Two new noncyanogenic cyanoglucoside dimers, simmonosides A and B (1 and 2), were identified from the aqueous extract of jojoba (Simmondsia chinensis) leaves. Compounds 1 and 2 are the first examples of noncyanogenic cyanoglucoside dimers containing a unique four-membered ring, representing novel dimerization patterns at α,β-unsaturated carbons of a nitrile group in 1 and γ,δ-unsaturated carbons in 2. Their structures were elucidated based on spectroscopic evidence and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 exhibit promising COX-2 inhibition activity, with IC50 values of 13.5 and 11.4 μM, respectively

Abstract Background: A great number of novel compounds with rich chemical diversity and significant bioactivity have been reported from Red Sea sponges. Objective: To isolate, identify, and evaluate the cytotoxic activity of the chemical constituents of a sponge belonging to genus Haliclona collected from the Eastern coast of the Red Sea. Materials and Methods: The total ethanolic extract of the titled sponge was subjected to intensive chromatographic fractionation and purification guided by cytotoxic bioassay toward various cancer cell lines. The structures of the isolated compounds were elucidated using spectroscopic techniques including one-dimension and two-dimension nuclear magnetic resonance, mass spectrometry, ultraviolet, and infrared data, as well as comparison with the reported spectral data for the known compounds. X-ray single-crystal structure determination was performed to determine the absolute configuration of compound 4. The screening of antiproliferative activity of the compounds was carried on three tumor cell lines, namely the human cervical cancer (HeLa), human hepatocellular carcinoma (HepG2), and human medulloblastoma (Daoy) cells using MTT assay. Results: This investigation resulted in the isolation of a new indole alkaloid, 1-(1H-indol-3-yloxy) propan-2-ol (1), with the previously synthesized pyrrolidine alkaloid, (2R, 3S, 4R, 5R) pyrrolidine-(1-hydroxyethyl)-3,4-diol hydrochloride (4), isolated here from a natural source for the first time. In addition, six known compounds tetillapyrone (2), nortetillapyrone (3), 2-methyl maleimide-5-oxime (5), maleimide-5-oxime (6), 5-(hydroxymethyl) dihydrofuran-2 (3H)-one (7), and ergosta-5,24 (28)-dien-3-ol (8) were also identified. Most of the isolated compounds exhibited weak cytotoxic activity against HepG-2, Daoy, and HeLa cancer cell lines. Conclusion: This is the first report of the occurrence of the indole and pyrrolidine alkaloids, 1-(1H-indol-2-yloxy) propan-2-ol (1), and the - (1-hydroxyethyl)-3,4-diol hydrochloride (4), in the Red Sea Haliclona sp.

Abstract Calotropis procera L. is known as medicinal plant. The Phytochemical analyzes of its latex revealed that it possessed antioxidants, namely terpenes, phenolic compounds and cardenolides, flavonoids and saponins, while tannins, alkaloids and resin were absent in moderate to high concentration. In the present study, the role of latex of Calotropis procera as antioxidant and antiapoptotic was reported. To carry out this aim, fishes were exposed to 100 µg l−1 4-nonylphenol as chemical pollutant. The enzymes, superoxidase dismutase, catalase, acetlycholinstrase (AchE), glutathione s-transferase, cortisol, G6PDH) and apoptotic cells increased significantly (p0.05) accompanied by irregular disturbance of (Na+, K+) ions in the presence of 4-nonylphenol. On the other hand, these enzymes, ions, and apoptotic cells decreased normally and significantly (p0.05) in the presence of latex. Total phenol content, total capacity antioxidant, reducing power decrease significantly (p0.05) in the presence of 4-nonylphenol and increase normally in the presence of latex. Latex was used for the first time to protect catfish after 4-nonylphenol exposure. Our study confirms that crude latex of Calotropis procera possessed antioxidant and antiapoptotic activities against the toxicity of 4-Nonylphenol.

Abstract A radical-scavenging, guided phytochemical study of the latex of Calotropis Procera afforded five lignans (1–5), including a new one (4). The structural determination was accomplished using 1D- and 2D-NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and correlation with known compounds. Among the isolated compounds, acylated lignans (3–5) showed stronger antioxidant activity than non-acylated derivatives (1,2). Anti-inflammatory activity was evaluated by determining the inhibitory potential against 5- and 15-lipoxygenase enzymes. The highest anti-inflammatory activity was observed in compound 4, with IC50s values of 7.6 µM and 2.7 µM against 5-LOX and 15-LOX, respectively.

Abstract Microbes belonging to the genus Verrucosispora possess significant chemical diversity and biological properties. They have attracted the interests of many researchers and are becoming promising resources in the marine natural product research field. A bioassay-guided isolation from the crude extract of Verrucosispora sp. strain MS100047, isolated from sediments collected from the South China Sea, has led to the identification of a new salicylic derivative, glycerol 1-hydroxy-2,5-dimethyl benzoate (1), along with three known compounds, brevianamide F (2), abyssomicin B (3), and proximicin B (4). Compound 1 showed selective activity against methicillin-resistant Staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) value of 12.5 μg/mL. Brevianamide F (2), which was isolated from actinomycete for the first time, showed a good anti-BCG activity with a MIC value of 12.5 μg/mL that has not been reported previously in literatures. Proximicin B (4) showed significant anti-MRSA (MIC = 3.125 μg/mL), anti-BCG (MIC = 6.25 μg/mL), and anti-tuberculosis (TB) (MIC = 25 μg/mL) activities. This is the first report on the anti-tubercular activities of proximicins. In addition, Verrucosispora sp. strain MS100047 was found to harbor 18 putative secondary metabolite gene clusters based on genomic sequence analysis. These include the biosynthetic loci encoding polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) consistent with abyssomicins and proximicins, respectively. The biosynthetic pathways of these isolated compounds have been proposed. These results indicate that MS100047 possesses a great potential as a source of active secondary metabolites.

Abstract The biotransformation of tanshinone IIA to a new antibacterial agent tanshisorbicin (1) by the fungus Hypocrea sp. (AS 3.17108) is described. The structure of tanshisorbicin is a hybrid of tanshinone IIA (2) and sorbicillinol (3). The latter is a metabolite produced by Hypocrea sp. The structure of tanshisorbicin was determined using mass spectrometry, NMR spectroscopy, and ECD calculations. The anti-MRSA activity of 1 was found to be significantly higher than that of the parent substrate Tan IIA. Preliminary experiments indicate that tanshisorbicin is formed via a [4+2] cycloaddition reaction that is likely catalyzed by microbial enzyme.

Abstract Two potent anti-MRSA tanshinone glycosides (1 and 2) were discovered by targeted microbial biotransformation, along with rapid identification via MS/MS networking. Serial reactions including dehydrogenation, demethylations, reduction, glycosylation and methylation have been observed after incubation of tanshinone IIA and fungus Mucor rouxianus AS 3.3447. In addition, tanshinosides B (2) showed potent activities against serial clinical isolates of oxacillin-resistant Staphylococcus aureus with MIC values of 0.78 μg/mL. This is the first study that shows a significant increase in the level and activities of tanshinone glycosides relative to the substrate tanshinone IIA.

Abstract: A novel β-lactam derivative, albactam, was isolated from the alcoholic extract of the flowers of Albizia lebbeck. It showed a significant anti-aggregatory activity against adenosine diphosphate and arachidonic acid induced guinea-pigs’ platelets aggregation in vitro. Six more known compounds were also isolated and fully characterized by measuring 1D and 2D NMR, two of them are the triterpenes β- amyrin and 11α, 12α-oxidotaraxerol, two ceramide derivatives and two flavonoids, kampferol 3-O-rutinoside and rutin.

Drug delivery using synthetic nanoparticles including porous silicon has been extensively used to overcome the limitations of chemotherapy. However, their synthesis has many challenges such as lack of scalability, high cost, and the use of toxic materials with concerning environmental impact. Nanoscale materials obtained from natural resources are an attractive option to address some of these disadvantages. In this paper, a new mesoporous biodegradable silicon nanoparticle (SiNP) drug carrier obtained from natural diatom silica mineral available from the mining industry is presented. Diatom silica structures are mechanically fragmented and converted into SiNPs by simple and scalable magnesiothermic reduction process. Results show that SiNPs have many desirable properties including high surface area, high drug loading capacity, strong luminescence, biodegradability, and no cytotoxicity. The in-vitro release results from SiNPs loaded with anticancer drugs (doxorubicin) demonstrate a pH-dependent and sustained drug release with enhanced cytotoxicity against cancer cells. The cells study using doxorubicin loaded SiNPs shows a significantly enhanced cytotoxicity against cancer cells compared with free drug, suggesting their considerable potential as theranostic nanocarriers for chemotherapy. Their low-cost manufacturing using abundant natural materials and outstanding chemotherapeutic performance has made them as a promising alternative to synthetic nanoparticles for drug delivery applications.

Drug delivery using synthetic nanoparticles including porous silicon has been extensively used to overcome the limitations of chemotherapy. However, their synthesis has many challenges such as lack of scalability, high cost, and the use of toxic materials with concerning environmental impact. Nanoscale materials obtained from natural resources are an attractive option to address some of these disadvantages. In this paper, a new mesoporous biodegradable silicon nanoparticle (SiNP) drug carrier obtained from natural diatom silica mineral available from the mining industry is presented. Diatom silica structures are mechanically fragmented and converted into SiNPs by simple and scalable magnesiothermic reduction process. Results show that SiNPs have many desirable properties including high surface area, high drug loading capacity, strong luminescence, biodegradability, and no cytotoxicity. The in-vitro release results from SiNPs loaded with anticancer drugs (doxorubicin) demonstrate a pH-dependent and sustained drug release with enhanced cytotoxicity against cancer cells. The cells study using doxorubicin loaded SiNPs shows a significantly enhanced cytotoxicity against cancer cells compared with free drug, suggesting their considerable potential as theranostic nanocarriers for chemotherapy. Their low-cost manufacturing using abundant natural materials and outstanding chemotherapeutic performance has made them as a promising alternative to synthetic nanoparticles for drug delivery applications.