FARMACIA, 2008, Vol.LVI, 5
501
PHYSICO - CHEMICAL AND
ANTIMICROBIAL PROPERTIES OF NOVEL
RUTIN DERIVATIVES WITH 6AMINOPENICILLANIC ACID
DAN LUPAŞCU1*, CRISTINA TUCHILUŞ2, LENUŢA PROFIRE1
University of Medicine and Pharmacy “Gr. T. Popa” Iaşi
1
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, 16,
Universităţii Street, 700115
2
Department of Microbiology
*
corresponding author: danlup69@yahoo.com
Abstract
Many studies highlight the antibacterial properties of some vegetal species with high
amounts of flavonoids (especially rutin); furthermore, rutin is able to increase the antibacterial
activity of other compounds. On the other hand, classical penicillins have some disadvantages,
like low water solubility. Therefore, in the present study, we aimed to obtain some novel
derivatives of rutin with 6-aminopenicillanic acid and characterize them phisico-chemically and
microbiologically; these derivatives are water soluble and showed a good antimicrobial activity,
both on gram-positive and gram-negative bacteria, similar to ampicillin, amoxicillin/ clavulanic
acid or chloramphenicol.
Rezumat
Numeroase studii evidenţiază proprietăţile antimicrobiene ale unor specii
vegetale cu conţinut ridicat de flavonoide (şi în special rutozid); ba mai mult, există dovezi
că rutozidul ar potenţa acţiunea antimicrobiană a unor compuşi cunoscuţi a avea astfel de
proprietăţi. Pe de altă parte, penicilinele prezintă o serie de dezavantaje, dintre care amintim
slaba solubilitate în apă. Prin urmare, în prezentul studiu ne-am propus obţinerea unor
derivaţi ai rutozidului cu acidul 6-aminopenicilanic şi caracterizarea fizico-chimică şi
microbiologică a acestora; respectivii derivaţi s-au dovedit a fi hidrosolubili şi posedă o
bună activitate antimicrobiană, atât pe germeni gram-pozitiv, cât ţi gram-negativ,
comparabilă cu ampicilina, amoxicilina / acidul clavulanic sau cloramfenicolul.



Rutin
Flavonoids
Penicillin
INTRODUCTION
The multitude of the studies performed showed that flavonoids
have many biological properties through various mechanisms of action and
in many cases, are capable to protect against chronic and degenerative
diseases 1, 2. Some studies highlight the antibacterial properties of some
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FARMACIA, 2008, Vol.LVI, 5
vegetal species with high amounts of flavonoids (especially rutin);
furthermore, rutin is able to increase the antibacterial activity of other
compounds 3-5. On the other hand, classical penicillins, in their acid form,
have low water solubility; of course their potassium and sodium salts are
water soluble, but these cations are responsible for some undesired effects at
cardiovascular and renal level.
The aim of this study was the synthesis of some novel rutin
derivatives, containing in the 7th position the 6-aminopenicillanic acid
moiety, bound through a hydrocarbonated chain, and also their physicochemical and microbiological characterization.
MATERIALS AND METHODS
Reagents and materials
Rutin (97-102%) was purchased from Acros Organics, New Jersey,
USA. Dibrommethane, 1, 2-dibrom-ethane, 1-brom-3-chloro-propane and 1,
3-dichloro-2-propanol was purchased from Merck-Schuchardt, Hohenbrunn,
Germany and 6-aminopenicillanic acid was purchased from Sigma-Aldrich,
Germany. All the other reagents and solvents corresponded to the quality
requirements. Bacterial strains used were from Microbiology Department
collection.
Methods
Four originally rutin - 6-amino-penicillanic acid derivatives (A-D)
were synthesized through reaction of rutin (I) with dibrommethane (II); 1,
2-dibrom-ethane (III); 1-brom-3-chloro-propane (IV) and 1, 3-dichloro-2propanol (V), in sodium methoxide and finally, stirring for 6 hours with 6amino-penicillanic acid (X) (figure 1). The crude compounds were purified
on the column chromatography (0.5 cm x 15 cm; Silicagel H (10-40 m),
elution with 50c alcohol: 0.25-0.30 mL/min.).
The molecular formula, weight, yield, melting point and solubility
were established for the new derivatives, A-D. Elemental analysis (performed
with an Exeter Analytical CE 440 elemental analyzer) and IR (performed with
an IR spectrophotometer Specord 71 IR (Carl Zeiss-Jena)) and UV spectral
analysis (performed with an UV-VIS spectrophotometer “Hewlett-Packard”
8453E) have confirmed the structure of the novel compounds.
We evaluated the antimicrobial potential of the synthesized
compounds using the difusimetric test. The samples per se and diluted at
half with Tween 80 (20 L) were put on the plates inoculated with test
microorganisms: Staphylococcus aureus ATCC 25923, Sarcina lutea ATCC
9341, Bacillus cereus, Bacillus subtilis, Escherichia coli ATCC 25922,
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FARMACIA, 2008, Vol.LVI, 5
Candida albicans. The inhibition areas were measured after 24 hours of
incubation at 37C.
OH
OH
HO
HO
O
O
OH
glu
ram O
+
O
glu
ram O
O
II-V
S
H2N
N
X'
R2
OH
I
R1 CH R3
X'
R2
O
O
CH3ONa
+ X R1 CH R3
OH
VI-IX
OH
CH3
CH3
HO
COOH
O
X
O
R1 CH R3
R2
glu
S
NH
O
N
CH3
CH3
COOH
ram O
O
OH
A-D
Compound No
II; VI
III; VII
IV; VIII
V; IX
X
Br
Br
Br
Cl
X’
Br
Br
Cl
Cl
R1
CH2
CH2
CH2
R2
H
H
H
OH
R3
CH2
CH2
Figure 1
Synthesis of rutin - 6-amino-penicillanic acid derivatives (A-D)
RESULTS AND DISCUSSION
We obtained four novel derivatives of rutin with 6aminopenicillanic acid (with 82-90% yields); these compounds are
crystalline, hygroscopic, yellow powders, with distinctive odour and
slightly bitter taste, soluble in water and alcohol and insoluble in acetone,
ether, chloroform.
(2S, 5R, 6R)-3,3-dimethyl-7-oxo-6-amino-7’-(oxy-methyl)- 3’6’-O-(6’-deoxy--L-manopyranosyl)- - D - glucopyranosyl - oxy - 2’
- (3’,4’-dihydroxyphenyl)-5’-hydroxy-4H-1’-benzopyran-4’-on-4-tia-1azabicyclo 3. 2. 0 heptane-2-carboxylic acid (A)
Molecular formula: C36H42N2O19S; Mol wt.: 892.85; Melting point:
150-160C (dec);
Elemental analysis: Calculated: C: 48.42; H: 4.70; N: 3.13;
Experimental: C: 49.00; H: 4.78; N: 2.98; UV (nm): 258.362; IR (cm-1):
3300 (linked OH), 2920 (CH), 1660 (C=O on aromatic ring), 1600
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FARMACIA, 2008, Vol.LVI, 5
(aromatic structure), 1500 (aromatic C=C), 1365, 1300, 1210, 1060 (C-OC), 810 (aromatic substitutes), 1765 (beta-lactamic -C=O);
(2S, 5R, 6R)-3,3-dimethyl-7-oxo-6-amino-7’-(oxy-ethyl)- 3’6’-O-(6’-deoxy--L-manopyranosyl)- - D - glucopyranosyl - oxy - 2’
- (3’,4’-dihydroxyphenyl)-5’-hydroxy-4H-1’-benzopyran-4’-on-4-tia-1azabicyclo 3. 2. 0 heptane-2-carboxylic acid (B)
Molecular formula: C37H44N2O19S; Mol wt.: 906.86; Melting point:
159-166C (dec);
Elemental analysis: Calculated: C: 49.00; H: 4.85; N: 3.08;
Experimental: C: 49.22; H: 4.98; N: 3.00; UV (nm): 256, 363; IR (cm-1):
3330 (linked OH), 2910 (CH), 1660 (C=O on aromatic ring), 1600
(aromatic structure), 1520 (aromatic C=C), 1350, 1290, 1200, 1070 (C-OC), 820 (aromatic substitutes), 1765 (beta-lactamic -C=O);
(2S, 5R, 6R)-3,3-dimethyl-7-oxo-6-amino-7’-(oxy-propyl)- 3’6’-O-(6’-deoxy--L-manopyranosyl)- - D - glucopyranosyl - oxy - 2’
- (3’,4’-dihydroxyphenyl)-5’-hydroxy-4H-1’-benzopyran-4’-on-4-tia-1azabicyclo 3. 2. 0 heptane-2-carboxylic acid (C)
Molecular formula: C38H46N2O19S; Mol wt.: 920.87; Melting point:
170-177C (dec);
Elemental analysis: Calculated: C: 49.55; H: 4.99; N: 3.04;
Experimental: C: 49.29; H: 5.11; N: 3.11; UV (nm): 261, 367; IR (cm-1):
3340 (linked OH), 2920 (CH), 1670 (C=O on aromatic ring), 1610
(aromatic structure), 1510 (aromatic C=C), 1370, 1295, 1250, 1060 (C-OC), 800 (aromatic substitutes), 1770 (beta-lactamic -C=O);
(2S, 5R, 6R)-3,3-dimethyl-7-oxo-6-amino-7’-(oxy-(-hydroxypropyl)- 3’-6’-O-(6’-deoxy--L-manopyranosyl)- - D - glucopyranosyl
- oxy - 2’ - (3’,4’-dihydroxyphenyl)-5’-hydroxy-4H-1’-benzopyran-4’on-4-tia-1-azabicyclo 3. 2. 0 heptane-2-carboxylic acid (D)
Molecular formula: C38H46N2O20S; Mol wt.: 936.87; Melting point:
190-205C (dec);
Elemental analysis: Calculated: C: 48.71; H: 4.90; N: 2.98;
Experimental: C: 48.52; H: 5.10; N: 3.03; UV (nm): 259, 362; IR (cm-1):
3330 (linked OH), 2930 (CH), 1660 (C=O on aromatic ring), 1590
(aromatic structure), 1500 (aromatic C=C), 1360, 1290, 1210, 1050 (C-OC), 810 (aromatic substitutes), 1770 (beta-lactamic -C=O);
In the difusimetric test we compared the antimicrobial activity of
the samples with standards (oxacillin (1 g), ampicillin (10 g), amoxicillin
/ clavulanic acid (20 / 10 g), ceftriaxone (30 g) and chloramphenicol (30
g) discs). The results are presented in figure 2 and table I:
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FARMACIA, 2008, Vol.LVI, 5
Figure 2
Antimicrobial activity of A-D compounds on Staphylococcus aureus ATCC 25923
and Escherichia coli ATCC 25922
Table I
Antimicrobial activity of A-D samples. Inhibition area diameter (mm)
Inhibition area diameter (mm)
Sample / standard
A
B
C
D
A1/2
B1/2
Oxacillin (1 g)
Ampicillin
(10 g)
Amoxicillin
/clavulanic acid
(20 / 10 g)
Ceftriaxone
(30 g)
Chloramphenicol
(30 g)
S.
aureus
ATCC
25923
13
17
0
4
10
11
18
26
Sarcina
lutea
ATCC
9341
20
18
13
20
12
12
-
Bacillus
cereus
Bacillus
subtilis
E. coli
ATCC
25922
Candida
sake
Candida
albicans
0
0
0
0
0
0
-
14
15
0
8
9
9
-
20
17
0
4
13
9
16
0
0
0
0
0
0
-
0
0
0
0
0
0
-
30
-
-
-
20
-
-
24
-
-
-
32
-
-
20
20
0
17
30
0
0
The results show a good antimicrobial activity, both on grampositive and gram-negative bacteria, compared to standard antibiotics,
especially for compounds A and B. The antimicrobial activity is maximum
when the hydro carbonated chain that bound the rutin and 6-
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aminopenicillanic acid has a single carbon and decrease with chain
elongation.
CONCLUSIONS
-
-
Four novel rutin and 6-amino-penicillanic acid derivatives have been
synthesized;
Molecular formula, weight, yield, melting point and solubility were
established for these compounds;
generally penicillins are very slightly water soluble, only the
potassium or sodium salts being soluble in water, but the
administration of these salts may cause undesired side effects; an
important advantage of novel derivatives is the solubility in water;
Elemental analysis and spectral analysis have confirmed the
structure of the new compounds.
The results show a good antimicrobial activity, both on grampositive and gram-negative bacteria, compared to standard
antibiotics, especially for compounds A and B.
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