New cyclic sulfides extracted from Allium sativum: garlicnins P, J2, and Q

Abstract

Two atypical cyclic-type sulfides, garlicnin P (1) and garlicnin J (2), and one thiabicyclic-type sulfide, garlicnin Q (3), were isolated from the acetone extracts of garlic, Allium sativum, bulbs cultivated in the Kumamoto city area, and their structures characterized. Their production pathways are also discussed.

Thiolane-type sulfides from garlic, onion, and Welsh onion

“…Structures of garlicnins and onionins isolated from garlic filtrate was concentrated at 40 °C in vacuum to obtain the extract in a small volume that was partitioned between ethyl acetate and water. The ethyl acetate extractive (5.9 g) was separated by column chromatography on silica gel eluting with n-hexane: acetone (from 6: 1 to 2: 1) to yield 21 new sulfides named garlicnins A (48.2 mg) [12], B 1 (242.0 mg), B 2 (47.2 mg), B 3 (29.8 mg), B 4 (19.3 mg), C 1 (26.4 mg), C 2 (23.4 mg), C 3 (14.6 mg) [13,14], G (17.2 mg), I 1 (17.4 mg) [15], I 2 (15.6 mg) [16], J 1 (17.4 mg) [15], J 2 (19.4 mg) [17], L-1 (47.2 mg), L-2 (19.8 mg), L-3 (19.3 mg), L-4 (23.4 mg) [18], M (21.1 mg) [16], P (18.4 mg) [17], and onionins B 1 (27.4 mg), and B 2 (26.2 mg) [19], together with the known sulfide, (E)-ajoene (279.7 mg) [10], and kujounin A 1 derivative (22.1 mg), which related to kujounin A 1 obtained from Allium fistulosum by Matsuda et al [20]. The structures of the obtained sulfides were characterized using high-resolution fast atom bombardment mass spectroscopy (HR-FABMS), 1 H-NMR, 13 C-NMR, 1 H-1 H NMR correlation spectroscopy (COSY), 1 H-detected heteronuclear correlation through multiplet quantum coherence (HMQC), heteronuclear multiple bond correlation (HMBC) and nuclear Overhauser effect spectroscopy (NOESY).…”

“…Next, the filtrate was concentrated at 40 °C in vacuum to obtain the extract in a small volume that was partitioned between ethyl acetate and water. The ethyl acetate extractive (5.9 g) was separated by column chromatography on silica gel eluting with n -hexane: acetone (from 6: 1 to 2: 1) to yield 21 new sulfides named garlicnins A (48.2 mg) [ 12 ], B 1 (242.0 mg), B 2 (47.2 mg), B 3 (29.8 mg), B 4 (19.3 mg), C 1 (26.4 mg), C 2 (23.4 mg), C 3 (14.6 mg) [ 13 , 14 ], G (17.2 mg), I 1 (17.4 mg) [ 15 ], I 2 (15.6 mg) [ 16 ], J 1 (17.4 mg) [ 15 ], J 2 (19.4 mg) [ 17 ], L-1 (47.2 mg), L-2 (19.8 mg), L-3 (19.3 mg), L-4 (23.4 mg) [ 18 ], M (21.1 mg) [ 16 ], P (18.4 mg) [ 17 ], and onionins B 1 (27.4 mg), and B 2 (26.2 mg) [ 19 ], together with the known sulfide, ( E )-ajoene (279.7 mg) [ 10 ], and kujounin A 1 derivative (22.1 mg), which related to kujounin A 1 obtained from Allium fistulosum by Matsuda et al . [ 20 ].…”