Nitro musks

Musks are pleasant smelling fragrances found in various personal and home care products. Since the 1950s, the usage of natural musks has declined due to the relatively easy and inexpensive production of their synthetic counterparts. There are three major types of synthetic musks, nitro musks, polycyclic musks, and macro... 

Herren D, Berset JD (2000) Nitro musks, nitro musk amino metabolites and polycyclic musks in sewage sludges. Quantitative determination by HRGC-ion-trap-MS/MS and mass spectral characterization of the amino metabolites. Chemosphere 40, 565-574. 

Synthetic musks including nitro musks, nitro musk amino metabolites, and polycyclic musks have been determined in effluents and sludges using GC-MS or GC-ion-trap-MS/ MS [45,162,163]. Galaxolide and tonalide were detected in Canadian and Swedish STP effluents at concentrations of up to 1300 and 520 ng/L, respectively [162], LLE for Canadian samples and SPE for Swedish samples were employed, musks (galaxolide. 

Benzyl saUcylate can be prepared by the reaction of ben2yl chloride with an alkaU salt of saUcyhc acid at 130—140°C or by the transesterification of methyl saUcylate with benzyl alcohol. It is used as a fixative and solvent for nitro musks and as a fragrance for detergents. Benzyl saUcylate was priced at... 

In some cases, especially when the family is directed more toward Oriental fragrances, the use of vanillin can be up to 5%. These types of perfumes include Spanish fougnre, sweet or fmity chypres, woody Oriental, or spicy Oriental notes. AH the perfumes based on the sweet, warm, and powdery impressions brought by vanillin belong to the great family of the Oriental notes and of the amber notes. Vanillin, when used together with coumarin and nitro-musks, can have a concentration of up to 10%. 

Cohn points out that position isomerism is of the greatest importance as regards the odours of isomerides, this is strikingly instanced in the case of the tri-nitro tertiary butyl xylenes since the only one possessing the powerful musk odour is that in which the nitro groups are situated each in the meta position to the two others again the ortho-amido-benzaldehyde has a strong odour but the meta and para isomerides are odourless. 

There are a number of nitro-compounds known under the name of artificial musk, all of which may conveniently be grouped together here. The natural odorous constituents of musk appear to be, in the main, ketonic compounds free from nitrogen, so that the term artificial musk must be understood to mean artificially prepared bodies, having musklike odours, but not having any direct chemical relationship with natural musk perfume. 

We add to the above-mentioned hydrocarbons, which during the operation should be kept thoroughly cool, a little more than the molecular quantity of fuming nitric acid or nitro-sulphuric acid. The acid should be gradually run in and the whole then allowed to stand undisturbed for from one to two hours, the resulting mass being then poured into water in order to get rid of the excess of acid. The well-washed substances thus obtained are then subjected to distillation by means of steam, whereupon simultaneously formed bodies, which smell like nitro-benzol and overpower the musk odour, readily distil over, whilst the pure substances remain behind. ... 

The raw nitro product is then purified by recrystallisation from alcohol of 90 per cent, strength. The purified product crystallises out in yellowish-white needles, possessing a strong smell of musk. 

Musk ambrette, which is usually regarded as the finest of all the artificial musks, is a nitro-compound of the methyl ether of butyl-meta-cresol, usually described as dinitro-butyl- ieia-cresol methyl ether. It should melt at 85°. 

The cross-dimerization reaction is very commonly employed for the manufacture of intermediates for synthetic musks, which have become an important class of perfumery chemicals. Synthetic musks have been the target of extensive research over the years due to a conservation order placed on the musk deer. Nitro musks are being steadily replaced by non-nitro polycyclic musks becau.se of technical drawbacks and health aspects of the former, which are explosive, sensitive, and virtually nonbiodegradable. Non-nitro musks, on the other hand exhibit better stability to light and alkali, and more nearly duplicate the odour of the macrocyclic musks occurring in nature. Indian musk odorants are easily soluble in alcohol and perfume compositions. They have the added advantage of non-discoloration in soap and domestic products. In view of the low price, their future in the perfume industry appears very promising. 

A method with LOQ at ppt levels was developed based on LLE followed by GC-AFID for the determination of trace concentrations of nitrobenzene, l-chloro-2-nitrobenzene and synthetic fragrances such as musk xylene (223) and musk ketone (224). The method was applied to study the distribution of these compounds in environmental samples of North Sea waters460. GC with atomic emission detection (AED) has been successfully applied to the determination of nitro musks in human adipose tissues, at ppb concentration levels. A clean-up procedure for nonpolar substances and element-specific detection with AED enabled for the first time target screening analysis for lipophilic nitro aromatic compounds. The lack of sensitivity of AED was compensated by higher concentrations of the extracts... 

Gatermann, R. Siselli, S. Huhnerfuss, H. Rimkus, G. G. Hecker, M. Karbe, L. 2002, Synthetic musks in the environment. Part 1 Species-dependent bioaccumulation of polycyclic and nitro musk fragrances in freshwater fish and mussels. Arch. Environ. Con. Tox. 42 437 46. 

Serum and plasma Serum and plasma samples partially mimic the trend observed in human milk samples. Overall, polycyclic musks can be detected more frequently and at higher concentrations compared to the nitro musk compounds (Table 8). HHCB is by far the most common of the polycyclic musks as production and use of this compound increased at the same time as production and use of nitro musks decreased [168]. However, MX still seems to be a common contaminant in human serum, with a considerably high detection frequency compared to AHTN. A high percentage of the population is still exposed to nitro musk compounds [168], although a moderate decline in MX and a strong decline in MK are observed. 

Apostolidis S, Chandra T, Demirhan I, Cinatl J, Doerr HW, Chandra A (2002) Evaluation of carcinogenic potential of two nitro-musk derivatives, musk xylene and musk tibetene in a host-mediated in vivo/in vitro assay system. Anticancer Res 22 2657-2662... 

Fig. 4. A plot of the two largest principal components of the 312 compounds and the 871 molecular descriptors comprising the training set. 1 = macrocyclic nonmusk, 2 = aromatic nitro nonmusks, 3 = macrocyclic musks, and 4 = aromatic nitro musks. The plane defined by the two largest principal components accounts for 39% of the total cumulative variance.

Figure 5 suggests that nitrated and nitro-free musks have common structural features that can be used to differentiate them from nonmusks. We consider this to be a significant result. Fragrance chemists have long sought to find the overlap between nitrated and nitro-free musks in terms of the structural features that a compound must possess in order to evoke a musk odor. Further-... 

TABLE 2.2 Polycylic Musk Fragrances and Nitro Musks Detected in Various Waters in Canada and Sweden... 

Gatermann R., S. Biselli, H. Huhnerfuss, G.G. Rimkus, M. Hecker, and L. Karbe (2002). Synthetic musks in the environment. Part 1 Species-dependent hioaccumulation of polycyclic and nitro musk fragrances in fi eshwater flsh and mussels. Archives of Environmental Contamination and Toxicology 42 437-446. 

Similarity between odors arises because dissimilar substances or mixtures of compounds may interact with receptors to create similar sensory impressions in the sensory centers of the brain. The group of musk fragrances (comprising macro-cyclic ketones and esters as well as aromatic nitro compounds and polycyclic aromatics) are, for example, compounds with similar odors but totally different structures [5, 6]. Small changes in structure (e.g., the introduction of one or more double bonds in aliphatic alcohols or aldehydes) may, however, alter a sensory... 

Synthetic musks are important ingredients for the fragrance industry. They are heavily used in laundry detergents, fabric softeners, cleaning products, air fresheners, and so on, and in cosmetic and personal hygiene products such as hand soap, shampoo, and perfume. Nitro, polycyclic, macrocyclic, and the newest dass, alicydic musks constitute the four major classes. The OSPAR (Oslo-Paris) Commission summarized information on their environmental behavior that was relevant to its charge, namely protection of the northeast Atlantic marine environment [37]. Most of the identified uses of synthetic musks are expected to lead to their release to... 

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