A series of pyromellitic diimides that improve the efficiency of rumen fermentation

Abstract

A number of pyromellitic diimides were prepared and found to alter rumen fermentation in a potentially beneficial way. In vitro rumen test procedures and chemical syntheses for preparation of novel unsymmetrical N-substituted pyromellitic diimides were developed. Structure-activity investigations showed that a variety of N substituents could be tolerated while retaining high activity. The most potent compounds in the series had ID^v alues for methane suppression of approximately 1 Pg/mL and blocked methane production completely at higher levels. Volatile fatty acid composition was shifted from acetic to propionic and butyric acids. Two compounds, pyromellitic diimide and pyromellitic N-(2hydroxyethyl)diimide, have been selected for further study in sheep and cattle.The rumen, in ruminating animals, provides an ecosystem in which microorganisms, living at a pH between 5.5 and 7.0 in an anaerobic environment, can metabolize incoming materials into nutrients to be used by the host. The principal end products of carbohydrate metabolism in this system are volatile fatty acids (VFA's) such as acetic acid, propionic acid, and butyric acid, which are absorbed by the host and the gases carbon dioxide and methane.Methane is formed by the reduction of carbon dioxide by hydrogen. An outline of the principal pathways of carbohydrate metabolism is shown in Scheme I [adapted from Hungate (1966) and Leng (1970)]. Methane is expelled.A typical rumen fermentation may be approximated by the equation (Wolin, 1974) 57.5C6H1206 -65CH3COOH + 20CH3CH2COOH + 15CH3CH2CH2COOH + 60CO2 + 35CH4 + 25H20 (1) If one considers energy utilization and conservation via glycolysis, the following generalization applies (Hungate,

Effect of α‐cyclodextrin‐allyl isothiocyanate on ruminal microbial methane production in vitro

“…1997), halogenated methane analogs (Bauchop 1967; Trei et al . 1971), and pyromellitic diimide (Linn et al . 1982).…”

An Anthracene‐Appended β‐Cyclodextrin‐Based Dyad: Study of Self‐Assembly and Photoinduced Electron‐Transfer Processes

“…The yield of purified product was 25 %. 98, 60.31, 64.65, 68.85, 70.73, 71.80, 72.09, 72.48, 73.12, 73.52, 81.57, 82.05, 102.34, 102.58, 124.86, 125.22, 126.48, 126.74, 127.7, 127.93, 128.77, 129.40, 130.47, 130.99 ppm; IR (KBr): ñ = 1031, 1080,1153,1246,1334,1365,1448,1587,1662,2895,2939 PMDI was prepared by adapting a standard procedure [32] (see the Supporting Information Scheme S5 for synthetic scheme and experimental details). 19.75, 40.34, 42.99, 59.58, 117.29, 128.09, 136.67, 136.99, 145.47, 146.20, 166.05, 166.10 The 9-chloromethylanthracene used in the study was purchased from Aldrich and converted to AMTAC by adapting standard procedures.…”

Efficacy of ionophores in cattle diets for mitigation of enteric methane1

“…Chemical Supplementation It has been shown that chlorinated methane analogues (i.e. clrlorofornL carbon tetra-chloride and methylene chloride) (Bauchop 1967) and related compounds such as trichloroethyl adipate (Clapperton 1977) and pyromellitic diimide (Linn et al 1982) inhibited methnogensis by directly inhibiting methanogens. Prins et al (1972) (Itabashi 2002).…”