Cycloartane triterpenoids from Cassia occidentalis

Synthesis of Cycloartan-16β-ol from 16β 24R-Epoxy-Cycloartane and Their Cytotoxicity Evaluation Against Human Cancer Cell Lines

It was found that Argentatins A and B triterpenoids make up approximately 20-30 % of the waste resin produced from the industrial processes to isolate rubber from P. argentatum. We have developed an efficient protocol for synthesizing cycloartane-16β-ol derivatives by opening the oxepane ring of argentatin B acetate (2) with BF3-OEt2. Although three new cycloartenol derivatives showed high cytotoxicity against PC-3 and HCT-15 cancer cell lines, nevertheless, the best results were obtained for (16β,24R) -(16,24-epoxy-cycloartan-2(1H)-ylidene) acetate (14), compound with intact oxepane ring. These results indicate that the substituents in the argentatin nucleus and a side chain account for the cytotoxic activity. However, according to the selectivity index (SI), 14 did not show selectivity activity to cancer cell lines over the HaCat noncancerous cell line. The compound 3β,16β-Dihydroxy-cycloartan-24-one (5), synthesized by oxepane opening, demonstrated high cytotoxic activity to cancer cell lines and showed a remarkable selectivity to cancer cell lines over the noncancerous ones. These results suggest that 5 could lead to the development of new anticancer compounds.

A Review of Recent Studies on the Antioxidant and Anti-Infectious Properties of Senna Plants

The use of phytochemicals is gaining interest for the treatment of metabolic syndromes over the synthetic formulation of drugs. Senna is evolving as one of the important plants which have been vastly studied for its beneficial effects. Various parts of Senna species including the root, stem, leaves, and flower are found rich in numerous phytochemicals. In vitro, in vivo, and clinical experiments established that extracts from Senna plants have diverse beneficial effects by acting as a strong antioxidant and antimicrobial agent. In this review, Senna genus is comprehensively discussed in terms of its botanical characteristics, traditional use, geographic presence, and phytochemical profile. The bioactive compound richness contributes to the biological activity of Senna plant extracts. The review emphasizes on the in vivo and in vitro antioxidant and anti-infectious properties of the Senna plant. Preclinical studies confirmed the beneficial effects of the Senna plant extracts and its bioactive components in regard to the health-promoting activities. The safety, side effects, and therapeutic limitations of the Senna plant are also discussed in this review. Additional research is necessary to utilize the phenolic compounds towards its use as an alternative to pharmacological treatments and even as an ingredient in functional foods.

Recent advances in natural anti-HIV triterpenoids and analogs

The human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic is one of the world's most serious health challenges. Although combination antiretroviral therapy provides effective viral suppression, current medicines used against HIV cannot completely eradicate the infectious disease and often have associated toxicities and severe side effects in addition to causing drug resistance. Therefore, the continued development of new antiviral agents with diverse structures and novel mechanisms of action remains a vital need for the management of HIV/AIDS. Natural products are an important source of drug discovery, and certain triterpenes and their analogs have demonstrated potential as pharmaceutical precursors for the treatment of HIV. Over the past decade, natural triterpenoids and analogs have been extensively studied to find new anti-HIV drugs. This review discusses the anti-HIV triterpenoids and analogs reported during the period of 2009-2019. The article includes not only a comprehensive review of the recent anti-HIV agent development from the perspective of medicinal chemistry, but also discusses structure-activity relationship analyses of the described triterpenoids.

The Chemical Structure and Bioactivity of Cycloartane-type Compounds

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For decades now, compounds in the cycloartane-type series have been shown to have versatile pharmacological activities. However, no extensive review has been written to summarize these health-beneficial activities. Therefore, the purpose of this paper is to systematically highlight the biological activities of these compounds, including their antitumor and anti-osteoporosis effects, their effects on receptors, cytokine release, and chronic renal failure, as well as their tyrosinase inhibitory, anticomplement, anti-parasite, anti-HIV, and antituberculosis activities. In this review, we have summarized the structures of over 200 compounds based on their characteristics and described their structureactivity relationships (SARs), and potential mechanisms of action.

Phytochemical screening and biological assays of ethanolic leaf extract of Senna rugosa

Abstract Senna rugosa (Fabaceae) is a common specie of the Brazilian territory, especially in the Cerrado biome. It is widely used in the popular medicine although not yet adequately investigated as to its phytoconstituents and pharmacological activities. In this study, the preliminary phytochemical analysis of ethanolic leaf extract of S. rugosa was performed and its cytotoxicity, antitumoral and antimicrobial activities (antibacterial, antifungal, anti-Trypanosoma and anti-Leishmania) were evaluated. The crude extract was analyzed in HPLC-DAD and fractions were also characterized using GC-MS and ESI-MS techniques. Results indicate phenolic compounds majority presence, including flavonol, anthraquinone and anthrones derivatives. Relative antimicrobial activities were detected against Staphylococcus aureus, Pseudomonas aeruginosa, Candida famata, Candida krusei and Candida tropicalis. As well as, a weak anti-trypanosomatids activity against M2269 strain and BH46 strain of Leishmania sp. A relative antitumoral activity was also identified but in counterpoint were also observed a toxicity in fibroblast cells (L929). Phytochemically, results provide evidence that phenolic compounds in S. rugosa leaves might be the responsible for its antimicrobial activity and cell toxicity inferred in our research.

An Explorer of Chemical Biology of Plant Natural Products in Southwest China, Xiaojiang Hao

Xiaojiang Hao, who obtained Master Degree from Kunming Institute of Botany (KIB), Chinese Academy of Sciences (CAS) in 1985, and Doctor in Pharmacy degree in Pharmacy from Institute for Chemical Research, Kyoto University, in 1990, was born in Chongqing in July, 1951. In 1991, he returned to KIB, CAS, as an Associate professor and served as the chair of the Department of Phytochemistry. In 1994, he was promoted to a full professor at the current institute. He served as the Deputy Director of KIB and the Director of Open Laboratory of Phytochemistry from 1995 to 1997, and the Director of KIB from 1997 to 2005. Professor Hao has published more than 450 peer-reviewed SCI papers, which have been cited over 6000 times. He has obtained one PCT patent and 23 patents in China. Due to his tremendous efforts, one candidate drug, phenchlobenpyrrone, has entered the Phase II clinical trail for the treatment of Alzheimer's disease. Moreover, he won the First Prize of Natural Sciences in Yunnan Province for three times, and Ho Leung Ho Lee Fund Science and Technology Innovation Award in 2017.

Cycloartane triterpenoid and its glucoside isolated from Cassia occidentalis

In the present study, one new cycloartane triterpenoid, named cycloccidentalic acid C (1) and its glucoside, cycloccidentaliside VI (2) were isolated from the whole plant of Cassia occidentalis. Their structures were elucidated by a combinational analyses of 1D and 2D NMR data and HRMS. Compound 2 showed modest anti-HIV-1 activity with EC₅₀ value of 1.44 μmol·L^-1 and TI (Therapeutic Index) value of 15.59.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids reported during 2012 including squalene derivatives, lanostanes, holostanes, cycloartanes, cucurbitanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes, isomalabaricanes and saponins; 348 references are cited.

New flavanol and cycloartane glucosides from Landoltia punctata

Chemical investigation on the constituents of Landoltia punctata led to the isolation and identification of 17 compounds, four of which were new and identified as (3β,24S)-9,19-cycloartane-3,22,24,25-tetraol 3-O-[β-d-glucopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside (1), (3β,24S)-9,19-cycloartane-3,24,25-triol 3-O-[β-d-glucopyranosyl-(1→2)]-[β-d-glucopyranosyl-(1→6)]-β-d-glucopyranoside (2), 3,4'-dihydroxy-7,3'-dimethoxyflavan-5-O-β-d-glucopyranoside (3) and 3,4'-dihydroxy-4,7,3'-trimethoxyflavan-5-O-β-d-glucopyranoside (4). Their structures were elucidated by spectroscopic, chemical, and biochemical methods. Thus, cycloartane triterpenoids were discovered in the Lemnaceae family for the first time. Compound 3 showed antioxidant capacity in the positively charged 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS^+•) and superoxide anion radical scavenging assays.