Vacillantins A and B, New Anthrone C-glycosides, and a New Dihydroisocoumarin Glucoside from Aloe vacillans and Its Antioxidant Activities.

Maram Al-Tamimi,Maged S Abdel-Kader,Wael M Abdel-Mageed,Ali A El-Gamal,Omer A Basudan,Shaza M Al-Massarani

doi:10.3390/plants9121632

Abstract

A new dihydroisocoumarin glucoside, vacillanoside (3), and two new anthrone C-glycosides microdantin derivatives; vacillantin A (10) and B (11), together with nine known compounds belonging to the anthraquinone, anthrone and isocoumarin groups were isolated from the leaves of Aloe vacillans. The structures were determined based on spectroscopic evidence including 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high resolution mass spectrometry (HRESIMS) data, along with comparisons to reported data. The leaves were used to extract compounds with different solvents. The extracts were tested for antioxidant activity with a variety of in vitro tests including 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate (ABTS•+), ferric reducing antioxidant power assay (FRAP), superoxide, and nitric oxide radical scavenging assays. The dichloromethane fraction was most active, displaying significant free radical scavenging activity. The n-butanol fraction also showed notable activity in all assays. Therefore, these findings support the potential use of A. vacillans leaves as an antioxidant medication due to the presence of polyphenolic compounds.

Highlights

Aloe spp. are members of the bitter or Asphodelaceae family.This family is represented by more than 600 species endemic to tropical and southern Africa, Madagascar, Jordan, the Arabian Peninsula, East Asian countries, and various islands in the Indian Ocean [1].Aloe plants are used as traditional medicines and dietary supplements in several countries includingEgypt, China, and India [2,3].In Arabic, Aloe is known as “Alloeh”, which means “shiny substance with bitter taste”, in reference to its exudate [4]
Antioxidant activity was evaluated by five different spectrophotometric methods, namely DPPH
Mean percent scavenging ± SD, was measured in DPPH, ABTS, and ferric reducing antioxidant power assay (FRAP) assays at four concentrations (10, 20, 50, and 100 μg/mL) (Table 3), while for the superoxide and nitric oxide scavenging assays, it was calculated at 20, 40, 60, 80, and 100 μg/mL

Summary

Introduction

Aloe spp. are members of the bitter or Asphodelaceae family (previously known as Liliaceae).This family is represented by more than 600 species endemic to tropical and southern Africa, Madagascar, Jordan, the Arabian Peninsula, East Asian countries, and various islands in the Indian Ocean [1].Aloe plants are used as traditional medicines and dietary supplements in several countries includingEgypt, China, and India [2,3].In Arabic, Aloe is known as “Alloeh”, which means “shiny substance with bitter taste”, in reference to its exudate [4]. Aloe spp. are members of the bitter or Asphodelaceae family (previously known as Liliaceae). This family is represented by more than 600 species endemic to tropical and southern Africa, Madagascar, Jordan, the Arabian Peninsula, East Asian countries, and various islands in the Indian Ocean [1]. Aloe plants are used as traditional medicines and dietary supplements in several countries including. In Arabic, Aloe is known as “Alloeh”, which means “shiny substance with bitter taste”, in reference to its exudate [4]. Aloe spp., with a waxy surface on succulent leaves, are well-adapted to harsh climatic conditions with infrequent precipitation [5]. The Greek Herbal of Dioscorides (41–68 AD) recommended oral use of Aloe spp

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Results

Conclusion