Tags

Type your tag names separated by a space and hit enter

Identification and in vitro biological activities of hop proanthocyanidins: inhibition of nNOS activity and scavenging of reactive nitrogen species.
J Agric Food Chem. 2002 Jun 05; 50(12):3435-43.JA

Abstract

Oligomeric proanthocyanidins constitute a group of water-soluble polyphenolic tannins that are present in the female inflorescences (up to 5% dry wt) of the hop plant (Humulus lupulus). Humans are exposed to hop proanthocyanidins through consumption of beer. Proanthocyanidins from hops were characterized for their chemical structure and their in vitro biological activities. Chemically, they consist mainly of oligomeric catechins ranging from dimers to octamers, with minor amounts of catechin oligomers containing one or two gallocatechin units. The chemical structures of four procyanidin dimers (B1, B2, B3, and B4) and one trimer, epicatechin-(4beta-->8)-catechin-(4alpha-->8)-catechin (TR), were elucidated using mass spectrometry, NMR spectroscopy, and chemical degradation. When tested as a mixture, the hop oligomeric proanthocyanidins (PC) were found to be potent inhibitors of neuronal nitric oxide synthase (nNOS) activity. Among the oligomers tested, procyanidin B2 was most inhibitory against nNOS activity. Procyanidin B3, catechin, and epicatechin were noninhibitory against nNOS activity. PC and the individual oligomers were all strong inhibitors of 3-morpholinosydnonimine (SIN-1)-induced oxidation of LDL, with procyanidin B3 showing the highest antioxidant activity at 0.1 microg/mL. The catechin trimer (TR) exhibited antioxidant activity more than 1 order of magnitude greater than that of alpha-tocopherol or ascorbic acid on a molar basis.

Authors+Show Affiliations

Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

12033808

Citation

Stevens, Jan F., et al. "Identification and in Vitro Biological Activities of Hop Proanthocyanidins: Inhibition of nNOS Activity and Scavenging of Reactive Nitrogen Species." Journal of Agricultural and Food Chemistry, vol. 50, no. 12, 2002, pp. 3435-43.
Stevens JF, Miranda CL, Wolthers KR, et al. Identification and in vitro biological activities of hop proanthocyanidins: inhibition of nNOS activity and scavenging of reactive nitrogen species. J Agric Food Chem. 2002;50(12):3435-43.
Stevens, J. F., Miranda, C. L., Wolthers, K. R., Schimerlik, M., Deinzer, M. L., & Buhler, D. R. (2002). Identification and in vitro biological activities of hop proanthocyanidins: inhibition of nNOS activity and scavenging of reactive nitrogen species. Journal of Agricultural and Food Chemistry, 50(12), 3435-43.
Stevens JF, et al. Identification and in Vitro Biological Activities of Hop Proanthocyanidins: Inhibition of nNOS Activity and Scavenging of Reactive Nitrogen Species. J Agric Food Chem. 2002 Jun 5;50(12):3435-43. PubMed PMID: 12033808.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Identification and in vitro biological activities of hop proanthocyanidins: inhibition of nNOS activity and scavenging of reactive nitrogen species. AU - Stevens,Jan F, AU - Miranda,Cristobal L, AU - Wolthers,Kirsten R, AU - Schimerlik,Michael, AU - Deinzer,Max L, AU - Buhler,Donald R, PY - 2002/5/30/pubmed PY - 2002/7/13/medline PY - 2002/5/30/entrez SP - 3435 EP - 43 JF - Journal of agricultural and food chemistry JO - J Agric Food Chem VL - 50 IS - 12 N2 - Oligomeric proanthocyanidins constitute a group of water-soluble polyphenolic tannins that are present in the female inflorescences (up to 5% dry wt) of the hop plant (Humulus lupulus). Humans are exposed to hop proanthocyanidins through consumption of beer. Proanthocyanidins from hops were characterized for their chemical structure and their in vitro biological activities. Chemically, they consist mainly of oligomeric catechins ranging from dimers to octamers, with minor amounts of catechin oligomers containing one or two gallocatechin units. The chemical structures of four procyanidin dimers (B1, B2, B3, and B4) and one trimer, epicatechin-(4beta-->8)-catechin-(4alpha-->8)-catechin (TR), were elucidated using mass spectrometry, NMR spectroscopy, and chemical degradation. When tested as a mixture, the hop oligomeric proanthocyanidins (PC) were found to be potent inhibitors of neuronal nitric oxide synthase (nNOS) activity. Among the oligomers tested, procyanidin B2 was most inhibitory against nNOS activity. Procyanidin B3, catechin, and epicatechin were noninhibitory against nNOS activity. PC and the individual oligomers were all strong inhibitors of 3-morpholinosydnonimine (SIN-1)-induced oxidation of LDL, with procyanidin B3 showing the highest antioxidant activity at 0.1 microg/mL. The catechin trimer (TR) exhibited antioxidant activity more than 1 order of magnitude greater than that of alpha-tocopherol or ascorbic acid on a molar basis. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/12033808/Identification_and_in_vitro_biological_activities_of_hop_proanthocyanidins:_inhibition_of_nNOS_activity_and_scavenging_of_reactive_nitrogen_species_ L2 - https://doi.org/10.1021/jf0116202 DB - PRIME DP - Unbound Medicine ER -