Browsing by Author "LOPEZ, J"
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- ItemA NOVEL PARTIAL SYNTHESIS OF (-)-WARBURGANAL(1985) RAZMILIC, I; SIERRA, J; LOPEZ, J; CORTES, M
- ItemA SYNTHETIC APPROACH TO RING-B OF FORSKOLIN(MARCEL DEKKER INC, 1993) RAZMILIC, I; LOPEZ, J; CORTES, MA model bicyclic diol (3) incorporating the complete array of oxygenated function of the B ring portion of forskolin (1) has been synthetized using (-)drimenol (2) as starting material.
- ItemAN ALTERNATIVE PARTIAL SYNTHESIS OF (-)-POLYGODIAL(1987) RAZMILIC, I; LOPEZ, J; SIERRA, J; CORTES, M
- ItemMICROBIOLOGICAL HYDROXYLATION IN THE DRIMANE SERIES(PERGAMON-ELSEVIER SCIENCE LTD, 1992) ARANDA, G; FACON, I; LALLEMAND, JY; LECLAIRE, M; AZERAD, R; CORTES, M; LOPEZ, J; RAMIREZ, HThe Products of the microbiological hydroxylation of drimenol and related compounds by Mucor plumbeus and Rhizopus arrhizus were investigated. Complementary results (hydroxylation at 3beta- and/or 6alpha-positions) were obtained with both microorganisms.
- ItemPOST-OVULATORY AGING OF HUMAN OVA .1. LIGHT MICROSCOPIC OBSERVATIONS(1982) ORTIZ, ME; SALVATIERRA, AM; LOPEZ, J; FERNANDEZ, E; CROXATTO, HBThe morphologic changes undergone by the human secondary oocyte following ovulation were assessed by light microscopy in 57 specimens recovered from the Fallopian tube and endometrial cavity between 24 and 144 h after the luteinizing hormone [LH] peak in plasma. Ova recovered shortly after ovulation were surrounded by a large cumulus mass comprising .apprx. 20,000 follicular cells. Whenever it was possible to perform a detailed observation of the perivitelline space in these ova, the presence of a polar body was recognized. The oocyte usually occupied an excentric position within the cumulus. Ovum denudation appeared to proceed by breakdown of the cumulus into fragments and release of the oocyte with a small number of cells attached to the zona. As a consequence of this process, the oocyte, surrounded by a few layers of the cells, frequently coexisted with large fragments of the cumulus. Progress of ovum denudation was time dependent and proceeded at a relatively slow pace. Some uterine ova still had cells attached to the zona. At 96 h after the LH peak 40% of the ova underwent fragmentation of the cytoplasm giving rise to anucleated pieces of varying sizes. The dimensions of the zona pellucida and ooplasm presented wide individual variations as well as some time related changes. The mean external diameter of the zona .+-. SD of 43 ova was 161.6 .+-. 14.6 .mu.m. The occurrence of denudation and cytoplasmic fragmentation were more clearly related to the postovulatory age of the ovum than to the site of recovery. The rate of denudation of human oocytes seems to proceed at a much lower speed in comparison with small mammals currently used as laboratory animals.
- ItemSYNTHESIS OF (-)-ENT-YAHAZUNOL DIMETHYL ETHER(SOCIEDAD CHILENA DE QUIMICA, 1990) CORTES, M; PENA, W; ARMSTRONG, V; LOPEZ, JThe synthesis of (-)-ent-yahazunol dimethyl ether (7) from the unsaturated ketone 2 is described. The present work confirms the proposed absolute configuration of the naturally occuring (-)-yahazunol (1).
- ItemSYNTHESIS OF 1.3 DIOXANES RELATED WITH AMBERGRIS(1984) MATURANA, H; SIERRA, J; LOPEZ, J; CORTES, M
- ItemSYNTHESIS OF AMBRAOXIDE FROM DRIMENOL(1991) MATURANA, H; LOPEZ, J; CORTES, MThe conversion of (-) drimenol (1) into the cyclic ether Ambraoxide (2) is reported.
- ItemSYNTHESIS OF GAMMA-BICYCLOHOMOFARNESAL AND 14,15,16,20-TETRANORLABDAN-8-BETA-13-DIOL(1992) LOPEZ, J; TRESPALACIOS, C; PENA, W; CORTES, MThe preparation of the ambergris odorant, gamma-bicyclohomofarnesal (1) and 14,15,16,20-tetranorlabdan-8-beta-13-diol (4) from chiral enone 5 is described.
- ItemSYNTHESIS OF NATURAL UVIDIN-C(1986) LOPEZ, J; SIERRA, J; CORTES, M