Yan-Hong Wang

Yan-Hong Wang
University of Mississippi | UM · National Center for Natural Products Research

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329
Publications
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Publications

Publications (329)
Article
Introduction: Methylliberine and theacrine are methylurates found in the leaves of various Coffea species and Camellia assamica var. kucha, respectively. We previously demonstrated that the methylxanthine caffeine increased theacrine’s oral bioavailability in humans. Methods: Consequently, we conducted a double-blind, placebo-controlled pharmacokin...
Article
Full-text available
Saffron, the most expensive spice in the world, is comprised of the dried and dark red stigma of Crocus sativus L. flowers of the Iridaceae family. It is mainly used as a spice for imparting color, fragrance, and flavor to food but its medicinal and dyeing properties were also well known. In the USA, saffron products are used as dietary supplements...
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Rooibos tea (Aspalathus linearis) is a leguminous shrub endemic to the western parts of the Cape region in South Africa and a well-known herbal tea that is enjoyed worldwide. Due to its increased use, there is a possible risk of its interaction with conventional pharmaceuticals if administered simultaneously. In addition, the gap in the provision o...
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Aspalathus linearis (Burm.f.) R. Dahlgren, commonly known as rooibos tea, was consumed traditionally by the indigenous South African inhabitants as an herbal remedy. Beside antioxidant properties, it displays antiallergic, antispasmodic, and hypoglycemic activities. An ultra-high-performance liquid chromatography method coupled with photodiode arra...
Article
Licorice is obtained from the roots of several species of Glycyrrhiza (Fabaceae), a genus containing about 20 species. The Chinese Pharmacopeia specifies three Glycyrrhiza species (G. glabra, G. uralensis, G. inflata). In an effort to unambiguously differentiate roots of five Glycyrrhiza species (G. glabra, G. uralensis, G. inflata, G. echinata, an...
Article
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Primaquine (PQ) is a racemic drug used in treatment of malaria for six decades. Recent studies suggest that the two enantiomers of PQ are differentially metabolized in animals, and this results in different pharmacological and toxicological profiles. The current study characterizes the pharmacokinetic (PK) properties, metabolism and tolerability of...
Article
Simultaneous identification and quantification of phenolic acid (chlorogenic acid), sesquiterpene lactone (cnicin), lignan (arctiin), and flavonoids (bracteoside, 6-methoxybracteoside, isokaempferide and viscosine) in mixed parts of Centaurea benedicta (Syn. Cnicus benedictus) were performed for the first time. The liquid chromatography method show...
Article
This work was initiated to develop a simple, quick, and reliable UHPLC-PDA-MS method to identify chemical markers for authentication and compare fruit samples of four elder species, Sambucus nigra, S. ebulus, S. canadensis, and S. cerulea. The UHPLC method showed an adequate separation of 11 compounds including anthocyanins, phenolic acids, and fla...
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Background Primaquine (PQ) has been used for the radical cure of relapsing Plasmodium vivax malaria for more than 60 years. PQ is also recommended for prophylaxis and prevention of transmission of Plasmodium falciparum . However, clinical utility of PQ has been limited due to toxicity in individuals with genetic deficiencies in glucose 6-phosphate...
Article
Background: Bulbine natalensis Baker and Bulbine frutescens (L.) Willd. belonging to the family Asphodelaceae are widely distributed in South Africa and traditionally used as an aphrodisiac and skin remedies. Objective: The aim of this study is to develop an analytical method for chemical profiling and identification of components in Bulbine spe...
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The presence of bio-macromolecules as major ingredients is a primary factor in marketing many biologically derived macromolecular supplements. Workflows for analyzing these supplements for quality assurance, adulteration, and other supply-chain difficulties must include a qualitative assessment of small-molecule and macromolecular components; howev...
Article
Stem and leaf of Cissus quadrangularis L. (Vitaceae), indigenous to Asia and Africa, were used for medicinal and dietary purposes with limited information about the plant's phytochemistry. Stem and leaf samples were assessed for the simultaneous determination of polyphenolic compounds (catechin, epicatechin, quercetin-3-O-β-glucopyranoside, kaempfe...
Article
The antimalarial drug primaquine (PQ) causes methemoglobinemia and hemolysis in individuals with a genetic deficiency of glucose 6-phosphate dehydrogenase. Reactive oxygen species (ROS) generated by redox cycling of the metabolite primaquine-5,6-orthoquinone (POQ) in erythrocytes has been attributed to be responsible for the toxicity of PQ. Carboxy...
Preprint
Full-text available
Methylliberine and theacrine are methylurates found in the leaves of various Coffea species and Camellia assamica var. kucha, respectively. We previously demonstrated that the methylxanthine caffeine increased theacrine oral bioavailability in humans. Consequently, we conducted a double-blind, placebo-controlled study pharmacokinetic study in human...
Article
Volatile compounds (VCs) and triglycerides (TGs) are the primary groups of constituents in the fruits of five well-known species used in traditional Chinese medicine (TCM), viz. Alpinia oxyphylla Miq. (AO), Alpinia katsumadai Hayata (AK), Amomum villosum Lour. (FAL), Amomum villosum Lour. var. xanthioides T. L. Wu et Senjen (FALX) and Amomum longil...
Article
Moringa oleifera is known as a drumstick tree and cultivated in subtropics and tropics. It exhibits antihypertensive and antidiabetic effects. An ultra-high-performance liquid chromatography method was developed for the determination of nine phytochemicals in M. oleifera leaves and marketed products. The efficient separation was achieved within 7 m...
Article
Coffea liberica possesses stimulant properties without accumulating the methylxanthine caffeine. The basis for this peculiar observation is that methylurates (e.g., theacrine and methylliberine) have replaced caffeine. The stimulant properties of methylurates, alone and in combination with caffeine, have recently been investigated. However, human p...
Article
Phytochemical investigation of the ethanolic extract of Glandularia x hybrida roots resulted in the isolation and identification of five previously undescribed saponins, 3-O-β-ᴅ-xylopyranosyl-hederagenin-28-O-β-ᴅ-glucopyranosyl (1→2)-O-β-ᴅ-glucopyranosyl ester, 3-O-β-ᴅ-xylopyranosyl-hederagenin-28-O-β-ᴅ-glucopyranosyl (1→2)-[β-ᴅ-glucopyranosyl (1→6...
Article
Vangueria agrestis is a shrub indigenous to tropical Africa, belonging to family Rubiaceae and traditionally is used as a decoction for treatment of fever, pain and malaria. The current study was undertaken to investigate the chemical constituents based on precursor exact mass and fragment ion information. The chemical profiling and structural char...
Article
The hepatotoxic potential of the methanolic extract of the stems of Tinospora crispa and of its furano-diterpenoid–borapetosides B, C, and F–was investigated in normal and health-compromised mice. Health-compromised condition was established by a single intraperitoneal injection of LPS (6 mg/kg). Two different sets of experiments were conducted to...
Article
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Avocado oil is prized for its high nutritional value due to the substantial amounts of triglycerides (TGs) and unsaturated fatty acids (FAs) present. While avocado oil is traditionally extracted from mature fruit flesh, alternative sources such as avocado seed oil have recently increased in popularity. Unfortunately, sufficient evidence is not avai...
Article
Background: Dietary supplements targeting brain health have quickly emerged in the marketplace as cognitive performance becomes an important public health issue. While manufacturers are required to report the exact ingredients and formulations listed on the Supplement Facts labels of products, many reports have indicated such labels are not always...
Article
Context: Public health concerns are emerging surrounding huperzine A commonly found in dietary supplements. We sought to determine the actual content of products claiming to contain huperzine A and whether the ingredients on the supplement facts labels matched the analyses. Methods: We identified and analyzed 22 dietary supplement products listing...
Article
Eleven diarylpentanoid/norlignan glucosides, along with five other specialized metabolites, were isolated and characterized from the hydro-alcoholic extract of Hypoxis hemerocallidea corms. Hypoxhemerolosides A-F were found to be undescribed compounds. Curcapicycloside was isolated and identified for the first time in its original form, previously...
Article
Methylene blue (MB) with 10-N-carbamoyl linkage was discovered and developed as a multifunctional far-red (660 nm) photocleavable ligand capable of rendering a series of MB-conjugated compounds an off-to-on fluorescence switch property through the controlled release of MB. The photosensitivity of the MB derivatives proportionally depends on the sta...
Article
A UHPLC-photodiode array-MS method was developed and validated for the quantification of one chromone and six anthraquinone type of compounds from Bulbine natalensis plant samples and dietary supplements. Metabolites 1 – 7 were identified based on their retention times and electrospray ionization-MS spectra compared with a mix of previously isolat...
Article
Tinospora species are morphologically similar. Several cases of human toxicity have been reported in association with T. crispa. A chemical fingerprint was developed to differentiate T. crispa from its closely related species and to quantitate its major furanoditerpenes namely as borapetosides B, C and F. The rapid, sensitive and repeatable method...
Article
An UHPLC method was developed for the determination of 15 prenylflavonoids from aerial parts of Epimedium grandiflorum and related species (Berberidaceae). The separation was achieved using a reverse phased column and water/acetonitrile gradient as a mobile phase at a temperature of 40°C. The developed analytical method was validated for linearity,...
Article
The rhizomes of Bulbine natalensis furnished six previously unreported anthraquinone derivatives (1-6), together with eight known specialized metabolites. Their structures were determined by interpretation of 1D and 2D NMR and HRESIMS data. The absolute configurations of compounds 1-6 were determined by specific rotation and circular dichroism expe...
Article
A new rearranged clerodane diterpenoid, tinocrispide was isolated from the stems of Tinospora crispa along with thirteen known compounds including eight clerodane diterpenoids. Among the known compounds baenzigeride A, (6S, 9 R)-vomifoliol and steponine are being reported for the first time from T. crispa. Their structures were elucidated by 1 D an...
Article
A new rearranged clerodane diterpenoid, tinocrispide was isolated from the stems of Tinospora crispa along with thirteen known compounds including eight clerodane diterpenoids. Among the known compounds baenzigeride A,(6S, 9R)-vomifoliol and steponine are being reported for the first time from T. crispa. Their structures were elucidated by 1D and 2...
Article
Phytochemical investigation of the root bark of Sarcocephalus latifolius resulted in isolation and identification of eight compounds, including triterpenoid glycosides (1-4), ethyl glucoside (5), monoterpene indole alkaloids (6-7), and sterol (8). The structure elucidation of isolated compounds was achieved on the basis of NMR and mass spectral dat...
Article
Sceletorines A and B, two unique alkaloids, were isolated for the first time from the aerial parts of Mesembryanthemum tortuosum. Their structures were determined by the extensive spectroscopic methods and their absolute configuration was established with ECD calculations. Plausible biosynthetic pathways for 1 and 2 are proposed and a relationship...
Article
The use of supplements for weight loss and in sports as pre-workout (ergogenic) products is widespread. Many of these supplements were found to contain active components, which were not claimed on the products labels. A validated liquid chromatography high-resolution mass spectrometry quadrupole time-of-flight (LC-QToF-MS) method was developed for...
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Full-text available
Introduction The application of skin bleaching products to inhibit melanogenesis is a common practice within the African diaspora. Despite the adverse health effects of skin bleaching, rigorous studies investigating skin bleaching behavior among these populations in the United States are limited. In our P30 pilot study, we explored predictors of sk...
Article
Introduction: Herb-drug interaction is an important clinical risk associated with the concomitant consumption of herbal supplements with conventional drugs. African potato (AP) (Hypoxis hemerocallidea) is widely used by HIV and cancer patients as an immune enhancer. In this study, we determined the effects of AP hydroethanolic extract, its ethyl ac...
Article
A previously unidentified purported botanical ingredient was found in dietary supplements marketed for anabolic benefits. In an attempt to assess the ‘naturalness’ of a group of steroid-like compounds called laxogenins, a UHPLC-QToF method was developed. Several dietary supplements claim to contain 5α-hydroxy laxogenin, which is a derivative of a n...
Article
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Background The activity and haemolytic toxicity associated with primaquine has been linked to its reactive metabolites. The reactive metabolites are thought to be primarily formed through the action of cytochrome P450-mediated pathways. Human erythrocytes generally are not considered a significant contributor to drug biotransformation. As erythrocy...
Article
Full-text available
Eleutherococcus senticosus Maxim. belongs to the Araliaceae family. Phytochemical studies reveal that E. senticosus leaves contain triterpene glycosides along with organic acid derivatives and flavonoid compounds. It is believed that E. senticosus is similar to ginseng because they come from same family and both contain triterpene saponins. E. sent...
Article
Terpenes are the major components of the essential oils present in various Cannabis sativa L. varieties. These compounds are responsible for the distinctive aromas and flavors. Besides the quantification of the cannabinoids, determination of the terpenes in C. sativa strains could be of importance for the plant selection process. At the University...
Article
In the current study, an extensive set of oils distilled from black pepper (P. nigrum) plants was investigated to assess the scope of chemodiversity in samples originated from seven major producing countries. A robust GC-MS method was developed and used to identify twenty-two volatile organic components (VOCs) in these oils. A chiral GC-MS method w...
Article
Resiniferatoxin (RTX) is a daphnane diterpene isolated from the latex of Euphorbia resinifera O. Berg, a potent activator of transient receptor potential vanilloid 1 (TrpV1), with a potency 10³-10⁵ times greater than pure capsaicin. Intravenous administration of RTX at very low concentration improves urodynamic parameters in patients with neurogeni...
Article
The growing demand and commercial value of black pepper (Piper nigrum) has resulted in considerable interest in developing suitable and cost-effective methods for chemical characterization and quality evaluation purposes. In the current study, an extensive set of oil samples (n = 23) that were extracted by steam distillation from black pepper seeds...
Article
Twenty‐four pure fragrance ingredients of concern as potential skin sensitizers were previously subjected to degradation studies and evaluated using the high throughput with dansyl cysteamine (HTS‐DCYA) method. The experimental results showed that two‐thirds of the 24 fragrance ingredients underwent chemical degradation. In some cases, such degrada...
Article
Fadogia agrestis is used in traditional African medicine as an analgesic and for anti-inflammatory and aphrodisiac activities. An ultra-high-performance liquid chromatography method was developed for the determination of 11 chemical constituents from roots and aerial parts of F. agrestis. The separation was achieved within 7 min by using C-18 colum...
Article
Full-text available
Background: Primaquine (PQ), an 8-aminoquinoline, is the only drug approved by the United States Food and Drug Administration for radical cure and prevention of relapse in Plasmodium vivax infections. Knowledge of the metabolism of PQ is critical for understanding the therapeutic efficacy and hemolytic toxicity of this drug. Recent in vitro studie...
Article
In current work, targeted and non-targeted analysis of alkaloids and acetogenins from methanolic extracts of Asimina, Annona species and dietary supplements have been performed using UHPLC-QToF in positive ion mode. Thirty-five standard compounds (twelve alkaloids and twenty-three acetogenins) were used for the analysis. The fragment ions produced...
Article
Yellow tea, also known as huángchá in Chinese, is a lightly fermented tea unique to China. As a rare and precious variety of tea, it has gained increasing popularity in recent years because of its pleasant mellow taste and known health benefits such as anti-oxidation, anti-inflammation and anti-cancer properties. Yellow tea is similar to green tea...
Article
Current study aimed at formulating and optimizing natamycin (NT) loaded PEGylated NLCs (NT-PEG-NLCs) using Box-Behnken Design and investigating their potential in ocular applications. Response surface methodology (RSM) computations and plots for optimization were performed using Design Expert® software, to obtain optimum values for response variabl...
Article
Correct identification of the true bay leaf (Laurus nobilis) and its substitutes is important not only for the quality control of the products, but also for the safety of the consumers. L. nobilis is often substituted or confused with other species, such as Cinnamomum tamala, Pimenta racemosa, Syzygium polyanthum, and Umbellularia californica. In t...
Article
Cannabinoids are a group of terpenophenolic compounds in the medicinal plant Cannabis sativa (Cannabaceae family). Cannabigerolic acid, Δ9-tetrahydrocannabinolic acid A, cannabidiolic acid, Δ9-tetrahydrocannabinol, cannabigerol, cannabidiol, cannabichromene, and tetrahydrocannabivarin are major metabolites in the classification of different strains...
Article
Bioassay-guided fractionation and chemical investigation of Colvillea racemosa stems led to identification of two new α, β-dihydroxydihydrochalcones, colveol A (1) and colveol B (2) along with fifteen known compounds. The structures were elucidated via interpretation of spectroscopic data. The absolute configurations of the dihydrochalcones 1 and 2...
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A new iridoid glycoside; 6-O-β-D-xylopyranoside-shanzhiside methyl ester (1) along with six known compounds; shanzhiside methyl ester (2), lamalbid (3), geniposidic acid (4), theveside (5), verbascoside (6) and arenarioside (7) were isolated from the roots of Lantana montevidensis. The structures of the compounds were determined through 1D and 2D N...
Article
Ultrahigh-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QToF-MS) profiling was used for the identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. UHPLC-QToF-MS was used to generate comprehensive fingerprints of three botanicals (...
Article
A hexose phosphate recycling model previously developed to infer fluxes through the major glucose consuming pathways in cultured cerebellar granule neurons (CGNs) from neonatal rats metabolizing [1,2–¹³C2]glucose was revised by considering reverse flux through the non-oxidative pentose phosphate pathway (PPP) and symmetrical succinate oxidation wit...
Article
A rapid, effective method applying vortex-assisted liquid-liquid microextraction before ultra high performance liquid chromatography with mass spectrometry and evaporative light scattering detection was developed for the analysis of four cucurbitane triterpenoids (momordicoside L, momordicoside K, momordicoside F2 , and 3?,7?,25-trihydroxy cucurbit...
Article
The roots of Eleutherococcus senticosus (Rupr. & Maxim.) Maxim., a well-known medicinal plant from Eastern Asia, are used worldwide for their known beneficial medicinal properties. Recently, the leaves have been used as an alternative to the roots. The present study was aimed at exploring the leaf essential oil as a potential source of compounds fo...
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Ultra-high-performance supercritical fluid chromatography (UHPSFC) is an efficient analytical technique and has not been fully employed for the analysis of cannabis. Here, a novel method was developed for the analysis of 30 cannabis plant extracts and preparations using UHPSFC/PDA-MS. Nine of the most abundant cannabinoids, viz. CBD, ∆8-THC, THCV,...
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Introduction: Decarboxylation is an important step for efficient production of the major active components in cannabis, for example, Δ⁹-tetrahydrocannabinol (Δ⁹-THC), cannabidiol (CBD), and cannabigerol (CBG). These cannabinoids do not occur in significant concentrations in cannabis but can be formed by decarboxylation of their corresponding acids,...
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Skin-bleaching practices, such as using skin creams and soaps to achieve a lighter skin tone, are common throughout the world and are triggered by cosmetic reasons that oftentimes have deep historical, economic, sociocultural, and psychosocial roots. Exposure to chemicals in the bleaching products, notably, mercury (Hg), hydroquinone, and steroids,...