Ten new prenylated flavonoids from Macaranga denticulata and their antitumor activities.

Ten new prenylated flavonoids, named denticulains A-J (1-10), together with seven known prenylated flavonoids (11-17) were isolated from Macaranga denticulata. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with literature data. In addition, compounds 1 and 14 inhibited the proliferation of SW620 and HCT-116 cell lines with an IC50 value of 46.08 µM and 56.83 µM, respectively.

Aspulvins A-H, Aspulvinone Analogues with SARS-CoV-2 Mpro Inhibitory and Anti-inflammatory Activities from an Endophytic Cladosporium sp.

Eight new aspulvinone analogues, aspulvins A-H (1-8) and aspulvinones D, M, O, and R (9-12), were isolated from cultures of the endophytic fungus Cladosporium sp. 7951. Detailed spectroscopic analyses were conducted to determine the structures of the new compounds. All isolates displayed different degrees of inhibitory activity against the severe acute respiratory syndrome coronavirus 2 main protease (SARS-CoV-2 Mpro) at 10 µM. Notably, compounds 9, 10, and 12 showed potential SARS-CoV-2 Mpro inhibition with IC50 values of 10.3 ± 0.6, 9.4 ± 0.6, and 7.7 ± 0.6 µM, respectively. For all compounds except 3 and 4, the anti-inflammatory activity occurred by inhibiting the release of lactate dehydrogenase (LDH) with IC50 values ranging from 0.7 to 7.4 µM. Compound 10 showed the most potent anti-inflammatory activity by inhibiting Casp-1 cleavage, IL-1ß maturation, NLRP3 inflammasome activation, and pyroptosis. The findings reveal that the aspulvinone analogues 9, 10, and 12 could be promising candidates for coronavirus disease 2019 (COVID-19) treatment as they inhibit SARS-CoV-2 infection and reduce inflammatory reactions caused by SARS-CoV-2.

Previously undescribed pyridyl-steroidal glycoalkaloids and 23S,26R-hydroxylated spirostanoid saponin from the fruits of Solanum violaceum ortega and their bioactivities.

Three previously undescribed pyridyl-steroidal glycoalkaloids, solanindiosides A‒C, one rare 23S,26R-hydroxylated spirostanoid saponin, and two steroidal alkaloid aglycones, solanindins A and B, derived from the acid hydrolysis of solanindiosides A‒C, were isolated from the fruits of Solanum violaceum, together with five known analogues, including two rare steroidal glycosides, two lignans and a diterpene. Structurally, they comprise a 16ß-methoxy-23-deoxy-22,26-epimino-cholest-type skeleton moiety, and a 16ß-methoxy-3,23-dideoxy-22,26-epimino-cholest-3,5-dien derivative. The hitherto undescribed structures were established on the basis of extensive spectroscopic analyses. Configurations of sugar moieties were resolved by chemical derivations. Solanindiosides A‒C, (22R,23S,25R,26R)-spirost-5-ene-3ß,23,26-triol3-O-ß-d-xylopyranosyl-(1→3)-ß-d-glucopyranoside, solanindins A and B, and (1S,2S)-1-(4-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-[(2S,3R,4R)-tetrahydro-4-[(4-hydroxy-3-methoxyphenyl)methyl]-3-(hydroxymethyl)-2-furanyl]phenoxy]-1,3-propanediol were evaluated for their cytotoxic and antibacterial activities. (1S,2S)-1-(4-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-[(2S,3R,4R)-tetrahydro-4-[(4-hydroxy-3-methoxyphenyl)methyl]-3-(hydroxymethyl)-2-furanyl]phenoxy]-1,3-propanediol showed the most potent cytotoxic activity against MCF-7 cells (IC50 = 4.386 ± 0.098 µM), while solanindin B displayed some inhibitory effects against Staphylococcus aureus Rosenbach with MIC50 value of 37.32 ± 0.793 µM. In addition, (1S,2S)-1-(4-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-[(2S,3R,4R)-tetrahydro-4-[(4-hydroxy-3-methoxyphenyl)methyl]-3-(hydroxymethyl)-2-furanyl]phenoxy]-1,3-propanediol induced dose dependent apoptosis effect in MCF-7 cells.

Ten new glycosides, carissaedulosides A-J from the root barks of Carissa edulis and their cytotoxicities.

Ten previously undescribed glycosides, carissaedulosides A-J (1-10) referring to six apiosylated phenylpropanoids (1-6), one coumarin-secoiridoid hybrid (7), and three furofuran lignans (8-10) were isolated from the root barks of Carissa edulis, together with 13 known analogues (11-23). Their structures were elucidated by spectroscopic analysis, ECD computational methods, and chemical derivations for configurations of sugar moieties. The new lignan bisdesmoside, 10, exhibited significant cytotoxicity against A549 (IC50 = 3.87 ± 0.03 µM) and MCF-7 (IC50 = 9.231 ± 0.290 µM) cell lines, while the known lignan monodesmoside, 12, showed impressive cytotoxic efficacy (IC50 = 5.68 ± 0.180 µM) against only MCF-7 cell line. It is noted that a known cardenolide, 11, displayed strong cytotoxic potency against HL-60, A549, MCF-7 and SW480 cell lines with IC50 values ranging from 0.023 to 0.137 µM. Moreover, compound 11 induced dose-dependent apoptosis on SW480 cell, but not explicit dose-dependent apoptosis on HL-60 cells.

Two new 23S,26R-hydroxylated spirostanoid saponins from the fruits of Solanum indicum var. recurvatum.

Solanum indicum var. recurvatum, distributed mainly in Hekou, Simao and Menghai areas of Yunnan province, China, is characterized by stellate pubescent leaves with irregular lengths and oblong, short, and downwardly curved anthers. The original species, S. indicum, has been used as an anti-inflammatory, wound-healing agent, an analgesic, and for the treatment of rhinitis, cough, and breast cancer in Chinese folk medicine. The variety was chemically studied for the first time, leading to the isolation of two new rare 23S,26R-hydroxylated spirostanoid saponins, together with five known steroidal components, two of which the rare natural ketosteroids 6-hydroxyandrosta-1,4-diene-3,17-dione and rostadienedione have been isolated from the genus Solanum for the first time. Elucidation of the structures was accomplished by extensive 1D and 2D NMR, UV, and HRESIMS spectroscopic methods.

The Genus Terminalia (Combretaceae): An Ethnopharmacological, Phytochemical and Pharmacological Review.

Terminalia Linn, a genus of mostly medium or large trees in the family Combretaceae with about 250 species in the world, is distributed mainly in southern Asia, Himalayas, Madagascar, Australia, and the tropical and subtropical regions of Africa. Many species are used widely in many traditional medicinal systems, e.g., traditional Chinese medicine, Tibetan medicine, and Indian Ayurvedic medicine practices. So far, about 39 species have been phytochemically studied, which led to the identification of 368 compounds, including terpenoids, tannins, flavonoids, phenylpropanoids, simple phenolics and so on. Some of the isolates showed various bioactivities, in vitro or in vivo, such as antitumor, anti HIV-1, antifungal, antimicrobial, antimalarial, antioxidant, diarrhea and analgesic. This review covers research articles from 1934 to 2018, retrieved from SciFinder, Wikipedia, Google Scholar, Chinese Knowledge Network and Baidu Scholar by using "Terminalia" as the search term ("all fields") with no specific time frame setting for the search. Thirty-nine important medicinal and edible Terminalia species were selected and summarized on their geographical distribution, traditional uses, phytochemistry and related pharmacological activities.

Two New Phenolic Constituents from the Stems of Euphorbia griffithii.

Phytochemical studies on MeOH extract of stems of Euphorbia griffithii led to the isolation of one new hydrolyzable tannin dimer, corilagiffithiin (1) and one new galloyl-glucoside (2), alongside six known ones (3-8). Their structures and absolute configurations were determined by in depth spectroscopic analyses and comparison of their 1D NMR and MS data with literature reported values. Configurations of sugar moieties were determined by acidic hydrolysis and subsequent GC analysis of their corresponding trimethylsilylated L-cysteine adduct. At a concentration of 50 µM, compounds 1-3 showed no anti-inflammatory activities.

The Genus Solanum: An Ethnopharmacological, Phytochemical and Biological Properties Review.

Over the past 30 years, the genus Solanum has received considerable attention in chemical and biological studies. Solanum is the largest genus in the family Solanaceae, comprising of about 2000 species distributed in the subtropical and tropical regions of Africa, Australia, and parts of Asia, e.g., China, India and Japan. Many of them are economically significant species. Previous phytochemical investigations on Solanum species led to the identification of steroidal saponins, steroidal alkaloids, terpenes, flavonoids, lignans, sterols, phenolic comopunds, coumarins, amongst other compounds. Many species belonging to this genus present huge range of pharmacological activities such as cytotoxicity to different tumors as breast cancer (4T1 and EMT), colorectal cancer (HCT116, HT29, and SW480), and prostate cancer (DU145) cell lines. The biological activities have been attributed to a number of steroidal saponins, steroidal alkaloids and phenols. This review features 65 phytochemically studied species of Solanum between 1990 and 2018, fetched from SciFinder, Pubmed, ScienceDirect, Wikipedia and Baidu, using "Solanum" and the species' names as search terms ("all fields").

The Genus Carissa: An Ethnopharmacological, Phytochemical and Pharmacological Review.

Carissa L. is a genus of the family Apocynaceae, with about 36 species as evergreen shrubs or small trees native to tropical and subtropical regions of Africa, Asia and Oceania. Most of Carissa plants have been employed and utilized in traditional medicine for various ailments, such as headache, chest complains, rheumatism, oedema, gonorrhoea, syphilis, rabies. So far, only nine Carissa species have been phytochemically studied, which led to the identification of 123 compounds including terpenes, flavonoids, lignans, sterols, simple phenolic compounds, fatty acids and esters, and so on. Pharmacological studies on Carissa species have also indicated various bioactive potentials. This review covers the peer-reviewed articles between 1954 and 2016, retrieved from Pubmed, ScienceDirect, SciFinder, Wikipedia and Baidu, using "Carissa" as search term ("all fields") and with no specific time frame set for search. Fifteen important medicinal or ornamental Carissa species were selected and summarized on their botanical characteristics, geographical distribution, traditional uses, phytochemistry, and pharmacological activities.