Correction: Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids.

Correction for 'Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids' by Yong Shen et al., Nat. Prod. Rep., 2020, 37, 763-796, https://doi.org/10.1039/D0NP00002G.

Grafting: a potential method to reveal the differential accumulation mechanism of secondary metabolites.

Plant secondary metabolites make a great contribution to the agricultural and pharmaceutical industries. Their accumulation is determined by the integrated transport of target compounds and their biosynthesis-related RNA, protein, or DNA. However, it is hard to track the movement of these biomolecules in vivo. Grafting may be an ideal method to solve this problem. The differences in genetic and metabolic backgrounds between rootstock and scion, coupled with multiple omics approaches and other molecular tools, make it feasible to determine the movement of target compounds, RNAs, proteins, and DNAs. In this review, we will introduce methods of using the grafting technique, together with molecular biological tools, to reveal the differential accumulation mechanism of plant secondary metabolites at different levels. Details of the case of the transport of one diterpene alkaloid, fuziline, will be further illustrated to clarify how the specific accumulation model is shaped with the help of grafting and multiple molecular biological tools.

Structural diversity, bioactivities, and biosynthesis of natural diterpenoid alkaloids.

Covering: 2009 to 2018. Diterpenoid alkaloids, originating from the amination of natural tetracyclic diterpenes, are a diverse class of compounds having complex structural features with many stereocenters. The important pharmacological activities and structural complexity of the diterpenoid alkaloids have long interested scientists due to their medicinal uses, infamous toxicity, and unique biosynthesis. Since 2009, 373 diterpenoid alkaloids, assigned to 46 skeletons, have been isolated and identified from plants mostly in the Ranunculaceae family. The names, classes, molecular weight, molecular formula, NMR data, and plant sources of these diterpene alkaloids are collated here. This review will be a detailed update of the naturally occurring diterpene alkaloids reported from the plant kingdom from 2009-2018, providing an in-depth discussion of their diversity, biological activities, pharmacokinetics, toxicity, application, evolution, and biosynthesis.

Jaboticabin and Related Polyphenols from Jaboticaba ( Myrciaria cauliflora) with Anti-inflammatory Activity for Chronic Obstructive Pulmonary Disease.

Myrciaria cauliflora (jaboticaba) is an edible fruit common in Brazil that has been used for treating respiratory diseases, including chronic tonsillitis and asthma. This study explores the distribution of an anti-inflammatory depside, jaboticabin, in different parts of the jaboticaba plant as well as major polyphenols from the wood of jaboticaba, some with biological activity similar to jaboticabin. The peel of the fruit was found to be the major source of jaboticabin. This is the first phytochemical study of the wood of M. cauliflora. The antioxidant-activity-guided fractionation strategy successfully identified 3,3'-dimethylellagic acid-4- O-sulfate from jaboticaba wood. This ellagic acid derivative, in a manner similar to jaboticabin, showed antiradical activity and inhibited the production of the chemokine interleukin-8 after treating the human small airway epithelial cells with cigarette smoke extract. The human intestinal Caco-2 cell studies demonstrated the jaboticabin transport in vitro. The polyphenols, jaboticabin and 3,3'-dimethyellagic acid-4- O-sulfate, from jaboticaba were both found to exhibit anti-inflammatory activities, thus suggesting the potential use of these compounds or even the fruits themselves for chronic obstructive pulmonary disease.

[Testing methods for seed quality of Bletilla striata].

In order to provide a basis for establishing seed testing rules and seed quality standard of Bletilla striata, the seed quality of B.striata from different producing area was measured referring to the Rules for Agricultural Seed Testing(GB/T 3543-1995).The results showed that the seeds of B.striata passed through 20-mesh sieve for purity analysis.The weight of seeds was measured by 1000-seed method and the water content was measured at the higher temperature (133±2) ℃ for 3 hours.The seeds were cultured on the wet filter paper at 30 ℃ for 4-20 days in light for germination testing.The method of testing seed viability was that seeds were dipped into 1% TTC solution for 7 hours at temperature of 40 ℃.

[Double mulching application for Panax notoginseng growing seedlings].

OBJECTIVE: In order to improve the irrigation for Panax notginseng growing seedlings, different mulching ways were carried out to investigate the effects of double mulching. METHOD: Field experiment was applied to study soil moisture, soil temperature and bulk density of different mulching ways while the germination rate and seedlings growth also were investigated. RESULT: Compared with the traditional single mulching with pine leaves or straw, double mulching using plastic film combined with pine leaves or straw could reduce 2/3 volumes of irrigation at the early seedling time Double mulching treatments didn't need to irrigate for 40 days from seeding to germination, and kept soil moisture and temperature steady at whole seedling time about 30% and 9.0-16.6 degrees C, respectively. The steady soil moisture and temperature benefited to resist late spring cold and germinate earlier while kept germination regularly, higher rate and seedlings quality. In contrast, single mulching using pine leaves or straw had poor soil moisture and temperature preserving, needed to irrigate every 12-day, meanwhile dropped the germination and booming time 14 days and 24-26 days, respectively, reduced germination rate about 11.3%-8.7%. However, single pine leaves mulching was better than straw mulching. In addition, though better effects of soil moisture and temperature preserving as well as earlier and higher rate of germination with single plastic films mulching had, some disadvantages had also been observed, such as daily soil temperature changed greatly, seedling bed soil hardened easily, more moss and weeds resulted difficulty in later management. CONCLUSION: To the purpose of saving water and labor as well as getting higher germination rate and seedlings quality, double mulching using plastic films combined pine leaves at the early time and single mulching removing plastic films at the later time is suggested to apply in the growing seedlings of P. notoginseng.

[Species and ecological control of disease on cultivated Gentiana rigescens in Yunnan].

OBJECTIVE: To find out variety of the fungal diseases of cultivated Gentiana rigescens and provide important basis for prevention. METHODS: The diseases were diagnosed based on field investigate, symptoms observation, pathogen isolation, determination the size of morphological and verification following the Koch's Postulate procedures. RESULTS: Anthracnose (Colletotrichum gloeosporioides), grey mould (Botrytis cinerea), brown spot (Alternaria tenuis), rust (Aecidiumpers), circular spot (Pestalotiopsis), leaf blight (Stemphylium, Ascochyta, Pleospora) and nematodes (Heterodera spp., Meloidogyne spp.) were found on Gentiana rigescens. Anthracnose was the first main disease, the diseased plant rate was over 40% and disease severity was 4 - 5 degree and second disease was rust, incidence of rate was less 10% and other diseases rate was not enough 2%. CONCLUSION: All these diseases on Gentiana rigescens are reported for the first time and Gentiana rigescens is the new host plant of the diseases.

Carboxymethyl flavonoids and a monoterpene glucoside from Selaginella moellendorffii.

A new dihydroflavone, 5-carboxymethyl-7,4'-dihydroxyflavonone (1), and its glucoside 5-carboxymethyl-7,4'-dihydroxyflavonone-7-O-ß-D: -glucopyranoside (2), and one new monoterpene glucoside, (4Z,6E)-2,7-dimethyl-8-hydroxyocta-4,6-dienoic acid 8-O-ß-D: -glucopyranoside (3), were isolated from the whole plants of Selaginella moellendorffii. Their structures were determined by spectroscopic methods and chemical transformation. Compound 2 was evaluated for the ability to enhance glucose consumption in normal and insulin-resistant L6 muscle cells induced by high concentrations of insulin and glucose. Glucose consumption in insulin-resistant cells (but not in normal cells) was increased 15.2 ± 3.3% (p < 0.01) by compound 2 at a concentration of 0.1 µM in the presence of insulin (1 nM).

Clerodane diterpenoids and prenylated flavonoids from Dodonaea viscosa.

Repeated column chromatography of the EtOAc-soluble fraction of the aerial parts of Dodonaea viscosa led to the isolation of two new modified clerodanes, methyl dodovisate A (1) and methyl dodovisate B (2), two new prenylated flavonoids, 5,7,4'-trihydroxy-3',5'-di(3-methylbut-2-enyl)-3,6-dimethoxyflavone (10) and 5,7,4'-trihydroxy-3'-(4-hydroxy-3-methylbutyl)-5'-(3-methylbut-2-enyl)-3,6-dimethoxyflavone (11), together with eight known compounds, dodonic acid (3), hautriwaic acid (4), hautriwaic lactone (5), (+)-hardwickiic acid (6), 5alpha-hydroxy-1,2-dehydro-5,10-dihydroprintzianic acid methyl ester (7), strictic acid (8), dodonolide (9), and aliarin (12). The structures of the new compounds were elucidated by spectroscopic data analysis. Compounds 1-9 and 11 were evaluated on larvicidal activity against the fourth-instar larvae of Aedes albopictus and Culex pipens quinquefasciatus.

Sesquiterpenoids from Pilea cavaleriei subsp. crenata.

Three new humulane-type sesquiterpenes, 8-O-(p-coumaroyl)-5beta-hydroperoxy-1(10)E,4(15)-humuladien-8alpha-ol (1), 8-O-(3-nitro-p-coumaroyl)-1(10)E,4(15)-humuladien-5beta,8alpha-diol (2) and 8-O-(p-coumaroyl)-1(10)E,4(5)E-humuladien-8-ol (3), and a new copaborneol derivative, 1-O-p-coumaroyl-copaborneol (4), have been isolated from the methanol extract of Pileacavaleriei Lévl. subsp. crenata C. J. Chen. Their structures were elucidated using spectroscopic methods. Cytotoxic and antimicrobial activities of the isolated compounds were evaluated.

Pyrrolidinoindoline alkaloids from Selaginella moellendorfii.

Eight new pyrrolidinoindoline alkaloids (1-8) were isolated from the whole plant of Selaginella moellendorfii. Their structures were determined by mass spectrometry, 1D and 2D NMR spectroscopy, and chemical interconversions. These alkaloids have a 3-carboxybut-2-enyl group at C-3a and two methyl groups at N-8. The possible biogenetic route from selaginellic acid (1) to neoselaginellic acid (6) was postulated and chemically mimicked. Tautomerization between 6 and 6a was observed. Selected compounds were evaluated for antibacterial, cytotoxic, and acetylcholinesterase inhibitory activities.

Chemical constituents of Aeschynanthus bracteatus and their weak anti-inflammatory activities.

Chemical examination of the EtOAc extract from the aerial parts of Aeschynanthus bracteatus led to isolation of four phenylethanol glycosides, aeschynanthosides A-D (1-4), and 55 known constituents, including 8 phenylethanoids, 23 phenols, 5 lignans, 7 flavonoids, 9 terpenoids, and 4 others. Their structures were elucidated mainly by detailed spectroscopic studies and comparison with published data. All 59 compounds were isolated for the first time from an Aeschynanthus species. The isolates were also tested for inhibitory activities against LPS-induced NO production in RAW 264.7 macrophages. Aeschynanthoside D (4) and naringenin (41), within the concentration arrange tested (50-100 microg/mL), showed very weak dose-dependent effects with the inhibition rate of 24.2%, 35.4%, 66.0%, and 9.5%, 40.1%, 65.0%, respectively, relative to positive controls.