ZbI. Bakt. Abt. II, Bd. 131, S. 110-112 (1976)

[National Research Centre, Soil Microbiology Unit, Dokki, Cairo, A.R.E.]

Antimicrobial Substances in Certain Members of Solanaceae IV. Detection of Active Principles in Pepper Plant

M. S. M. Saber

With one fjgure

Summary

Eight spots with antimicrobial activity were detected in pepper plant. Paper chromatographic studies showed that four of these spots were frequently occurring in roots, stems, and leaves, whereas the other four spots were detected in stems and leaves only. While all the eight spots exhibited moder­ate activity against O. utilis, only two spots were slightly active against S. aureus.

Zusammenfassung

Acht Farbflecke mit antimikrobieller Aktivitat wurden in Pfefferpflanzen festgestellt. Papier­chromatographische Untersuchungen zeigten, daL1 vier von diesen Farbflecken haufig in den Wurzeln. Stengeln und Blattern vorkommen, wobei die anderen vier Farbflecke nur in den Stengeln und Blattern festgesteHt werden konnten, Wahrend aHe acht Farbflecke eine miiJ3ige Aktivitat gegen O. utilis aufwiesen, waren zwei Farbflecke schwach aktiv gegen S. aU'l'eus.

In the past few years some workers have been interested in studying the anti­microbial activity of the pepper plant, Capsicum annuum (GAL 1966 and MARCHOUX

and ROUGIER 1968). During a survey of the presence of antimicrobial substances in the various organs of the pepper plant, SABER (1975a) found that the ethyl ether extract of the roots, and the ethyl ether and chloroform extracts each of stems and leaves possessed principles with antimicrobial properties. In the current study further investigations were carried out on these extracts to detect such active principles.

Materials and Methods

The scheme of the experiment, preparation of the plant samples, extraction, paper chromatogra­phy, and bioautography were the same as described in a previous paper (SAllER 1976b).

Results and Discussion

It is clear in Table 1 and Fig. 1 that none of the active spots is particularly occurring in a certain plant organ. All the eight active spots were found in both plant stems and leaves, and only four of these spots were detectable in the plant roots.

Among the eight active spots, only No.3 and 4 (Fig. 1) had neither travelled to the top of the chromatograms nor did they show any movement in the solvent sys­tems. Meanwhile, spot No.3 was the only one that responded to the dyeing reagents

Antimicrobial Rubstances in Certain Members of Solanaceae. IV. III

Ether Ether Chloroform Ether Chloroform (rools ) ( sIems) (sIems) (l eaves) (leaves)

fi; 51 S2 SJ 5+ 10

t -

(£ 0. 8 a:

5, S2 S3 S. S, Sz S3 5~ S,SZSJ~ S, 52 S3 5+ ,- r- ~ jrr r- r- ~ :$ -

a I p;~

0.6 ~ -

o. ~ ... -

0..2 l7 0. 2

Fig. 1. Bioautographic analysis of the chromatograms prepared from the various plant extracts. SI> S2' Sa, and S4 are solvent systems (Table 1).

Table 1. Properties of the active spots, detected in the various extracts of pepper plant

Spot RF Plant Biopotency2) Colour Reagents No.1) organ S. aureU8 O. utili8 FeCla AgNOa -Dragen·

dorf

I 0.02 RSL + ++ 2 0.02 RSL -+- ++ 3 0.85 RSL + yellow 4 0.90 RSL ++ 5 0.97 SL ++ 6 0.02 SL ++ 7 0.02 SL +++ 8 0.02 SL +++

1) See Fig. 1. 2) With of zones of inhibition (mm); +: < 2.5, ++: 2.5-5.0, +++: > 5.0. R: roots, S: stems, and L: leaves.

Bindict Fluores-cein

and was stained yellow with ferric chloride (Table 1). It seems reasonable to conclude that, with the exception of the spots No.3 and 4, there is still much doubt as to the presence of a single compound in any of the other active spots.

Regarding the biological activity of the eight active spots, recorded in this study, it is clear from Table 1 that, while all these spots exhibited activity towards the uni­cellular fungus C. utilis, the bacterium S. aureU8 NRRL-B-313 was slightly sensitive only to the spots No.1 and 2. The antifungal activity of the afore-mentioned spots exerted variable potency. Three spots (No.5, 7, and 8) showed high potency, four spots (No.1, 2, 4, and 6) showed moderate activity, and one spot (No.3) was slightly effective.

The results obtained from the present work, however, throw double on the con­clusion reported by NICKELL (1959) that pepper plants do not contain any anti­microbial substances. This could possibly be ascribed to a variety of reasons, e.g., plant age, method of extraction, type of test micro-organism ... etc. On the other hand, the present results confirme the findings of GAL (1966) and MARCHOUX and ROUGIER (1968). The former isolated the antimicrobial agent capsicidin from the pepper plant and the latter isolated an unidentified active fraction from the plant leaves. Consider­ing that little informat.ion had yet. been devot.ed t.o t.he eight act.ive spots recorded in t.he present. experiment., t.hl' lines of demareation between t.hem and those of GAL

112 }I. S. 1\1. SABER. Antimicrobial Substanee~. IV.

and MARCHOUX and ROUGIER are fuzzy and largely a matter of scepticism. Never­theless, they all do emphasize the presence of active principles in the pepper plant.

While the obtained map (Fig. 1) elucidates the active spots, actually, the need of more detailed work is of great importance.

References

GAL, I. E.: Composition of capsicidin. Z. Lebensm.-Unters. Forsch. 132 (1966), 82. MARCHOUX, G., and ROUGIER, J.: Inhibitory effect of extracts from pepper leaves (CapBicum an­

nuum). II. Concentration and purification of an inhibitory fraction. Ann. Epiphyl. 19 HoI's. Sevie (1968), 21.

NICKEl" L. G.: Antimicrobial activity of vascular plants. Econ. Bot. 13 (1959),281. SABER, M. S. M.: Antimicrobial substances in certain members of Solanaceae. I. Preliminary in­

vestigations. Zbl. Bakt. II, 131 (1976a), 40-45. Antimicrobial substances in certain members of Solanaceae II. Detection of active principles in egg-plant. Zbl. Bakt. II, 131 (1976b), 46-52.

Author's address:

Dr. M. S. M. SABER, National Research Centre, Soil Microbiology Unit, Dokki, Cairo (Egpt).