ABSTRACT
We analyze the correlation between different assets in the cryptocurrency market throughout different phases, specifically bearish and bullish periods. Taking advantage of a fine-grained dataset comprising 34 historical cryptocurrency price time series collected tick-by-tick on the HitBTC exchange, we observe the changes in interactions among these cryptocurrencies from two aspects: time and level of granularity. Moreover, the investment decisions of investors during turbulent times caused by the COVID-19 pandemic are assessed by looking at the cryptocurrency community structure using various community detection algorithms. We found that finer-grain time series describes clearer the correlations between cryptocurrencies. Notably, a noise and trend removal scheme is applied to the original correlations thanks to the theory of random matrices and the concept of Market Component, which has never been considered in existing studies in quantitative finance. To this end, we recognized that investment decisions of cryptocurrency traders vary between bearish and bullish markets. The results of our work can help scholars, especially investors, better understand the operation of the cryptocurrency market, thereby building up an appropriate investment strategy suitable to the prevailing certain economic situation.
ABSTRACT
A new benzofuran derivative, pumiloside (1), together with seven known flavonoid glycosides, afzelin (2), astragalin (3), quercitrin (4), isoquercitrin (5), kaempferol 3-O-rutinoside (6), rutin (7) and kaempferol 3-O-sophoroside (8) were isolated from the leaves of Ficus pumila. Their structures were established by spectroscopic data and comparison with the literature values.
Subject(s)
Benzofurans/chemistry , Ficus/chemistry , Plant Leaves/chemistry , Benzofurans/analysis , Benzofurans/isolation & purification , Flavonoids/chemistry , Glycosides/chemistry , Glycosides/isolation & purification , Kaempferols/isolation & purification , Molecular Structure , Plant Extracts/chemistry , Quercetin/analogs & derivatives , Quercetin/isolation & purification , Rutin/isolation & purification , Spectrometry, Mass, Electrospray IonizationABSTRACT
Cassia grandis is used for the treatment of skin disorders, back pain, aches, etc. in Vietnamese traditional medicine. In this paper, phytochemicals of the leaves were investigated. A new naphthalene derivative (1, cassgranon D) and, seven known compounds rutin (2), afzelin (3), quercitrin (4), epicatechin (5), (-)-epiafzelechin (6), isoquercitrin (7) and aloe emodin (8) were isolated from the ethyl acetate and methanol extracts. Their structures were elucidated by spectral evidences (UV, IR, MS, 1H, 13C, DEPT, HSQC and HMBC NMR), as well as by comparing with published data.
Subject(s)
Cassia/chemistry , Naphthalenes/chemistry , Plant Leaves/chemistry , Anthraquinones/chemistry , Anthraquinones/isolation & purification , Cassia/metabolism , Magnetic Resonance Spectroscopy , Mannosides/chemistry , Mannosides/isolation & purification , Methanol/chemistry , Molecular Structure , Plant Extracts/chemistry , Plants, Medicinal/chemistry , Proanthocyanidins/chemistry , Proanthocyanidins/isolation & purification , Quercetin/analogs & derivatives , Quercetin/chemistry , Quercetin/isolation & purification , Rutin/analysis , Secondary MetabolismABSTRACT
In Vietnam, the medicinal plant Drynaria bonii H. Christ is used for the treatment of osteoporosis, bone fractures, and stimulate the growth of hair, treat tinnitus (Ho 2002; Loi 2004). In this article, experiments were designed to investigate the proliferation activity of ethanol, n-hexane, chloroform, ethyl acetate and methanol extracts from D. bonii rhizomes on MG-63 human osteoblast-like cells. The results showed that methanol and hexane extracts had the ability to proliferate MG-63 cells at the concentration varying from 0.1 to 0.01 µg/mL. In particular, at the concentration of 0.01 µg/mL, hexane and methanol extracts illustrated the highest proliferation ratio with 9.31% and 6.16%, respectively. By column chromatography, a new compound named drynaether A (1) and five known compounds uracil (2), 4'-hydroxy-7-methoxyflavan (3), kaempferol (4), indole-3-carboxylic acid (5) and protocatechuic acid (6) were isolated and identified from the methanol extract.
