Peruvioses A to F, sucrose esters from the exudate of Physalis peruviana fruit as α-amylase inhibitors

Article abstract of DOI:10.1016/j.carres.2018.03.003

The fruit of Physalis peruviana is widely used in traditional Colombian medicine as an antidiabetic treatment. The aim of the study reported here was to identify the compounds responsible for the hypoglycemic activity using the α-amylase inhibition test. Bioguided fractionation of a dichloromethane extract of the sticky exudate that covers the fruit allowed the isolation and identification of three new sucrose esters, named as peruvioses C–E (1–3), along with the known peruvioses A (6), B (5) and F (4), the structures of which were elucidated by extensive NMR and MS experiments. These compounds proved to be responsible for the hypoglycemic activity observed in the extract. Peruviose D (2) showed the highest activity, with an inhibitory activity value of 84.8%. This is the first study to establish the potential of sucrose esters as α-amylase inhibitors and to explain the hypoglycemic effect that has traditionally been attributed to gooseberry fruit.

Full text of DOI:10.1016/j.carres.2018.03.003

Accepted Manuscript
Peruvioses A to F, sucrose esters from the exudate of Physalis peruviana fruit as α-
amylase inhibitors
Carlos-A. Bernal, Leonardo Castellanos, Diana M. Aragón, Diana Martínez-
Matamoros, Carlos Jiménez, Yolima Baena, Freddy A. Ramos
PII:
S0008-6215(18)30102-2
10.1016/j.carres.2018.03.003
CAR 7534
DOI:
Reference:
To appear in: Carbohydrate Research
Received Date: 15 February 2018
Revised Date: 1 March 2018
Accepted Date: 5 March 2018
Please cite this article as: C.-A. Bernal, L. Castellanos, D.M. Aragón, D. Martínez-Matamoros,
C. Jiménez, Y. Baena, F.A. Ramos, Peruvioses A to F, sucrose esters from the exudate of
Physalis peruviana fruit as α-amylase inhibitors, Carbohydrate Research (2018), doi: 10.1016/
j.carres.2018.03.003.
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to
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ACCEPTED MANUSCRIPT
OH
O
OH
OH
O
O
O
O
O
O
OH
O
1
0
O
O
O
Peruviose D
Inhibition of α-amylase = 84.8%.

ACCEPTED MANUSCRIPT
Peruvioses A to F, sucrose esters from the exudate of Physalis peruviana fruit as α-amylase inhibitors
a
b
a
c
c
a
Carlos-A. Bernal, Leonardo Castellanos, Diana M. Aragón, Diana Martínez-Matamoros, Carlos Jiménez, Yolima Baena, and
b 1
Freddy A. Ramos.
a
Universidad Nacional de Colombia – Sede Bogotá – Facultad de Ciencias – Departamento de Farmacia – Tecnología de
productos naturales–Carrera 30 # 45-03, Bogotá D.C., (111321), Colombia.
b
Universidad Nacional de Colombia – Sede Bogotá – Facultad de Ciencias – Departamento de Química – Carrera 30 # 45-03,
Bogotá D.C., (111321), Colombia.
c
Departamento de Química Fundamental, Facultade de Ciencias e Centro de Investigacións Científicas Avanzadas (CICA),
Universidade da Coruña, A Coruña E-15071, Spain
1
To whom correspondence should be addressed. Phone: (57) (1) 3165000. Ext. 14451. Email: faramosr@unal.edu.co

ACCEPTED MANUSCRIPT
Abstract
The fruit of Physalis peruviana is widely used in traditional Colombian medicine as an antidiabetic treatment. The aim of the
study reported here was to identify the compounds responsible for the hypoglycemic activity using the α-amylase inhibition test.
Bioguided fractionation of a dichloromethane extract of the sticky exudate that covers the fruit allowed the isolation and
identification of three new sucrose esters, named as peruvioses C–E (1–3), along with the known peruvioses A (6), B (5) and F (4),
the structures of which were elucidated by extensive NMR and MS experiments. These compounds proved to be responsible for
the hypoglycemic activity observed in the extract. Peruviose D (2) showed the highest activity, with an inhibitory activity value of
8
4.8%. This is the first study to establish the potential of sucrose esters as α-amylase inhibitors and to explain the hypoglycemic
effect that has traditionally been attributed to gooseberry fruit.
Keywords: Physalis peruviana, Cape gooseberry, Sucrose esters, Peruvioses A–F, hypoglycemic activity, α-amylase inhibitory
activity.
2

ACCEPTED MANUSCRIPT
1
.
Introduction
Physalis peruviana is a Solanaceae plant that grows in the Andes Mountains from Bolivia to Venezuela at altitudes between 1700
and 2900 m. Its edible fruit, which is known as cape gooseberry or ‘uchuva’, is well known for its flavor and for its uses in the
prevention and treatment of diabetes and pterygia, along with its use as a diuretic, anti-helminthic, and expectorant, amongst other
applications [1]. This wide range of uses has encouraged various studies on the pharmacological properties of different parts of
the plant and these have shown antioxidant, anti-inflammatory, diuretic, antispasmodic, anti-asthmatic, anti-lithiasic,
immunosuppressive, and antipyretic activities [2,3]. Anti-inflammatory activity, as assessed by ear edema and plantar edema
models in mice [1,4–6], along with larvicidal activity [7] were reported for calyces crude ethanolic extract and also for some of its
fractions. Studies on the anti-inflammatory activity of extracts and fractions of P. peruviana calyces suggest that the compounds
responsible for this activity are sucrose esters [5]. These types of sugars bear short-chain fatty acids and they are commonly found
in other species of these genera such as P. angulate [8], and P. philadelphica [8,9], among other species. In addition to this type of
compounds, other studies highlighted the presence of withanolides [7,10–13], alkaloids, esters, flavonoids , vitamins, glycosidic
flavor precursors and steroids.
As part of our ongoing research on the hypoglycemic activity of functional foods, we decided to study Physalis peruviana as a
source of compounds that may exert such activity. A worldwide increase in the incidence and prevalence of type 2 diabetes has
occurred in recent decades, and a variety of the currently available antidiabetic drugs are known to act by at least one of three
different mechanisms: (i) drugs that stimulate insulin secretion such as glibenclamide; (ii) drugs that decrease insulin sensitivity
such as metformin; and (iii) drugs that reduce the glucose absorption such as acarbose, which is one of the few drugs that act by
this mechanism. Therefore, the discovery of new drugs with this last mechanism has been the focus of recent studies. Several
substances isolated from plants show hypoglycemic activity and the main mode of action is to inhibit intestinal carbohydrases such
as α-amylase and α-glucosidase [14,15].
Two independent studies in the literature have highlighted the antidiabetic properties of extracts from P. peruviana fruits collected
in India and Colombia. Sathyadevi et al. reported that the oral administration of ethanolic extracts from P. peruviana fruits
collected in India improved insulin sensitivity and ameliorated hyperglycemia in high-fat diet/low dose streptozotocin-induced
type 2 diabetic rats [16]. A qualitative analysis of this extract was performed by the same authors and this revealed the presence of
phenols, flavonoids, glycosides, sterols, saponins, tannins, lactones and alkaloids. Moreover, the fruit extract was also found to
contain significant amounts of phenolic compounds and flavonoids, such as rutin, myricetin, quercetin and kaempferol [17]. The
same authors reported that the major flavonoids present in the fruit extracts proved to be aldose reductase inhibitors in molecular
3

ACCEPTED MANUSCRIPT
docking studies approach against that receptor [16,18]. It was reported that the oral administration of P. peruviana extracts from
fruits collected in Colombia, reduced blood glucose levels in rats in which diabetes had been induced by a single administration of
streptozotocin [19]. In a later study, it was found that the ethanolic extract of P. peruviana fruits showed competitive inhibition on
α-glucosidase and on the non-competitive type of α-amylase, suggesting that inhibition of intestinal carbohydrases is one of the
modes of action by which the fruits of P. peruviana exert hypoglycemic and antidiabetic activity [15]. More recently, a dry
powder formulation from standardized extracts of the fruit was reported to have hypoglycemic activity [20]. However, the studies
outlined above did not address the identities of the compounds responsible for the activity observed.
In order to identify the compounds responsible for the hypoglycemic activity, we studied the organic extracts from the sticky
exudate that covers the fruit by carrying out a bio-guided fractionation using an
α-amylase inhibition test model [15]. These
enzymes (carbohydrases) are present in the intestinal villi and they are necessary for polysaccharide digestion because they
participate in the cleavage of these compounds to give monosaccharides (glucose, fructose, galactose). Thus, inhibition of the
enzymes is one of the different possible mechanisms of antidiabetic drugs because such inhibition slows carbohydrate absorption
and decreases postprandial blood glucose levels in both normal and diabetic subjects [14]. We describe here the isolation and
structural elucidation of several sugar esters that are responsible for the effects of P. peruviana fruit on sugars levels. The
biological evaluation of these compounds allowed us to establish some structure-activity relationships.
2
.
Results and discussion
The α-amylase activity test conducted on the ethanolic extracts from P. peruviana fruit showed an inhibitory activity (IA) of
8.3%, which is similar to that determined for acarbose used as a positive control (IA 77.4%). These results, along with the
6
reported antidiabetic properties, indicate that this fruit has great potential as a source of compounds with hypoglycemic activity.
The sticky exudate was first extracted by direct immersion of the fruits in CH Cl to give the DF extract, followed by MeOH
2
2
extraction of the fruit (MF), and finally, the remaining fruit were dried, homogenized and extracted with EtOH to afford the
ethanolic extract (EF). The -amylase inhibition bioassay on the three extracts allowed us to locate the activity in the DF extract,
with an IA value of 77.4% (Figure 1), while the other evaluated extracts where less active.
α
4

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1
00
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
DF
2
5
3
1
6
4
Acarbose
Figure 1. In vitro inhibition of α-amylase for the DF extract and its major components, peruvioses A–F, displayed from higher to
lower inhibitory activity. CH Cl extract (DF), peruviose C (1), peruviose D (2), peruviose E (3), peruviose F (4), peruviose B (5),
2
2
peruviose A (6) and acarbose as a positive control. All compounds were tested at 640 ꢀg/mL. Results are expressed as mean ±
S.D.
The bioguided fractionation of the DF extract using several chromatographic techniques, allowed us the isolation of six
compounds (1–6). The structures of these compounds were elucidated by analysis of their 1D and 2D NMR data and mass spectra
and by basic hydrolysis and comparison of the products with authentic standards (Figure 2. Supporting information SI 2 – SI 21).
5

ACCEPTED MANUSCRIPT
3
b''''
3
a''''
OH
2
''''
''''
6
4
1
5
O
OH
2
1'
2'
O
1
3
a''O'
O
3
1
'''
OH5'
OR1
2
'''
O
O
OH
3
'
3
b'''
O
4'
6
'
OR2
2
'''''
1
'''''
4a'''''
1
''
Peruviose C (1)
R
1
=
R
2
=
8
''
6
3'''''
O
O
4
b'''''
2
'''''
1
'''''
4a'''''
Peruviose D (2) R =
1''
R =
2
1
1
2''
1
0
3'''''
O
O
4
b'''''
2
'''''
1
'''''
4a'''''
1
''
Peruviose B (5)
R
1
=
R =
2
1
0''
8
3'''''
O
O
4
b'''''
3
a'''''
1
'''''
2'''''
Peruviose E (3) R =
1''
R =
2
1
1
2''
1
0
3b'''''
O
O
3
a'''''
1
'''''
2'''''
Peruviose F (4)
Peruviose A (6)
R =
1''
R =
1
2
8
''
6
3b'''''
3b'''''
O
O
3
a'''''
1
'''''
2'''''
1''
R =
1
R =
2
1
0''
8
O
O
Figure 2. Sucrose esters isolated from Physalis peruviana fruits
56 15
Compound 1 (12 mg) was isolated as a colorless viscous liquid. The molecular formula of 1 was determined as C33H O
+
on the basis of its (+)-HRESIMS, which shows the [M + Na] ion peak at m/z 715.3511, (calcd for C H O Na, 715.3511, ∆ 0.0
3
3
56 15
1
ppm) and the NMR data. The presence of a disaccharide sucrose structure in 1 was suggested by the H-NMR spectrum in CDCl3
(
Table 1), which contained eight oxymethine proton signals at δ 5.59, 5.46, 5.21, 4.95, 4.91, 4.52, 4.15 and 3.95, along with three
H
6

ACCEPTED MANUSCRIPT
oxymethylene signals at δH 3.88 /3.72, 3.55 and 3.59 /3.46. The NMR carbon signals at δ 103.84, 89.41, 82.61, 79.11, 72.03,
C
1
3
7
1.32, 70.10, 69.05, 68.29, 64.62, 61.55 and 59.90 observed in the C-NMR spectrum of 1, which were correlated to their
1
1
corresponding protons signals by an HSQC experiment and linked by a H- H COSY experiment, confirmed the existence of a
13
C
sucrose structure. The signals of four ester carbonyl carbons observed in the C-NMR spectrum of 1 at δ 177.80, 175.96, 175.71
and 172.87 suggested the presence of four acyl substituents. Thus, the presence of two isobutanoyl groups in 1 was deduced from
the proton and carbon NMR methine signals at δH 2.51 /δC 33.92 and δH 2.45 /δC 33.88, which were connected by a COSY
experiment to four methyl protons at δH 1.13, 1.11, 1.08 and 1.06 /δ 18.67–19.07. The methylene proton signal at δH 2.39 /δC
C
4
3.13, which correlates by COSY to the methine proton signal at δ 2.20/δ 25.84 and this is in turn to two methyl proton groups
H C
H H
at δ 1.05 and 1.03, is indicative of a 3-methylbutanoyl moiety. HMBC correlations between the methylene proton signals at δ
2
.39 and methyl carbon at δC 25.84, between the methyl protons at δH 1.05 and 1.03 and carbons at δC 43.13 and 25.84, and
between the methine proton at δH 2.20 and methylene carbon at δC 43.13 allowed us to confirm the presence of the 3-
methylbutanoyl subunit. Finally, methylene NMR signals between δH 2.25 and 1.25/δC 33.86–22.58 in combination with a
terminal methyl group at δ 0.87/δ 14.03, were indicative of an alkyl chain of a saturated fatty acid in 1. An HMBC experiment
H
C
allowed us to connect each acyl group to the sucrose structure by the key long-range correlations shown in Table 1 [5,21].
All of the above data are similar to those of peruviose B (5) [5], which was also isolated in this study and is a sucrose ester
bearing a C10 fatty acid at position C2 in the glucose moiety, two isobutanoyl groups at C3 and C4 and one 3-methylbutanoyl
group at C3' in the fructose moiety. The difference of 28 mass units between the molecular weight of compound 1 (m/z 715
+
+
observed for the [M + H] ion peak in the ESIMS) and the reported value for peruviose B (5, m/z 743 reported for [M + Na] ion
peak in the FABMS), are indicative of the lack of two methylene groups in 1. This finding allowed us to determine the presence of
an octanoyl group attached to C2 in 1 rather than the decanoyl subunit in peruviose B (5). Thus, the structure of compound 1,
named as peruviose C, was established as is presented in Figure 2.
7

ACCEPTED MANUSCRIPT
Peruviose C (1)
, m, (J in Hz)
Peruviose D (2)
Peruviose E (3)
Peruviose F (4)
δ
H
, m, (J in
δ
H
, m, (J
in Hz)
Position
xδ
C
, type
δ
H
HMBC
δ
C
, type
δ
H
, m, (J in Hz)
HMBC
C
δ , type
HMBC
C
δ , type
HMBC
Hz)
Glucose unit
5, 2’
1
2
3
4
5
6
89.41, CH
70.10, CH
69.05, CH
68.29, CH
72.03, CH
5.59, d, (3.6)
4.91, m
5, 2’
3, 1’’
89.47, CH
70.16, CH
69.08, CH
68.34, CH
72.02, CH
5.47, d, (3.7)
4.91, m
89.40, CH
70.06, CH
69.02, CH
68.25, CH
72.18, CH
5.59, d, (3.7)
4.92, m
5, 2’
3, 1’’
89.38, CH
70.03, CH
68.98, CH
68.24, CH
72.04, CH
5.60, d, (3.3)
4.92, m
5, 2’
3, 1’’
3, 1’’
5.46, t, (9.9)
4.95, t, (9.9)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.46, t, (10.0)
4.95, t, (10.0)
4.14, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.47, t, (10.0)
4.95, t, (10.0)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.47, t, (9.9)
4.95, t, (9.9)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
61.55, CH
2
3.55, m
61.56, CH
2
3.58, m
61.60, CH
2
3.58, m
61.50, CH
2
3.60, m
Fructose unit
1
’a
’b
64.62, CH
2
3.59, m
3.46, m
64.55, CH
2
3.57, m
3.47, m
-
64.69, CH
2
3.58, d, (12.5)
3.46, d, (12.5)
-
64.54, CH
2
3.58, d, (13.0)
3.46, d, (13.0)
-
1
2
’
’
’
’
103.84, C
79.11, CH
71.32, CH
82.61, CH
103.94, C
79.21, CH
71.28, CH
82.61, CH
103.81, C
79.12, CH
71.19, CH
82.55, CH
103.82, C
79.05, CH
71.30, CH
82.54, CH
3
5.21, d, (8.1)
4.52, t, (8.1)
3.95, m
1’, 4’, 1’’’’’
5.22, d, (8.1)
4.55, t, (8.1)
3.91, m
1’, 4’, 1’’’’’
5.18, d, (8.2)
4.59, t, (8.2)
3.93, m
1’, 4’, 1’’’’’
5.20, d, (7.9)
4.52, t, (7.9)
3.92, m
1’, 4’, 1’’’’’
4
5
3’, 5’, 6’
3’, 5’, 6’
3’, 5’, 6’
3’, 5’, 6’
4’
4’
4’
4’
4’
4’
4’
4’
6
’a
’b
59.90, CH
2
3.88, m
59.88, CH
2
3.73, m
59.73, CH
2
3.89, m
59.92, CH
2
3.89, m
6
3.72, br d, (13.4)
3.70, m
3.73, br d, (12.3)
3.75, m
Substituent at C2
1
2
3
4
5
6
7
8
9
’’
’’
’’
’’
’’
’’
’’
’’
’’
172.87, C
-
172.88, C
-
172.78, C
-
172.87, C
-
33.86, CH
24.54, CH
29.14, CH
2
2.25, m
3’’
2’’
33.93, CH
2
2.25, m
3’’
2’’
34.05, CH
2
2.25, m
3’’
2’’
33.83, CH
24.54, CH
28.85, CH
29.00, CH
31.56, CH
22.56, CH
14.04, CH
2
2.25, m
3’’
2’’
2
2
1.53, m
24.57, CH
2
1.56, m
24.57, CH
2
1.54, m
2
2
2
2
2
3
1.54, m
1.24, br s
1.24, br s
1.24, br s
1.24, br s
0.86, t, (6.8)
29.57, CH
2
**
**
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
0.87, t, (7.0)
29.08, CH
29.22, CH
29.31, CH
29.39, CH
29.58, CH
29.69, CH
2
**
**
**
**
**
**
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
0.88, t, (6.8)
1.25, br s
1.25, br s
1.25, br s
1.25, br s
0.87, t, (6.7)
2
9.05 – 29.01,
CH **
2
29.57, CH
2
2
31.75, CH
22.58, CH
14.03, CH
2
2
3
29.39 , CH
2
**
**
2
29.30 , CH
2
2
6’’, 7’’
2
29.21, CH **
2
6’’, 7’’
2
29.09, CH **
2
10’’
11’’
12’’
31.88, CH
22.66, CH
14.07, CH
2
2
3
31.89, CH
22.66, CH
14.08, CH
2
2
3
6’’, 7’’
10’’, 11’’
8

ACCEPTED MANUSCRIPT
Substituent at C3
1
2
’’’
’’’
175.71, C
33.88, CH
-
174.05
33.87
-
175.73, C
33.89, CH
-
175.76, C
33.87, CH
-
2.45, sp, (7.0)
1.08 d, (7.0)
1.06 d, (7.0)
2.45, sp, (7.0)
1.08 d, (7.0)
1.07 d, (7.0)
2.45, sp, (7.0)
1.07, d, (7.0)
1.08, d, (7.0)
2.45, sp, (7.0)
1.07, d, (7.0)
1.08, d, (7.0)
1
8.66-19.08,
CH
8.66-19.08,
CH
3
3
’’’a
’’’b
18.67-19.07, CH
3
*
*
2’’’
2’’’
2’’’
2’’’
18.88-18.75, CH
3
3
18.71-19.06, CH
3
*
2’’’
2’’’
2’’’
2’’’
3
*
1
18.67-19.07, CH
3
18.88-18.75, CH
18.71-19.06, CH
3
*
3
*
Substituent at C4
1
2
’’’’
’’’’
175.96, C
33.92, CH
-
175.63, C
33.89, CH
-
175.98, C
33.93, CH
-
176.00, C
33.90, CH
8.66-19.08,
-
2.51, sp (7.0)
1.13, d (7.0)
1.11, d, (7.0)
3’’’’
2.52, sp, (7.0)
1.13, d, (7.0)
1.11 d, (7.0)
3’’’’
2’’’’
2.51, sp, (7.0)
1.14, d, (7.0)
1.05, d, (7.0)
3’’’’
2’’’’
2’’’’
2.51, sp, (7.0)
1.14, d, (7.0)
1.06 , d, (7.0)
3’’’’
2’’’’
2’’’’
1
3
’’’’a
’’’’b
18.67-19.07, CH
3
*
*
2’’’’
2’’’’
18.88-18.75, CH
18.88-18.75, CH
3
3
18.71-19.06, CH
3
*
CH
8.66-19.08,
CH
3
*
1
3
18.67-19.07, CH
3
2’’’’
18.71-19.06, CH *
3
3
*
Substituent at C3’
1
2
3
’’’’’
’’’’’
’’’’’
177.80, C
-
176.06, C
177.93, C
34.02, CH
-
177.81, C
33.99, CH
-
2
.40, dd, (14.0,
.0)
43.13, CH
2
2.39, dd, (12.8, 6.7)
2.20, m
4´´´´a
2’’’’’
43.15, CH
2
4´´´´a
2’’’’’
2.75, sp, (7.0)
3’’’’’
2.75, sp, (7.0)
3’’’’’
7
25.84, CH
25.87, CH
2.19, m
1
8.66-19.08,
CH
8.66-19.08,
CH
3’’’’’a
3’’’’’b
4’’’’’a
4’’’’’b
18.71-19.06, CH
3
*
1.33, d, (7.0)
1.29, d, (7.0)
2’’’’’
2’’’’’
1.32, d, (7.0)
1.29, d, (7.0)
2’’’’’
2’’’’’
3
*
1
18.71-19.06, CH
3
*
3
*
2
2
’’’’’, 3’’’’’,
2’’’’’, 3’’’’’,
4’’’’’b
22.54, CH
3
1.05 , d, (6.5)
1.03, d, (6.5)
22.30, CH
3
1.06, d, (6.4)
1.04, d, (6.4)
4
’’’’’b
’’’’’, 3’’’’’,
’’’’’a
2’’’’’, 3’’’’’,
4’’’’’a
24.54, CH
3
22.42, CH
3
4
*The multiplicity could not be determined
** Signals may be interchanged
1
Table 1. NMR- H data (CDCl
3
, 400 MHz) for Compound 1 to compound 4 (Peruvioses C-F).
9

ACCEPTED MANUSCRIPT
Compound 2 (7 mg) was isolated as a colorless viscous liquid. The molecular formula of 2 was established as C H O
64 15
3
7
+
64
by the [M + Na] sodium adduct ion observed in the (+)-HRESIMS at m/z 771.4156 (cald for C37H O15Na, 771.4137, ∆ 1.9 ppm)
1
13
and the NMR data. The H-NMR and C-NMR (Table 1) spectra along with 2D NMR experiments (COSY, HSQC and HMBC)
of 2 are consistent with a sucrose ester structure bearing two isobutanoyl groups at C3 and C4, one 3-methylbutanoyl group at C3'
and a fatty acid chain at C2. The NMR data for 2 were very similar to those of peruviose C (1) and peruviose B (5), only differing
in the length of the fatty acid chain attached to C2. The difference of 56 mass units between the molecular weight of compounds 1
and 2, indicating the presence of four additional methylene groups, allowed us to establish presence of a dodecanoyl group bonded
to C2 in 2 rather than the octanoyl subunit in peruviose C (1). Thus, the structure of compound 2, named as peruviose D, was
established and is presented in Figure 2.
Compound 3 (4 mg) was isolated as a colorless viscous liquid with molecular formula C36
62
H O15, as evidenced by (+)-
HRESIMS at m/z 757.3982 (calcd for C H O Na, 757.3981, ∆ 0.1 ppm). Once again, the presence of a sucrose structure in 3
3
6
62 15
1
was suggested by its H-NMR spectrum (Table 1), with eight oxymethine signals at δ 5.59, 5.47, 5.18; 4.95, 4.92, 4.59, 4.15 and
H
3
H
.93 along with three oxymethylenes at δ 3.89 /3.73, 3.58 and 3.58 /3.46. This was confirmed by the presence of two anomeric
carbons (δC 103.81 and 89.40), seven oxymethines (δC 82.55, 79.12, 72.18, 71.19, 70.06, 69.02 and 68.25) and three
13
oxymethylenes (δ 64.69, 61.60 and 59.73) in the C-NMR spectrum (Table 1). Similarly, the presence of four acyl substituents
C
13
in 3 was suggested by the four characteristic ester carbonyl carbons at δ 177.81, 176.00, 175.76 and 172.87 observed in the C-
C
NMR spectrum of 3 (Table 1). However, the proton and carbon NMR data of 3 show the presence of three methine NMR signals
H C H C H C H
at δ 2.75/δ 34.02, δ 2.51/δ 33.93 and δ 2.45/δ 33.89, which correlated by COSY to the corresponding methyl groups at δ
1
.33, 1.29, 1.14, 1.08, 1.07, 1.05 /δ 19.06–18.71, thus indicating the presence of three isobutanoyl groups in 3 instead of two
C
isobutanoyl and one 3-methylbutanoyl subunits as in 1 and 2. The presence of a fatty acid group was also deduced from the
methylene signals between δ 2.25 and 1.27 and the terminal methyl at δ 0.88. The NMR chemical shifts of 3 are very similar to
H
H
those of peruviose A (6), a sucrose ester previously isolated from P. peruviana calyces [5] and also isolated in this study .
This compound is characterized by a long-chain fatty acid (C10) bonded to position C2 and three isobutanoyl groups at
positions C3, C4 and C3' of the sucrose moiety (Figure 2). Analysis of the 2D NMR spectra of 3, including COSY, HSQC and
HMBC (Table 1), allowed us to assign unambiguously most of the signals for compound 3. The difference of 28 mass units
+
between the molecular weight of 3 (its (+)-LRESIMS shows an [M + H] ion peak at m/z 757) in regard to that of peruviose A
(
reported m/z 729) indicated the presence of dodecanoic acid bonded at position C2. The 12 carbon signals assigned to carbons C-
" to C-12" (Table 1) of the fatty acid confirmed that proposal. Thus, the structure of 3, named as peruviose E, was established and
is presented in Figure 2.
Compound 4 (9 mg) was isolated as a colorless viscous liquid. The molecular formula of 4 was determined as C H O
1
3
2
54 15
1
0

ACCEPTED MANUSCRIPT
+
on the basis of its HRFABMS, which shows the [M + Na] ion peak at m/z 701.3375 (calculated for C H O Na, 701.3355, ꢁ 2.0
3
2
54 15
1
13
ppm), and its NMR data. The H- and C-NMR spectra in combination with COSY, HSQC and HMBC experiments on 4 (Table
) showed the signals of eight oxymethine and three oxymethylenes that are characteristic of another sucrose ester, along with
three septets that are indicative of three isobutanoyl groups at δ 2.75/δ 33.99, 2.51/δ 33.90 and δ 2.45/δ 33.87 and the typical
1
H
C
C
H
C
methylene signals corresponding to a fatty acid subunit. All of these NMR signals were very similar to those of peruviose E (3)
and only differ in the long-chain fatty acid that forms the ester on the hydroxyl group at C2 of the glucose unit. The presence of a
C fatty acid in 4 was proposed from the eight carbon signals at δ 172.87, 33.83, 24.54, 28.85, 29.00, 31.56, 22.56 and 14.04
8
C
1
3
observed in the C-NMR spectrum and from the molecular formula C H O . Thus, the structure of peruviose F (4) is proposed
32
54 15
as shown in Figure 2. Although the structure of this compound was recently included in an International Patent related to a P.
peruviana extract comprising sucrose esters as the active agents for use in a cosmetic application, the NMR and mass spectral data
for 4 are here reported for the first time [22].
Peruviose B (5, 42 mg) and peruviose A (6, 44 mg) were also isolated from the DF extract and identified by comparison of
1
13
their H- and C-NMR data with those reported by Franco et al., from a mixture of these compounds from the same plant [5].
Thus, this is the first time that peruviose A (6) and peruviose B (5) have been isolated as pure compounds. For the absolute
configuration of the sucrose moiety, the basic hydrolysis of 1–4 was performed. The work up of the reaction gave a residue that
showed an optical rotation value ([α] = +52.7) that is similar to the one reported for a standard of sucrose ([α] = +66).
D
D
Once compounds 1–6 had been fully characterized, they were tested in the α-amylase inhibition assay. The results
obtained (Figure 1), were very similar to those obtained for the DF extract. Peruvioses D (2) and B (5) gave IA values of 84.8%
and 78.2%, respectively, and they were the most active compounds followed by peruvioses E (3), C (1), A (6) and F (4). These
results highlight the importance of the length of the fatty acid chain at C2 of the glucose and the presence of an isobutanoyl group
at C3 of the fructose subunit for α-amylase inhibition. Thus, an increase in the length of the fatty acid results in increased
inhibition. Indeed, for compounds bearing one 3-methylbutanoyl and two isobutanoyl units, the inhibition activity (IA) values
increase from an IA < 50% for peruviose F (4), which has a C fatty acid, to an IA of 78% for peruviose B (5), which has a C ,
8
10
and to an IA of 84% for peruviose D (2) with a C12 fatty acid. A similar increase was found for compounds bearing three
isobutanoyl units: peruviose F (4, C , < 50%) < peruviose A (6, C , 53%) < peruviose E (3, C , 61%). Those compounds bearing
8
10
12
the same fatty acid chain but with one 3-methylbutanoyl and two isobutanoyl units, peruvioses D (2), B (5) and C (1), were more
active than those having three isobutanoyl units (peruvioses E (3), A (6) and F (4), respectively).
Thus, peruvioses A to F are described here as a family of sucrose esters characterized by the presence of an isobutanoyl
group at C4 in the sucrose moiety. This class of compounds has been described in other Physalis species such as P. philadelphica
1
1

ACCEPTED MANUSCRIPT
Lam. P. angulate [8,9], as well as in other exudates commonly observed in Solanaceae such as those from the genera
Lycopersicon, Nicotiana, Petunia, and Solanum [23,24]. Besides the fruits, these sucrose esters are also present in the trichome
and they are believed to protect plants and fruits from insects and fungi. Moreover, this type of compound is responsible for the
anti-inflammatory activity found in the extracts of these species [9]. As in other species, these sucrose esters are considered to be
the main material in the exudates obtained mainly in the DF fraction.
3
.
Conclusion
In conclusion, bioguided fractionation of a dichloromethane extract of P. peruviana fruit, which showed a considerable
inhibitory effect on the
separation of that mixture afforded three new sucrose esters, named as peruvioses C–E (1–3), along with three known esters,
namely peruvioses A (6), B (5) and F (4). The results of -amylase enzyme inhibition assays showed that peruviosides D (2) and
α-amylase enzyme, allowed us to obtain a fraction with a high sucrose ester content. Subsequent
α
B (5) are the most active. The structure-activity relationships of the isolated compounds highlighted the importance of the fatty
acid length at C2 and the presence of a 3-methylisobutnoyl at C3' on the sucrose ester skeleton. Although peruvioses A (6) and B
(
5) were previously reported as a mixture, this is the first time that they have been isolated as pure compounds. Moreover, the
NMR and MS spectroscopic data are reported for the first time for peruviose F (4). This work constitutes the first study in which
the potential of sucrose esters as -glucosidase inhibitors has been described and the hypoglycemic effect that has been attributed
α
to gooseberry fruit has been explained. Studies for the evaluation of hypoglycaemic activity in mice are ongoing in our
laboratories.
4
.
Experimental section
4
.1. General Experimental Procedures.
1
13
1
H- and C-NMR (1D and 2D) spectra were recorded on a Bruker Avance 400 spectrometer (400 MHz for H and 100 MHz for
13
C) using CDCl as a solvent and residual solvent signals as internal standards. High-resolution mass data were collected on an
3
Applied Biosystems QSTAR Elite hybrid quadrupole Time-of-Flight (TOF) mass spectrometer, ESI positive mode. Column
chromatography (CC) was carried out under vacuum using silica gel 60 G Merck and flash chromatography was carried out on
silica gel 60 (230–400 mesh, Macherey-Nagel). Optical rotations were measured on a Polartronic E, Schmidt + Haensch
polarimeter. HPLC-PDA was carried out with a Perkin-Elmer LC 480 system equipped with an AD224 controller, a Perkin-Elmer
series 410 LC pump and a LC-480 auto scan diode array detector. HPLC-ELSD was performed on a Thermo Dionex ultimate
1
2

ACCEPTED MANUSCRIPT
3
000 system, coupled to an ELSD Sedex 85 detector with a gain of 10 for the ELSD detector and a temperature of 40 ºC for the
analysis. A TECAN GENIOS spectrophotometer was used to study the α-amylase inhibition activity.
4
.2 Plant Material. Physalis peruviana fruit (uchuva or cape gooseberry) was purchased in a commercial culture located at Subia
in the state of Cundinamarca (Colombia). A voucher specimen of the plant was identified and deposited (COL-574701) at the
Herbario Nacional Colombiano of the Universidad Nacional de Colombia at Bogotá (Colombia).
4
.3. Extraction and Isolation. The entire mass of fruit (5000 g) of Physalis peruviana was immersed in CH Cl for 5 minutes to
2 2
obtain, after filtration and evaporation of solvent under vacuum, the dichloromethane extract (DF, 4.1 g). The fruit containing the
CH Cl insoluble material was immersed in MeOH for 5 minutes to give, after evaporation under vacuum, the methanolic extract
MF, 6.7 g). After these extractions, the remaining fruit matter was ground, dried in an air oven and then extracted with EtOH to
yield, after removal of the solvent, the ethanolic extract (EF, 283.7 g). All of the extracts were evaluated in vitro for hypoglycemic
activity using the -amylase inhibition test.
2
2
(
α
The most active extract, DF, was fractionated by silica gel column chromatography and eluted under a gradient using
hexane (100%), Hex-EtOAc (80:20, v/v), Hex-EtOAc (50:50, v/v), Hex-EtOAc (20:80, v/v), EtOAc (100%), EtOAc-MeOH
(
90:10, v/v), EtOAc-MeOH (50:50, v/v), MeOH (100%) and MeOH-H O (90:10, v/v). Fractions of 125 mL were collected to
2
obtain 16 fractions (DF1 to DF16). The in vitro α-amylase inhibition bioassay showed that DF8 was the most active fraction.
Fraction DF8 (676.3 mg) was separated by HPLC-PDA on a semi-preparative Zorbax Eclipse XDB C18 column (250 mm × 9.4
mm, 5 ꢀm) using a mobile phase consisting of a gradient of H O-MeOH mixtures: (30:70, v/v) for 5 min, (0:100, v/v) for 20 min,
2
(0:100, v/v) for 10 min and (30:70, v/v) for 5 min at a flow rate of 2 mL/min. Fractions were collected every 5 min to give eight
sub-fractions (DF8-1 to DF8-8). Fraction DF8-6 (300 mg), which showed the highest α-amylase inhibition activity, was further
fractionated by HPLC-ELSD on a Zorbax Eclipse XDB C18 column (250 mm × 9.4 mm, 5 ꢀm) using a mobile phase consisting of
a gradient of H
2
O-MeOH mixtures: (10:90, v/v) for 30 min, (0:100, v/v) for 15 min and finally, (10:90, v/v) for 5 min, at a flow of
1
.5 mL/min, to yield compounds 1 (12 mg), 2 (7 mg), 3 (4 mg), 4 (9 mg), 5 (42 mg) and 6 (44 mg).
4
.4. Basic hydrolysis of compounds 1 to 4. Compounds 1–4 (2 mg each) were separately heated under reflux in a 5% methanolic
KOH solution (10 mL) for 1 h. The basic solution was cooled, neutralized carefully with 2 N HCl and diluted with water (10 mL).
The resulting solution was extracted with Et O (3 × 10 mL) to give, in the aqueous fraction after evaporation under vacuum, an
2
amorphous powder. The solid was treated under standard acetylation conditions (Ac O/pyridine, overnight) and the peracetylated
2
1
product was analysed by NMR spectroscopy. H NMR (400 MHz, CDCl ) δ 5.71 (1H, d, J = 8.3 Hz, anomeric), 5.47 (1H, t, J =
3
1
3

ACCEPTED MANUSCRIPT
9
4
1
.9 Hz, –CHOH), 5.36 (1H, d, J = 5.7 Hz, –CHOH), 5.24 (1H, dd, J = 20.2, 10.7 Hz, CHOH), 4.95 (1H, d, J = 5.4 Hz, –CHOH),
.61 (1H, d, J = 11.2 Hz, –CH OH), 4.21 (1H, m, –CH), 3.87 (1H, s, –CH), 3.84 (1H, d, J = 9.7 Hz, –CHOH), 3.72 (1H, d, J =
2
3.3 Hz, –CHOH), 3.64 (2H, m, –CH OH), 3.55 (1H, d, J = 12.0 Hz, –CHOH), 3.49 (1H, d, J = 9.0 Hz, –CHOH), 1.9–2.2
2
(overlapped singlets, AcO). These NMR data matched those of a sucrose standard and the NMR data reported for sucrose in the
literature [25,26,23,24]
4
.5. α-Amylase inhibition assay. All of the extracts, fractions and compounds 1–6 were evaluated for α-amylase inhibition
activity according to the methodology described by Hansawasdi-Kawabata [27] and modified by us [15]. Briefly, 200 µL of
insoluble corn starch covalently linked with Remazol Brilliant Blue [28] (10 mg/mL) were boiled for 5 min with subsequent
addition of 100 µL of Tris-HCl buffer (0.05 M, pH 6.9 with calcium chloride 0.01 M), 100 µL of porcine pancreatic
α-amylase
(PPA, 2.1 IU/mL) and 200 µL of the extract, fraction or pure compounds of P. peruviana or acarbose (positive control) at a
concentration of 640 ꢀg/mL. After incubation at 37 °C for 1 h, the absorbance was measured at 595 nm using a TECAN GENIOS
spectrophotometer.
Acknowledgments
We would like to thank the Universidad Nacional de Colombia for the scholarship of C.A. Bernal (DIB; grant 15192) and the
Ministry of Economy and Competitiveness (MINECO) (Grant AGL2015-63740-C2-2-R) of Spain, co-funded by the FEDER
Programme from the European Union.
1
4

ACCEPTED MANUSCRIPT
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ACCEPTED MANUSCRIPT
Peruviose C (1)
, m, (J in Hz)
Peruviose D (2)
, m, (J in Hz)
Peruviose E (3)
, m, (J in Hz)
Peruviose F (4)
δ
H
, m, (J in
Position
xδ
C
, type
δ
H
HMBC
δ
C
, type
δ
H
HMBC
δ
C
, type
δ
H
HMBC
δ
C
, type
HMBC
Hz)
Glucose unit
5, 2’
1
2
3
4
5
6
89.41, CH
70.10, CH
69.05, CH
68.29, CH
72.03, CH
5.59, d, (3.6)
4.91, m
5, 2’
3, 1’’
89.47, CH
70.16, CH
69.08, CH
68.34, CH
72.02, CH
5.47, d, (3.7)
4.91, m
89.40, CH
70.06, CH
69.02, CH
68.25, CH
72.18, CH
5.59, d, (3.7)
4.92, m
5, 2’
3, 1’’
89.38, CH
70.03, CH
68.98, CH
68.24, CH
72.04, CH
5.60, d, (3.3)
4.92, m
5, 2’
3, 1’’
3, 1’’
5.46, t, (9.9)
4.95, t, (9.9)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.46, t, (10.0)
4.95, t, (10.0)
4.14, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.47, t, (10.0)
4.95, t, (10.0)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
5.47, t, (9.9)
4.95, t, (9.9)
4.15, m
2, 4, 1’’’
3, 5, 6, 1’’’’
61.55, CH
2
3.55, m
61.56, CH
2
3.58, m
61.60, CH
2
3.58, m
61.50, CH
2
3.60, m
Fructose unit
1
1
’a
’b
64.62, CH
2
3.59, m
3.46, m
64.55, CH
2
3.57, m
3.47, m
-
64.69, CH
2
3.58, d, (12.5)
3.46, d, (12.5)
-
64.54, CH
2
3.58, d, (13.0)
3.46, d, (13.0)
-
2
’
’
’
’
103.84, C
79.11, CH
71.32, CH
82.61, CH
103.94, C
79.21, CH
71.28, CH
82.61, CH
103.81, C
79.12, CH
71.19, CH
82.55, CH
103.82, C
79.05, CH
71.30, CH
82.54, CH
3
5.21, d, (8.1)
4.52, t, (8.1)
3.95, m
1’, 4’, 1’’’’’
5.22, d, (8.1)
4.55, t, (8.1)
3.91, m
1’, 4’, 1’’’’’
5.18, d, (8.2)
4.59, t, (8.2)
3.93, m
1’, 4’, 1’’’’’
5.20, d, (7.9)
4.52, t, (7.9)
3.92, m
1’, 4’, 1’’’’’
4
5
3’, 5’, 6’
3’, 5’, 6’
3’, 5’, 6’
3’, 5’, 6’
4’
4’
4’
4’
4’
4’
4’
4’
6
6
’a
’b
59.90, CH
2
3.88, m
59.88, CH
2
3.73, m
59.73, CH
2
3.89, m
59.92, CH
2
3.89, m
3.72, br d, (13.4)
3.70, m
3.73, br d, (12.3)
3.75, m
Substituent at C2
1
2
3
4
5
6
7
8
9
’’
’’
’’
’’
’’
’’
’’
’’
’’
172.87, C
-
172.88, C
-
172.78, C
-
172.87, C
-
33.86, CH
24.54, CH
29.14, CH
2
2.25, m
3’’
2’’
33.93, CH
24.57, CH
2
2.25, m
3’’
2’’
34.05, CH
2
2.25, m
3’’
2’’
33.83, CH
24.54, CH
28.85, CH
29.00, CH
31.56, CH
22.56, CH
14.04, CH
2
2.25, m
3’’
2’’
2
2
1.53, m
2
1.56, m
24.57, CH
2
1.54, m
2
2
2
2
2
3
1.54, m
1.24, br s
1.24, br s
1.24, br s
1.24, br s
0.86, t, (6.8)
29.57, CH
2
**
**
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
1.24, br s
0.87, t, (7.0)
29.08, CH
29.22, CH
29.31, CH
29.39, CH
29.58, CH
29.69, CH
2
**
2
**
2
**
2
**
2
**
2
**
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
1.25, br s
0.88, t, (6.8)
1.25, br s
1.25, br s
1.25, br s
1.25, br s
0.87, t, (6.7)
2
29.05 – 29.01, CH **
29.57, CH
2
31.75, CH
22.58, CH
14.03, CH
2
2
3
29.39 , CH
2
**
**
29.30 , CH
2
6’’, 7’’
2
29.21, CH **
6’’, 7’’
2
29.09, CH **
10’’
11’’
12’’
31.88, CH
22.66, CH
14.07, CH
2
2
3
31.89, CH
22.66, CH
14.08, CH
2
2
3
6’’, 7’’
Substituent at C3
-
10’’, 11’’
1
2
’’’
’’’
175.71, C
33.88, CH
-
174.05
33.87
175.73, C
33.89, CH
-
175.76, C
33.87, CH
-
2.45, sp, (7.0)
1.08 d, (7.0)
1.06 d, (7.0)
2.45, sp, (7.0)
1.08 d, (7.0)
1.07 d, (7.0)
2.45, sp, (7.0)
1.07, d, (7.0)
1.08, d, (7.0)
2.45, sp, (7.0)
1.07, d, (7.0)
1.08, d, (7.0)
3
’’’a
’’’b
18.67-19.07, CH
18.67-19.07, CH
3
*
2’’’
2’’’
2’’’
2’’’
18.88-18.75, CH
3
3
18.71-19.06, CH
3
*
2’’’
2’’’
18.66-19.08, CH
3
*
*
2’’’
2’’’
3
3
*
18.88-18.75, CH
18.71-19.06, CH *
3
18.66-19.08, CH
3

ACCEPTED MANUSCRIPT
Substituent at C4
1
2
’’’’
’’’’
175.96, C
33.92, CH
-
175.63, C
33.89, CH
-
175.98, C
33.93, CH
-
176.00, C
33.90, CH
-
2.51, sp (7.0)
1.13, d (7.0)
1.11, d, (7.0)
3’’’’
2’’’’
2’’’’
2.52, sp, (7.0)
1.13, d, (7.0)
1.11 d, (7.0)
3’’’’
2’’’’
2.51, sp, (7.0)
1.14, d, (7.0)
1.05, d, (7.0)
3’’’’
2’’’’
2’’’’
2.51, sp, (7.0)
1.14, d, (7.0)
1.06 , d, (7.0)
3’’’’
2’’’’
2’’’’
3
’’’’a
18.67-19.07, CH
18.67-19.07, CH
3
*
18.88-18.75, CH
3
3
18.71-19.06, CH
3
*
18.66-19.08, CH
3
*
*
3
’’’’b
3
*
18.88-18.75, CH
2’’’’
18.71-19.06, CH *
3
18.66-19.08, CH
3
Substituent at C3’
1
2
3
’’’’’
’’’’’
’’’’’
177.80, C
-
176.06, C
177.93, C
34.02, CH
-
177.81, C
33.99, CH
-
43.13, CH
2
2.39, dd, (12.8, 6.7)
2.20, m
4´´´´a
2’’’’’
43.15, CH
2
2.40, dd, (14.0, 7.0)
2.19, m
4´´´´a
2’’’’’
2.75, sp, (7.0)
3’’’’’
2.75, sp, (7.0)
3’’’’’
25.84, CH
25.87, CH
3
3
4
4
’’’’’a
’’’’’b
’’’’’a
’’’’’b
18.71-19.06, CH
3
*
1.33, d, (7.0)
1.29, d, (7.0)
2’’’’’
2’’’’’
18.66-19.08, CH
3
*
*
1.32, d, (7.0)
1.29, d, (7.0)
2’’’’’
2’’’’’
18.71-19.06, CH
3
*
18.66-19.08, CH
3
22.54, CH
3
1.05 , d, (6.5)
1.03, d, (6.5)
2’’’’’, 3’’’’’, 4’’’’’b
2’’’’’, 3’’’’’, 4’’’’’a
22.30, CH
3
1.06, d, (6.4)
1.04, d, (6.4)
2’’’’’, 3’’’’’, 4’’’’’b
2’’’’’, 3’’’’’, 4’’’’’a
24.54, CH
3
22.42, CH
3
*The multiplicity could not be determined
** Signals may be interchanged
1
3
Table 1. NMR- H data (CDCl , 400 MHz) for Compound 1 to compound 4 (Peruvioses C-F).

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT
1
00
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
DF
2
5
3
1
6
4
Acarbose
Figure 1. In vitro inhibition of α-amylase for the DF extract and its major components, peruvioses A–F, displayed from
higher to lower inhibitory activity. CH Cl extract (DF), peruviose C (1), peruviose D (2), peruviose E (3), peruviose F (4),
2
2
peruviose B (5), peruviose A (6) and acarbose as a positive control. All compounds were tested at 640 μg/mL. Results are
expressed as mean ± S.D.

ACCEPTED MANUSCRIPT
3
b''''
3
a''''
OH
2
''''
''''
6
4
1
5
O
OH
2
1'
2'
O
1
3
a''O'
O
3
1
'''
OH5'
OR1
2
'''
O
O
OH
3
'
3
b'''
O
4'
6
'
OR2
2
'''''
1
'''''
4a'''''
1
''
Peruviose C (1)
R
1
=
R
2
=
8
''
6
3'''''
O
O
4
b'''''
2
'''''
1
'''''
4a'''''
Peruviose D (2) R =
1''
R =
2
1
1
2''
1
0
3'''''
O
O
4
b'''''
2
'''''
1
'''''
4a'''''
1
''
Peruviose B (5)
R
1
=
R =
2
1
0''
8
3'''''
O
O
4
b'''''
3
a'''''
1
'''''
2'''''
Peruviose E (3) R =
1''
R =
2
1
1
2''
1
0
3b'''''
O
O
3
a'''''
1
'''''
2'''''
Peruviose F (4)
Peruviose A (6)
R =
1''
R =
1
2
8
''
6
3b'''''
3b'''''
O
O
3
a'''''
1
'''''
2'''''
1''
R =
1
R =
2
1
0''
8
O
O
Figure 2. Sucrose esters isolated from Physalis peruviana fruits

ACCEPTED MANUSCRIPT
Highlights
•
The dichloromethane extract of P. peruviana fruit showed a considerable inhibitory effect on the α-amylase
enzyme.
•
Sucrose esters were responsible for α-glucosidase inhibition and this explains the hypoglycemic effect that has
been attributed to gooseberry fruits.
•
Three new sucrose esters were isolated, peruvioses C–E (1–3), along with three known sucrose esters,
peruvioses A (6), B (5) and F (4).
•
Peruviosides D (2) and B (5) showed the highest inhibitory effect on the α-amylase enzyme.