Carotenoids history

C. H. Eugster, History 175 years of carotenoid chemistry , in Carotenoids, Birkhaeuser, Basel, 1995, pp. 1-12. 

If history is any guide, then we foresee great potential for growth in the field of carotenoid analysis in the coming years. Sample preparation methods that quickly and effectively break down and remove sample matrix while preserving carotenoids intact will improve the accuracy of both parent carotenoid and carotenoid metabolite identification and quantitation. 

Eugster, C.H. 1995. History 175 years of carotenoid chemistry. In Carotenoids, Volume lA Isolation and Analysis (Britton, G. Liaaen-Jensen, S. Pfander, H., Eds.). Birkhauser Verlag, Basel, Switzerland, pp. 1-12. 

Carotenoid synthesis has a long and distinguished history. It also has an exciting future. The old objectives remain valid, namely to synthesize new natural carotenoids and to improve methods both in laboratory and industrial scale processes. But now there are new and more diverse challenges as carotenoid science expands into new areas. 

In the past two decades, investigations of the enol ether condensation have concentrated almost exclusively upon this alternative, the history and development of which were rather different from those of the alkyl enol ether method. Whereas the work in the field of alkyl enol ethers concentrated mostly on the C2- and Ca-building blocks 77-75, with which significant results were achieved particularly in the chemistry of polyenes and carotenoids, the C.<5-reagents 75 and 16 were applied less frequently, because of the problem of side... 

The history of major publications in the carotenoid field, leading to the development of this series, was outlined in the preface to the series published in Vol. lA. The general philosophy outlined in that preface, with emphasis on practical guidance and the inclusion of worked examples of some of the most useful procedures, is maintained in Vol. 2. In keeping with this philosophy, Vol. 2 is not intended to be an exhaustive review of the literature, but is planned as a practical book, as well as a source of information. 

Several studies have provided information about the relationship between dietary intake of L and Z and MPOD. Macular, peripheral retina, and crystalline lens levels of L, Z, and their metabolites were chemically measured in 228 eyes of 147 human donors in one study [105]. The results were then correlated with retrospective supplement histories from families of selected members of the study population. Investigators found that those eyes with unusually high levels of macular carotenoids tended... 

Oils from macadamia nut and the soft parts of sea buckthorn berries are both rich sources of palmitoleic acid. A wide range of positive health effects of sea buckthorn oil are indicated by the long history of application of the berries in China, and by clinical trials and animal experiments carried out in several countries. In addition to the fatty acids, several unsaponifiable components in sea buckthorn oil (phytosterols, tocopherols, and carotenoids) probably play an inportant role in the health effects of the oil. Isolation of palmitoyl-ACP-specific A -desaturases and expression of the corresponding genes in plants and microorganisms provides promising alternative enriched sources of palmitoleic acid. 

The breakthrough experiment came in 1906, although hardly anyone noticed until decades later—and then, as they say, the rest is history. At that time, the Italian-Russian botanist, Mikhail Tsvet (1872-1919), was trying to separate the plant pigments, chlorophylls and carotenoids, by adsorbing them from a petroleum ether solution onto a solid material. Let us read his own words as he describes his discovery [14] ... 

Since the pathways by which many of the carotenoids were discovered covers several centuries and is somewhat convoluted, a tabular form for this history is very convenient as well. 

It is important to state here that these compounds have not been found to increase communication between established tumor cells and normal cells [5] this would be consistent with their inability in the lOTl/2 system to inhibit expression of the transformed phenotype i.e. growth of tumor cells in a background of normal cells, and with the experimental animal data showing that these compounds are active in the post-initiation phase of carcinogenesis prior to the establishment of tumors. These observations would also be consistent with the lack of ability of retinoic acid to inhibit solid tumor growth in clinical trials in head and neck cancer [16]. Thus, in general, the actions of carotenoids and retinoids are considered to be preventive and not therapeutic. In a recent study of dysplastic regions of the oral cavity in patients with a prior history of oral carcinoma, we discovered that even in these pre-cancerous lesions major reductions in connexin 43 expression had occurred [17]. Studies are underway to determine if retinoids can counter this decrease. 

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