[Study on chemical constituents of Cinnamomi Ramulus].

The chemical constituents of Cinnamomi Ramulus were investigated in this study. Twenty-two compounds were isolated by silica gel, Sephadex LH-20 gel column chromatographies and preparative HPLC and their structures were identified by various spectral analyses as dihydrorosavin(1), rosavin(2), 1-phenyl-propane-1,2,3-triol(3), patchoulol(4), graphostromane B(5),(+)-lyoniresinol-3 a-O-ß-D-glucopyranoside(6),(-)-lyoniresinol-3 a-O-ß-D-glucopyranoside(7), cinnacaside(8), subaveniumin A(9), 3-phenyl-2-propenyl-6-O-L-arabinopyranosyl-ß-glucopyranoside(10), 2-phenylethyl-ß-vicianoside(11), cinnacasol(12), [(2R,3S,4S,5R,6R)-6-(benzyloxy)-3,4,5-trihydroxytetrahydro-2H-pyran-2-yl] methyl hydrogen sulfate(13), coniferyl aldehyde(14),(2R,3R)-5,7-dimethoxy-3',4'-methylenedioxyflavan-3-ol(15), cinnacassin L(16), E-cinnamic alcohol(17),(E)-3-(2-methoxyphenyl)-2-propen-1-ol(18), 2-hydroxyphenylpropanol(19), cinnamomulactone(20),(+)-syringaresinol(21) and cinnamomumolide(22), respectively. Among them, 1 is a new compound and 3-7, 9-11, 13, 15, 18 and 19 were isolated from the plant for the first time.

Inhibitory Activity of Plant Essential Oils against E. coli 1-Deoxy-d-xylulose-5-phosphate reductoisomerase.

The rate-limiting enzyme of the 2-methyl-d-erythritol-4-phosphate (MEP) terpenoid biosynthetic pathway, 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), provides the perfect target for screening new antibacterial substances. In this study, we tested the DXR inhibitory effect of 35 plant essential oils (EOs), which have long been recognized for their antimicrobial properties. The results show that the EOs of Zanbthoxylum bungeanum (ZB), Schizonepetae tenuifoliae (ST), Thymus quinquecostatus (TQ), Origanum vulgare (OV), and Eugenia caryophyllata (EC) displayed weak to medium inhibitory activity against DXR, with IC50 values of 78 µg/mL, 65 µg/mL, 59 µg/mL, 48 µg/mL, and 37 µg/mL, respectively. GC-MS analyses of the above oils and further DXR inhibitory activity tests of their major components revealed that eugenol (EC) and carvacrol (TQ and OV) possess medium inhibition against the protein (68.3% and 55.6%, respectively, at a concentration of 20 µg/mL), whereas thymol (ST, TQ, and OV), carveol (ZB), and linalool (ZB, ST, and OV) only exhibited weak inhibition against DXR, at 20 µg/mL (23%-26%). The results add more details to the antimicrobial mechanisms of plant EOs, which could be very helpful in the direction of the reasonable use of EOs in the food industry and in the control of phytopathogenic microbials.

Cinnamtannin D1 Protects Pancreatic ß-Cells from Glucolipotoxicity-Induced Apoptosis by Enhancement of Autophagy In Vitro and In Vivo.

In our previous study, cinnamtannin D1 (CD-1), one of the A-type procyanidin oligomers isolated from Cinnamomum tamala, was reported to have the activity of antiapoptosis in palmitic acid-treated pancreatic ß cells via alleviating oxidative stress in vitro. In this study, the aim was to further disclose its protective effect and underlying mechanisms against glucolipotoxicity-induced ß-cells apoptosis in vitro and in vivo. We found that CD-1 was able to dose-dependently and time-dependently activate autophagy in INS-1 pancreatic ß-cells. High glucose and palmitic acid (HG/PA)-induced apoptosis and autophagy impairment could be attenuated by CD-1 in INS-1 cells as well as primary cultured murine islets. We also demonstrated that CD-1-induced autophagy was through AMPK/mTOR/ULK1 pathway. Moreover, it was shown that the effects of CD-1 on activation of Keap1/Nrf2 antioxidant signaling pathway and the amelioration of inflammation, endoplasmic reticulum stress, and apoptosis were through autophagy induction in HG/PA-treated INS-1 cells. These protective effects in vivo and hypoglycemic activity of CD-1 were also observed in diabetic db/db mice. These findings have great significance in revealing the antidiabetic mechanisms of procyanidin oligomers and paving the way for their application in the treatment of diabetes.