Aloinoside A

Fast and easily applicable LC-UV method for analysis of bioactive anthrones from Aloe leaf latex.[Pubmed:33402271]

J Pharm Biomed Anal. 2021 Feb 20;195:113834.

Aloe leaf latex is a commonly used plant preparation in traditional medicine. However, quality control on the content of medicinally important constituents is often limited. Hence, establishing a reliable quality control method to identify and quantify bioactive markers is important to ensure safety and efficacy. In the present study, a novel liquid chromatographic (LC) method was developed and validated for efficient analysis of bioactive markers to evaluate the quality of aloe leaf latex. Quantification of marker compounds was possible in only 7 min on a monolithic column using gradient elution with 0.1 % formic acid in acetonitrile and water as mobile phases. The major compounds (aloins A and B) could be baseline separated together with related compounds within 10 min. The method showed excellent linearity with determination coefficients (r(2)) of 0.9999. Detection limits were 0.017 and 0.013 mug/mL, while quantification limits were 0.057 and 0.043 mug/mL for aloin A and aloin B, respectively. Relative standard deviation (RSD) values for intra- and inter-day precision were less than 2% and recoveries for both aloins were close to 100 %. The robustness was evaluated using an experimental design. The method was applied to some aloe leaf latex samples from Ethiopia. Aloin contents varied from 14 to 35 % and two unknown peaks were tentatively identified as Aloinoside And microdontin.

Characterization and Evaluation of Antioxidant Activity of Aloe schelpei Reynolds.[Pubmed:32184569]

Drug Des Devel Ther. 2020 Mar 5;14:1003-1008.

BACKGROUND: The role of free radical reactions in disease pathology is well known to be involved in many acute and chronic disorders in human beings, such as diabetes, atherosclerosis, aging, immunosuppression and neurodegeneration. The search for new drugs of plant origin becomes increasingly urgent due to drug resistance. Aloe schelpei is an endemic Aloe species traditionally used for the treatment of infectious and chronic diseases. AIM: This study was conducted to evaluate free radical scavenging activities of leaf latex of Aloe schelpei and its isolated compounds. METHODS: The leaf latex of A. schelpei was subjected to preparative thin-layer chromatography to afford three compounds. Free radical scavenging activities of the leaf latex and its constituents was carried out using a 2, 2-diphenyl-1-picrylhydrazyl method. RESULTS: Phytochemical investigation of the leaf latex Aloe schelpei by prepartive thin layer chromatography led to the isolation of three compounds, identified as microdontin A/B (1), aloin A/B (2) and Aloinoside A/B (3). The results showed that the leaf latex had a strong free radical scavenging activity reaching a maximum of 84.3% at a concentration of 100 mug/mL, and with an IC(50) value of 25.3 +/- 2.45 mug/mL (p < 0.05). Among the isolated compounds, microdontin A/B (1) was found to have the strongest free radical scavenging activity with an IC(50) value of 0.07 +/- 0.005 mmu, followed by Aloinoside A/B (IC(50) = 0.13 +/- 0.01 mM) and aloin A/B (IC(50) = 0.15 +/- 0.02 mM). CONCLUSION: The traditional medicinal practice of the leaf latex may be due to the antioxidant activities of the leaf latex of A. schelpei and the isolated compounds.

Use of Random Amplified Polymorphic DNA (RAPD) Technique to Study the Genetic Diversity of Eight Aloe Species.[Pubmed:27336317]

Planta Med. 2016 Oct;82(15):1381-1386.

The genus Aloe comprises over 400 species of flowering succulent plants. Aloe leaves are used in the treatment of asthma, gastrointestinal ulcers, cardiovascular disease, tumors, burns, and diabetes. They are rich in anthraquinones, such as aloin, aloe-emodin, chrysophanol, Aloinoside A, and aloinoside B. The various species of Aloe show chemical and morphological similarity and diversity, which depend on the genotype and environmental conditions. In a continuity to our interest in the genus Aloe, this study targets the authentication of eight different Aloe species, Aloe vera (A(1)), Aloe arborescens (A(2)), Aloe eru (A(3)), Aloe grandidentata (A(4)), Aloe perfoliata (A(5)), Aloe brevifolia (A(6)), Aloe saponaria (A(7)), and Aloe ferox (A(8)), grown in Egypt by using the technique of random amplified polymorphic DNA. Twelve decamer primers were screened in amplification with genomic DNA extracted from all species, of which five primers yielded species-specific reproducible bands. Out of 156 loci detected, the polymorphic, monomorphic, and unique loci were 107, 26, and 23, respectively. Based on a dendrogram and similarity matrix, the eight Aloe species were differentiated from each other and showed more divergence. Aloe species prevailed similarity coefficients of 54-70 % by which they could be classified into three major groups. Thus, this technique may contribute to the identification of these Aloe species that have great morphological similarity in the Egyptian local markets.

The occurrence and taxonomic distribution of the anthrones aloin, aloinoside and microdontin in Aloe.[Pubmed:11068124]

Biochem Syst Ecol. 2001 Jan 1;29(1):53-67.

A chemotaxonomic survey of 380 species of Aloe indicated the presence of the anthrone isomers aloin A and B together with the aloinoside isomers and microdontin A and B in 36 (10%) species of Aloe. This group, referred to as the microdontin chemotype, is thus characterised by a combination of exudate compounds and not merely a single phytochemical marker, implying taxonomic significance of leaf exudate compounds. The 36 representatives of the group occupy disparate taxonomic positions in the largely artificial hierarchy of the present classification system. Although many of the species have previously been considered as related (based on macromorphology only), a large number of species have not been associated with one another before. The chemical profiles and leaf exudate compositions of the species are presented, followed by a brief summary of the morphological diversity. Whilst conceding the possibility of convergent evolution, the geographical distribution of the species and thoughts on possible relationships between the taxa are discussed.

High-performance liquid chromatographic profiles of aloe constituents and determination of aloin in beverages, with reference to the EEC regulation for flavouring substances.[Pubmed:8556168]

J Chromatogr A. 1995 Dec 1;718(1):99-106.

Characteristic HPLC profiles of fresh and aged aloe solutions, detected at 360 and 220 nm, are presented and compared. Several aloe constituents (aloesin, aloeresin A, hydroxyaloin, aloin A and B and Aloinoside A and B) were simultaneously separated and identified. The determination of aloin is described (detection limit 0.15 ppm) and discussed. In aloe-based alcoholic beverages, the aloins could not be detected, owing to their instability and degradation in solution; this is discussed in relation to the EEC Council Directive 88/388, which fixed the values of maximum allowable concentrations for aloin in food and beverages. Instead of aloin, other aloe compounds (e.g., aloeresin A or aloesin) should perhaps be used as an index of the presence of aloe in alcoholic beverages.

Geographical variation in the major compounds of Aloe ferox leaf exudate.[Pubmed:7617769]

Planta Med. 1995 Jun;61(3):250-3.

Geographical variation in fresh Aloe ferox leaf exudate of which the dried product is commercially known as Cape Aloes, was investigated throughout the natural distribution range of the species. The composition of the major compounds is remarkably invariable, with aloeresin A, aloesin, and aloin (both epimers A and B) contributing between 70% and 97% of total dry weight, in a ratio of approximately 4:3:2, respectively. Minor compounds are less evenly distributed, with Aloinoside A and aloinoside B more frequent in the western parts of the distribution area and aloeresin C and 5-hydroxyaloin A generally present in small quantities throughout the distribution area. The aloin content of the exudate is clearly related to provenance but there are no distinct geographical discontinuities. The selection of high-yielding provenances, with total aloin levels above 25%, is recommended for commercial cultivation.