Antifungal Effects of Different Plant Extracts and their Major Components of Selected Aloe Species Mohamed I. A. Ali, 1 * Nagwa M. M. Shalaby, 2 Mohamed H. A. Elgamal 2 and Ahmed S. M. Mousa 3 1 Botany Department, Faculty of Science, Cairo University, Giza 12613, Egypt 2 Department of Chemistry of Natural and Microbial Products, National Research Centre, Dokki, Cairo, Egypt 3 Botany Department, Faculty of Science, Cairo University Beni-suef Branch, Egypt Different extracts of both fresh and dry leaves of Aloe eru A. Berger, A. vera L. Webb & Berth and A. ar- borescens Mill. were screened for their antifungal activity against Aspergillus niger, Cladosporium herbar- um and Fusarium moniliforme. The toxicity of the isolated pure components were evaluated on the tested fungi. A comparative chromatographic study was performed to differentiate between natural compo- nents existing in various fractions and extracts of Aloe species and specific spray reagents were used for the detection of anthraquinones in the isolated components. Copyright # 1999 John Wiley & Sons, Ltd. Keywords: Aloe species; aloe-emodin; aleonin; antifungal activities; chromatographic investigation; specific colour reagents. INTRODUCTION Plants belonging to the genus Aloe (Liliaceae) have been known for their medicinal value (Tyler et al., 1976). The dried latex (juice) obtained from the transversely cut leaves of various species of Aloe is known in the market as Aloe. Previously Rizk and Al Nowaihi (1989) reported on anthraquinone glycosides, aloe-emodin and anthra- cene derivatives from Aloe species. Barbaloin (Hirata and Suga, 1977; Nakagomi et al., 1987; Yagi et al., 1987), aloin (Stepanova et al., 1977), aloe-emodin (De Siqueira et al.,1976; Hirata and Suga, 1977) and aloe-emodin glucoside (De Siqueira et al., 1976; Hirata and Suga, 1977) were found in the leaf juice of Aloe arborescens. Abdurakhmanova et al. (1978) states that Aloe eru and Aloe arborescens contained aloe-emodin and chrysopha- nic acid, besides aloinaside A and B. Diasteroisomers of aloins (Grun and Franz, 1979), differing in the con- figuration at C-10 of the aglycone were isolated from A. arborescens. Rauwald and Voetig (1982) isolated 7- hydroxy aloin from A. barbadensis (Aloe vera), while Mahabale and Kamble (1978) determined the percentage of aloin in Aloe vera. Antiinflammatory C-glucosyl chromone (Hutter et al., 1996) and chromone aglycone (aloesone) were isolated from Aloe vera by Holdworth (1972). Makino et al. (1973) isolated aloearbonaside (chromone glucoside) and two aloesin esters (Makino et al., 1974) from the fresh leaves of A. arborescens. Yuan (1993) found that the leaves of A. vera Chinensis contained isoaloesin and aloesin. Recently three chromone components (Park et al., 1996) and neoaloesin A (Okamura, 1996) were isolated from the leaves of A. vera. The present work studied the antifungal activity of different successive extracts of Aloe species (Aloe arborescens, Aloe eru and Aloe vera) against test fungi (Aspergillus niger, Cladosporium herbarum and Fusar- ium moniliforme) and isolated extract components which may be responsible for their biological activities. Chromatographic studies were carried out to characterize the components of different extracts and fractions. MATERIALS AND METHODS General. UV spectra were measured in methanol on a Shimadzu UV-visible recording spectrophotometer UV- 240 Graphicard. 1 H NMR spectra were measured at 500.13 MHz, while 13 C NMR at 125.26 MHz in CH 3 OD for compound C. High resolution MS and negative ionization were measured with a Varian MAT 8500 (Finnigan, matrix glycerol). Plant material. The tested plant samples from the genus Aloe were Aloe arborescens Mill., Aloe vera L. Webb & Berth (A. barbadensis) and Aloe eru A Berger. All the samples were collected from Orman’s gardens, Giza, Egypt in November 1994. The plant materials were identified by Dr M. Elgabaly. A voucher specimen of each aloe was deposited at the Chemotaxonomy Depart- ment, National Research Centre. Extraction of the plant samples. Fresh leaves of each Aloe species (500 g) were digested in a mixer to give a homogeneous mass which was filtered. The filtrate of each plant sample was placed in a separating funnel and PHYTOTHERAPY RESEARCH Phytother. Res. 13, 401–407 (1999) CCC 0951–418X/99/050401–07 $17.50 Copyright # 1999 John Wiley & Sons, Ltd. * Correspondence to: M. I. A. Ali, Botany Department, Faculty of Science, Cairo University, Giza 12613, Egypt. Received 7 October 1998 Revised 5 December 1998 Accepted 12 March 1999