Mohamed El-Shazly

Copper catalysed oxidative coupling reaction of formamides
with β-keto esters and 2-carbonyl-substituted phenols successfully
proceeded through direct C–H bond activation of
formamides. The corresponding carbamates were formed
with high stereoselectivity under mild reaction conditions.This protocol was successfully applied to the synthesis of
three novel halogenated carbamates and a carbaryl insecticide
derivative. Our results suggest the use of 6.0 equiv.
TBHP is crucial… عرض المزيد

Copper catalysed oxidative coupling reaction of formamides
with β-keto esters and 2-carbonyl-substituted phenols successfully
proceeded through direct C–H bond activation of
formamides. The corresponding carbamates were formed
with high stereoselectivity under mild reaction conditions.This protocol was successfully applied to the synthesis of
three novel halogenated carbamates and a carbaryl insecticide
derivative. Our results suggest the use of 6.0 equiv.
TBHP is crucial for this type of reaction. عرض أقل

10-Acetylirciformonin B, a furanoterpenoid derived from irciformonin B
found in a marine sponge, has been reported to possess potent cytotoxic activity against
several cancer cell lines. However, the mechanism of its apoptotic activity against human
leukemia cells has never been reported. The purpose of this study was to investigate the
cytotoxic effects of 10-acetylirciformonin B and its possible mechanism of action against
leukemia HL 60 cells. We found that… عرض المزيد

10-Acetylirciformonin B, a furanoterpenoid derived from irciformonin B
found in a marine sponge, has been reported to possess potent cytotoxic activity against
several cancer cell lines. However, the mechanism of its apoptotic activity against human
leukemia cells has never been reported. The purpose of this study was to investigate the
cytotoxic effects of 10-acetylirciformonin B and its possible mechanism of action against
leukemia HL 60 cells. We found that 10-acetylirciformonin B decreased cell viability
through the inhibition of cell growth as well as the induction of DNA damage and
apoptosis in a dose-dependent manner. The induction of DNA damage was mediated by
the increase of p-CHK2 and γ-H2A.X, which was suggested from the increase of tail
movement in the neutral Comet assay. Induction of apoptosis was mediated with the
increase in caspases 8, 9 and 3 activation as well as PARP cleavage. In summary, our
resultsindicate that 10-acetylirciformonin B treatment causes apoptosis in leukaemia cells;
probably through a caspase-dependent regulatory pathway. عرض أقل

An efficient method for the synthesis of flavones and γ-
benzopyranones has been developed utilizing a mild Sonogashira
coupling and 18-crown-6 ether mediated 6-endo cyclization
of o-alkynoylphenyl acetates. By using this strategy, flavones and γ-benzopyranones bearing electron-donating
groups, halogens, and simple alkyl substituents were synthesized
in satisfactory yields.

Chalcones bearing electron donating or electron withdrawing substitutions were prepared and their glucose
uptake activity was evaluated. Chalcone derivatives were synthesized in one step protocol with high
purity and yield. Chalcones with chloro, bromo, iodo and hydroxy substitutions at position 2 on A-ring
exhibited the highest activity with glucose medium concentration (210 to 236 mg/dl) compared to pioglitazone
and rosiglitazone (230 and 263 mg/dl, respectively). Also chalcones… عرض المزيد

Chalcones bearing electron donating or electron withdrawing substitutions were prepared and their glucose
uptake activity was evaluated. Chalcone derivatives were synthesized in one step protocol with high
purity and yield. Chalcones with chloro, bromo, iodo and hydroxy substitutions at position 2 on A-ring
exhibited the highest activity with glucose medium concentration (210 to 236 mg/dl) compared to pioglitazone
and rosiglitazone (230 and 263 mg/dl, respectively). Also chalcones with iodo substitution at
position 3 on A-ring were comparably active (6 238 mg/dl). The structure–activity relationship of the
tested chalcones was studied and the findings were supported statistically عرض أقل

Antrodia camphorata (AC) is a native Taiwanese mushroom which is used in Asian folk medicine as a
chemopreventive agent. The triterpenoid-rich fraction (FEA) was obtained from the ethanolic extract of
AC and characterized by high performance liquid chromatography (HPLC). FEA caused DNA damage in
leukemia HL 60 cells which was characterized by phosphorylation of H2A.X and Chk2. It also exhibited
apoptotic effect which was correlated to the enhancement of PARP cleavage and to the… عرض المزيد

Antrodia camphorata (AC) is a native Taiwanese mushroom which is used in Asian folk medicine as a
chemopreventive agent. The triterpenoid-rich fraction (FEA) was obtained from the ethanolic extract of
AC and characterized by high performance liquid chromatography (HPLC). FEA caused DNA damage in
leukemia HL 60 cells which was characterized by phosphorylation of H2A.X and Chk2. It also exhibited
apoptotic effect which was correlated to the enhancement of PARP cleavage and to the activation of
caspase 3. Five major triterpenoids, antcin K (1), antcin C (2), zhankuic acid C (3), zhankuic acid A (4),
and dehydroeburicoic acid (5) were isolated from FEA. The cytotoxicity of FEA major components (1–5)
was investigated showing that dehydroeburicoic acid (DeEA) was the most potent cytotoxic component.
DeEA activated DNA damage and apoptosis biomarkers similar to FEA and also inhibited topoisomerase
II. In HL 60 cells xenograft animal model, DeEA treatment resulted in a marked decrease of tumor weight
and size without any significant decrease in mice body weights. Taken together, our results provided
the first evidence that pure AC component inhibited tumor growth in vivo model backing the traditional
anticancer use of AC in Asian countries. عرض أقل

A new series of 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile such as hydrazide
hydrazones 3a-h; ethane-1,2-diaminopyridine 6; phthalimidopyridines 8a,b; hydrazides 10a,b; urea 11a
and thiourea 11b were synthesized in a good to excellent yield in step efficient process, using 1-amino-
4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) as a key intermediate. The antibacterial and
antifungal activities of the synthesized compounds were evaluated. The obtained… عرض المزيد

A new series of 1- substituted amino-4,6-dimethyl-2-oxo-pyridine-3-carbonitrile such as hydrazide
hydrazones 3a-h; ethane-1,2-diaminopyridine 6; phthalimidopyridines 8a,b; hydrazides 10a,b; urea 11a
and thiourea 11b were synthesized in a good to excellent yield in step efficient process, using 1-amino-
4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (1) as a key intermediate. The antibacterial and
antifungal activities of the synthesized compounds were evaluated. The obtained data indicated that the
majority of the tested compounds exhibited both antibacterial and antifungal activities, particularly
compounds 8a and 8b showed a comparable effect to a well known antibacterial and antifungal agents. عرض أقل

Difficult-to-access chiral primary amines
were formed in good to high yield and ee using a
rare example of a one-pot synthesis from prochiral
ketones (sequential reductive amination-hydrogenloysis).
As a highlight we also demonstrate a one-pot
reductive amination-hydrogenolysis-reductive amination
(five reactions) of ortho-methoxyacetophenone
resulting in the chiral diamine 1-(2-methoxy-
ACHTUNGTRENUNGphenyl)ethyl-(2-pyridylmethyl)-amine (4) (58% overall
yield… عرض المزيد

Difficult-to-access chiral primary amines
were formed in good to high yield and ee using a
rare example of a one-pot synthesis from prochiral
ketones (sequential reductive amination-hydrogenloysis).
As a highlight we also demonstrate a one-pot
reductive amination-hydrogenolysis-reductive amination
(five reactions) of ortho-methoxyacetophenone
resulting in the chiral diamine 1-(2-methoxy-
ACHTUNGTRENUNGphenyl)ethyl-(2-pyridylmethyl)-amine (4) (58% overall
yield, >99% ee), a new organocatalyst for aqueous
enantioselective aldol reactions. عرض أقل

Recycling agricultural resources has become an important issue worldwide promoting the economical value of
agricultural production processes. Desugared sugar cane extract (DSE) from Saccharum officinarum is a byproduct obtained
during sugar production. Two new neolignan glucosides, saccharnan A (1) and saccharnan B (2), together with 10 known phenolics
(3?12) were isolated from DSE, and their structures were elucidated on the basis of NMR spectral analysis. Compounds 3, 4, 8,
and 9… عرض المزيد

Recycling agricultural resources has become an important issue worldwide promoting the economical value of
agricultural production processes. Desugared sugar cane extract (DSE) from Saccharum officinarum is a byproduct obtained
during sugar production. Two new neolignan glucosides, saccharnan A (1) and saccharnan B (2), together with 10 known phenolics
(3?12) were isolated from DSE, and their structures were elucidated on the basis of NMR spectral analysis. Compounds 3, 4, 8,
and 9 showed good activity against DPPH radical (IC50 e 51.20 μM) and compounds 3?8 and 12 exhibited strong ABTS+
free radical scavenging activity (IC50 e 51.57 μM) compared to those of the positive controls, ascorbic acid and Trolox.
Moreover, compounds 7 and 12 acted as potent tyrosinase inhibitors (IC50 e 42.59 μM) compared to the positive control arbutin.
Our results highlighted the economical value of recycling DSE for the future development of natural antioxidants and/or tyrosinase
inhibitors. عرض أقل

The review examines the chiral amine literature
from 2000–2009 (May) concerning enantioselective
and diastereoselective methods for N-acylen-
ACHTUNGTRENUNGamide and enamine reduction, reductive amination,
and imine reduction. The reaction steps for each
strategy, from ketone to primary chiral amine, are
clearly defined, with best methods and yields for
starting material preparation and final deprotection
noted. Categories of chiral amines have been defined
in Section… عرض المزيد

The review examines the chiral amine literature
from 2000–2009 (May) concerning enantioselective
and diastereoselective methods for N-acylen-
ACHTUNGTRENUNGamide and enamine reduction, reductive amination,
and imine reduction. The reaction steps for each
strategy, from ketone to primary chiral amine, are
clearly defined, with best methods and yields for
starting material preparation and final deprotection
noted. Categories of chiral amines have been defined
in Section 1 to allow the reader to quickly understand
whether their specific target amine falls within
a difficult to synthesize, or not, structural class.
Amino acids are not considered in this work. عرض أقل

Reductive amination of prochiral unhindered 2-alkanones 1 with (R)- or (S)-R-MBA in the presence of
Yb(OAc)3 (50-110 mol %), Raney-Ni, and hydrogen (120 psi) results in increased diastereoselectivity
for the amine products 2 (80-89% de) with good yield (80-87%). The increased de is based on
comparison with the best previously reported de’s when using (R)- or (S)-R-MBA, regardless of the
strategy employed [stepwise (isolation of ketimines) or one-pot (reductive amination)], reducing… عرض المزيد

Reductive amination of prochiral unhindered 2-alkanones 1 with (R)- or (S)-R-MBA in the presence of
Yb(OAc)3 (50-110 mol %), Raney-Ni, and hydrogen (120 psi) results in increased diastereoselectivity
for the amine products 2 (80-89% de) with good yield (80-87%). The increased de is based on
comparison with the best previously reported de’s when using (R)- or (S)-R-MBA, regardless of the
strategy employed [stepwise (isolation of ketimines) or one-pot (reductive amination)], reducing agent
examined, or achiral Lewis acid or Brønsted acid examined. An in situ cis- to trans-ketimine isomerization
mechanism, promoted by Yb(OAc)3, has been proposed to account for the observed increase in
diastereoselectivity and suggests a new entry into the control of ketimine geometry. عرض أقل