Allium species from Central and Southwest Asia are rich sources of marasmin

Biosynthesis, behavior and fate of volatile organic sulfide in Lentinus edodes (Berk.) upon hot-air drying treatment

This study elucidated the biosynthesis and changing behaviors of organic sulfide in shiitake mushrooms upon hot-air drying treatment. The changes of aw, moisture migration, contours of taste and flavor, organic sulfide, and 4 key enzyme activities were monitored throughout three drying procedures (CT/ST1/ST2). Results showed that drying rate was related to the moisture migration. Key enzymes of γ-GTase, ASFase and CS lyase were heat-resistant proteases, while C-Dase exhibited low thermal stability with the activity decreased during treatment. A total of 17 organic sulfides were identified and PLS analyses suggested 6 cyclic polysulfides were formed by C-Dase desulfurization, while 5 thioethers generation were related to the thermal cleavage of direct precursors (straight-chain di/tris/tetrasulfonyl esters) and Maillard reaction. These results indicated that ST2 drying procedures had a positive effect on the formation of cyclic polysulfides at the end of drying pried and the achievement of premium flavor qualities.

Natural Antioxidants, Health Effects and Bioactive Properties of Wild Allium Species

BACKGROUND

There is an increasing interest from the pharmaceutical and food industry in natural antioxidant and bioactive compounds derived from plants as substitutes for synthetic compounds. The genus Allium is one of the largest genera, with more than 900 species, including important cultivated and wild species, having beneficial health effects.

OBJECTIVE

The present review aims to unravel the chemical composition of wild Allium species and their healthrelated effects, focusing on the main antioxidant compounds. For this purpose, a thorough study of the literature was carried out to compile reports related to health effects and the principal bioactive compounds. Considering the vast number of species, this review is divided into subsections where the most studied species are presented, namely Allium ampeloprasum, A. flavum, A. hookeri, A. jesdianum, A. neapolitanum, A. roseum, A. stipitatum, A. tricoccum, and A. ursinum, with an additional composite section for less studied species.

METHODS

The information presented in this review was obtained from worldwide accepted databases such as Scopus, ScienceDirect, PubMed, Google Scholar and Researchgate, using as keywords the respective names of the studied species (both common and Latin names) and the additional terms of"antioxidants" "health effects" and "bioactive properties".

CONCLUSION

The genus Allium includes several wild species, many of which are commonly used in traditional and folklore medicine while others are lesser known or are of regional interest. These species can be used as sources of natural bioactive compounds with remarkable health benefits. Several studies have reported these effects and confirmed the mechanisms of action in several cases, although more research is needed in this field. Moreover, considering that most of the studies refer to the results obtained from species collected in the wild under uncontrolled conditions, further research is needed to elucidate the effects of growing conditions on bioactive compounds and to promote the exploitation of this invaluable genetic material.

Garlic and onions: An eastern tale

ETHNOPHARMACOLOGICAL RELEVANCE

Garlic and its wild relatives have a long tradition of use world-wide dating back to the early ages as food and medicine. This exceptional group deserves to be taken into consideration to rethink its potential health effects in light of its cultural and historical background, as well as ethnobotanical practices.

AIM OF THE STUDY

Garlic, onion, and other related vegetables have been indispensable for Turkish daily life. This review focuses on the wild, as well as cultivated, Allium species from the broad historical perspective of Turkish culture. Its goal is also analyze how food and medicine have been perceived as closely connected entities in a specific cultural sphere.

METHODS

A comprehensive literature survey was conducted on these species by referencing scientific databases such as Google Scholar, Science Direct, PubMed, Elsevier E-Book, Scopus, ISI-Web of Science, and E book Central (Ebrary).

RESULTS

The integration of historical and ethnobotanical data have enabled us to understand the unique position of Alliums in a specific human geography. Garlic and onions have been used in this region as food and for medicinal purposes for thousands of years. The perceived health benefits of consuming garlic and onions are well documented in the literature. There are more than 200 Allium species naturally distributed in Turkey, and around 30 of those have been widely used for various purposes by local people as a vegetable, spice, condiment, and medicine.

CONCLUSIONS

The desire for good health and wellness has been traced across many cultures throughout history. Healthy foods like garlic were and will be a critical component of maintaining good health.

Identification and expression analysis of S-alk(en)yl-L-cysteine sulfoxide lyase isoform genes and determination of allicin contents in Allium species

Alliinase is the key enzyme in allicin biosynthesis pathway. In the current study, the identification and sequencing of alliinase genes along with determination of allicin contents were reported for Allium species with a novel report for Iranian endemic species. The presence of different isoforms in the Allium being discovered for the first time. In bulbs tissue, the highest allicin concentration was in Allium sativum, A. umbilicatum, and A. fistolosum (1.185%, 0.367%, and 0.34%, respectively), followed by A. spititatum (0.072%), A. lenkoranicum (0.055%), A. atroviolaseum (0.36%), A. rubellum (0.041%), and A. stamineum (0.007%). The highest allicin content in the leaves and roots were in A. sativum (0.13%), and A. stamineum (0.195%), respectively. The ORFs length ranged from 1416 in A. sativum (iso-alliinase2; ISA2) to 1523 bp in A. sativum (alliinase); the identity with A. sativum (alliinase) varies from 95% to 68% for A. ampeloprasum, and A. sativum (iso-alliinase1, ISA1) respectively. These data suggested that both ISA1 and ISA2 had a high expression in the roots and bulbs compared to A. sativum as the control in all species. Note that ISA1 and ISA2 were not expressed in the leaves. The results showed that isoforms expression patterns among different tissues in Allium species were variable. The presence of various isoforms is a possible explanation for the difference between the species in terms of obtained results, especially the amount of allicin.

Allium ekimianum: a new species (Amaryllidaceae) from Turkey

Allium ekimianum is described here as a new species. This taxon belongs to the genus Allium section Allium and grows in Elazığ Province (East Anatolia, Turkey). It is a narrowly distributed species and morphologically most similar to Allium asperiflorum and Allium sintenisii, and Allium erzincanicum but it is clearly differentiated due to the curved stem, smooth pedicel surfaces, bracteole arrangements at pedicel bases, tepal lengths and surfaces. In this study, a comprehensive description, distribution map of Allium ekimianum, identification key, and detailed illustrations are provided for Allium ekimianum and related taxa.

Tulbaghia--A Southern African Phytomedicine

The phytomedicine Tulbaghia consists of the fresh or dried subterranean organs of various Tulbaghia species. The genus is endemic to Southern Africa and includes about 20 species, of which only T. alliacea and T. capensis are naturally found in the winter rainfall climate area (the Western Cape). The genus forms part of the Alliaceae family and is a geophyte (plants with an underground perennation organ and leaves that die back annually). Their habitat can range from semi-desert to wet and boggy terrain. Wild garlic is most commonly prepared as an infusion or boiled in water and taken orally. Externally, as a medicated bath, wild garlic is used to treat paralysis and rheumatism and to reduce the temperature in a feverish patient. Internally, rhizome or bulb preparations are taken orally to treat fever; as a remedy for colds and influenza, asthma, tuberculosis, and stomach problems; as an antihypertensive; or to expel intestinal worms. It is also used as a prophylactic against winter infections. Rhizome pieces are often placed in castor oil to make eardrops. For fever and high blood pressure, a tea is made from the bulbs or rhizomes and a small cup taken three times daily. The leaves of the plant are used to treat esophageal cancer and may also be eaten as a vegetable. The demand for Tulbaghia in both formal and informal markets has grown exponentially. Sustainable harvesting focuses on only harvesting enough of the plant so that it still has the capacity for self-renewal. However, because both the above-ground and underground parts of Tulbaghia are commonly used in African traditional medicine, destructive harvesting of the whole plant is inevitable, thus necessitating the large-scale organized propagation of these plants. It is therefore important to establish a new strategy for the sustainable harvesting of these plants as commercial crops.

Antiinflammatory and neurological activity of pyrithione and related sulfur-containing pyridine N-oxides from Persian shallot (Allium stipitatum)

ETHNOPHARMACOLOGICAL RELEVANCE

Persian shallot (Allium stipitatum) is a bulbous plant native to Turkey, Iran and Central Asia. It is frequently used in folk medicine for the treatment of a variety of disorders, including inflammation and stress. Antiinflammatory and neurological activities of pyrithione and four related sulfur-containing pyridine N-oxides which are prominent constituents of Allium stipitatum were tested.

METHODS

The antiinflammatory activity was tested by the ability of the compounds to inhibit cyclooxygenase (COX-1 and COX-2), whereas the neurological activities were evaluated by assessing the compounds ability to inhibit monoamine oxidase-A (MAO-A) and acetylcholinesterase (AChE). The compounds׳ affinity for the serotonin transport protein (SERT) and the GABAA-benzodiazepine receptor were also investigated.

RESULTS

2-[(Methylthio)methyldithio]pyridine N-oxide showed very high antiinflammatory effects which are comparable with those of common pharmaceuticals (IC₅₀ of 7.8 and 15.4 µM for COX-1 and COX-2, respectively). On the other hand, neurological activities of the compounds were rather modest. Some compounds moderately inhibited AChE (IC₅₀ of 104-1041 µM) and MAO-A (IC₅₀ of 98-241 µM) and exhibited an affinity for the SERT and GABAA-benzodiazepine receptor.

CONCLUSIONS

Our findings may help to rationalize the wide use of Persian shallot for the treatment of inflammatory disorders.

Flavor precursors and sensory-active sulfur compounds in alliaceae species native to South Africa and South America

Profiles of S-substituted cysteine flavor precursors were determined in 42 Alliaceae species native to South Africa and South America. It was found that the pool of cysteine derivatives present in these plants is remarkably very simple, with S-((methylthio)methyl)cysteine 4-oxide (marasmin) being the principal flavor precursor, typically accounting for 93-100% of the pool. Out of the other cysteine derivatives, only minor quantities of methiin were present in some species. The marasmin-derived thiosulfinate marasmicin (2,4,5,7-tetrathiaoctane 4-oxide), a major sensory-active compound of the freshly disrupted plants, was isolated, and its organoleptic properties were evaluated. Furthermore, sulfur-containing volatiles formed upon boiling of these alliaceous species were studied by GC-MS. The profile of the volatiles formed was relatively simple, with 2,3,5-trithiahexane and 2,4,5,7-tetrathiaoctane being the major components. Despite the traditional belief, ingestion of the marasmin-rich plants was always accompanied by development of a strong "garlic breath". We believe that especially several Tulbaghia species deserve to attract much greater attention from the food industry thanks to their pungent garlicky taste and unusual yet pleasant alliaceous smell.