Non-Polar Natural Products from Bromelia laciniosa, Neoglaziovia variegata and Encholirium spectabile (Bromeliaceae).

Extensive regional droughts are already a major problem on all inhabited continents and severe regional droughts are expected to become an increasing and extended problem in the future. Consequently, extended use of available drought resistant food plants should be encouraged. Bromelia laciniosa , Neoglaziovia variegata and Encholirium spectabile are excellent candidates in that respect because they are established drought resistant edible plants from the semi-arid Caatinga region. From a food safety perspective, increased utilization of these plants would necessitate detailed knowledge about their chemical constituents. However, their chemical compositions have previously not been determined. For the first time, the non-polar constituents of B. laciniosa , N. variegata and E. spectabile have been identified. This is the first thorough report on natural products from N. variegata , E. spectabile , and B. laciniosa . Altogether, 20 non-polar natural products were characterized. The identifications were based on hyphenated gas chromatography-high resolution mass spectrometry (GC-HRMS) and supported by 1D and 2D Nuclear Magnetic Resonance (NMR) plant metabolomics.

Toxic aromatic compounds from fruits of Narthecium ossifragum L.

The intake of Narthecium ossifragum, commonly known as bog asphodel, has been associated with toxic effects observed in sheep for centuries. Although the plant has been studied for five centuries little is known about its chemical constituents. Six previously undescribed natural products, naringenin(3 â†’ 6″)luteolin, naringenin(3 â†’ 6″)chrysoeriol, liovil 4-O-ß-glucopyranoside, 2,6-dimethoxy cinnamic acid, (E)-4-(3-hydroxy-2,2-dimethylchroman-6-yl)but-3-en-2-one and (E)-4-(4-(((E)-4-hydroxy-3-methylbut-2-en-1-yl)oxy)phenyl)but-3-en-2-one, have been identified from fruits of N. ossifragum for the first time. In addition, the rare natural product 4-hydroxy-3-(3-methylbut-2-enyl)benzaldehyde and the five known compounds 4-hydroxycinnamic acid, quercetin 3,3'-dimethyl ether, quercetin 3,7-dimethyl ether, chrysoeriol 7-O-ß-glucopyranoside and the di-C-glycosylflavone isoschaftoside were all characterized for the first time from the fruits of N. ossifragum. The discovery of sufficient amounts of 4-hydroxy-3-(3-methylbut-2-enyl)benzaldehyde in fresh plant material of N. ossifragum to allow complete structure elucidation by NMR and HRMS supports the possibility that fungi associated with N. ossifragum may be able to produce enough toxins to play a significant role in the pathogenicity of N. ossifragum. 4-Hydroxy-3-(3-methylbut-2-enyl)benzaldehyde showed mild toxicity towards normal rat kidney (NRK) and more profound activity towards MOLM13 acute myeloid leukemia cells (IC50 = 430 µM and 68 µM, respectively). Naringenin(3 â†’ 6″)luteolin had IC50 of 230 µM towards NRK cells, and 115 µM towards MOLM13 cells. Microscopic evaluation suggests that these two compounds induce cell death by different mechanisms.

Growing with dinosaurs: natural products from the Cretaceous relict Metasequoia glyptostroboides Hu & Cheng-a molecular reservoir from the ancient world with potential in modern medicine.

After the sensational rediscovery of living exemplars of the Cretaceous relict Metasequoia glyptostroboides-a tree previously known exclusively from fossils from various locations in the northern hemisphere, there has been an increasing interest in discovery of novel natural products from this unique plant source. This article includes the first complete compilation of natural products reported from M. glyptostroboides during the entire period in which the tree has been investigated (1954-2014) with main focus on the compounds specific to this plant source. Studies on the biological activity of pure compounds and extracts derived from M. glyptostroboides are reviewed for the first time. The unique potential of M. glyptostroboides as a source of bioactive constituents is founded on the fact that the tree seems to have survived unchanged since the Cretaceous era. Since then, its molecular defense system has resisted the attacks of millions of generations of pathogens. In line with this, some recent landmarks in Metasequoia paleobotany are covered. Initial spectral analysis of recently discovered intact 53 million year old wood and amber of Metasequoia strongly indicate that the tree has remained unchanged for millions of years at the molecular level.

First identification of natural products from the African medicinal plant Zamioculcas zamiifolia - A drought resistant survivor through millions of years.

Zamioculcas zamiifolia, an unusually drought resistant medicinal plant native to tropical east Africa and subtropical southeast Africa, including the countries Kenya, Malawi, Mozambique, South-Africa, Tanzania and Zimbabwe, is described as a living fossil which may have evolved as early as 42 million years ago. It belongs to the notoriously toxic family Araceae giving it, through association, a reputation for being toxic; despite little or no systematic evidence exists to support this claim. As an ancient plant it has sustained substantial climate changes and attacks from millions of generations of pathogenic microorganisms, which encouraged search for novel natural products from this source. Seven natural products have been characterized from leaves and petioles of Z. zamiifolia, including the novel main compound of the leaves, apigenin 6-C-(6″-(3-hydroxy-3-methyl-glutaroyl)-ß-glucopyranoside). The structure determinations were based on extensive use of 2D NMR spectroscopic techniques and high-resolution mass spectrometry. Initial toxicological experiment on extracts from Z. zamiifolia using brine shrimp lethality assay did not indicate lethality to the shrimps providing disproving evidence for the assumption of Z. zamiifolia's toxic character.

6-carboxydihydroresveratrol 3-O-ß-glucopyranoside--a novel natural product from the Cretaceous relict Metasequoia glyptostroboides.

Metasequoia glyptostroboides, a tree native to China, is described as a living fossil and has existed for millions of years. The oldest fossils recorded have been dated to the late Cretaceous era. During the time of its existence, the molecular defence system of the tree has apparently resisted millions of generations of pathogens, which encouraged search for novel natural product from this source. Eight compounds have been characterised from needles of M. glyptostroboides, including the novel natural product 6-carboxydihydroresveratrol 3-O-ß-glucopyranoside. The structure determinations were based on extensive use of 2D NMR spectroscopic techniques and high-resolution mass spectrometry.

Novel GHB-derived natural products from European mistletoe (Viscum album).

CONTEXT: The European white-berry mistletoe [Viscum album L. (Loranthaceae)] is among the oldest known medicinal plants. At present the most important application of mistletoe extracts is in the treatment of cancer. However, natural products specific to mistletoe have rarely been encountered in the current literature. OBJECTIVE: To discover novel natural products specific to European mistletoe. MATERIALS AND METHODS: European mistletoe was extracted with methanol, purified to partition against diethyl ether and further purified with XAD-7 column chromatography. Pure compounds were separated by Sephadex column chromatography and preparative HPLC. The structures of the novel compounds were established using a combination of several 2D NMR spectroscopic techniques and mass spectrometry. RESULTS: A new type of natural product derived from the methyl ester of γ-hydroxybutyric acid (GHB) coupled to hydroxybenzoic acids, namely 3-(3'-carbomethoxypropyl) gallic acid and 3-(3'-carbomethoxypropyl)-7→3″-protocatechoyl galloate were characterized from European white-berry mistletoe. Condensation of the 3-hydroxyl of gallic acid with the 4-hydroxyl of GHB significantly reduced the radical scavenging properties of the former compound. DISCUSSION AND CONCLUSION: The characterized compounds define a novel group of natural products that may be of particular interest because it appears that the two new compounds are not closely related to any known natural product.