Polyacetylene compounds

Itoh, A., Sasaki, K., Mizukami, H., Ohashi, H., Sakurai, T. and Hiraoka, N. 1997. Geographical variation in the furanocoumarin and polyacetylenic compound compositions of wild Glehnia littoralis plants. Nat. Med. 51 50-55. 

Representative trace constituents HNC,c-C3H2) polyacetylenic compounds Cyanopolyynes, polycarbon sulfides, metal cyanides, silicon compounds Methylated organics Alcohols, ethers, esters, carboxylic acids, amino acids ( )... 

Baeyer, A. Uber Polyacetylenverbindungen. [Concerning polyacetylene compounds.] Ber. Deutsch. Chem. Gesell. 18,2269-2281 (1885). English translation In Leicester, H. M., and Klickstein, H. S. A Source Book in Chemistry I4OO-1900. p. 465. McGraw-Hill New York, Toronto, London (1952). 

Fig. (33). Effects of polyacetylene compounds isolated from Saposhnikoviae Radix on arachidonate metabolism in human platelets.

Human platelet (5 x 10 cells//Zl)(l 30/zl) were preincubated with the indicated amount of polyacetylene compounds for 5 min at 37 C. Then, [1- C] aiachidonic acid (50/zl, 0.05/zCi/tube) was added to give a final volume of 200ZZl, and die mixture was incubated for 5 min. 

The petroleum ether extract of Panax ginseng has antiproliferative effects on various cancer cell lines (murine sarcoma, murine leukaemia, human colon carcinoma, etc ). Polyacetylenic compounds from this extract such as panaxynol, panaxydol (46) and panaxytriol have been reported to be responsible for these effects [112, 113]. In order to identify the molecular mechanism of the polyacetylene compounds, one of the major cytotoxic compounds, panaxydol, was examined to see if it is able to disrupt cell cycle-related events. It was observed that panaxydol induces cell cycle arrest at Gi-S transition in SK-MEL-1 cells. This effect is related to the decreased Cdk2 activity, which seems to be caused by the increased level of p27 protein expression. The protein synthesis inhibitor cycloheximide reversed the growth suppression induced by panaxydol (80 j,g/ml) by... 

When acetylenic halogen compounds are treated with base, dehydrohalogenation occurs followed by rearrangement to yield the more stable conjugated acetylenic compounds exclusively [ 123,124]. This reaction is used for the preparation of polyacetylenic compounds. 

Bohimann, F., Schoenowsky, H., Inhoffen, E., Grau, G. Polyacetylenic compounds. Lll. The mechanism of oxidative dimerization of... 

Schulte, K.E., Rucker, G. and Perlick, J. 1967. The presence of polyacetylene compounds in Echinacea purpurea Munch and Echinacea angustifolia DC. Arzneimittelforschung. 17(7) 825—9. 

Yanovskaya, L.A., Stepanova, R.N., and Kucherov, V.F., Chemistry of polyene and polyacetylenic compounds. Part 23. Synthesis of some unsymmetrically a.CO-disubstituted polyenes, kv. Akad. Nauk SSSR, Ser. Khim., 1334, 1967 Bull. Acad. Sci. USSR. Div. Chem. Sci. (Engl. Transl.). 1282, 1967. 

Selective hydrogenation of isolated triple bonds in polyacetylenic compounds is possible with preference for a terminal triple bond to an internal one. Partial reduction of long-chain polyacetylenes affords all-c long-chain unsaturated acids, e.g., arachi-donic acid, is prepared by hydrogenation of 5,8,11,14-eicosatetraynoic acid over a deactivated Pd-on-CaCOj catalyst" ... 

The roots of Saposhnikovia divaricata ("Bou-hu" in Japan and "Fang-Feng" in China) have been traditionally used as an antiphlogistic, an antipyretic and an analgesic in China and Japan. We isolated three polyacetylene compounds, i.e., falcarindiol, panaxynol and (8E)-heptadeca-l,8-dien-4,6-diyn-3,10-diol "Fig. (32)", from Saposhnikoviae Radix. As shown in "Fig. (33)", these polyacetylene compounds inhibited the formation of cyclooxygenase products HHT and TXB2dose-dependently in human platelets. 

Polyynes (polyacetylenes). Compounds with very diverse structures containing several C/C triple bonds are produced mainly by fungi (basidiomycete cultures) and plants of the families Asteraceae, Apiaceae, and Araliaceae. In addition to conjugated triple bonds the R often also contain C/C double bonds, allene units, thiophene and furan rings. On account of the close biosynthetic relationships between these compounds, the term R is used as a collective name even when only one C/C triple bond is present in the molecule. As result of the work of Bohimann, E. R. H. Jones, Sorensen, and others more than one thousand natural R are now known. The antibiotically active mycotnycin (C H, g02, Mr 198.22, mp. 75 °C) from basidiomycete cultures, dehydromatricaria ester (CiiHgO, Mr 172.18, mp. 105-106°C) from Asteraceae, and the thiarubrins may be mentioned as typical examples (see also ter-thienyls). 

Several poly acetylenes and phenolic compounds have been reported from Gymnopilus spectabilis (22) while the white rot fungus Lyophillum ulmarium produces unusual amino acids (53, 54) and polyacetylenic compounds (55-58) 38, 39) (Chart 11). 

New Polyacetylenic Compounds from Terrestrial Plants.- The majority of new compounds have been isolated from members of the large Compositae family, and many are reported as a result of Bohlmann s continuing study of this family. Most are closely related to known structural types and their structures therefore follow easily from spectral data. The growing use of high resolution n.m.r. for this purpose is apparent. Unless otherwise indicated the species mentioned belong to the Compositae. 

Known Polyacetylenic Compounds from Terrestrial Plants.- A large number of new sources of known polyacetylenic compounds have been reported, mainly by Bohlmann and co-workers, often as an offshoot of their studies on the Compositae terpenes. These new sources are recorded in Table 1, along with the major compound types isolated from them. Known compounds which were isolated along with the compounds described in the previous section are not included in the table. 

---