Price Neil Pj, Bischoff Kenneth M, Leathers Timothy D, Cossé Allard A, Manitchotpisit Pennapa
Renewable Product Technology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL, USA.
Crop Bioprotection Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, US Department of Agriculture, Peoria, IL, USA.
J Antibiot (Tokyo). 2017 Feb;70(2):136-141. doi: 10.1038/ja.2016.92. Epub 2016 Jul 20.
Liamocins are polyol lipids produced by the fungus Aureobasidium pullulans, and have selective antibacterial activity against Streptococcus species. Liamocins produced by A. pullulans strain NRRL 50380 on sucrose medium have a d-mannitol head group ester-linked to 3,5-dihydroxydecanoate acyl chains, three or four of which are joined together by 1,5-polyester bonds (liamocins Man-A1 and Man-B1), and similar 3'-O-acetylated analogs (Man-A2 and Man-B2). However, other types of liamocins are produced depending on the choice of strain and growth conditions. In the current study, growth on different polyols, but not sugars, resulted in considerable structural variation, including liamocins with d-galactitol (dulcitol), d-sorbitol (glucitol), d- and l-arabitol, d-xylitol, l-threitol and glycerol head groups. The head groups of liamocins produced on arabitol were shown to be entirely composed of d-arabitol. These liamocin variants were structurally characterized by NMR and MS, and tested for antibacterial activity. The new liamocin variants also had selective activity against Streptococcus. Liamocin structural variants are novel antibacterials against Streptococcus sp. that merit further investigation.
梨孢菌素是由出芽短梗霉产生的多元醇脂质，对链球菌具有选择性抗菌活性。出芽短梗霉NRRL 50380菌株在蔗糖培养基上产生的梨孢菌素具有与3,5-二羟基癸酸酰基链酯连接的d-甘露糖醇头部基团，其中三条或四条通过1,5-聚酯键连接在一起（梨孢菌素Man-A1和Man-B1），以及类似的3'-O-乙酰化类似物（Man-A2和Man-B2）。然而，根据菌株和生长条件的选择会产生其他类型的梨孢菌素。在当前研究中，在不同多元醇而非糖类上生长会导致相当大的结构变化，包括具有d-半乳糖醇（卫矛醇）、d-山梨醇（葡糖醇）、d-和l-阿拉伯糖醇、d-木糖醇、l-苏糖醇和甘油头部基团的梨孢菌素。在阿拉伯糖醇上产生的梨孢菌素的头部基团被证明完全由d-阿拉伯糖醇组成。这些梨孢菌素变体通过核磁共振和质谱进行结构表征，并测试其抗菌活性。新的梨孢菌素变体对链球菌也具有选择性活性。梨孢菌素结构变体是针对链球菌的新型抗菌剂，值得进一步研究。
