Introduction
Methodology
Plant selection
Obtaining extracts and fractions
Isolation and purification of the compounds present in the active fractions
Virus and cell maintenance
Determination of the selectivity index (SI)
Multiwell plate focus assay
Determining the antiviral effects of the fractions and compounds on virus cell entry
Determining the antiviral effects of the fractions and compounds after virus cell entry
Viral inhibition assay in VERO cells
Indirect immunofluorescence
Molecular docking
Statistical analysis
Results
Antiviral effects of the ethanolic extracts
Type of compound | Scientific name | Family | Voucher number | Plant part | CC50 | CE50 | SI |
---|---|---|---|---|---|---|---|
Ethanolic extracts |
Cymbopogon citratos Staf
| Poaceae |
JBC 12015
| Leaves | 155.1 | 343.1 | 0.5 |
Sarcostemma clausum Jacq
| Asclepiadaceae |
JBC 2502
| Leaves | 565.7 | 458.7 | 1.2 | |
Diospyros inconstans Jacq
| Ebenaceae |
JBC 1438
| Bark | 727.1 | 538.6 | 1.4 | |
Chrysobalanus icaco L
| Chrysobalanaceae |
JBC 934
| Seeds | 550.8 | 325.8 | 1.7 | |
Trichilia hirta L
| Meliaceae |
JBC 917
| Seeds | 213.6 | 62.9 | 3.4 | |
Croton malambo Karst
| Euphorbiaceae |
JBC 12008
| Bark | 127.3 | 31.3 | 4.1 | |
Ambrosia cumanensis Kunt
| Asteraceae |
COL 538448
| Leaves | 112.4 | 26.7 | 4.2 | |
Chenopodium ambrosioides L
| Chenopodiaceae |
JBC 4005
| Leaves | 131.6 | 24.8 | 5.3 | |
Cavanillesia platanifolia Bonpl
| Bombacaceae |
JBC 47576
| Almond | 252.6 | 43.5 | 5.8 | |
Momordica charantia L
| Cucurbitaceae |
JBC 793
| Seeds | 125.3 | 15.9 | 7.9 | |
Mammea americana L
| Calophyllaceae |
JBC 467
| Leaves | 440.7 | 52.3 | 8.4 | |
Psidium guajava L
| Myrtaceae |
JBC 1209
| Bark | 1000.0 | 7.8 | 128.2 | |
Fractions |
Psidium guajava L
| – |
HUA 140931
| Pg-YP-I-22A | 130.5 | 134.4 | 1.0 |
Pg-YP-I-22B | 308.9 | 26.5 | 11.7 | ||||
Pg-YP-I-22C | 625.7 | 17.7 | 35.4 | ||||
Pg-YP-I-22D | 177.9 | 56.1 | 3.2 | ||||
Pg-YP-I-22E | 102.2 | 16.7 | 6.1 | ||||
Compounds | Pg-YP-I-22C | – | – | Gallic Acid | 543.4 | 25.8 | 21.1 |
Naringin | 646.8 | 47.9 | 13.5 | ||||
Quercetin | 659.8 | 19.2 | 34.3 | ||||
Catechin | 833.3 | 33.7 | 24.8 | ||||
Hesperidin | 413.8 | 225.8 | 1.8 |
Preliminary phytochemical screening of the Psidium guajava bark fractions
Metabolite | Pg-YP-22A | Pg-YP-22B | Pg-YP-22C | Pg-YP-22D | Pg-YP-22E |
---|---|---|---|---|---|
Alkaloids | – | +++ | +++ | +++ | +++ |
Tannins | – | + | +++ | +++ | +++ |
Flavonoids | – | – | +++ | ++ | ++ |
Glycosides | – | – | + | ++ | – |
Triterpenes | ++ | ++ | – | – | – |
Sterols | ++ | ++ | + | – | – |
Coumarins | – | – | – | + | – |
Saponins | – | – | – | – | – |
Quinones | – | – | – | – | – |
Antiviral effects of the fractions obtained from the P. guajava extract
Identification of the compounds in the Pg-YP-I-22C fraction
Fraction code | Mobile phasea | Weight (mg) | Performance (%) |
---|---|---|---|
22CK001 | MeOH:Acetic acid 0.1% (10:90) | 77.5 | 7.8 |
22CK002 | MeOH:Acetic acid 0.1% (15:85) | 17.5 | 1.8 |
22CK003 | MeOH:Acetic acid 0.1% (20:80) | 22.0 | 2.2 |
22CK004 | MeOH:Acetic acid 0.1% (25:75) | 44.5 | 4.5 |
22CK005 | MeOH:Acetic acid 0.1% (25:75) | 27.9 | 2.8 |
Anti-DENV effects of the compounds obtained from the Pg-YP-I-22C fraction
Anti-DENV effects of the compounds on some steps of the DENV replication cycle
In silico analysis of binding between the compounds and viral proteins
Target | Compound | Binding energy (Kcal/mol) | Hydrogen bonds | Minimum distance between H bonds (Å) | Residues forming H bonds | Residues participating in hydrophobic interactions |
---|---|---|---|---|---|---|
E | SURAMIN | - 7.9 | 5 | 2.88 | Val2, Lys3, Tyr106, Lys361 | Leu4, Pro179, Lys181, Leu182, Glu191, Ser192, Asp362 |
GALLIC ACID | - 4.9 | 3 | 2.97 | Tyr106, Ser192, Lys361 | Ala105,Lys181, Glu191, Ile194, Asp362 | |
NARINGIN | - 8.0 | 9 | 2.71 | Lys3, Tyr106, Trp107, Lys175, Glu191, Ser192, Lys361 | Ala105, Gln178, Pro179, Pro180, Lys181, Ile194, Asp362 | |
QUERCETIN | - 6.6 | 2 | 2.86 | Lys361 | Leu4, Ala105, Ty106, Trp107, Pro179, Lys181 | |
CATECHIN | - 6.4 | 4 | 2.70 | Pro179, Pro180, Glu191, Ser192 | Ala105, Tyr106, Lys181 | |
HESPERIDIN | - 8.2 | 11 | 2.83 | Lys3, Ala105, Trp107, Ser192, Gly330, Ser331, Lys361 | Pro180, Lys181, Glu191, Asp329 | |
NS5 | SURAMIN | - 12 | 7 | 2.80 | Gly536, Thr539, Asn609, Ser661, Asp663, His798 | Gln350, Phe354, Val358, Ala535, Asp538, Gln597, Arg598, Ser600, Thr605, Tyr606, Gly662, Lys689, Cys709, Trp795, Ser796, Ile797 |
GALLIC ACID | - 5.3 | 4 | 2.87 | Trp477, Lys578, Gly601 | Val450, Arg481, Lys575, Val576, Val577, Gly599, Gln602 | |
NARINGIN | - 8.4 | 5 | 2.80 | Trp477, Gln597, Gly601, Gln602 | Trp302, Gln350, Phe354, Val358, Val450, Arg481, Asp538, Thr539, Lys578, Val576, Val577, Val579, Arg598, Ser600 | |
QUERCETIN | - 7.8 | 1 | 2.92 | Trp477 | Val353, Phe354, Val358, Arg481, Lys577, Val577, Val579, Gly599, Gly601, Gln602 | |
CATECHIN | - 7.2 | 6 | 2.73 | Ser600, Tyr606, Asn609, Ser661, Asp663, His798 | Thr605, Gly662, Ile797 | |
HESPERIDIN | - 8.8 | 7 | 2.86 | Asp533, Asp538, Asn609, Asp663, Lys689, Arg729, His798 | Tyr606, Gly662, Asp664, Cys709, Ser710, His711, Thr794, Ser796, Ile797 |