(9Z)-capsanthin-5,6-epoxide, a new carotenoid from the fruits of Asparagus falcatus.

From the fruits of Asparagus falcatus a novel minor (Z)-carotenoid has been isolated and, on the basis of spectral data interpretation, characterized as (9Z)-capsanthin-5,6-epoxide [(9Z,3S,5R,6S,3'S,5'R)-5,6-epoxy-3,3'-dihydroxy-5,6-dihydro-beta,kappa-caroten-6'-one, (1)]. In addition, seven other (Z)-carotenoids [namely, (9Z)-, (9'Z)-, (13Z)-, and (13'Z)-capsanthins, (9Z)- and (13Z)-capsorubins, and (9Z)-violaxanthin], which have been previously described from other plants, were isolated and identified.

Hyperlactatemia and hepatic abnormalities in 10 human immunodeficiency virus-infected patients receiving nucleoside analogue combination regimens.

During a 6-and-a-half month period, we identified 10 human immunodeficiency virus (HIV)-infected men who were receiving antiretroviral regimens, including nucleoside analogues, and who developed unexplained reproducible hyperlactatemia in association with either abdominal symptoms or an unaccounted-for elevated alanine aminotransferase level, or both. After careful consideration of the possible etiologies, antiretrovirals were discontinued; lactate levels normalized in all patients. The estimated incidence of this phenomenon in our clinic was 20.9 cases per 1000 person-years of nucleoside analogue treatment. These observations extend the spectrum of the nucleoside analogue-induced lactic acidosis/hepatic steatosis syndrome by the identification of a subtle and perhaps earlier form, which has characteristic symptoms and laboratory abnormalities, and a favorable prognosis on discontinuation of antiretroviral therapy.

Total synthesis of coraxeniolide-A.

The first total synthesis of optically active coraxeniolide-A (1a) and 4-epi-coraxeniolide-A (1b) is described. The approach is highly stereoselective and flexible in the preparation of a wide variety of members of the xeniolide family. The use of the Grob-fragmentation was pivotal for the stereospecific elaboration of the nine-membered ring. Coraxeniolide-A (1a) was synthesized in 28 steps by using the Hajos-Parrish diketone 2 as starting material which is available enantiomerically pure.

Carotenoids from guava (Psidium guajava l.): isolation and structure elucidation.

Sixteen carotenoids were isolated from the flesh of Brazilian red guavas (Psidium guajava L.). Their structures were established by means of UV-visible, 400 and 500 MHz (1)H NMR, 120 and 125 MHz (13)C NMR, mass, and circular dichroism spectra. The carotenoids were identified as phytofluene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-beta-carotene, (all-E)-gamma-carotene, (all-E)-, (9Z)-, (13Z)-, and (15Z)-lycopene, (all-E,3R)-beta-cryptoxanthin, (all-E, 3R)-rubixanthin, (all-E,3S,5R,8S)-cryptoflavin, (all-E,3R,3'R, 6'R)-lutein, (all-E,3S,5R,6R,3'S,5'R,8'R)-, and (all-E,3S,5R,6R,3'S, 5'R,8'S)-neochrome. Thirteen of the carotenoids identified are reported as guava carotenoids for the first time.

Isolation and structural elucidation of (13Z,13'Z,3R,3'R,6'R)-lutein from marigold flowers, kale, and human plasma.

(13Z,13'Z,3R,3'R,6'R)-Lutein has been isolated and purified from extracts of marigold flowers, fresh raw kale (Brassica oleracea var. Acephala), and human plasma and fully characterized by (1)H and (13)C NMR, UV/vis, and MS. While the concentration of (13Z, 13'Z)-lutein in kale and human plasma compared to (all-E,3R,3'R, 6'R)-lutein was found to be quite low, this compound was readily isolated by fractional crystallization of lutein from marigold extracts. Thus, the mother liquors from two consecutive crystallizations of lutein from a saponified extract of marigold flowers were enriched in (13Z,13'Z)-lutein (8.7% of total carotenoids) and employed for the isolation of this compound by HPLC. The identity of the di-Z-lutein in kale and human plasma has been established by comparison of the HPLC-UV/vis-MS profiles of the purified compounds with those of a fully characterized sample, isolated from marigolds. 3-Hydroxy-beta,epsilon-caroten-3'-one and 3'-epilutein have also been identified in extracts from marigolds.

Lycopene in association with alpha-tocopherol inhibits at physiological concentrations proliferation of prostate carcinoma cells.

The effect of lycopene alone or in association with other antioxidants was studied on the growth of two different human prostate carcinoma cell lines (the androgen insensitive DU-145 and PC-3). It was found that lycopene alone was not a potent inhibitor of prostate carcinoma cell proliferation. However, the simultaneous addition of lycopene together with alpha-tocopherol, at physiological concentrations (less than 1 microM and 50 microM, respectively), resulted in a strong inhibitory effect of prostate carcinoma cell proliferation, which reached values close to 90 %. The effect of lycopene with alpha-tocopherol was synergistic and was not shared by beta-tocopherol, ascorbic acid and probucol.

Bioassay-guided isolation of a diastereoisomer of kolavenol from Entada abyssinica active on Trypanosoma brucei rhodesiense.

Bioassay-guided fractionation of the dichloromethane rootbark extract of Entada abyssinica (Leguminosae), a plant used by traditional healers in Uganda for the treatment of sleeping sickness, led to the isolation of a diastereoisomer of the clerodane type diterpene kolavenol. This is the first report on this compound. It showed a trypanocidal activity with an IC50 value of 2.5 microg/ml (8.6 microM) against Trypanosoma brucei rhodesiense, the causing agent of the acute form of human African trypanosomiasis.

Identification, quantification, and relative concentrations of carotenoids and their metabolites in human milk and serum.

Thirty-four carotenoids, including 13 geometrical isomers and eight metabolites, in breast milk and serum of three lactating mothers have been separated, identified, quantified, and compared by high-performance liquid chromatography (HPLC)-photodiode array (PDA) detection-mass spectrometry (MS). Among the metabolites were two oxidation products of lycopene and four of lutein/ zeaxanthin. In addition, two metabolites of lutein, formed as a result of dehydration of this dihydroxycarotenoid under acidic conditions similar to those of the stomach, have also been identified in plasma and breast milk. The oxidative metabolites of lycopene with a novel five-membered-ring end group have been identified as epimeric 2,6-cyclolycopene-1,5-diols by comparison of their HPLC-UV/visible-MS profiles with those of fully characterized (1H- and 13C-NMR spectroscopy) synthetic compounds. The HPLC procedures employed also detected vitamin A, two forms of vitamin E (gamma- and alpha-tocopherol), and two non-carotenoid food components, i.e., piperine and caffeine, in serum and breast milk.