Bergamot Oil Research Articles

Selective Extraction and Determination of Bergapten, a Photosensitive Substance, from Bergamot Oil as well as from Cosmetics Containing Bergamot Oil

A reliable method for the extraction and determinatin of bergapten was established. When hydrophobic bergapten was treated with alkali, it became soluble in water through unfolding of its lactone ring. Hydrophobic substances were removed by washing with ether, then it was subjected to the closing reaction of lactone ring by heating with 10% sulfuric acid and the revival bergapten was extracted with chloroform. An aliquot of the solvent layer was injected into an FID gas chromatograph fitted with 5% SE-30 column and subjected to the determination by use of chrysene as an internal standard. A good linearity of calibration curve was obtained within 5-500μg/ml of bergapten, variation coefficient at 33.3μg/ml level being 4.6%. Recovery of 92.6% was obtained at the spike level of 100μg/g of bergapten into bergamot oil. The maximal bergapten content in seven commercial bergamot oils was as high as 1, 000ppm.

Etude expérimentale de la phototoxicité de l’essence de Bergamote

Phototoxicity of bergamot oil in solar simulating radiation (SSR greater than or equal to 290 nm) and in long ultraviolet radiation (LUV greater than or equal to 320 nm) has been compared by studying photoaugmentation of erythema in the guinea pig after 24 h and pigmentary photoaugmentation in man on the 8th day. The results show that a close relationship exists between guinea pig and human responses, with both radiations used, and that man seems to be slightly more sensitive to phototoxic effects of bergamot oil than the guinea pig. This difference of sensitivity necessarily implies the participation of UVA (320--400 nm) in the phototoxic reaction of bergamot oil with solar radiation. This UVA participation is particularly obvious in the guinea pig; in man, the results are less clear and a certain synergy of UVB rays (290--320 nm) may be involved in the phototoxic UVA-induced reaction of bergamot oil. Despite these slight differences, the erythematous reaction in the guinea pig appears to be a remarkable experimental model to show out potential phototoxic reactions of products containing psoralens in man.

Selective fluorescence detection of citrus oil components separated by high-performance liquid chromatography

The analysis of citrus oils is aided by the use of selective fluorescence detection with high-pressure liquid chromatography. The differing fluorescence properties of the nonvolatile components present in the oil make detection at one excitation and emission wavelength unsuitable. Therefore, replicate chromatograms are obtained at particulare wavelength combinations for the classification of those components based on peak intensity variations. From results with lime oil, this technique is successfully appied to lemon, grapefruit and bergamot oils.

3344. The light shines on bergamot: Zaynoun, S. T., Johnson, B. E. & Frain-Bell, W. (1977). A study ofoil of bergamot and its importance as a phototoxic agent. I. Characterization and quantification of the photoactive component. Br. J. Derm.96, 475

Oil of bergamot is an extract from the rind of bergamot orange (Citrus aurantium ssp bergamia) that has a pleasant, refreshing scent; until a few years ago it had been widely used as an ingredient in cosmetics but was restricted or banned in most countries because of certain adverse effects. More recently, oil of bergamot preparations have been gaining renewed popularity in aromatherapy. Oil of bergamot possesses photosensitive and melanogenic properties because of the presence of furocoumarins, primarily bergapten (5-methoxypsoralen [5-MOP]). However, 5-MOP is also potentially phototoxic and photomutagenic. Despite its increasing application, there are only a few recent reports of phototoxic reactions to bergamot aromatherapy oil. We describe two patients with localized and disseminated bullous phototoxic skin reactions developing within 48 to 72 hours after exposure to bergamot aromatherapy oil and subsequent ultraviolet exposure. One patient (case 2) had no history of direct contact with aromatherapy oil but developed bullous skin lesions after exposure to aerosolized (evaporated) aromatherapy oil in a sauna and subsequent UVA radiation in a tanning salon. This report highlights the potential health hazard related to the increasing use of psoralen-containing aromatherapy oils. (J Am Acad Dermatol 2001;45:458-61.)

A study of oil of bergamot and its importance as a phototoxic agent. I. Characterization and quantification of the photoactive component.

It is important in the technique of photopatch testing, using oil of bergamot, to have determined the concentration of the active psoralen, bergapten, so as to avoid false negative responses in the assessment of phototoxic reactions. Techniques for assessing the phototoxic components of oil of bergamot are described and quantitative analyses of bergapten, the only significant photoactive compound in the samples examined, are reported. The phototoxicity of bergapten was found to be nearly the same as that of xanthotoxin (8-MOP) in tests on human skin.

A study of oil of bergamot and its importance as a phototoxic agent. II. Factors which affect the phototoxic reaction induced by bergamot oil and psoralen derivatives.

Using a standardized open photopatch test technique, the phototoxic reactions produced by bergamot oil bergapten (5-methoxypsoralen) the active component of the oil, and xanthotoxin (8-methoxypsoralen) were studied. The reaction was affected by a range of factors such as the vehicle (PMF or ethanol), the concentration of ethanol in the vehicle, the skin site, the interval between application of the psoralen and irradiation, the hydration of the skin, and the degree of natural or sun-induced pigmentation. Repeated photopatch testing at the same skin site produced an increase in sensitivity. Eye colour, natural susceptibility to suntanning, age, and sex, had no effect on the phototoxic response to psoralens.

Liquid Chromatographic Determination of Bergapten Content in Treated or Natural Bergamot Oils

Abstract The method presented is a simplified and sensitive liquid chromatographic approach to the assay of the furocoumarin, bergapten, present in oil of bergamot. The method is faster and more reliable than thin layer chromatographicultraviolet assays currently in use. Various oils, treated and untreated, are tested for detection down to 0.001% or 10 ppm levels. Repetitive analyses give a standard deviation of 0.139 or a relative value of 1.61 %.

About perfume phototoxity of the essential oils from citrus fruits

The essential oils made from citrus fruits are often used in the compound perfumes for cosmetics, and they cause photodermatitis sometimes. The typical examples are bergamot oil, lemon oil, lime oil and grapefruit oil. The phototoxitic reaction is due to some furocoumarins (5-MOP, 8-MOP, etc.) contained in those oils. UV absorption spetcrums of the furocoumarin group are observed at approximately 320nm. We examined the relation between UV absorption at 320nm and the result of actual photopach test on human skin by exposure to xenonlamp and sunlight. The authors found the fact that the citrus oils showing UV absorption at 320nm will have posibility to cause photodermatis. When we use genuine citrus oils for skin cosmetics, we must take care of the quality of them. Now, we can get some refined citrus oils and synthetic ones without the photosensitic substances that show UV absorption at 320nm. If we use them, the problem of the phototoxity will be avoided.

Synthesis of Jasmonoids, a Review

Abstract cis-Jasmone (I), a constituent of the Jasminum genus, and dihydrojasmone (II), which is present in bergamot oil, are important perfume ingredients. These compounds have focused continuous attention owing to their economic values and their being convenient testing targets for many new synthetic methodologies.

Monographs on fragrance raw materials: Bergamot oil expressed

Monographs on fragrance raw materials: Bergamot oil expressed

The teratogenic effect of cosmetic constituents on the chick embryo.

Cosmetic products have a more extended usage than drugs, especially if we consider their wide and habitual usage by healthy people, particularly women. The scent is the particular constituent in these preparations which make their reputation and thus their success on the market; the characteristic bouquet of perfumes, creams, soaps, shampoos, sprays, etc., is obtained by adding different mixtures of essential oils which bear the name of the plants and flowers (1) from which they are extracted in small quantities (rose, citronella, lemon, bergamot oils). Currently, they are produced industrially at high purity; these industrial products are called by their original name, to which the suffix of alcoholic or aldehyde derivate is added (citral = lemon oil, citronellal = citronella oil, etc.).

Qualitative and quantitative in situ fluorimetry of citrus oil thin-layer chromatograms

The development of direct fluorimetric scanning for thin-layer chromatogram analysis has introduced a versatile tool which has diversified applications in the analysis of citrus oils and potential for analysis of a wide variety of other natural products. The characterization of citrus oils from fluorescence and fluorescence quenching profiles which result from the presence of crystalline components in the oils can be accomplished. Quantitative determination of two coumarin derivatives, 5-geranoxy-7-methoxycoumarin and 5,7-dimethoxycoumarin, by in situ fluorimetry of lemon, lime, and bergamot oil thin-layer chromatograms provides an accurate and rapid procedure for quality control based on coumarin derivative content.

Characterization of the Steam Nonvolatile Residue of Bergamot Oil and Some Other Essential Oils

Abstract A method is presented for identifying and estimating the coumarins and furocoumarins present in bergamot oil and four other essential oils. Solutions of the nonvolatile residue of the oils are spotted on silica gel thin layer plates and developed in hexane-ethyl acetate (75+25) for 4 hr. The separated compounds are identified by their Rf values and characteristic fluorescence under short wave UV light; the spots are marked, scraped from the plate, and extracted with chloroform. The centrifuged extracts are scanned in a recording spectrophotometer from 400 to 240 mμ. Bergaptene, citroptene, bergamottin, and 7-methoxy-5-geranoxycoumarin were also individually estimated. Bergaptol, isopimpinellin, and xanthotoxin could be estimated only roughly because of low absorbance readings or lack of standards. A procedure to isolate and purify bergamottin from bergamot oil and 7-methoxy-5-geranoxycoumarin from lime oil, to serve as reference standards, is also included.

A scheme for the preparative chromatographic isolation and concentration of trace components in natural products using 4-inch diameter columns

A general method is demonstrated for effective use of large-scale preparative gas chromatography to isolate and concentrate minor components in natural products. A gas chromatograph equipped with 4 inch O.D. preparative columns was used to collect four fractions enriched in the minor components found in a Bergamot oil sample. The mixed fractions were analyzed directly by a combination gas chromatograph–mass spectrometer, or by subsequent small-scale preparative gas chromatography and collection of individual components. The collected components were characterized by N.M.R., I.R., and mass spectrometry. With the suggested methodology, the time required for characterization of a natural product is significantly reduced, and information not accessible by other means is obtained.

Sesquiterpenes. I. Nootkatone, A New Grapefruit Flavor Constituent

SUMMARYThe bicyclic conjugated sesquiterpene ketone, nootkatone, has been found in grapefruit peel oil and in peel‐oil‐free grapefruit juice. The flavor intensity of grapefruit oil appears to be related to the relative abundance of nootkatone. A combination of gas‐liquid chromatography and thin‐layer chromatography revealed the presence of this ketone, which was identified by its infrared spectrum and the melting point of its 2,4‐dinitrophenylhydrazone derivative. Traces of nootkatone were found also in bergamot, lemon, lime, orange, and tangerine oils.

Spectrophotometric Characterization of Some Authentic Oil of Bergamot and a Few Related Oils

Abstract Steam distillation separates oil of bergamot into a volatile fraction (85—95% of the original pressed oil) which has a qualitatively significant IR absorption but no appreciable UV absorption in the 270—375 mμ, range. The relatively small steam nonvolatile fraction, however, has significant absorption in the 270—375 mμ range; maximum at 313 mμ, minimum at 277 mμ, and a ratio of 2.45 ± 0.07 for A313/A277. The steam nonvolatile fraction of bergamot consists primarily of the furocoumarin bergaptene. These compounds classed as psoralens have been reported to induce sensitization of the skin under the influence of sunlight or UV irradiation. Initial studies to separate bergamot oil constituents from mixtures have been partially successful. Work on commercial mixtures, and on characterizing the nonvolatile fraction by chemical and physical means, will be continued.

Separation and Identification of Carbon Tetrachloride and Other Halogenated Hydrocarbons from Multicomponent Mixtures

Abstract Steam distillation separates oil of bergamot into a volatile fraction (85—95% of the original pressed oil) which has a qualitatively significant IR absorption but no appreciable UV absorption in the 270—375 mμ, range. The relatively small steam nonvolatile fraction, however, has significant absorption in the 270—375 mμ range; maximum at 313 mμ, minimum at 277 mμ, and a ratio of 2.45 ± 0.07 for A313/A277. The steam nonvolatile fraction of bergamot consists primarily of the furocoumarin bergaptene. These compounds classed as psoralens have been reported to induce sensitization of the skin under the influence of sunlight or UV irradiation. Initial studies to separate bergamot oil constituents from mixtures have been partially successful. Work on commercial mixtures, and on characterizing the nonvolatile fraction by chemical and physical means, will be continued.

Analyse des parties acides de l'essence de bergamote saponifiée

AbstractAnalysis of the acid‐lactonic parts of bergamot oil (Citrus bergamia, RISSO, from Calabria, Italy) yb chromatographic (Column, thin‐layer, paper, vapour phase) and spectrometric (mass, NMR., IR., UV.) methods has confirmed previous resuits and in addition revealed the presence of cis and trans jasmone, dihydrojasmone, cis and trans 5‐octen‐2‐one, the following saturated fatty acids : octanoic, nonanoic, decanoic, undecanoic, hexadecanoic, octadecanoic, eicosanoic, tetracosanoic, small quantities of docosanoic, tricosanoic, pentacosanoic, hexacosanoic acid, and two unsaturated acids : 9‐octadecenoic and 9,12‐octadecadienoic. We have further identified cis geranic acid, possibly trans‐ and dihydrogeranic acid.

USE AND ABUSE OF PSORALENS

The psoralens 1 are furocoumarins to which most people in the United States have been exposed. Celery contains psoralen. Oil of bergamot, widely used in perfumes, contains 5-methoxypsoralen. Thus, there are few persons who have not ingested psoralen and probably no adult woman who has not applied a psoralen to her skin. Plants containing psoralen have been used to produce pigmentation for at least 3,000 years. Recently, oil of bergamot has been used for this purpose. Scientific investigation of the psoralens began when Kuske 2 and, later, Fahmy and his group 3 isolated the active chemicals from a variety of plants. Many physicians in different countries began to study these compounds. Lerner, Denton, and Fitzpatrick 4 and Kelly and Pinkus 5 initiated clinical evaluation in the United States. The chemical alterations in the psoralesn which occur after oral ingestion or topical application to the skin are not known. Exposure of

Tinea nigra palmaris; a disorder easily confused with junction nevus of the palm.

Tinea nigra palmaris is an uncommon skin disease caused by the fungus Cladosporium Wernecki. In the western hemisphere nearly all reported cases have involved the palms; however, cases involving other areas of the body, such as the neck or thorax, do occur.1The asymptomatic macular lesions, neither elevated nor scaly, are brown or black, appearing like an India ink2or silver nitrate stain.3The disease must be differentiated from nevi, contact dermatitis, pigmentation of Addison's disease, and drug eruptions. The pigmented lesions of photodermatitis due to bergamot or lime oil can be differentiated easily since they never occur on the palms.4 Only five cases of tinea nigra acquired in the United States have been reported, although cases acquired in Brazil,5Cuba,2Panama,6and Puerto Rico7in the western hemisphere are described in the literature. The first case to be reported from the