- New neryl esters from Helichrysum italicum (Roth) G. Don (Asteraceae) essential oil
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Helichrysum italicum (immortelle) is a dwarf aromatic shrub native to the Mediterranean region. The typical subspecies (italicum) produces an essential oil rich in neryl acetate and characteristic β-diketones, italidiones, highly valued in the perfume industry. As esters are an important group of aroma-active volatiles, herein the composition of the ester fraction of this immortelle chemotype essential oil was studied in detail. Chromatographic separation of Corsican immortelle essential oil enabled the discovery of numerous potentially olfactory-interesting esters of nerol and/or angelic acid, undetectable by direct GC-MS analyses of the unfractioned oil. Four esters of nerol and medium-chain branched fatty acids represent new natural products, while several other esters have a rather restricted occurrence in the Plant Kingdom.
- ?or?evi?, Miljana R.,?ivkovi? Sto?i?, Milena Z.,Aksi?, Jelena M.,Gen?i?, Marija S.,Mladenovi?, Marko Z.,Radulovi?, Niko S.
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supporting information
(2020/11/02)
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- Efficient Enzymatic Preparation of Flavor Esters in Water
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A straightforward biocatalytic method for the enzymatic preparation of different flavor esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalyzed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and proceeded with excellent yields (80-97%) and short reaction times (30-120 min), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared with already known methods in terms of reduced use of organic solvents, paving the way to sustainable and efficient preparation of natural flavoring agents.
- Perdomo, Igor Chiarelli,Gianolio, Stefania,Pinto, Andrea,Romano, Diego,Contente, Martina Letizia,Paradisi, Francesca,Molinari, Francesco
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p. 6517 - 6522
(2019/06/20)
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- Tyrosinase inhibitors
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Methods and compositions are provided for inhibiting the activity of tyrosinase in a host and, as a result, inhibiting melanin-formation. The tyrosinase-inhibitor active ingredient is a compound or mixture of compounds represented by the following structural formulae (I) and (II): STR1 wherein the dotted lines at a, b, c, d, e, f, g, represent an optional double bond, provided that double bonds are not at both b and c, or at both f and g, at the same time; R1, R5, R6, and R7 are each hydrogen or methyl; R2 and R8 are each no group, or each hydrogen or hydroxyl when there is no double bond at a and at f, respectively; R3 is methylene when there is a double bond at b, or hydrogen or methyl when there is no double bond at b; R4 is formyl or --(CH2)n --R10, wherein R10 is hydrogen, hydroxyl, acyloxy, or cyano and n is an integer of from 1 to 3; and R9 is methylene when there is a double bond at g, or --(CH2)n --R10 when there is no double bond at g.
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- Synthesis of Fatty Acid Ester by Corynebacterium sp. S-401
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Resting cells and acetone-dried cells of Corynebacterium sp.S-401 catalyzed the fatty acid ester synthesis of various alcohols and fatty acids.These reactions were carried out in phosphate buffer and/or organic solvents.In some cases synthetic reactions of esters in nonpolar solvents, such as n-hexane and benzene, gave better results compared with those obtained in phosphate buffer.
- Seo, Chull Won,Yamada, Yasuhiro,Okada, Hirosuke
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p. 405 - 410
(2007/10/02)
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