Lactucaxanthin,an ε,ε-carotene-3,3′-diol from Lactuca sativa

Chemical and spectroscopic evidence including ¹H NMR and CD is presented, demonstrating the (3R,6R,3′R,6′R)-ε,ε-carotene-3,3′-diol structure of a new carotenoid, lactucaxanthin. Lactucaxanthin, isolated from Lactuca sativa, is the sixth chiral isomer encountered in nature ofthe ten possible chiral isomers of ε,ε-carotene-3,3?diol. In achemosystematic screening,lactucaxanthin was restricted to Lactuca and a few closely related genera within the tribe Cichorieae of the Compositae.     

Volume contraction on photoexcitation of the reaction center from Rhodobacter sphaeroides R-26: internal probe of dielectrics.

Reaction centers of Rhodobacter sphaeroides undergo a approximately 20 A3/mole volume contraction in < 50 ns after excitation. The rapid volume change is tentatively assigned to electrostriction. From its magnitude, we infer that the effective dielectric coefficient is 10-15 if the compressibility of the reaction center is similar to that of globular proteins. The volume contraction is not sensitive to replacement of the natural ubiquinone at the QA site by other quinones or to the occupancy of the QB site. The quenching caused by pressure on the reaction centers most likely occurs on a faster time scale than that of electron transfer.     

Minor Carotenoid Sulfates from lanthella basta

The structural elucidation of the minor carotenoid sulfates from the marine sponge lanthella basta is discussed in context with the structure assigned to the major sulfate bastaxanthin (c; 3,19,17′-trihydroxy-7,8-didehydro-β-κ-carotene-3′,6′-dione 3-sulfate. Plausible structures are assigned to other bastaxanthins (b,b₂, c₂, d, e and f) on the basis of electroic, IR, ¹H NMR, mass and CD spectra, electrophoretic behaviour, chemical derivatization and enzymatic or acid-catalysed hydrolysis. The minor sulfates represent structural variation in the cylopentane end group with different oxidation levels. Bastaxanthol b (desulfated bastaxanthin b) was a minor carotenoid constituent of l. basta. Including tentative chiralities, the structures favoured for the bastaxanthins are: c₂, (3R,3′R, 5′R)-3,19,3′-trihydroxy-7,8-didehydro-β,κ-caroten-6′-one 3-sulfate; b₂, (3R,3′R,5′R)-3, 19-dihydroxy-7,8-didehydro-β,κ- dione 3-sulfate; b, (3R,1′R, 5′R)-3, 19-dihydroxy 3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-al 3-sulfate; d. (3R,1′R,3′R,5′R)-3, 19,3′,17′-tetrahydroxy 7,8 didehydro-β,κ-caroten-6′-one 3-sulfate; e. hydrogen (3R,1′R,5′R)-3, 19-dihydroxy-3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-oate 3 sulfate (?); and f, hydrogen (3R.1′R,3′R,5′R)-3,19,3′-trihydroxy-7,8-didehydro-6′-oxo-β,κ-caroten-17′-oate 3-sulfate; for bastaxanthol b(3R.1′R.5′R)-3, 19-dihydroxy-3′,6′-dioxo-7,8-didehydro-β,κ-caroten-17′-al. The bastaxanthins are considered as metabolic products of l. basta, diadinoxanthin of phytoplankton origin representing a plausiable precursor.     

Studies on the Occurrence of Peptococcus Indolicus and Corynebacterium Pyogenes in Apparently Healthy Cattle

A total of 1050 samples from apparently healthy cattle were examined bacteriologically with special regard to Pc. indolicus and Cb. pyogenes. Pc. indolicus was found in 58 % of 130 samples from tonsils (slaughterhouse material), in 23 % of 620 samples from the vagina of cows, in 22 % of 100 samples from the vagina of calves and heifers, in 5 % of 100 samples from the conjunctival sac of cows, and in 10 % of 100 samples from the nasal cavity of cows (Table 1). Cb. pyogenes was found in 51 %, 17 %, 19 %, 8 %, and 6 %, respectively. Both organisms were found in each of 9 herds examined, though with varying frequency (Tables 2, 3, and 4). Altogether Pc, indolicus was found in 254 (24 %) and Cb. pyogenes in 205 (20 %) of the samples examined (Table 1). In 127 samples both organisms were present. Eleven of the strains of Pc. indolicus were β-hemolytic, the rest non-hemolytic. By gel diffusion analysis the strains of Pc. indolicus as well as those of Gb. pyogenes could be identified with strains originating from pathological conditions in cattle. With Serotype B occurring most frequently, usually two or three different types of Pc. indolicus were found in each of the herds examined (Tables 5, 6, and 7). The investigation has shown that Pc. indolicus is widespread among healthy cattle, and given evidence to suggest that Pc. indolicus and Cb. pyogenes are natural cohabitants.     

Carotenoids of cryptophyceae

The carotenoids of selected Cryptophyceae, Rhodomonas D3 and Cryptomonas ovata, have been examined by methods including HPLC, mass spectrometry ¹H NMR and circular dichroism. $\text{3′R,6′R-}\text{Chirality}$ has been assigned to monadoxanthin from ¹H NMR and CD data; β,?-carotene possessed the common $\text{6′R-}\text{chirality}$. The quantitative distribution pattern of carotenoids in Cryptophyceae established here and previously, totalling five species' is discussed in chemosystematic context. β,?-Carotene (3–8% of total) is the major carotene, accompanied by ?,?-carotene (0.2%), β,β-carotene (0–1%) and lycopene (0-trace). Zeaxanthin (2%) was identified in C. ovate. The diacetylenic alloxanthin is the major carotenoid (70–88%), and the monoacetylenic crocoxanthin (5–15%) and monadoxanthin (0–16%) less abundant. No epoxidic or allenic carotenoids could be detected. The biosynthetic precursor of acetylenic carotenoids in this primitive algal class is discussed. The significance of Cryptophyceae in the marine food chain is commented on, using alloxanthin as an indicator.