The study of structure and effects of two new proanthocyanidins from Anogeissus pendula leaves on rumen enzyme activities

Abstract

Two novel proanthocyanidins, (2R, 3R)-(+)-Gallocatechin-(4β → 8)4-(2R, 3R)-(+)-gallocatechin (compound 1) and 3-O-galloyl-(2S, 3S)-(–)-epicatechin-(4α → 8)-[3-O-galloyl-(2S, 3S)-(–)-epicatechin (4α → 8)]2-(2S, 3S)-(–)-epicatechin (compound 2), were structurally characterized from leaves of Anogeissus pendula. The structures were determined by ultraviolet spectroscopy (UV), proton nuclear magnetic resonance (1H NMR), 13C NMR, and heteronuclear multiple bond correlation. Molinspiration and Osiris property explorer applications were used to predict bioactivity and drug score. Drug scores of 0.08 and 0.05 were predicted for compounds 1 and 2, respectively. Predicted bioactivity scores were high. Due to their molecular weight, chemical structure, and conformation, the newly discovered proanthocyanidins possess an inclination to interact with proteins. Based on this premise, both compounds were subjected to in vitro testing against ruminal enzymes. They exhibited significant inhibition activities (p < 0.01) with a range of half maximal effective concentration (EC50) of 14.80–17.88 mg/mL of glutamic oxaloacetic transaminase in both protozoa and bacteria fractions. The ruminal glutamic pyruvic transaminase activity was significantly inhibited (p < 0.01) from EC50 12.59–16.29 mg/mL, and R-cellulase inhibition was recorded with EC50 18.20–21.98 mg/mL by compounds 1 and 2, respectively. Protease activity decreased with increasing incubation time and concentration of both compounds. The novel proanthocyanidins have potential roles in improving feed conversion ratios and in drug development.

Proanthocyanidins isolated from the leaves of Ficus glomerata evaluated on the activities of rumen enzymes: in vitro and in silico studies

“…Phenolic compounds exhibited the inhibition effect due to their anti-microbial properties and additional metabolites generated during the fermentation process ( Kamra et al, 2022 ). Similar trends were observed in rumen kinetics by using phenolic/methanolic leaf extracts of Ficus species ( Koli et al, 2022 ) and Anogeissus pendula ( Singh et al, 2022 ; Lata et al, 2023 ), as well as other phenolic plant extracts ( Patra et al, 2006 ; Dhanasekaran et al, 2020 ; Kamra et al, 2022 ). It is believed that plant phenolic compounds could be a strong antioxidant after breaking down from plant extract, resulting in the reduction of ruminal enzymatic activities ( Ishida et al, 2015 ).…”

“…A similar observation of lowering the concentration of liberated rumen protein in the presence of isolated compounds 1 and 2 with elevated concentrations and incubation times with phenolic extracts of Lotus pendunculatus (McNabb et al, 1996), tannin-rich forage leaves (Aerts et al, 1999;Bhatta et al, 2012), proanthocyanidins obtained from Ficus (Koli et al, 2022) and Anogeissus species (Singh et al, 2022;Lata et al, 2023), phenolics extracted from pomegranate skin (Abarghuei et al, 2021). The movement of protein from the stomach to the intestine, where the animal can use it, depends on how strongly it binds.…”

“…The drug score for compounds 1 and 2 were obtained as 0.03 and 0.05, respectively ( Table 4 ). The obtained scores were varied in the range of low risk of undesired behavior, viz., mutagenicity or poor intestinal absorption, and thus indicated drug-conform behavior with a good signal for druglikeness and bioactivity potential ( Lata et al, 2023 ). The drug score combines druglikeness, cLogP (logarithm of partition coefficient), logS (logarithm of solubility), molecular weight, and toxicity risks in one handy value that may be used to judge the compound’s overall potential to qualify for a drug ( Verma, 2012 ).…”

“…The inhibitory effects of forage legume phenolic extracts on cellulose digestion ( McAllister et al, 2005 ) and phenolic acids’ decreasing activities of rumen enzymes in vitro ( Berchez et al, 2019 ) help to support our findings on the reduction of ruminal cellulase activity. The observed decrease in ruminal GOT, GPT, and cellulase activity in ruminal enzymes signifies potential benefits for animal nutrient utilization ( Lata et al, 2023 ). This reduction implies improved amino acid metabolism and enhanced protein synthesis.…”

Agroecological Zone-Specific Diet Optimization for Water Buffalo (Bubalus bubalis) through Nutritional and In Vitro Fermentation Studies

“…During the fermentation process (digestion and metabolism) of diets in the gastrointestinal tract, between 2 and 12% of dietary gross energy is lost as methane [7]. Several factors, viz., animal species and size, animal physiological stage, feed intake, digestibility, diet composition, etc., influence enteric methane production [9,10]. Diet composition (chemical and physical qualities) and its intake level (quantity consumed) influence methane production due to their effect on the rate of digestion and the rate of passage [11].…”