Synthesis of dihydroquinopimaric acid conjugates with amino acids

Article abstract of DOI:10.1134/S1068162009030157

Synthesis of dihydroquinopimaric acid amides and their 2β-succinyl and 2β-phthalyl derivatives containing residues of amino acids was carried out for the first time. Antiviral properties of the compounds synthesized were investigated.

Full text of DOI:10.1134/S1068162009030157

ISSN 1068-1620, Russian Journal of Bioorganic Chemistry, 2009, Vol. 35, No. 3, pp. 385–390. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © O.B. Flekhter, I.E. Smirnova, E.V. Tret’yakova, G.A. Tolstikov, O.V. Savinova, E.I. Boreko, 2009, published in Bioorganicheskaya Khimiya, 2009, Vol. 35,
No. 3, pp. 424–430.
Synthesis of Dihydroquinopimaric Acid Conjugates
with Amino Acids
O. B. Flekhtera,1, I. E. Smirnovaa, E. V. Tret’yakovaa, G. A. Tolstikova,
O. V. Savinovab, and E. I. Borekob
a Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences,
pr. Oktyabrya 71, Ufa, 450054 Bashkortostan, Russia;
b Research Institute of Epidemiology and Microbiology, Ministry of Health of Belarus, Minsk, Belarus
Received January 30, 2008; in final form, November 25, 2008
Abstract—Synthesis of dihydroquinopimaric acid amides and their 2β-succinyl and 2β-phthalyl derivatives
containing residues of amino acids was carried out for the first time. Antiviral properties of the compounds syn-
thesized were investigated.
Key words: abietane diterpenoids, amino acids, antiviral activity, dihydroquinopimaric acid.
DOI: 10.1134/S1068162009030157
1
INTRODUCTION
6.51 ppm in the spectra of H NMR. The signals at δ
7.10–7.30 ppm for compound (VIII) are characteristic
of aromatic ring protons.
A number of compounds belonging to abietane
diterpenoids and possessing various biological activi-
ties have been isolated in recent years [1–4]. An antiul-
cer preparation Ecabet was developed on the basis of
sulfodehydroabietic acid [5]. Purposeful modifications
of podocarpic (12-hydroxydehydroabietic) acid were
carried out; they resulted in substances prospective for
the treatment of atherosclerosis [6]. A number of
amides of abietic and dehydroabietic have demon-
Alkaline hydrolysis of amides ((III‡)–(VIII‡) by
4 N NaOH in methanol led to the formation of the cor-
responding derivatives (IIIb)–(VIIIb) in an 87–93%
yield. The course of the reaction was monitored by the
appearance of carboxyl group signals at δ 9.74–10.71 ppm
in 1H NMR spectra.
Reduction of (IV‡) and (VII‡) by sodium borohy-
strated antiulcer, antiarhythmic, and antiasthmatic dride in methanol proceeds with the full conversion of
effects [7–9].
initial compounds and the formation of 2β-hydroxydi-
hydroquinopimaric acid amides with β-alanine (IX)
and L-methionine (X) in 84–86% yields. Signals corre-
sponding to C2 and H2 atoms were found in spectra
RESULTS AND DISCUSSION
13C- and H NMR at δ 68 and 3.88 ppm. Acylation of
1
We have modified for the first time carboxyl and
2-keto groups in dihydroquinopimaric acid (I), an
available synthetic derivative of abietane type. It was
synthesized from the quinone adduct of levopimaric
acid and p-benzoquinone [10]. The antiviral activity of
some of the obtained derivatives was investigated.
(IX) and (X) with succinic and phthalic anhydrides
under boiling in pyridine in the presence of DMAP
gave amides of 2β-succinyl (XI) and (XII), and 2β-
phthalyldihydroquinopimaric acid (XIII) and (XIV) in
65–77% yields after chromatographic purification. For
the benefit of formation (education) of the given con-
nections, the proton signals of acyl and amino acid moi-
The interaction of dihydroquinopimaric acid chlo-
ride (II) with methyl esters of L-alanine, L-valine,
L-leucine, L-methionine, L-phenyl-β-alanine, and β-
alanine at reflux in chloroform led to amides (III‡)–
(VIII‡) in 68–92% yields (see scheme). Their struc-
tures were confirmed by NMR spectroscopy. The for-
mation of CONH bonds was proved by the signals of
carbon atoms C21 at δ 176.1–177.9 ppm in the spectra
1
eties in the H NMR spectra of the compounds con-
firmed their structures.
The activities of (I), (VIIa), (IX), (XI), (XII), and
(XIV) toward the reproduction of influenza virus
A/FPV/Rostock/34 (H7N1) were investigated. A
decrease in the virus titer in the presence of the sub-
stances at various concentrations in comparison with
the control was insignificant; only for (XIV) at its max-
imal concentration nontoxic for the cell culture it
reached 0.76 log(PFU/ml) and did not exceed
13
of C NMR and protons of a CONH group at δ 6.15–
1
Corresponding author; phone/fax: (347) 235-5066; e-mail:
obf@anrb.ru
2
2
0.3 log(PFU/ml) in the case of other substances. Based
Abbreviations: PFU, plaque forming unit.
385

386
FLEKHTER et al.
O
O
2
O
O
20
19
17
16
1
6
3
4
i
ii
iv for (IVa) and (VIIa)
18
7
5
14
11
13
12
15
10
8
O
O
9
COOH
COCl
(II)
CONHR
(IIIa,b)–(VIIIa,b)
(I)
OR2
3'
4'
2' 1'
(IIIa,b) R = CH(CH3)CO2R1;
4' 3'
2' 1'
(IVa,b) R = (CH2)2CO2R1;
3'
2' 1' 4'
5' 6'
(Va,b) R = CH(CO2R1)CH(CH3)2;
O
3'
2' 1' 4'
5' 6' 7'
(VIa,b) R = CH(CO2R1)CH2CH(CH3)2;
CONHR
3'
2' 1'
4' 5'
6'
(VIIa,b) R = CH(CO2R1)(CH2)2SCH3;
(VIIIa,b) R = C3H' (C2'O2R1)CH2(C6H4);
(IX)–(XIV)
1'
4'
5'–10'
(IX) R = (CH2)2CO2CH3, R2 = H;
1
vi
(X) R = CH(CO2CH3)(CH2)2SCH3, R2 = H;
(IIIa)–(VIIIa) R = CH3
v
1
iii
1'' 2'' 3''
4''
(XI) R = (CH2)2CO2CH3, R2 = CO(CH2)2COOH;
(XII) R = CH(CO2CH3)(CH2)2SCH3, R2 = CO(CH2)2COOH;
(IIIb)–(VIIIb) R = H
1''
4''
(XIII) R = (CH2)2CO2CH3, R2 = CO(C6H4)COOH;
(XIV) R = CH(CO2CH3)(CH2)2SCH3, R2 = CO(C6H4)COOH
Conditions: i. (COCl)2, CHCl3, 2 ˜; ii. HCl · H-Ala-OMe for (III), HCl · H-βAla-OMe for (V), HCl · H-Val-OMe for (V),
HCl · H-Leu-OMe for (VI), HCl · H-Met-OMe for (VII), HCl · H-PhβAla-OMe for (VIII), Et3N, CHCl3;
iii. NaOH/MeOH; iv. NaBH4/MeOH; v. succinic anhydride, pyridine, DMAP, ∆; vi. phthalic anhydride, pyridine
DMAP, ∆.
Scheme.
on the obtained data, other parameters of the antiviral
action of the investigated substances were also calcu-
lated (see the table). Values of the relation of the maxi-
mal nontoxic concentrations of (I), (VIIa), (XI), (XII),
EXPERIMENTAL
TLC analysis was carried out on Silufol plates (Che-
mapol, Czechia) in a 20 : 1 chloroform–methanol sys-
tem with detection by 5% a phosphotungstic acid solu-
and (XIV) to their 50% effective concentrations were tion in ethanol (2–3 min at 100–120°C). Spectra 1H- and
13C NMR (δ, ppm, J, Hz) were registered on a Bruker
near 1; i.e., these substances showed insignificant
AM-300 spectrometer (Germany, 300 and 75.5 MHz,
inhibiting action on the virus reproduction practically
only at the maximal nontoxic concentration. For (IX),
this relation was much less than 1. The value of the ratio
of the maximal nontoxic concentration to 90% of effec-
tive concentration was near to 1 only for (XIV). This
substance was the most active among all those investi-
gated.
respectively) in CDCl3, with SiMe as an internal stan-
4
dard. Optical rotation was measured on a Perkin Elmer
241 MC polarimeter in a cuvette of 1-dm length. Melt-
ing temperatures were determined on a Boetius micro
melting plate. A description of the dihydroquinopima-
ric acid synthesis (I) is given in work [10]. Methyl
esters of amino acid hydrochlorides were obtained by
the standard procedure [11] and were recrystallized
from ethyl acetate.
Thus, the amides of dihydroquinopimaric acid and
its 2β-succinyl and 2β-phthalyl derivatives containing
residues of amino acids practically do not possess the
ability to inhibit the reproduction of influenza virus A
(H7N1) in a cell culture.
Synthesis of dihydroquinopimaric acid chloride
(11-chlorocarbonyl-11,15-dimethyl-19-isopropyl-2,5-
dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-18(19)-
ene) (II). Oxalyl chloride (0.3 ml) was dropwise added
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 35 No. 3 2009

SYNTHESIS OF DIHYDROQUINOPYMARIC ACID CONJUGATES
387
Antiviral activity of compounds (I), (VIIa), (IX), (XI),
(XII), and (XIV)
to dihydroquinopimaric acid (I) (1 mmol, 0.41 g) in dry
chloroform (10 ml) under stirring; the mixture was kept
for 4 h in a nitrogen atmosphere. The solvent was evap-
orated in the vacuum of a water-jet pump; yield 0.42 g
(97%). Found, %: C 72.09, H 7.92, Cl 6.06.
C26H35ClO5. Calculated, %: C 72.45, H 8.18, Cl 8.23.
Synthesis of derivatives (III‡)–(VIII‡). A solu-
tion of amino acid methyl ester hydrochloride (L-ala-
nine, β-alanine, L-valine, L-leucine, L-methionine, or
L-phenyl-β-alanine) (1.3 mmol) and triethylamine
(0.25 ml) in dry chloroform (5 ml) was added to a
stirred solution of (II) (1 mmol, 0.43 g) in 10–15 ml of
dry chloroform; the reaction mixture was refluxed for
2 h, washed with 5% HCl (3 × 20 ml) and water (2 ×
100 ml); dried with MgSO4, and evaporated in the vac-
uum of a water-jet pump. The reaction product was
purified by column chromatography on a Al2O3 eluted
with chloroform.
Influenza virus FPV
Compound
EC50 (I95), µM
EC90(I95), µM
MTC/EC50
MTC/EC90
(I)
~60.6
~1
ꢀ60.6
ꢁ1
(VIIa)
194.0
0.9
0.5
0.2
0.003
1.1
0.3
0.8
0.4
1.3
0.9
(275.6–136.6)
369.7
(524.8–260.3)
(IX)
67.0
(2 × 106–2 × 10–5)
11-(1'-Methoxyalanino)-11,15-dimethyl-19-iso-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene) (IIIa); yield 0.39 g (78%); Rf 0.64;
4338.8
(1.6 × 109–1.4 × 10–4)
(XI)
38.2
(67.2–21.8)
mp 158–160°C; [α]2D0 +31.0° (c 0.04, CHCl3); H
1
NMR: 0.55 (3 ç, s, ëç3), 0.81–0.95 (2 H, m, CH), 0.97
and 1.05 (6 H, both d, J 6.9, ëç3), 1.13 (3 ç, s, ëç3),
1.15–1.79 (15 H, m, ëç2, CH), 2.20–2.59 (6 H, m,
ëç2, CH), 2.78 (1 H, d, J 9.8, H1), 3.18 (1 H, br. s,
CH), 3.71 (3 ç, Ò, Oëç3), 4.53 (1 H, quintet, all J 7.0,
H3'), 5.47 (1 H, br. s, CH), 6.28 (1 H, d, J 6.8,
C(21)ONH); 13C NMR: 209.6 (C5), 208.8 (C2), 177.9
(C21), 173.6 (C2'), 149.3 (C19), 125.4 (C18), 60.4,
55.7, 54.8, 53.3 (C3'), 52.2 (C1'), 49.7, 46.4 (C11),
41.1, 38.6, 37.9, 37.7, 37.5, 36.6, 36.3, 34.6, 32.7, 29.9,
20.6, 19.8, 16.9, 16.5, 16.2 (C4'), 15.9, 15.1. Found, %:
C 71.89, N 2.24, H 7.53. C30H43NO5. Calculated, %: C
72.4, N 2.8, H 8.7.
156.7
(275.4–89.2)
(XII)
(XIV)
23.6
(38.9–14.2)
49.8
(52.1–30.1)
13.6
(16.0–11.6)
19.5(22.7–16.7)
Note: I , confidence interval.
95
11-(1'-Methoxy-b-alanino)-11,15-dimethyl-19-
isopropyl-2,5-dioxopentacyclo-[[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene (IVa); yield 0.29 g (58%); Rf 0.55,
0.55 (3 ç, s, ëç3), 0.86 (3 ç, s, ëç3), 0.88 (3 ç, s,
ëç3), 0.97 and 0.99 (6 H, both d, J 6.9, 2ëç3), 1.00–
1.11 (2 H, m, CH), 1.15 (3 ç, s, ëç3), 1.17–1.79 (13
H, m, ëç2, CH), 2.07–2.52 (6 H, m, ëç2, CH), 2.78
(1 H, dd, J1 1.8, J2 10.2, H1), 3.16 (1 H, br. s, CH), 3.71
(3 ç, s, éëç3), 4.53 (1 H, dd, J1 4.8, J2 8.0, H3'), 5.49
(1 H, br. s, CH), 6.21 (1 H, d, J 8.2, C(21)ONH);
13C NMR: 209.5 (C5), 208.5 (C2), 177.9 (C21), 172.4
(C2'), 149.1 (C19), 125.3 (C18), 60.3, 57.0 (C3'), 55.6,
54.6, 51.8 (C1'), 49.5, 46.6 (C11), 40.9, 38.7, 38.2,
37.9, 37.6, 36.8, 36.7, 34.4, 32.6, 30.9 (C4'), 27.5, 21.1,
20.5, 19.7, 18.8 (C6'), 17.8 (C5'), 16.8, 16.5, 15.9.
Found, %: C 72.49, N 1.65, H 8.52. C32H47NO5. Calcu-
lated, %: C 73.11, N 2.66, H 9.01.
mp 120–123°ë; [α]2D0 +4.2° (c 0.16, CHCl3); H NMR:
1
0.56 (3 ç, s ëç3), 0.80–0.92 (2 H, m, CH), 0.93 and 0.98
(6 H, both d, J 6.9, ëç3), 1.05 (3 ç, s, ëç3), 1.09–1.76
(14 H, m, ëç2, CH), 2.13–2.54 (6 H, m, ëç2, CH),
2.75 (1 H, dd, J1 2.3, J2 9.8, H1), 3.15 (1 H, br. s, CH),
3.46 (2 H, q, J 5.6, H4'), 3.64 (3 ç, s, éëç3), 5.46 (1 H,
13
br. s, CH), 6.28 (1 H, t, J 5.6, C(21)ONH); C NMR:
209.5 (C5), 208.7 (C2), 178.2 (C21), 173.2 (C2'), 149.3
(C19), 125.4 (C18), 60.2, 55.7, 54.7, 51.6 (C1'), 49.7,
46.5 (C11), 41.0, 38.8, 38.3, 37.9, 37.5, 36.9, 36.7, 35.1
(C4'), 34.6 (C3'), 33.4, 32.7, 27.6, 21.0, 20.6, 19.7,
16.9, 16.4, 15.9. Found, %: C 71.65, N 2.61, H 7.64.
C30H43NO5. Calculated, %: C 72.40, N 2.80, H 8.70.
11-(1'-Methoxyvalino)-11,15-dimethyl-19-iso-
11-(1'-Methoxyleucino)-11,15-dimethyl-19-iso-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene (Va); yield 0.31 g (59%); Rf 0.68, mp eicos-18(19)-ene (VIa); yield 0.3 g (84%); Rf 0.65;
135–136°ë; [α]2D0 +22.9° (c 0.07, CHCl3); H NMR: mp 118–120°ë; [α]2D0 +14.3° (c 0.04, CHCl3);
1
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 35 No. 3 2009

388
FLEKHTER et al.
1H NMR: 0.55 (3 ç, s, ëç3), 0.91 (3 ç, s, ëç3), 0.94
(3 ç, s, ëç3), 0.99 and 1.02 (6 H, both d, J 6.9, 2ëç3),
1.05–1.10 (2 H, m, CH), 1.16 (3 ç, s, ëç3), 1.18–1.77
(15 H, m, ëç2, CH), 2.13–2.58 (6 H, m, ëç2, CH),
2.80 (1 H, d, J 9.8, CH), 3.19 (1 H, br. s, CH), 3.71
(3 ç, Ò, éëç3), 4.54 (1 H, q, J 7.7, H3'), 5.51 (1 H, br. s,
CH), 6.11 (1 H, d, J 7.6, C(21)ONH); 13C NMR: 209.6
(C5), 208.8 (C2), 176.1 (C21), 173.6 (C2'), 149.4
(C19), 125.5 (C18), 60.5, 55.8, 54.8, 52.1 (C3'), 50.9
(C1'), 49.7 (C11), 49.6, 41.5 (C4'), 41.2, 38.9, 38.4,
38.0, 37.6, 36.9, 36.7, 34.5, 32.6, 27.7, 25.0 (C5'), 22.7
(C6'), 21.9 (C7'), 21.2, 20.7, 19.8, 17.0, 16.6, 16.0.
Found, %: C 72.82, N 2.01, H 8.32. C33H49NO5. Calcu-
lated, %: C 73.43, N 2.60, H 9.15.
for 4 h under TLC monitoring. The reaction mixture
was poured out in 100 ml of 5% HCl; the precipitate
was filtered, washed with water to neutral reaction,
dried, and crystallyzed from ethyl alcohol.
11-(2'-Carboxyalanino)-11,15-dimethyl-19-iso-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18 (19)-ene (IIIb); yield 0.43 g (89%); Rf 0.30;
mp 190–192°ë; [α]2D0 –5.0° (c 0.01, CHCl3); 1H NMR:
0.77 (3 ç, s, ëç3), 0.89–1.09 (2 H, m, CH), 1.11 and
1.14 (6 H, both d, J 6.9, 2ëç3), 1.23 (3 ç, s, ëç3),
1.25–1.85 (15 H, m, ëç2, CH), 2.00–2.79 (8 H, m,
ëç2, CH), 4.91 (1 H, br. s, CH), 5.80 (1 H, br. s, CH),
6.74 (1 H, br. s, C(21)ONH), 10.57 (1 H, br. s,
C(2')OOH). Found, %: C 71.56, N 2.13, H 7.33.
C29H41NO5. Calculated, %: C 72.02, N 2.9, H 8.54.
11-(1'-Methoxymethionino)-11,15-dimethyl-19-
isopropyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene (VIIa); yield 0.36 g(65%); Rf 0.63;
11-(2'-Carboxy-b-alanino)-11,15-dimethyl-19-iso-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (IVb); yield 0.46 g (91%); Rf 0.29;
mp 192–195°ë; [α]2D0 –4.2° (c 0.01, CHCl3); 1H NMR:
0.85 (3 ç, s, ëç3), 0.96–1.15 (2 H, m, CH), 1.23 and
1.28 (6 H, both d, J 6.9, 2ëç3), 1.45 (3 ç, s, ëç3),
1.50–1.89 (14 H, m, ëç2, CH), 1.90–3.05 (8 H, m,
ëç2, CH), 3.46 (2 H, t, J 7.3, H3'), 5.75 (1 H, br. s, CH),
6.43 (1 H, br. s, C(21)ONH), 9.74 (1 H, br. s,
C(2')OOH). Found, %: C 71.67, N 2.35, H 7.28.
C29H41NO5. Calculated, %: C 72.02, N 2.9, H 8.54.
mp 123–125°ë; [α]2D0 +5.5° (c 0.13, CHCl3); 1H NMR:
0.55 (3 ç, s, ëç3), 0.81–0.94 (2 H, m, CH), 0.97 and
1.01 (6 H, both d, J 6.9, 2ëç3), 1.13 (3 ç, s, ëç3),
1.14–1.74 (12 H, m, ëç2, CH), 2.06 (3 ç, s, ëç3),
1.90–2.52 (10 H, m, ëç2, CH), 2.76 (1 H, dd, J1 2.6, J2
9.9, CH), 3.16 (1 H, br. s, CH), 3.71 (3 ç, s, éëç3),
4.62 (1 H, td, J1 7.1, J2 7.2, J3 5.4, H3'), 5.48 (1 H, td,
CH), 6.52 (1 H, d, J 7.2, C(21)ONH). 13C NMR: 209.3
(C5), 208.5 (C2), 178.9 (C21), 172.3 (C2'), 149.4
(C19), 125.3 (C18), 60.3, 55.6, 54.6, 52.1 (C3'), 51.7
(C1'), 49.5, 46.4 (C11), 40.9, 38.6, 38.1, 37.8, 37.4,
36.8, 36.7, 34.3, 32.6, 30.9 (C4'), 29.9 (C5'), 27.5, 21.1,
20.5, 19.6, 16.8 (C6'), 16.4, 15.8, 15.2. Found, %:
C 67.88, N 1.67, H 7.65, S 4.87. C32H47NO5S. Calcu-
lated, %: C 68.91, N 2.51, H 8.49, S 5.75.
11-(1'-Methoxyphenylalanino)-11,15-dimethyl-
19-isopropyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene (VIIIa); yield 0.33 g (58%); Rf 0.68;
mp 107–109°ë; [α]2D0 +6.1° (c 0.18, CHCl3); 1H NMR:
0.50 (3 ç, s, ëç3), 0.75–0.90 (2 H, m, CH), 0.94 and
0.98 (6 H, both d, J 6.9, 2ëç3), 1.02 (3 ç, s, ëç3),
1.07–1.71 (12 H, m, ëç2, CH), 2.13–2.50 (6 H, m,
ëç2, CH), 2.71 (1 H, d, J 9.8, CH), 3.05 (2 H, dd,
11-(2'-Carboxyvalino)-11,15-dimethyl-19-isopro-
pyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (Vb); yield 0.47 g (87%); Rf 0.30; mp 186–
189°ë; [α]2D0 –3.5° (c 0.01, CHCl3). H NMR: 0.70
1
(3 ç, s, ëç3), 0.95 (3 ç, s, ëç3), 0.97 (3 ç, s, ëç3),
1.07 and 1.09 (6 H, both d, J 6.9, 2ëç3), 1.15–1.21
(2 H, m, CH), 1.23 (3 ç, s, ëç3), 1.27–1.95 (13 H, m,
ëç2, CH), 2.27–3.44 (8 H, m, ëç2, CH), 3.78 (1 H, br.
s, CH), 5.65 (1 H, br. s, CH), 6.56 (1 H, br. s,
C(21)ONH), 10.71 (1 H, br. s, C(2')OOH). Found, %:
C 72.09, N 1.87, H 8.12. C31H45NO5. Calculated, %:
C 72.77, N 2.74, H 8.86.
11-(2'-Carboxyleucino)-11,15-dimethyl-19-isopro-
J1 5.6, J2 16.1, H4'), 3.16 (1 H, br. s, CH), 3.71 (3 ç, s, pyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (VIb); yield 0.50 g (93%); Rf 0.26;
mp 193–195°ë; [α]2D0 –2.0° (c 0.05, CHCl3); 1H NMR:
éëç3), 4.80 (1 H, q, J 7.6, H3'), 5.48 (1 H, br. s, CH),
6.15 (1 H, d J 7.6, C(21)ONH), 6.95–7.12 (2 H, m,
2 CH), 7.13–7.30 (3 H, m, 3 CH); 13C NMR: 209.2
(C5), 208.5 (C2), 177.5 (C21), 170.8 (C2'), 149.1
(C19), 136.2 (C5'), 128.3 (C7', C9'), 128.9 (C6', C10'),
127.1 (C8'), 125.4 (C18), 81.9 (C3'), 60.3, 55.5, 54.6,
53.4 (C1'), 49.3, 46.4 (C11), 40.9, 38.7, 38.2, 37.9
(C4'), 37.8, 37.3, 37.5, 36.7, 34.5, 32.6, 27.7, 20.8,
20.6, 19.8, 19.7, 16.8, 16.4. Found, %: C 74.98, N 1.83,
H 7.76. C36H47NO5. Calculated, %: C 75.3, N 2.44, H
8.26.
0.77 (3 ç, s, ëç3), 0.80–1.05 (2 H, m, CH), 1.13 (3 ç,
s, ëç3), 1.15 (3 ç, s, ëç3), 1.19, 1.22 (6 H, both d,
J 6.9, 2ëç3), 1.25 (3 ç, s, ëç3), 1.30–1.89 (15 H, m,
ëç2, CH), 2.23–3.18 (8 H, m, ëç2, CH), 4.78 (1 H, br. s,
CH), 5.62 (1 H, br. s, CH), 6.69 (1 H, br. s, C(21)ONH),
10.05 (1 H, br. s, C(2')OON). Found, %: C 72.73,
N 2.11, H 8.53. C32H47NO5. Calculated, %: C 73.11,
N 2.66, H 9.01.
11-(2'-Carboxymethionino)-11,15-dimethyl-19-iso-
propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (VIIb); yield 0.49 g (92%); Rf 0.25;
Synthesis of derivatives (IIIb)–(VIIIb). A 4 M
NaOH/MeOH solution (0.5 ml) was added to a solution
of (III‡)–(VIII‡) (1 mmol) in 5 ml ofAcOH and stirred
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 35 No. 3 2009

SYNTHESIS OF DIHYDROQUINOPYMARIC ACID CONJUGATES
389
mp 179–182°ë; [α]2D0 –3.4° (c 0.01, CHCl3); H NMR:
(12 H, m, ëç2, CH), 1.98 (2 H, br. s, ëç2), 2.06 (3 ç, s,
ëç3), 2.35–2.59 (8 H, m, ëç2, CH), 2.76 (1 H, dd, J1 2.6,
J2 7.6, ëç), 3.15 (1 H, br. s, OH), 3.68 (3 ç, s, éëç3),
3.87 (1 H, td, J1 6.7, J2 6.9, J3 4.5, H2), 4.62 (1 H, td, J1
7.2, J2 7.4, J3 5.1, H3'), 4.71 (1 H, br. s, CH), 5.50 (1 H, br.
s, CH), 6.61 (1 H, d, J 7.4, C(21)ONH); 13C NMR: 208.7
(C5), 178.5 (C21), 171.9 (C2'), 149.5 (C19), 124.9 (C18),
68.4 (C2), 60.5, 55.8, 54.7, 52.8 (C3'), 51.9 (C1'), 49.5,
46.6 (C11), 41.6, 38.8, 38.0, 37.7, 37.3, 36.9, 36.6, 34.1,
32.6, 30.9 (C4'), 29.9 (C5'), 27.6, 21.0, 20.7, 19.3, 16.0
(C6'), 16.4, 15.6, 15.1. Found, %: C 68.02, N 2.14, H 7.98,
S 4.96. C32H49NO5S. Calculated, %: C 68.66, N 2.50,
H 8.82, S 5.73.
Synthesis of derivatives (XI)–(XIV). Succinic
anhydride (0.2 g, 2 mmol) or phthalic anhydride (0.9 g,
5 mmol) and a catalytic amount of DMAP were added
to (IX) (0.50 g, 1 mmol) or (X) (0.56 g, 1 mmol) in
anhydrous pyridine. The mixture was refluxed for 12 h
and poured into 5% HCl (100 ml); the precipitate was
filtered, washed with water to neutral reaction, and
dried. The product was purified by column chromatog-
raphy on a Al2O3 column eluted with chloroform.
1
0.70 (3 H, s, CH3), 0.79–0.95 (2 H, m, CH), 1.22, 1.28
(6 H, both d, J 6.9, 2CH3), 1.32 (3 ç, s, ëç3), 1.33–
1.43 (12 H, m, ëç2, CH), 1.45 (3 ç, s, ëç3), 1.46–2.02
(12 H, m, ëç2, CH), 3.55 (1 H, br. s, CH), 5.55 (1 H,
br. s, CH), 6.59 (1 H, br. s, C (21) ONH), 9.86 (1 H, br. s,
C (2')OOH). Found, %: C 67.79, N 2.16, H 7.59, S 4.63.
C31H45NO5S. Calculated, %: C 68.48, N 2.58, H 8.34,
S 5.90.
11-(2'-Carboxyphenyl-b-alanino)-11,15-dimethyl-19-
iso-propyl-2,5-dioxopentacyclo[12.4.0.27,18.07,16.010,15]-
eicos-18(19)-ene (VIIIb); yield 0.5 g (90%); Rf 0.32; mp
160–162°ë; [α]2D0 −5.2° (c 0.01, CHCl3); 1H NMR: 0.62
(3 ç, s, ëç3), 0.69–0.97 (2 H, m, CH), 1.04 and 1.08 (6 H,
both d, J 6.9, 2ëç3), 1.12 (3 ç, s, ëç3), 1.18–1.86 (12 H,
m, ëç2, CH), 2.28–3.16 (10 H, m, ëç2, CH), 4.95 (1 H,
br. s, CH), 5.78 (1 H, br. s, CH), 6.57 (1 H, br. s,
C(21)ONH), 7.16–7.25 (2 H, m, 2 CH), 7.28–7.56 (3 H,
m, 3 CH), 10.15 (1 H, s, C(2')OOH). Found, %: C 74.87,
N 1.95, H 7.35. C35H45NO5. Calculated, %: C 75.10, N
2.50, H 8.10.
11-(1'-Methoxy-b-alanino)-11,15-dimethyl-19-
isopropyl-2b-carboxyethylcarbonyl-5-oxopentacy-
clo[12.4.0.27,18.07,16.010,15]eicos-18(19)-ene (XI); yield
Synthesis of derivatives (IX) and (X). A solution
of (IV‡) (0.50 g, 1 mmol) or (VII‡) (0.56 g, 1 mmol)
was treated portionwise under stirring by NaBH4 (0.1 g,
2.5 mmol) in 2.5 ml of methanol. After 30 min, the
reaction mixture was poured in 5% HCl solution
(20 ml), cooled to 0°ë, the precipitate was filtered,
washed with water to neutral reaction, and dried. The
residue was purifed by column chromatography on a
Al2O3 column eluted with chloroform.
0.45 g (77%); Rf 0.40; mp 170–172°ë; [α]2D0 +41.0°
1
(c 0.01, CHCl3); H NMR: 0.56 (3 ç, s, ëç3), 0.81–
0.99 (2 H, m, CH), 1.01 and 1.05 (6 H, both d, J 6.9,
2ëç3), 1.09 (3 ç, s, ëç3), 1.23–1.98 (12 H, m, ëç2,
CH), 1.99–2.40 (8 H, m, ëç2, CH), 2.45–2.67 (6 H, m,
ëç2, CH), 3.45 (2 H, q, J 5.9, H4'), 3.69 (3 ç, s,
éëç3), 4.89 (1 H, td, J1 5.1, J2 6.1, J3 10.2, H2), 5.49
(1 H, br. s, CH), 6.52 (1 H, t, J 5.9, C(21)ONH), 8.45
11-(1'-Methoxy-b-alanino)-11,15-dimethyl-19-isopro-
pyl-2b-hydroxy-5-oxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (IX); yield 0.43 g (86%); Rf 0.33; mp 123–
126°ë; [α]2D0 +44.0°(c 0.5, CHCl3); H NMR: 0.58
13
(1 H, br. s, C(4")OOH); C NMR: 211.5 (C5), 178.7
(C21), 175.2 (C1"), 173.0 (C2'), 171.1 (C4"), 147.2
(C19), 123.7 (C18), 70.7 (C2), 61.5, 54.3, 51.5 (C1'),
49.5, 46.3, 44.2 (C11), 39.9, 37.5, 36.3, 35.7, 35.4,
35.0, 34.8 (C4'), 34.6 (C3'), 33.2, 32.6, 30.9, 28.9
(C3"), 28.5 (C4"), 23.5, 21.1, 20.8, 19.2, 16.8, 16.3,
15.5. Found, %: C 69.75, N 2.02, H 7.82. C34H49NO8.
Calculated, %: C 68.09, N 2.34, H 8.23.
1
(3 ç, s, ëç3), 0.75–0.98 (2 H, m, CH), 1.02 and 1.04
(6 H, both d, J 6.9, 2ëç3), 1.11 (3 ç, s, ëç3), 1.21–
1.99 (14 H, m, ëç2, CH), 2.00–2.58 (7 H, m, ëç2,
CH), 2.78 (1 H, br. s, CH), 3.01 (1 H, br. s, OH), 3.48
(2 H, q, J 5.6, H4'), 3.67 (3 ç, s, éëç3), 3.88 (1 H, td,
J1 7.0, J2 7.1, J3 3.5, H2), 5.56 (1 H, br. s, CH), 6.45
(1 H, t, J1 5.6, C(21)ONH); 13C NMR: 209.5 (C5), 68.1
(C2), 178.2 (C21), 173.2 (C2'), 149.3 (C19), 125.4
(C18), 60.2, 55.7, 54.7, 51.6 (C1'), 49.7, 46.5 (C11),
41.0, 38.8, 38.3, 37.9, 37.5, 36.9, 36.7, 35.1 (C4'), 34.6
(C3'), 33.4, 32.7, 27.6, 21.0, 20.6, 19.7, 16.9, 16.4,
15.9. Found, %: C 71.89, N 2.34, H 8.12. C30H45NO5.
Calculated, %: C 72.11, N 2.80, H 9.08.
11-(1'-Methoxymethionino)-11,15-dimethyl-19-
isopropyl-2-carboxyethylcarbonyl-5-oxopentacy-
clo[12.4.0.27,18.07,16.010,15]eicos-18(19)-ene (XII); yield
0.45 g (75%); Rf 0.35; mp 165–167°ë; [α]2D0 +45.0° (c
0.01, CHCl3); 1H NMR: 0.56 (3 ç, s, ëç3), 0.81–1.01
(2 H, m, CH), 1.02 and 1.04 (6 H, both d, J 6.9, 2ëç3),
1.16 (3 ç, s, ëç3), 1.32–1.92 (12 H, m, ëç2, CH),
1.95–2.04 (2 H, m, CH), 2.13 (3 ç, s, ëç3), 2.19–2.73
(14 H, m, ëç2, CH), 3.76 (3 ç, s, éëç3), 4.70 (1 H,
td, J1 7.3, J2 7.4, J3 5.2, H3'), 4.95 (1 H, td, J1 5.0, J2 5.6,
J3 3.3, H2), 5.54 (1 H, br. s, CH), 6.61 (1 H, d, J 7.4,
11-(1'-Methoxymethionino)-11,15-dimethyl-19-isopro-
pyl-2β-hydroxy-5-oxopentacyclo[12.4.0.27,18.07,16.010,15]eicos-
18(19)-ene (X); yield 0.47 g (84%); Rf 0.35; mp 141–
143°ë; [α]2D0 +37.5° (c 0.05, CHCl3); H NMR: 0.56
(3 ç, s, ëç3), 0.79–0.96 (2 H, m, CH), 0.99 and 1.05
(6 H, both d, J 6.9, 2ëç3), 1.15 (3 ç, s, ëç3), 1.12–1.73
1
13
C(21)ONH), 8.61 (1 H, br. s, C(4'') OOH); C NMR:
210.7 (C5), 178.5 (C21), 174.9 (C1"), 172.8 (C2'),
170.4 (C4"), 149.3 (C19), 125.1 (C18), 71.9 (C2), 60.5,
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 35 No. 3 2009

390
FLEKHTER et al.
55.8, 54.9, 52.0 (C3'), 50.9 (C1'), 49.7, 46.7 (C11),
39.9, 38.4, 38.0, 37.6, 37.2, 36.4, 36.9, 34.2, 32.6, 31.2
(C4'), 29.5 (C5'), 28.6 (C3"), 28.3 (C4"), 27.5, 21.3,
20.5, 19.8, 16.3 (C6'), 16.8, 15.5, 15.0. Found, %: C
64.97, N 1.86, H 7.43, S 4.02. C36H53NO8S. Calculated,
%: C 65.53, N 2.12, H 8.10, S 4.86.
Antiviral properties of compounds toward the
influenza virus were investigated on a hen embryo
fibroblast culture A/FPV/Rostock/34 (H7N1) by the
method of plaque reduction as described earlier [12].
The investigated substances were preliminarily dis-
solved in 10% ethanol and then prepared in consecutive
twofold dilution cultivations on a support medium 199
(Sigma Chemical Co.). As quantitative criteria of the
observable antiviral action, a decrease in the virus titer
compared with control, 50 and 90% effective concen-
trations (EC50 and EC90) of the substances under study,
and also the ratio of their maximal tolerable concentra-
tion (MTC) to Öë50 (MTC/Öë50) and Öë90
(MTC/Öë90) were calculated. MTC of compounds
were determined after the incubation with an unin-
fected culture of the cells for 72 h at 37°ë.
11-(1'-Methoxy-β-alanino)-11,15-dimethyl-19-
isopropyl-2β-carboxybenzylcarbonyl-5-oxopenta-
cyclo[12.4.0.27,18.07,16.010,15]eicos-18(19)-ene (XIII);
yield 0.52 g (81%); Rf 0.33; mp 158–160°ë; [α]2D0
+30.3° (c 0.01, CHCl3); 1H NMR: 0.54 (3 ç, s, ëç3),
1.00, 1.03 (6 H, both d, J 6.9, 2ëç3), 1.12 (3 ç, s,
ëç3), 1.23–1.89 (14 H, m, ëç2, CH), 1.90–2.82 (10 H,
m, ëç2, CH), 3.50 (2 H, q, J 5.9, H4'), 3.61 (3 ç, s,
éëç3), 5.12 (1 H, td, J1 5.1, J2 6.1, J3 4.2, H2), 5.49
(1 H, br. s, CH), 6.60 (1 H, t, J 5.9, C(21)ONH), 7.49–
7.61 (2 H, m, 2 CH), 7.89–7.75 (2 H, m, 2 CH), 9.45 (1
H, br. s, C(4")OOH); 13C NMR: 211.8 (C5), 178.9
(C21), 173.4 (C1"), 169.9 (C2'), 167.0 (C4"), 147.5
(C19), 132.7 (C5"), 131.4 (C6"), 130.8 (C7"), 129.5
(C8"), 128.6 (C2"), 124.0 (C3"), 120.3 (C18), 72.3
(C2), 64.8, 54.5, 51.7 (C1'), 49.7, 46.6, 44.6 (C11),
40.2, 37.6, 36.7, 36.2, 35.2, 35.0, 33.5 (C4'), 32.9 (C3'),
32.7, 30.8, 23.8, 21.4, 21.2, 20.7, 19.2, 17.0, 16.6, 15.7.
Found, %: C 71.89, N 2.34, H 8.12. C38H49NO8. Calcu-
lated, %: C 70.46, N 2.16, H 7.62.
REFERENCES
1. Alvarez-Manzaneda, E.J., Chahdoun, R., Guardia, J.J.,
Lachkar, M., Dahdouh, A., Lara, A., and Mesouri, I., Tet-
rahedron Lett., 2006, vol. 47, pp. 2577–2580.
2. Kofujita, H., Ota, M., Taakahashi, K., Kawai, Y., and
Hayashi,Y., Phytochemistry, 2002, vol. 61, pp. 895–898.
3. Dellar, J.E., Cole, M.D., and Waterman, P.G., Phy-
tochemistry, 1996, vol. 41, pp. 735–738.
4. Tan, N., Kaloga, M., Radtke, O.A., Kiderlen, A.F.,
Oksuz, S., Ulubelen, A., and Kolodziej, H., Phytochem-
istry, 2002, vol. 61, pp. 881–884.
5. Kinoshita, M., Endo, M., Yasoshima, A., Saito, N.,
Yamasaki, K., Chishima, S., and Narita, H., Aliment.
Pharmacol. Ther., 1999, vol. 13, pp. 687–694.
11-(1'-Methoxymethionino)-11,15-dimethyl-19-
isopropyl-2-carboxybenzylcarbonyl-5-oxopentacy-
clo[12.4.0.27,18.07,16.010,15]eicos-18(19)-ene
(XIV);
6. Liu, W., Chen, S., Dropinski, J., Colwell, L., Robins, M.,
Szymonifka, M., Hayes, N., Sharma, N., MacNaul K.,
Hernandez M., Burton C., Sparrow C.P., Menke J.G.,
and Singh S.B, Bioorg. Med. Chem. Lett., 2005, vol. 15,
pp. 4574–4578.
yield 0.46 g (65%); Rf 0.30; mp 117–120°ë; [α]2D0
+20.5° (c 0.02, CHCl3); 1H NMR: 0.55 (3 ç, s, ëç3),
0.88, 0.99 (6 H, both d, J 6.9, 2ëç3), 1.19 (3 ç, s,
ëç3), 1.25–1.91 (14 H, m, ëç2, CH), 1.91–2.08 (2 H,
m, CH), 2.10 (3 ç, s, ëç3), 2.12–2.81 (10 H, m, ëç2,
CH), 3.75 (3 ç, s, éëç3), 4.62 (1 H, td, J1 7.3, J2 7.4,
J3 5.2, H3'), 5.15 (1 H, td, J1 5.7, J2 6.0, J3 4.0, H2), 5.50
(1 H, br. s, CH), 6.62 (1 H, d, J 7.5, C(21)ONH), 7.47–
7.63 (2 H, m, 2 CH), 7.90–7.78 (2 H, m, 2 CH), 9.17
7. Wada, H., Kodato, S.I., Kawamori, M., Morikawa, T.,
Nakai, H., Takoda, M., Onoda, Y., and Tamaki, H.,
Chem. Pharm. Bull., 1985, vol. 33, pp. 1472–1487.
8. Lui, T.P., Gao, G.Z., and Fong, L.Z., J. Tradit. Chem.,
1985, vol. 5, pp. 115–118.
9. Esteves, M.A., Narender, N., Marcelo-Curto, M.J., and
Gigante, B., J. Nat. Prod., 2001, vol. 64, pp. 761–766.
13
(1 H, br. s, C(4'')OOH); C NMR: 211.8 (C5), 179.4
10. Herz, W., Blakstone, R.C., and Nair, M.G., J. Org.
Chem., 1967, vol. 32, pp. 2292–2998.
(C21), 172.6 (C1"), 169.7 (C2'), 166.8 (C4"), 147.0
(C19), 132.3 (C5"), 132.2 (C6"), 132.1 (C7"), 132.1
(C8"), 132.0 (C2"), 129.2 (C3"), 123.9 (C18), 72.1
(C2), 61.7, 55.8, 54.4, 53.3, 51.8 (C1'), 51.3 (C3'), 49.7,
46.6 (C11), 44.7, 40.1, 37.9, 37.7, 36.7, 36.1, 35.0,
34.9, 32.6, 30.0 (C4'), 25.5 (C5'), 23.6, 21.2, 19.2, 17.0,
16.6, 16.5 (C6'), 15.7. Found, %: C 67.08, N 1.75,
H 6.93, S 3.91. C40H53NO8S. Calculated, %: C 67.87,
N 1.98, H 7.55, S 4.53.
11. Baltina, L.A. and Tolstikov, G.A., Zh. Org. Khim., 1991,
vol. 61, pp. 1227–1233.
12. Flekhter, O.B., Medvedeva, N.I., Kukovinets, O.S., Spi-
rikhin, L.V., Galkin, E.G., Galin, F.Z., Golovanov, D.G.,
Pavlova, N.I., Savinova, O.V., Boreko, E.I., and Tol-
stikov, G.A., Bioorg. Khim., 2007, vol. 33, pp. 629–634
[Russ. J. Bioorg. Chem. (Engl. Transl.), vol. 33, pp. 584–
588].
RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY Vol. 35 No. 3 2009