Terpenes halogenated

Aplysia 260 Terpenes and halogenated terpenes, halogenated cyclic ethers, peptides and cyclic depsipeptides, macrolactones, alkaloids... 

Fig. 5.12 Compounds 488-505, halogenated terpenes from Portieria and Laurencia species...

Various attempts have been made to improve the stability of amorphous sulphur. Addition of small amounts of halogens, i.e., chlorine, bromine, iodine, treatment with sulphur monochloride or the addition of a terpene have some effect on the rate of conversion. As far as is known, none of the modified materials are commercially available. 

A mammal may emit many volatile compounds. Humans, for instance, give off hundreds of volatiles, many of them chemically identified (Ellin etal., 1974). The volatiles include many classes of compound such as acids (gerbil), ketones, lactones, sulfides (golden hamster), phenolics (beaver, elephant), acetates (mouse), terpenes (elephant), butyrate esters (tamarins), among others. The human samples mentioned before contained hydrocarbons, unsaturated hydrocarbons, alcohols, acids, ketones, aldehydes, esters, nitriles, aromatics, heterocyclics, sulfur compounds, ethers, and halogenated hydrocarbons. Sulfur compounds are found in carnivores, such as foxes, coyotes, or mustelids. The major volatile compound in urine of female coyotes, Canis latrans, is methyl 3-methylhut-3-enyl sulfide, which accounts for at least 50% of all urinary volatiles (Schultz etal, 1988). 

An array of new and unusual halogenated terpenes have been isolated and characterized from Laurencia red algae [14], This genus is well known as a source of halogenated sesquiterpenes. New chamigrane-type derivatives were isolated from Laurencia species, some from Laurencia... 

The first survey of natural organohalogens documented 570 halogenated terpenes (1). The present update describes many additional new members of this important class of marine and terrestrial natural products. 

The emission of a complete set of personal computers and monitors are described by Nakagawa et al. (2003). Several VOC like benzene, toluene, etc. were identified and quantified. The results are shown in Table 17.3. The emission rates of aliphatic hydrocarbons, terpenes, esters, ketones, alcohols and halogens were not found to be significantly different for PCs with CRT and TFT monitors. In the case of aromatic hydrocarbons the emission rates were higher if a PC with CRT monitor was used. The same was found for aldehyde emissions but the differences in emission rates were lower. The separate test CRT monitor and the associated computer in this study proved that the monitor was the main source of chemical emissions. 

Laurencia spp. (e.g., L. synderae, L. obtusa) Halogenated terpenes Corps en cerise No 52 46... 

Participation of Br in marine terpene biosynthesis (Section II.C) is reflected in the impressive number (several hundred) of halogenated terpenes, some with useful biological activities, that have been identified. For example, the poly halogenated sesquiterpenes isoobtusol (14) and isoobtusol acetate (15), isolated from the red alga Laurencia obtussa, showed potent activity against HeLa 229 human carcinoma cells1011. 

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