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Monoterpenoids myrcene

The discussion of a series displacement index for classifying mass spectra and for correlation with structural stability includes some monoterpenoids e.g. myrcene limonene, santene). ... [Pg.5]

Allylic alcohols [e.g. citronellol, geraniol (8), and nerol (18)] exhibit strong shielding at the y-carbon and deshielding at the 5-carbon in the 13C n.m.r. upon acylation.127 Cationic exchange resins separate acyclic [e.g. myrcene (12)] from cyclic (e.g. limonene) monoterpenoids.128... [Pg.16]

Monoterpenoids are responsible for fragrances and flavors of many plants and thus their products are used in perfumery and as spices. To date over 1,500 monoterpenoids are known, and these constitute acyclic, monocyclic, and bicyclic monoterpenoids (32), which occur in nature as hydrocarbons, alcohols, aldehydes, and carboxylic acids and their esters. Several acyclic monoterpenoid hydrocarbons are known, and these include trienes such as 3-myrcene (Cl), a-myrcene (C2), (Z)-a-ocimene (C3), ( )-a-ocimene (C4), (Z)-3-ocimene (C5), and ( )-P-ocimene (C6). 3-Myrcene and 3-ocimene are constituents of basil (Oci-mum basilicum, Labiatae) and bay (Pimenta acris, Myrtaceae), pettitgrain (Citrus vulgaris, Rutaceae) leaves, strobiles of hops (Humulus lupulus, Cannabaceae), and several other essential oils. Unsaturated acyclic monoterpene alcohol constituents of plants and their derived aldehydes play a signihcant role in the perfume industry. Some common acyclic monoterpene alcohols and aldehydes include geraniol (C7), linalool (C8) (a... [Pg.479]

Several new fascinating halogenated monoterpenoids, e.g. (20) and (21), have been isolated from red algae of Chondroccus species their structure suggests formation by enzymic addition of BrCl to myrcene followed by dehydrohalogena-tion. [Pg.186]

Routes to furan monoterpenes from other monoterpenoids are well known, and the photooxygenation route from myrcene (7) to perillene (849) was discussed in Vol. 4 (p. 561). Using the aldehyde 863 led, by the same route ( 62, then ferrous ion) to perillenal (846). The simplest reported preparation of perillene (849) from a dimethyloctane monoterpenoid precursor is certainly the autoxidation of citral enol acetates (864), yielding 11% of a mixture of perillene (849) and rose furan (848) after passing air through a chloroform solution for 24 hours. [Pg.417]

In the case of myrcene, the result would be that the empirical formula is Ci0Hi6- The fact that the molecule contains 10 carbon atoms suggests that it may be a monoterpenoid. Nowadays, thanks to the isoprene rule, this would immediately suggest a few skeletal types such as... [Pg.45]

Green plants also release substantial quantities of isoprene (2) as well as monoterpenoid hydrocarbons such as a-pinene (3), myrcene (4), and limonene (5). These compounds contribute significantly to atmospheric organic concentrations in remote or forested areas (Altshuller, 1983 Hutte et al., 1984). It has been estimated that the global output of these substances may equal about 28% of the annual output of methane (Rasmussen and Went, 1965). [Pg.29]

Bark beetles oxidise toxic monoterpenoid hydrocarbons in their respiratory air, which originate from the resin of the tree they colonise, and thereby circumvent this defense barrier of the tree. Converting these compounds into less toxic secondary metabolites serves another purpose, by providing pheromones to attract insects of the same species, of both sexes. Therefore, an oxygen function is often introduced species-specifically and stereoselectively. European spruce bark beetles oxidise (-)-a-pinene to (S)-cis-verbenol, whereas pine beetles produce (R)-trans-verheno. In the California fivespined engraver Ips paraconfu-sus), myrcene is converted into (S)-ipsdienol and (S)-ipsenol. But Ips pint and Ips paraconfusus are also able to synthesise their pheromones de novo via the classical mevalonate biosynthetic pathway. [Pg.760]

Table V. Sublethal effect of short-term contact exposure to 5 fdl of monoterpenoids in the earthworm Eisenla fetlda. (c control d-lim = d-limonene pul = pulegone lin = linalool myr = myrcene)... Table V. Sublethal effect of short-term contact exposure to 5 fdl of monoterpenoids in the earthworm Eisenla fetlda. (c control d-lim = d-limonene pul = pulegone lin = linalool myr = myrcene)...
Conifer resin, which is a mixture of monoterpenes and diterpenes is an important protective compound against bark beetles and other conifer herbivores. The volatile monoterpenes emanating from a specific tree is often the cue for bark beetles to find a tree where the tree defenses could be compromised from abiotic or biotic stresses. The synchronized mass attack is the strategy bark beetles use to reduce the effects of resin-based defenses in conifers. Aggregation hormones released by bark beetles are oxidized monoterpenoids such as ipsdienol, ipsenol and verbenol. It is believed that these compounds can be oxidation products of host plant monoterpenes such as myrcene. Recently it has been observed that most of the monoterpenoid aggregation pheromone components are biosynthesized de novo in bark beetles [7]. [Pg.2919]

Myrcene (32) is also koown as p-myrcene and its systematic name is 7-methyl-3-methylene-l,6-octadiene. It is very widespread in nature. This is not surprising as it is formed in nature by elimination from geranyl pyrophosphate, the precursor of all monoterpenoids. It can also be formed by elimination of water from alcohols such as geraniol or linalool, and so its presence in namral extracts may be as an artifact (formed during the extraction process) rather than as a genuine plant metabolite. [Pg.264]


See other pages where Monoterpenoids myrcene is mentioned: [Pg.901]    [Pg.901]    [Pg.125]    [Pg.5]    [Pg.160]    [Pg.163]    [Pg.174]    [Pg.203]    [Pg.20]    [Pg.1837]    [Pg.5]    [Pg.39]    [Pg.44]    [Pg.305]    [Pg.312]    [Pg.2720]    [Pg.701]    [Pg.19]    [Pg.198]   
See also in sourсe #XX -- [ Pg.175 ]




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