Isolation from algae

Stanewskj A channel opsin has recently been isolated from algae which can function as a circadian receptor without even talking to a G protein. Have people looked in mammals to see if this exists there ... 

Chapman, V.J. (1966) Three new carotenoids isolated from algae. Phytochemistry 5,... 

Ester links between threonine and the terminal carboxyl of a peptide chain forming a lactone have been found in actinomycin (Bullock and Johnson, 1957), while Dekker et al. (1949) have found an imide link in the form of a pyrrolidonyl ring involving the N-terminal glutamic acid residue in a peptide isolated from algae. In teichoic acids (polymers present in... 

Several other less common polysaccharides were isolated from algae [62] and are indicated in Table 7.8.1. Some of these polysaccharides also have a certain degree of sulfation. 

Table 7.8.1. Polysaccharides with less common structure isolated from algae.

Violacene (733), the plocamenes, and other related polyhalogenated compounds, all isolated from algae, are the only naturally occurring 1-ethyl-1,3-dimethylcyclohexanes. A start has been made on a synthesis of violacene (733), which has resulted in the synthesis of epi-plocamene D (734), and its allylically rearranged trichloride 735, which is also naturally occurring. The route is shown in Scheme 60, but the way to an epimer of violacene was blocked when Williard and de Laszlo were unable to replace the hydroxyl group of compound 736. ... 

Macrolide-producing organisms are classified as shown in Table 11. Actino-mycetes produce the largest number of macrolides (more than 800). Myxobacte-ria produce about 100 macrolides, and the other bacteria produce about only 40 macrolides. A rather large number of macrolides have been isolated from fungi (about 200). Lichens produce only three compounds. About 70 macrolides have been isolated from algae. Though plants produce about 700 macrocyclic lactone compounds, most of them are tannins or alkaloids such as pyrrolizidines. So they... 

Pelvetin, pGlu-Gln-Ala-OH, a naturally occurring pyroglutamyl peptide isolated from algae. 

In the synthesis of hapalindole Q, an indolylterpene isolated from algae, coupling was achieved under Heck conditions with a tin enolate (Equation (117)) <93JA3499>. 

This protocol is particularly useful in the synthesis of the class of polychlorinated marine natural product known as chlorosulfolipids, which are believed to be responsible for seafood poisoning. ° With this protocol, Vanderwal et al. succeeded in the enantioselective total synthesis of maUiamensilipin A 11, a protein tyrosine kinase inhibitor isolated from alga Poterioochromonas malhamen-sis The enantioselective synthesis of (+)-danicalipin A 14, another chlorosulfolipid isolated from the alga Ochro-monas danica by Umezawa et al. also used this strategy as a key step (Scheme 42.5). 

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