Olfactophore

Even a cursory inspection of the known sandalwood odorants suggests a model that involves an alcohol function with a center of hydrophobic bulk at a set distance from it. This basic model has been refined by many workers that use different SAR techniques to define more closely the exact requirements of the hydrophobe and the distance between it and the alcohol function (55-60). Bajgrowicz et al. built an olfactophore model around this basic concept and used it to design a potent new sandalwood odorant successfully (61). 

Recent research resulted in new and potent impact odorants found in foods or Mail-lard reaction samples [26-28]. Systematic studies revealed common structural elements of sulphur-containing compounds required for developing a basic meat flavour (Fig. 5.53) [29[. The 1,2-oxygen, sulphur grouping has been suggested as a common element of the savoury olfactophore (Fig. 5.54). 

Fig. 5.54 The 1,2-oxygen, sulphur grouping as common element of the savoury olfactophore (according to D. Rowe, Oxford Chemicals)...

Kraft et al., 2000). This particular type of pharmacophore has been termed an olpfactophore and a review by Kraft includes the development of olfactophores and SAR for the major odor notes of relevance in perfumery "fruity, "marine," "green," "floral," "spicy," "woody," "amber," and "musky" (Kraft et al., 2000). In addition to perfumery, odors are also of great importance in the food industry, for example, in the development of flavors. 

Figure 3. The olfactophore" for tropical/vegetable notes with A H, SCH, ring B H, CH3, acyl, absent if carbonyl Rl, R2 H, alhyl R3 H, alkyl, ring R4 H, CHj, ring, OR R5 H, absent if carbonyl. Adapted from ref. 16.

In fact, the main criticism of the olfactophore approach is that it does not take into account these types of properties. 

Since the identification of olfactophores is best suited to sets of compounds with a limited amount of conformational flexibility, this technique has mostly been applied to the following odour areas ... 

Pelzer s analysis of 73 alcohols produced the following rules for olfactophore 1. 

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