ABSTRACT
From the EtOH-soluble extract of the roots of Piper nigrum, one new dimeric alkamide, pipercyclobutanamide D (1) was isolated. Its structure was elucidated on the basis of NMR spectroscopic interpretation. The relative configuration of 1 was determined based on the NOESY analysis. Compound 1 showed α-glucosidase inhibitory activity with an IC50 value of 158.5 µM. In addition, compound 1 exhibited cytotoxicity against the MCF-7 and HepG2 cell lines with the IC50 values of 45.6 and 63.9 µM, respectively. Plausible biosynthetic pathway for the formation of 1 was proposed based on regioselective [2 + 2] cycloaddition reaction.
Subject(s)
Alkaloids , Piper nigrum , Piper , Alkaloids/pharmacology , Molecular Structure , Plant Extracts , Plant RootsABSTRACT
From EtOAc-soluble fraction of the aerial parts of Ampelopsis cantoniensis (Vitaceae), two new meroterpenoids named ampechromonol A (1) and ampechromonol B (2), together with five known compounds (3-7), were isolated. Their structures were elucidated based on NMR spectroscopic analysis. The plausible biosynthesis pathway for the formation of two new meroterpenoids was proposed. This research is the first isolation of meroterpenoids from Ampelopsis genus. Compounds 1 and 2 showed weak cytotoxicity against MCF-7 breast cancer cells.
Subject(s)
Ampelopsis , Vitaceae , Molecular Structure , Plant Components, AerialABSTRACT
This paper presents a survey of recent developments using Doppler radar sensor in searching and locating an alive person under debris or behind a wall. Locating a human and detecting the vital signs such as breathing rate and heartbeat using a microwave sensor is a non-invasive technique. Recently, many hardware structures, signal processing approaches, and integrated systems have been introduced by researchers in this field. The purpose is to enhance the accuracy of vital signs' detection and location detection and reduce energy consumption. This work concentrates on the representative research on sensing systems that can find alive people under rubble when an earthquake or other disasters occur. In this paper, various operating principles and system architectures for finding survivors using the microwave radar sensors are reviewed. A comparison between these systems is also discussed.
Subject(s)
Biosensing Techniques , Disasters , Signal Processing, Computer-Assisted/instrumentation , Algorithms , Heart Rate/physiology , Humans , Radar , Respiratory Rate/physiologyABSTRACT
One bioactive flavonoid on brine shrimp test was isolated from leaves of Macaranga triloba (Blume) Muell-aRG...Its structure was elucidated based on spectral analysis, including UV, FT-IR, 1H-NMR, 13C-NMR, 13C-DEPT, and was determined as vitexin