the location of the Libby's® pumpkin processing plant which cans more than 85 percent of the world's pumpkin puree each year. P...

In this review we will discuss biotechnological progress for the following ingredients: amino acid derived flavor enhancers (umami-monosodium glutamate and kokumi – γ-glutamyl-valyl-glycine), Patchouli oil (patchoulol), Vanilla (natural vanillin), Sclareol (an ambergris scent intermediate) and Sandalwood oil (β-santalol).

A review of chemo-reception relative to historical developments in the cigarette industry.

The oxidative coupling of selected aldehydes and imines (and ketones) with metal oxide oxidants, e.g. MnO 2 , forms 2,2,3,3-tetraalkylsucinnaldehydes and aldimines to provide precursors for the synthesis of highly substituted pyrrolidines.

The oxidative coupling of selected aldehydes and imines with metal oxide oxidants, e.g. MnO2 , forms 2,2,3,3-tetraalkylsucinnaldehydes and aldimines to provide precursors for the novel syntheses of various di-& triazabicyclo-[3.2.1]octan-3-ones tropane alkaloid analogs via dipolar additions.

The oxidative coupling of selected aldehydes and imines with metal oxide oxidants, e.g. MnO2 , forms 2,2,3,3-tetraalkylsucinnaldehydes and aldimines to provide precursors for the synthesis of various novel 6,6,7,7-tetraalkyl tropane alkaloid analogs. Background:

History of the Wilkinson Sword Cooling Compounds and the impact on creation of new cooling compounds and research on cold receptors

The volatile constituents of Cyprian Latakia tobacco were determined by both dynamic and static headspace GC-MS analyses. In excess of 500 volatile constituents were identified, with the majority of volatiles being phenolics, polycyclic and related aromatic hydrocarbons, sesquiterpenoids and known tobacco constituents. Notably, five ambrettolide is...

Sweet, floral-fruity odor with a peach-apricotlike taste. 3211 / 13925-08-1 2-Methyl-5-vinylpyrazine (Re-GRAS) Coffeelike @ 10 ppm in sugar syrup. 1 4668 / 25394-57-4 Spilanthol; Affinin; (2E,4Z,6E)-N-isobutylocta-2,4,6-trienamide Imparts salivation, tingling effects, numbing effects and is perceived as salty by most persons. A flavor enhancer. 2–4...

The volatile compounds of fresh and air dried fruiting bodies of the wild edible giant puffball mushroom (Calvatia gigantea) were investigated by high resolution GC-MS using a sequential purge & trap technique. A total of 235 compounds were identified in this study with significant changes occurring during the ageing & sequential purging of the sam...

Chirality plays a very important role in flavour and fragrance chemistry. In this short review we will examine the chemistry and odour properties of such important chiral materials as menthol, carvone, methyl dihydrojasmonate, ambergris (Ambrox) and sandalwood odourants (β-santalol).

Discussion of Cooling Related Compounds

In the lost 25 years, the importance of chiral discrimination in olfaction has come a long way. This paper provides on overview of the progress mode in key chiral odorants that represent the scents of precious woods. The effect of chirality on the odor of sandalwood odorants (beta-santolols, 3-isocamphylcyclohexonols & Ebanol®s}, patchouli odorants...

The volatile constituents of Perique tobacco were determined by GC-MS. In excess of 330 components were identified. The distinct aroma of Perique is due to the extensive formation of components derived from the unique curing process of high-pressure anaerobic fermentation. 48 new tobacco constituents were identified. Perique tobacco is a minor toba...

This a part of our series on aroma materials produced by carotenoid degradation. As plants mature, or die, the chlorophyllic pigments rapidly decrease and virtually disappear (one of the normal catabolic changes during plant senescence). This is shown below for Burley tobacco after harvest, but is undoubtedly similar for other (green) plants. Many...

This is the introduction to our series on aroma materials produced by carotenoid degradation. Carotenoids are the pigments responsible for the colors of many plants, fruits and flowers. They serve as Light Harvesting Complexes (with proteins) in photosynthesis. Carotenoids are important in human nutrition as a source of Vitamin A (e.g., from beta-c...

Osmanthus fragrans is a flower native to China that is valued for its delicate fruity-floral apricot aroma. It is especially valued as an additive for tea and other beverages in the far east. While the flowers of osmanthus range from silver-white (Osmanthus fragrans Lour. var. latifolius Mak.) to gold-orange (Osmanthus fragrans Lour. var. thunbergi...

There are approximately 95 speciesof Boronia (Family Rutaceae), all but one of which occurred originally only in Australia. The majority of Boronia species are found in south-western Australia. The Brown Boronia (Boronia megastigma) is intensely fragrant (like Freesia and Osmanthus) and is valued in Australian floral arrangements for its intense ar...

Saffron is considered to be the worlds most expensive spice. The flower of Crocus sativa is a light purple, but it is the thread-like reddish colored stigma of the flower that is valued both as a spice and as a natural colorant. Saffron is hand harvested in the autumn, and the stigma is laboriously separated to yield the reddish colored spice. It t...

The sense of smell is a primal sense for humans as well as animals. From an evolutionary standpoint it is one of the most ancient of senses. Smell (or Olfaction) allows vertebrates and other organisms with olfactory receptors to identify food, mates, predators, and provides both sensual pleasure (the odor of flowers and perfume) as well as warnings...

Ten simple stimuli from the heterocyclic class of nitrogen chemicals known as pyrazines were arranged in a three-dimensional space by INDSCAL using similarity judgments by 12 young and 11 elderly subjects as input. Odor quality at two intensity levels, moderate and strong, was examined. At both concentrations, pyrazines with the highest intrinsic p...

In summary, we found that the volatile constituents of cocoa are, in the majority, identical or analogous to natural tobacco or tobacco smoke constituents.

The importance of cocoa powder as a casing material for tobacco is well known (I).* Virtually all blended cigarettes of the American type employ casing materials such as sugar and/or fruit extracts, licorice, and cocoa. These materials are used to mellow nicotine harshness and enhance the flavor of the tobaccos. From a historic standpoint, the use...

The alkylation of selected bicyclic imines via the Stork–Dowd reagent system under equilibrating conditions is reported to give products predictable by thermodynamic principles and in contrast to kinetic results.

The racent interest in the conformational and configurational relationships in the carane series prompts us to report an abnormality observed in the solvolysis of α-3,4-epoxycarane with a sodium acetate buffered solution of glacial acetic acid.

This invention relates to the synthesis of organic compounds and more particularly to a novel synthesis of organic compounds by treating organo primary amines with manganese dioxide. In general, the present invention relates to the discovery that monomeric or dimeric imines (Schiff bases) and pyrroles can be readily obtained by reacting manganese d...

Isophoron (I) liefert in Gegenwart von p-Toluolsulfonsäure mit Isopropenylacetat (II) ein Gemisch der isomeren Enolacetate (III)-(V).

We report that alpha-substituted aliphatic aldehydes readily undergo alpha-hydrogen abstraction and subsequent C-C and C-0 dimerization without further oxidation of the -CHO functionality or appreciable formation of alpha,beta-unsaturation.5

Activated manganese dioxide oxidatively dehydrogenates certain cyclohexene aldehydes, ketones, and Schiff bases to the corresponding aromatic derivatives.

Pure cis- and trans-limonene 1,2-oxides have been prepared, and certain of their reactions with nucleophilic and with electrophilic reagents have been studied in detail. It has been shown that the Fürstr-Plattner rule predicts the predominant products in all cases studied. Studies of the pyrolysis of hydroxyacetates derived from the limonene 1,2-ep...

Conformational effects on opening of the epoxides of limonene, carvomenthene & alpha-pinene were studied along with pyrolysis products of derivatives. The absolute configuration of the carvomenthols were determined. and the structure of dehydroacetic acid was deduced.