Flavonoids of Plantago species in Egypt

Biochemical Systematics and Ecology,Vol. 22, No. 7. pp. 729-733, 1994 Copyright 0 1994 Elsevier Science Ltd Printed in Great Britain. All rights reserved 0305-1978/94 $7.00+0.00 0305-1979(94)EOO31-A

Flavonoids of Plantago Species in Egypt S. A. KAWASHTY,* E. GAMAL-EL-DIN,t

M. F. ABDALLA* and N. A. M. SALEH*+

*Plant Systematics Department, National Research Centre, El-Dokki, Cairo, Egypt; tDepartment of Botany, Faculty of Science, Suez Canal University, Ismailia, Egypt

Key Word Index-P/anantago;

Plantaginaceae;

flavonoids;

chemosystematics.

Abstract-Flavonoid glycosides of 18 Plantago species belonging to six sections were investigated. Twentyfive glycosides were found to belong to the aglycones apigenin, luteolin, chrysoeriol, tricin and the less common hispidulin, nepetin and 5,6,7,3’-tetrahydroxy4’-methoxyflavone. Only one flavonol glycoside (isorhamnetin 3-rutinoside) was detected in three species belonging to sect. Leucopsyllium. Chemosystematic relationships are discussed.

Introduction The genus Plantago L. is the largest genus of the family Plantaginaceae with about 265 species (Feinbrun-Dothan, 1978). Taeckholm (1974) described 21 Plantago species which were distinguished on the basis of characters of stem, leaves, bracts, spike, corolla lobes and habit. In 1989 Greuter et a/. reported 18 Plantago species as being present in Egypt and cited /? coronopus and its close ally, F! crypsoides, as “Plantago coronopus” aggregate. However, the two taxa have been treated as separate species (Boissier, 1879; Taeckholm, 1974). The flavonoids of Plantago have also been widely reported. Thus apigenin, luteolin, scutellarein (5,6,7,4’-tetrahydroxyflavone) and hispidulin (5,7,4’-trihydroxyS-methoxyflavone) (Lebedev-Kosov, 1980; Giannasi, 1988), tricin (Giannasi, 1988), scutellarein 7-glucoside (Harborne, 1975), scutellarein 7-glucuronide (Moore et ab, 1973) and hispidulin 7-glucoside (Aritomi, 1964) were reported in Plantago species. 5,7,4’,5’-TetrahydroxyflavanoneS’-CI-gIucoside was reported as being present in Plantago major (Endo et al, 1981). Materials and Methods Plantmaterial.Fresh material was

collected whenever possible. Collection data (place, data and collector), an asterisk indicates a herbarium sample only: Plantago major L. (I*) Elephantine island, Aswan, 20.1.1979, Boulos; (2*) Khan El-Gin, 20 km north of Edfina, 5.4.1979, Boulos; (3) Garden of Faculty of Agriculture, 3.1993, Gamal-El-Din; (4) El-Azhar University, Nasr City, Cairo, 10.10.1991, Kawashty; p commutata Guss. (I*) Kalabsho, Delta, 10.4.1950, Shabetai; (2) El-Hammam, 80 km west of Alexandria, 7.5.1992, Kawashty; (3) 3 km west of Yamit, near Fiafah, 16.4.1992, Gamal El-Din; I? cyrpsoides Boiss. (I) El-Hammam, 80 km west of Alexandria, 7.2.1992, Kawashty; (2*) Burg El-Arab, Mediterranean coast, 28.3.1957, Saad; (3’) Mariut, 6.4.1935, Shabetai; (4) Gabal El-Maghara, N. Sina, 3.5.1991, Gamal El-Din; /? amplexicaulis Cav.; 35 km south east Nakhl, near road to Ras El-Naqb, 30.4.1991, Gamal El-Din; p lanceolata L.; Ismailia, 11.7.1990, Kawashty; i? lagopus L. (I) Burg El-Arab, 7.5.1993, Kawashty; (2) El-Azhar University gardens, Nasr City, Cairo, 22.5.1991, Kawashty; I! albicans L. (I*) Alexandria 21.4.1971, Abbus; (2*) Mariut, 5.4.1935, Shabetai; (3) 20 km Niuana at road to El-Arish, 2.5.1991, Gamal El-Din; (4) El-Kharouba, El-Arish, 15.4.1992, Kawashty; p cyhdrica Forssk. (1) Urn Bogma, Rafah, 16.4.1991; 12) Burg El-Arab, 7.2.1992, KawashtY; (3’) Wadi el-Tih, Maadi, Cairo, 1.3.1912, Bolland; F! ovata Forssk. (l*) Wadi Hof, H&van, Cairo, 16.2.1913, Bolland; (2) south east of Nakhl, near road to Ras El-Naqb, 30.4.1991, Gamal El-Din; (3*) Wadi Feiran, S. Sinai, 16.4.1962, Abdallah & El-Hadidi; (4) Gebel Halal, N. Sinai, 16.4.1992, Gamal El-Din; (5) El-Kharouba, El-Arish, 30.4.1991, Kawashty; /? nofata Lag. (I*) Alexandria, 5.1990, Ibrahim; (2’) Ain-El-Gedeirat, S. Sinai, 21.3.1990, W. Kamel; (3) Entrance to Rafah, 16.4.1992, Kawashty; /? ciliata Desf., 35 km south east of Nakhl, road to Ras El-Naqb, 30.4.1991, Gamal El-Din; p ah L. (I) Gebel ECMaghara, N. Sinai, 3.5.1991, Gamal El-Din; (2) El-Kharouba, El-Arish, 30.4.1991, Kawashty; p squarrosa Murr. (1) *Author

to whom

correspondence

should be addressed.

(Received 7 October 1993) 729

730

S.A. KAWASHTYETAL.

Um-Bogma, Sinai, 16.4.1991, Kawashty; (2) Yamit, EI-Arish, 30.4.1992, Kawashty; R phaeostoma Boiss. & Heldr.; 35 km southeast of Nakhl. near road to Ras EI-Naqb, 30.4.1991, Gamal El-Din; R arabica Boiss.; Wadi EI-Rahaa, 5 km north of St. Catherine City, Sinai, 26.4.1991, Gamal El-Din; R chamaepsyllium Zoh.; EI-Arish, 4.1992, Gamal El-Din; R indica L.; *EI-Qaser, Baharia Oasis, 12.4.1935, Drar; R pumila L. (1) EI-Arish, 27.4.1992, S. Heneidik; (2*) Boulak EI-Dacrour, Giza, 12.1926,Simpson; (3*) Bahariya Oasis, 2.10.1978,AbdeI-Ghani. Flavonoid identification. Plant material (leaves and stems) was extracted with 70% EtOH, and the extracts dried under vacuum. Flavonoids were separated on polyamide columns for large samples using water followed by increasing concentrations of EtOH. Fractions were further purified using elution techniques as well as final purification on Sephadex LH-20. Flavonoids were identified using standard methods (Harborne, 1967; Mabry et aL, 1970; Markham, 1982). These included complete and mild acid hydrolysis, hydrogen peroxide oxidation, enzymic hydrolysis, co-chromatography and UV spectrophotometry.

Results and Discussion In the present study, a detailed systematic investigation of Plantago species in Egypt revealed the presence of 18 species belonging to six sections. The flavonoids of the investigated species were also studied, and the results are outlined in Table 1. All the flavonoids detected were flavones with only one flavonol (isorhamnetin 3-rutinoside) being detected. A total of 25 flavonoids were detected, four being aglycones while the remaining 21 were glycosides. The flavonoid profile indicated that luteolin 7-glucoside (along with lesser amounts of apigenin 7-glucoside) was the major component in most species being replaced either with luteolin 7-glucuronide or tricin 7-glucuronide. The first section (Plantago) is characterized by the presence of hispidulin, nepetin (5,7,3',4'-tetrahydroxy-6methoxyflavone) and the less common 5,6,7,3'-tetrahydroxy-4'-methoxyflavone. All three are 6-hydroxyflavones, otherwise absent from the remaining sections investigated. The second section (Coronopus), contains three closely related species (R coronopus, R cornmutata and R crypsoides). Systematic studies indicated that two good species, R cornmutata and R coronopus, exist. Plantago commutata is recognized as a distinct species and not a subspecies as previously mentioned in several flora. Differentiation of both species was based on bract and indumentum characters (Kawashty, 1994): R crypsoides bracts: 2-3 × 0.8-1.0 mm (length × width), triangular-ovate, acuminate, longer or equal to sepals. corolla-lobe : lanceolate, acute. spike : cylindrical, densely hairy. sepals : adpressed hirsute. R commutata bracts: 2.0-2.5x0.5-0.7 mm (length×width), ovate, acuminate, glabrous. corolla-lobe : ovate, acuminate. spike : cylindrical (c-3.0 mm wide). sepals : glabrous. R coronopus bracts: 1.8-2.0x1.0 mm (length Xwidth), broadly ovate at base, abruptly attenuate at apex, adpressed short hairy. corolla-lobe : ovate-lanceolate, acuminate spike : cylindrical (c-5.0 mm wide) lax. sepals : distinctly ciliate. The flavonoid profile indicated that two species (R cornmutata and R crypsoides) contained the same flavonoids, however a quantitative difference exists. Thus R commutata contains luteolin 7-glucuronide as its major component, while R crypsoides contains luteolin 7-glucuronide-3'-glucoside as its major component. Both species also contain apigenin 6,8-di-C-glucoside in small amounts, but this was present in major amounts in samples of both species from N. Sinai. The third species (R coronopus) was not available for chemical investigation.

Boiss.

R crypsoides

R cylindnca

L.

Fo~.sk.

t~ albicans L.

Leucopsyllium

P lagopus L.

t? lanceolata

Amoglosssum(= Lagopus)

R amp/exicau/is Cav.

Bauphula

Guss

R commutm

Coronopus

R major L

Plantago

Section Rantagospecies

PLANTAGO

SPECIES

*

**

2

3

t

•

*

t

t

t

2

3

t

4

1

***

3

**

***

***

**

**

***

t

t

t

t

***

1

t

2

t

2

t

1

**

t

t

***

t

*

**

***

**

**

***

**

**

***

**

t

***

4

t

***

*

***

t

t

**

***

***

**

*

***

*

t

***

**

*

***

***

**

*

*

t **

*

*

***

***

t

t

***

*

t

t

t

*

**

t

t

*

*

*

*

*

*

*

*

*

LuTRut LutTdiG Lut7GGal Lut7Neo LutTGIG Lut7G13'G ChTG Ch7Gent HispTGI Lut6OHA'Me7Gal Nep7G Tr7GI Ap68diG Iso3Rut Ap

3

2

t

3

*

**

1

**

1

***

**

***

2

•

*

1

Sample Flavonoidst no. Ap7G ApTGI Ap7Rut Ap7GI43 Lut7G Lut7GI Lu4'G

TABLE 1. FLAVONOIDS OF

*

*

*

*

Con~nued overleaf

*

*

*

*

*

*

*

*

Lut Ch Tr

-<

7-

rn ct)

m

~:=

E~ 03

o_

Z

X 0

t

t

t

t

**

1

2

3

RchamepsylliumZoh,

/? indca L ( =/~ arenaira)

~?pumi/a L. ( = P exigua)

Ap7Rut

ApTGI-G

t

t

***

*

**

t

***

***

**

***

***

***

***

**

***

LutTG

t

t

t

*

*

LutTGI

**

t

*

**

Luz/G

Lu7Rut

Lut7diG

Lut7GGat

Lut7Neo

Lut7GIG

Lut7diG=luteolin

7-diglucoside;

Lu7GGal=luteolin

7-glucogalactoside;

Lu7Neo=luteolin

7-neohesperidoside;

side; Iso3Rut = i s o r h a m n e t i n 3-rutinoside; A p = apigenin; L u t = l u t e o l i n ; Ch = c h r y s o e r i o l ; Tr = tricin.

t

*

*

t

**

*

Ch7G

t

t

**

***

Ch7Gent

HispTGf

Lut6OH4'Me7Gal

Nep7G

**

*

***

**

***

**

**

**

**

Tr7GI

***

***

**

*

***

t

**

,

t

**

t

Ap68diG

t

**

Iso3Rut

Ap

Lut

Ch

Tr

Lut7GlG=luteolin

Lut7G13'G=luteolin

7-glucuronide-3'-glucoside;

Ch7G=chrysoeriol N e p 7 G = n e p e t i n 7 - g l u c o s i d e ; TrTGI = tricin 7 - g l u c u r o n i d e ; A p 6 8 d i G = a p i g e n i n 6,8-di-C-gluco

7-glucuronylglucoside;

Lut7G = l u t e o l i n 7 - g l u c o s i d e ; Lut7Gr = l u t e o l i n 7 - g l u c u r o n i d e ; L u 4 ' G = l u t e o l i n 4 ' - g l u c o s i d e ; L u 7 R u t = lute-

Lut7G13'G

7-glucoside; C h 7 G e n t = chrysoeriol 7-gentiobioside; Hisp7GI = h i s p i d u l i n 7 - g l u c o n i d e ; L u t 6 O H 4 ' M e 7 G a l = l u t e o l i m 6 H y d r o x y ~ , ' m e t h o x y * 7 - g a l a c t o s i d e ;

olin 7-rutinoside;

A p 7 G = apigenin 7*glucoside; A p 7 G = ap gen n 7-g u c u r o n i d e ; A p 7 R u t = a p i g e n i n 7 - r u t i n o s i d e ; Ap7GIG = a p i g e n i n 7 - g l u c u r o n y l g l u c o s i d e ;

* * * = m a j o r ; * * = strong; * = present; 1 = traces.

t

R arabica Boiss.

t

2

*

t

*

1

**

1

**

2

3

***

**

5

2

t

4

**

*

3

1

*

2

R phaeostoma Boiss. & Heidr,

~t squarrosa Nurr.

P afra ( = ,~ psyllium L)

Psyllium

P cihata Desf.

PnotataLay.

**

Ap7GI

Flavonoidst

Ap7G

1

no,

t? ovata Forssk.

Sample

Flantagospecses

1--Continued

Sec~on

TABLE

FLAVONOIDSOF PLANTAGOSPECIESIN EGYPT

733

Section 3 (Bauphula) and 5 (Leucopsyllium) both showed a relatively simple flavonoid profile, however section Leucopsyllium contained the only flavonol, isorhamnetin 3-rutinoside, otherwise absent from other Plantago species investigated. The fourth section (Arnoglossum), contains two species (R lanceolata and R lagopus). Plantago lagopus is characterized by the presence of three luteolin diglycosides otherwise absent in other Plantago species. Two of these diglycosides (luteolin 7-rutinoside and 7-neohesperidoside) were also reported elsewhere in aerial parts of the same plant (Michael et al., 1993). The last section (Psyllium) proved to contain tricin 7-glucuronide and apigenin-6,8-di-C-glucoside in all seven species, while chrysoeriol 7-glucoside and 7-gentiobioside were only detected in four species of this section. In conclusion, the flavonoid patterns of the investigated Plantago species proved to be of value in identifying some of the sections (e.g. isorhamnetin 3-rutinoside in section Leucopsyllium and tricin 7-glucuronide in section Psyllium). On the specific level, some variation is observed between some closely related species (e.g. R commutata and R crypsoides in section Coronopus; R lagopus and R lanceolata in section Arnoglossum). Finally, a slight quantitative variation observed between samples from different localities could be attributed to ecological variations. References Aritomi, M. (1964) Hispidulin 7-glucoside from P/antago asiatica. Chem. Pharm. Bull (Tokyo) 12, 841-843. Boissier, E. (1879) Flora Or/entails, Vol. IV: Corol/iflorae et Monoch/amydeae, pp. 876-893. A. H. George, Geneva. Endo, T., Taguchi, H. and Yosioka, I. (1981) The glycosides of Plantago major. Chem. Pharm. Bull. 20, 10001004. Feinbrun-Dothan, N. (1978) Flora Palaestina, Vol. III, pp. 220-232. Israel Academy of Science and Humanities, Jerusalem. Giannasi, D. E. (1988) The Flavonoids: Advances in Research since 1980. (Harborne, J. B., ed.), pp. 479-504. Chapman and Hall, London. Greuter, W., Burdet, H. M. and Long, C. (eds) (1989) Med-CheckJis~ pp. 296-304. Conservatoire et Jardin botaniques, Geneva. Harborne, J. B. (1975) The F/avonoids (Harborne, J. B., Mabry, T. J. and Mabry, H., eds), pp. 1056-1095. Chapman and Hall, London. Harborne, J. B. (1967) Comparative Biochemistry of the F/avonoids. Academic Press, London. Kawashty, S. A. (1994) Chemosystematic studies of some Plantago species in Egypt. Ph.D. Thesis. Faculty of Science, Suez Canal University, Egypt. Lebedev-Kosov, V. I. (1980) Flavonoids and iridoids of Plantago major and R asiatica. Rastitel'nye Resursy, 16, 403-406. Mabry, T. J., Markham, K. R. and Thomas, M. B. (1970) The Systematic Identification of Flavonoids. Springer, New York. Markham, K. R. (1982) Techniques of Flavonoid Identification. Academic Press, London. Michael, H. N., Ishak, M. S., EI-Sissi, H. I. and Ahmed, A. A. (1993) Some chemical constituents of Plantago lagopus. The 13th Egyptian Chemical Conference (9th Arab Chemical Conference), National Research Centre, Cairo. Moore, D. M., Williams, C. A. and Yates, B. (1973) Bipolar disjunct species II. Plantago maritima. Bot. Notiser 125, 261-272. Taeckholm, V. (1974) Student's Flora of Egyp~ pp. 511-516. Anglo-Egyptian Bookshop, Cairo.