10 research outputs found
Datos para el estudio de la fisiología de los leucocitos en las tuberculosis crónicas
El verso de las h. en blanco. Tesis de doctorado leída en la Universidad Central, el 12 de diciembre de 1903.Universidad Central (Madrid)TRUEProQuestpu
Datos para el estudio de la fisiología de los leucocitos en las tuberculosis crónicas
El verso de las h. en blanco. Tesis de doctorado leída en la Universidad Central, el 12 de diciembre de 1903.Universidad Central (Madrid)TRUEProQuestpu
Magnetite Mineralization inside Cross-Linked Protein Crystals
Crystallization in confined spaces is a widespread process in nature that also has important implications for the
stability and durability of many man-made materials. It has been reported that confinement can alter essential crystallization events,
such as nucleation and growth and, thus, have an impact on crystal size, polymorphism, morphology, and stability. Therefore, the
study of nucleation in confined spaces can help us understand similar events that occur in nature, such as biomineralization, design
new methods to control crystallization, and expand our knowledge in the field of crystallography. Although the fundamental interest
is clear, basic models at the laboratory scale are scarce mainly due to the difficulty in obtaining well-defined confined spaces allowing
a simultaneous study of the mineralization process outside and inside the cavities. Herein, we have studied magnetite precipitation in
the channels of cross-linked protein crystals (CLPCs) with different channel pore sizes, as a model of crystallization in confined
spaces. Our results show that nucleation of an Fe-rich phase occurs inside the protein channels in all cases, but, by a combination of
chemical and physical effects, the channel diameter of CLPCs exerted a precise control on the size and stability of those Fe-rich
nanoparticles. The small diameters of protein channels restrain the growth of metastable intermediates to around 2 nm and stabilize
them over time. At larger pore diameters, recrystallization of the Fe-rich precursors into more stable phases was observed. This study
highlights the impact that crystallization in confined spaces can have on the physicochemical properties of the resulting crystals and
shows that CLPCs can be interesting substrates to study this process.Ministry of Science and Innovation, Spain (MICINN) PID2020-116261GB-I00
PID2020-118498GB-I00
PDC2021-121135.100FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) A-FQM-340-UGR20
UCE-PP2016-0
Synthesis and Biological Activity of Triterpene-Coumarin Conjugates.
A set of 12 maslinic acid-coumarin conjugates was synthesized, with 9 being maslinic acid-diamine-coumarin conjugates at the C-28 carboxylic acid group of triterpene acid and the other three being maslinic acid-coumarin conjugates at C-2/C-3 and/or C-28 of the triterpene skeleton. The cytotoxic effects of these 12 triterpene conjugates were evaluated in three cancer cell lines (B16-F10, HT29, and Hep G2) and compared, respectively, with three nontumor cell lines from the same or similar tissue (HPF, IEC-18, and WRL68). The most potent cytotoxic results were achieved by a conjugate with two molecules of coumarin-3-carboxylic acid coupled through the C-2 and C-3 hydroxy groups of maslinic acid. This conjugate showed submicromolar IC50 values in two of the three cancer cell lines tested (0.6, 1.1, and 0.9 μM), being between 110- and 30-fold more effective than its corresponding precursor. Furthermore, this conjugate (10) showed percentages of cell viability for the three nontumor lines of 90%. Four maslinic acid-coumarin conjugates displayed apoptotic effects in the treated cells, with total apoptosis rates of between 40 and 85%, relative to the control. Almost all the compounds assayed caused cell-cycle arrest in all cancer cell lines, increasing the number of these cells in the G0/G1 phase
Magnetite Mineralization inside Cross-Linked Protein Crystals
Crystallization in confined spaces is a widespread process
in nature
that also has important implications for the stability and durability
of many man-made materials. It has been reported that confinement
can alter essential crystallization events, such as nucleation and
growth and, thus, have an impact on crystal size, polymorphism, morphology,
and stability. Therefore, the study of nucleation in confined spaces
can help us understand similar events that occur in nature, such as
biomineralization, design new methods to control crystallization,
and expand our knowledge in the field of crystallography. Although
the fundamental interest is clear, basic models at the laboratory
scale are scarce mainly due to the difficulty in obtaining well-defined
confined spaces allowing a simultaneous study of the mineralization
process outside and inside the cavities. Herein, we have studied magnetite
precipitation in the channels of cross-linked protein crystals (CLPCs)
with different channel pore sizes, as a model of crystallization in
confined spaces. Our results show that nucleation of an Fe-rich phase
occurs inside the protein channels in all cases, but, by a combination
of chemical and physical effects, the channel diameter of CLPCs exerted
a precise control on the size and stability of those Fe-rich nanoparticles.
The small diameters of protein channels restrain the growth of metastable
intermediates to around 2 nm and stabilize them over time. At larger
pore diameters, recrystallization of the Fe-rich precursors into more
stable phases was observed. This study highlights the impact that
crystallization in confined spaces can have on the physicochemical
properties of the resulting crystals and shows that CLPCs can be interesting
substrates to study this process