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We have clarified that Eriobotrya japonica seed extract has strong antioxidative activity, and is effective for the prevention and treatment of various diseases, such as hepatopathy and nephropathy. In this study, to investigate the influences of components of Eriobotrya japonica seed extract on its antioxidative activity, extracts were prepared using various solvents (n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (n-BuOH), methanol (MeOH) and H2O) and the antioxidative activity of the solvent fractions and components was evaluated based on the scavenging of various radicals (DPPH and O2(-)) measured by the ESR method and the inhibition of Fe3+-ADP induced NADPH dependent lipid peroxidation in rat liver microsomes. The radical scavenging activities and inhibitory activities on lipid peroxidation differed among the solvent fractions and components. In the n-BuOH, MeOH and H2O fractions, radical scavenging activity and inhibitory activity on lipid peroxidation were high. In addition, these fractions contained abundant polyphenols, and the radical scavenging activity increased with the polyphenol content. In the low-polar Hex and EtOAc fractions, the radical scavenging activity was low, but the lipid peroxidation inhibition activity was high. These fractions contained beta-sitosterol, and the inhibitory activity on lipid peroxidation was high. Based on these findings, the antioxidative activity of Eriobotrya japonica seed extract may be derived from many components involved in a complex mechanism, resulting in high activity.

Sixteen triterpene acids, viz., five of the oleanane-type (1-5), nine of the ursane-type (6-14), and two of the lupane-type (15, 16), were isolated and identified from the ethyl acetate-soluble fraction of the methanol extract of the leaves of loquat, Eriobotrya japonica LINDL. (Rosaceae). Twelve of these compounds, 1-4, 6, 8-13, and 15, were evaluated for their inhibitory effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation (1 microg/ear) in mice. All the compounds tested showed a marked anti-inflammatory effect, with a 50% inhibitory dose (ID50) of 0.03-0.43 mg per ear. In addition, an evaluation against the Epstein-Barr virus early antigen (EBV-EA) activation induced by TPA for all of the compounds, 12 and 13 showed potent inhibitory effects on EBV-EA induction. Furthermore, euscaphic acid (12) exhibited marked antitumor-promoting activity in an in vivo two-stage carcinogenesis test of mouse tumor by using 7,12-dimethylbenz[a]anthracene (DMBA) as an initiator and TPA as a promoter.

Tissue factor (TF, tissue thromboplastin) is a membrane bound glycoprotein, which accelerates the blood clotting, activating both the intrinsic and the extrinsic pathways to serve as a cofactor for activated factor VII (VIIa). The TF-factor VIIa complex (TF/VIIa) proteolytically activates factors IX and X, which leads to the generation of thrombin and fibrin clots. In order to isolate TF inhibitors, by means of a bioassay-directed chromatographic separation technique, from the leaves of Eriobotrya japonica Lindley (Rosaceae), a known sesquiterpene glycoside (2) and ferulic acid (3) were isolated as inhibitors that were evaluated using a single-clotting assay method for determining TF activity. Another sesquiterpene glycoside (1) was also isolated but was inactive in the assay system. Compound 3 was yielded by alkaline hydrolysis of compound 2. The structures of compounds 1, 2, and 3 were identified by means of spectral analysis as 3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl nerolidol (1), 3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-(4-trans-feruloyl)-rhamnopyranosyl-(1-->6)]-beta-D-glucopyranosyl nerolidol (2) and ferulic acid (3), respectively. Compounds 2 and 3 inhibited 50% of the TF activity at concentrations of 2 and 369 microM/TF units, respectively.

A new acylated flavonol glycoside was isolated from the leaves of Eriobotrya japonica along with two known flavonol glycosides. Their structures were determined by extensive spectroscopic investigation.

Two Asian small-clawed otters (Amblonyx cinereus) died acutely in their exhibit within a 4-day period. Neither animal had significant gross lesions at necropsy. Histologic findings were consistent with acute vascular shock and disseminated intravascular coagulation, and a toxic etiology was suspected. The animals' exhibit contained opened, uneaten loquat (Eriobotrya japonica) fruit with the seeds removed and large quantities of undigested loquat seed material in the feces of the remaining animals. Cyanide was detected in the stomach contents collected at necropsy and in fresh loquat seeds from the exhibit. Loquat is related to other cyanide-containing fruit trees, including cherries, peaches, and almonds.

Objective: To investigate the chemical composition of the flowers of Eriobotrya japonica., Methods: Four constituents were isolated from the ethanolic extracts of flowers of Eriobotrya japonica (Thunb) Lindl and were identified by chemical methods and spectroscopic (IR, MS, 1HNMR, 13CNMR)., Results: The structures were identified as: Oleanolic acid (I), Ursolic acid(II), 2 alpha, 3 alpha, 19 alpha-Trihydroxyurs-5,12-dien-28-acid (III) and 2 beta, 3 beta, 23 alpha-Trihydroxyolean-12-en-28-acid (IV)., Conclusion: The compounds I, II, III and IV were obtained from the flowers of Eriobotrya japonica for the first time.