The well-known class of compounds like 1, 3, 5-triazines
generated lots of interest,
mainly due to their widespread applications in different fields, including the
many herbicides and polymer photostabilizers. Among several others, 1, 3,
5-triazine-substituted polyamines have shown a good in vitro activity against protozoan parasites. Some derivatives of 1, 3, 5-triazines, also used as siderophore (microbial
iron shelter), hexamethylmelamine and 2-amino-4-morphlino-s-triazine are
clinically important due to their antitumor properties or to treat lungs, breast and ovarian
cancers, respectively. The drug tamoxifen is the most commonly used with chemotherapy of
breast tumor and was shown to activate JNK and p-38 MAP-kinases in connection
with programmed cell death, however, tamoxifen is effective in high concentrations and
its efficacy has often been debated. Therefore, triazine and its derivatives might be
good candidates as they are reported to have antitumor activities. The first paper, "Screening
of Triazine Derivatives, Inhibitors of MAP-Kinase p-38 Alpha, Through
Mathematical Modeling and Molecular Modeling", by Biswajit Das, Shyamal Sharma, Pranab
Ghosh, Subhasis Mukherjee and Asim Kumar Bothra, explains the viability of triazine
derivatives as potent inhibitors of MAP-kinase p-38. Different parameters and topological
indices, such as mean Information Content (IC), Structural Information Content
(SIC), Complementary Information Content (CIC) and some quantum chemical
parameters, namely, HOMO, LUMO, dipole moment and polarizability of the triazine
derivatives were calculated and a regression equation formulated and then the theoretical activity
of triazine derivatives was calculated in order to predict the inhibitor activity prior to
its synthesis.
Compounds containing azomethine (-CH=N-) group are known as Schiff bases.
Metal complexes of Schiff bases are extensively studied due to the strong ability of Schiff bases
to form a large number of chelates with most transition and non-transition metal ions.
More significantly, they are studied because they are useful in the biological field as
antibacterial, antitumor and antiviral agents; in the clinical field as sulpha drugs, anticancer drugs
and antibiotics; and they have several applications in the analytical field. Studies
on unsymmetrical tetradentate Schiff base ligands, however, are limited. The second
paper, "Antimicrobial Study of the Unsymmetrical Tetradentate Schiff Base and Its Cu(II),
Ni(II) and VO(II) Complexes", by C Anitha, S Prasad, M Senthil Vadivu and R Rajavel,
describes synthesis of novel unsymmetrical tetradentate Schiff base ligand and its Cu(II), Ni(II)
and VO(II) complexes, which were characterized by IR studies and elemental analysis.
Further, the unsymmetrical tetradentate Schiff base and its metal complexes were evaluated
for their antimicrobial activity against four negative bacterial species. The
antimicrobial activity of the Cu(II), Ni(II) and VO(IV) complexes was higher than that of the ligand.
Much progress has been made in synthesizing small functionalized antisense or
antigene DNA or RNA sequences that can block the expression of selected genes, thereby
assessing the function of gene. The modifications
in small fragments of DNA/RNA can render much desired properties which natural DNA and RNA do not have. Such new
properties can be extremely useful for the practical application of nucleic acids to
biotechnology, biochemistry, biology and medicine. Although the use of antisense DNA/RNA as a
new powerful research tool or rationally designed therapeutic agent has always remained
a frontier field of gene technology, an efficient intracellular transport and delivery of
modified DNA/RNA is the most critical and challenging problem to DNA/RNA potency. The
third paper, "C-5 Thiopropyne-Substituted Thymidine Containing
Oligonucleotides: Modulation of Oligonucleotide Duplex, DNA/DNA and DNA/RNA Stability via
Disulfide Bond", by Ajay Kumar describes modulation of oligonucleotide duplex DNA/DNA
and DNA/RNA stability via a disulphide bond. Tm studies of C-5 thiopropyne-substituted
thymidine oligonucleotides show that disulphide bond, even in the absence
of phosphodiester bond, between the two oligonucleotides modulates the stability of
both DNA/DNA and DNA/RNA duplexes and can have applications as
antisense oligonucleotides.
Thin Layer Chromatography (TLC) is the most frequently used technique in the
organic laboratories worldwide because it is a simple, quick and inexpensive technique.
With limited choice in the stationary phase, a mobile phase can be selected to suit the needs of
a given separation. In TLC, the most important influence on the retention of compounds
is their polarity relative to the stationary and mobile phases. The more polar compound
is retained more strongly by the stationary phase. Conversely, the less polar compound
is more likely to move with the mobile phase. Measurement of solvent polarity can be
carried out successfully either kinetically, thermodynamically, spectroscopically or by using
TLC technique. Moreover, the use of a number of polarity scales is in practice. Amongst
them, ET(30) is the most popular one. In the fourth paper, "Solvent Polarity as a Function
of Retardation Factor in Thin-Layer Chromatography of Selected Nitro Functions:
Two Mixed Solvents", by Anees Ahmad, Mohd. Rafatullah and Qasimullah, the effect
of solvent polarity on Rf values of nitro compounds in various solvents has been
investigated and it has been emphasized that the TLC is the best and simple choice to evaluate
the solvent polarity.
Calix[n]arenes (n = 4 to 14) are macrocylic-cyclooligomers formed from condensation
of phenol-formaldehyde. Interestingly, these compounds exist in a `cone' like
conformation, and by functionally modifying either the upper and/or lower rims it is possible to
prepare various derivatives with differing selectivities for binding of metal cations. Many
calixarene derivatives prepared are being used in both environmental and biomedical
monitoring. Further, incorporation of carboxyl group like ester, amide and ketone linkages into
phenolic oxygen atom of calixarenes makes them to function as ionophores. They also have
received much attention as recognition reagents in electroanalysis. The fifth paper, "Application
of Calixarene Ionophores in Pvc-Based Ion Selective Electrodes for Heavy Metal
Detection", by Sonika Tyagi, Himanshu Agarwal and Saiqa Ikram reports synthesis of two
functionalized calixarene molecules as neutral ionophore which are used in a PVC-based Ion
Selective Electrodes (ISEs) for detection of heavy metals like lead(II) and mercury(II) ions.
-- Sushama Viladkar
Consulting Editor
