Similarly to 14, the imaginary frequency of transition state 22 corresponds to the elongation of the C-H bond of the
acetylenic proton.
Caulerpenyne, a unique
acetylenic sesquiterpenoid that is closely related to flexilin, was first isolated from a Mediterranean collection of C.
Once the optimum molecule was achieved, its performance in pigment concentrates with and without a resin was compared to other conventional dispersants such as a styrent acrylate copolymr, an
acetylenic diol surfactant, and a styrene maleic anhydride comb polymer modified with a polyether.
Typical inhibitors are materials that have higher affinity for platinum than the siloxane polymer vinyl group and include such materials as peroxides, hydroperoxides, and
acetylenic derivatives.
The flower oil contains as minor constituents two
acetylenic thiophenes: 5'-methyl-5-(3-buten-1-ynyl)-2,2'-bithienyl (2) (Fig.
To the extent that both components originate from the same source,
acetylenic free radicals that generate polyaromatic structures in the flaming stage of combustion, one would expect similar [.sup.14]C composition.
These include genes for the production of hydroxy fatty acids, found in castor oil and used in lubricants and inks; conjugated fatty acids from tung seeds; and
acetylenic fatty acids found in another dandelion relative, Crepis alpina.
Tazarotene (Tazorac) is the first of a family of receptor-selective
acetylenic retinoids.
While examining the hydroformylation of
acetylenic substituted thiazoles, Van den Hoven and Alper discovered the new reaction, which has several remarkable features.
The rhizomes of Cang Xu (atractylodes lancea) and a related plant, Bai Xu (atractylodes macrocephalia) have been used for at least 2000 years in China for the removal of dark spots on the face and hands and skin whitening liniments.[12] Atractylodin, an
acetylenic furan derivative present in high amounts in these extracts, may be a tyrosinase inhibitor.
Newest chemical catalog for 2000-2001 integrates classic product lines with new acquisitions such as Sodium Biphenyl, QUAT products, and greatly expanded organic product line including
acetylenic derivatives and cholesteryl products.
Called linear
acetylenic carbon, the new allotrope, or form, of the otherwise sooty element shows up as amber-colored, "gossamerlike" threads, whose texture resembles "angel hair," according to Richard J.