449
properties is still a subject of debate until now. In one study an increased antioxidant
activity was found when garlic was boiled at 100 °C for 30 min (Shobana and
Akhilender Naidu 2000) while in another study increased beneficial effects were
found after heating (Benkeblia 2004). In another study, the antioxidants present in
garlic were found to be thermally unstable (Lai and Roy 2012) and that allicin formation was prevented when the enzyme allinase is inactivated by heat (Banerjee
et al. 2003; Schäfer and Kaschula 2014). Although OSCs are known to be antioxidants, their property is believed to be brought about and mediated indirectly through
the sulfane-sulfur derivatives of these compounds (Colín-González et al. 2012;
Toohey and Cooper 2014). Several mechanisms of these indirect effects were thoroughly reviewed by Goncharov et al. (2016).
21.3 Commonly Known Organosulfur Compounds
21.3.1 Allicin
Allicin is an organic compound, also known as allyl-2-propenethiosulfinate or diallyl thiosulfinate or S-allyl cysteine sulfoxide. It is a sulfur-containing volatile agent
generally found in plants such as wild garlic (Allium ursinum L.), field garlic
(A. vineale L.), elephant garlic (A. ampeloprasum L.), white garlic (A. sativum L.)
and alpine leek (A. victorialis L.). It is one of the major organosulfur bioactive
agents found in Allium plant species and is accountable for the pungent taste and
smell (Salehi et al. 2019). Allicin is a predominant thiosulfinate compound typically
responsible for 70% (w/w) of the entire thiosulfinates. It is a colourless oil compound with negligible polarity in water and not found in intact garlic clove, rather,
it is naturally formed alongside with ammonia and pyruvate from S-allyl-L-cysteine
sulfoxide (alliin precursor). It is an odourless precursor with a stable, non-protein
amino acid via the alliin lyase (alliinase, α, β-eliminating endogenous lyase from
Allium spp., EC 4.4.1.4) enzyme activity. It is noteworthy that the maceration or
pulverisation of garlic cloves will lead to this type of enzyme activity (Marchese
et al. 2016). Allicin was first reported to exhibit biological activity in 1944 by John
Hays Bailey and Chester John Cavallito. Hence, decades of substantial research
focused on exploring their biological properties began (Josling 2007). The extensive
research has provided evidence that allicin possesses a wide range of biological
activities such as anti-bacterial, anti-diabetic, anti-cancer, anti-angiogenesis and
anti-hyperlipidemic effects (Chan et al. 2013; Chu et al. 2013; Fujisawa et al. 2009).
21 Health Benefits of Organosulfur Compounds
properties is still a subject of debate until now. In one study an increased antioxidant
activity was found when garlic was boiled at 100 °C for 30 min (Shobana and
Akhilender Naidu 2000) while in another study increased beneficial effects were
found after heating (Benkeblia 2004). In another study, the antioxidants present in
garlic were found to be thermally unstable (Lai and Roy 2012) and that allicin formation was prevented when the enzyme allinase is inactivated by heat (Banerjee
et al. 2003; Schäfer and Kaschula 2014). Although OSCs are known to be antioxidants, their property is believed to be brought about and mediated indirectly through
the sulfane-sulfur derivatives of these compounds (Colín-González et al. 2012;
Toohey and Cooper 2014). Several mechanisms of these indirect effects were thoroughly reviewed by Goncharov et al. (2016).
21.3 Commonly Known Organosulfur Compounds
21.3.1 Allicin
Allicin is an organic compound, also known as allyl-2-propenethiosulfinate or diallyl thiosulfinate or S-allyl cysteine sulfoxide. It is a sulfur-containing volatile agent
generally found in plants such as wild garlic (Allium ursinum L.), field garlic
(A. vineale L.), elephant garlic (A. ampeloprasum L.), white garlic (A. sativum L.)
and alpine leek (A. victorialis L.). It is one of the major organosulfur bioactive
agents found in Allium plant species and is accountable for the pungent taste and
smell (Salehi et al. 2019). Allicin is a predominant thiosulfinate compound typically
responsible for 70% (w/w) of the entire thiosulfinates. It is a colourless oil compound with negligible polarity in water and not found in intact garlic clove, rather,
it is naturally formed alongside with ammonia and pyruvate from S-allyl-L-cysteine
sulfoxide (alliin precursor). It is an odourless precursor with a stable, non-protein
amino acid via the alliin lyase (alliinase, α, β-eliminating endogenous lyase from
Allium spp., EC 4.4.1.4) enzyme activity. It is noteworthy that the maceration or
pulverisation of garlic cloves will lead to this type of enzyme activity (Marchese
et al. 2016). Allicin was first reported to exhibit biological activity in 1944 by John
Hays Bailey and Chester John Cavallito. Hence, decades of substantial research
focused on exploring their biological properties began (Josling 2007). The extensive
research has provided evidence that allicin possesses a wide range of biological
activities such as anti-bacterial, anti-diabetic, anti-cancer, anti-angiogenesis and
anti-hyperlipidemic effects (Chan et al. 2013; Chu et al. 2013; Fujisawa et al. 2009).
21 Health Benefits of Organosulfur Compounds