Marine Microorganism-Invertebrate Assemblages: Perspectives to Solve the “Supply Problem” in the Initial Steps of Drug Discovery

The chemical diversity associated with marine natural products (MNP) is unanimously acknowledged as the “blue gold” in the urgent quest for new drugs. Consequently, a significant increase in the discovery of MNP published in the literature has been observed in the past decades, particularly from marine invertebrates. However, it remains unclear whether target metabolites originate from the marine invertebrates themselves or from their microbial symbionts. This issue underlines critical challenges associated with the lack of biomass required to supply the early stages of the drug discovery pipeline. The present review discusses potential solutions for such challenges, with particular emphasis on innovative approaches to culture invertebrate holobionts (microorganism-invertebrate assemblages) through in toto aquaculture, together with methods for the discovery and initial production of bioactive compounds from these microbial symbionts.     

Biomedical Compounds from Marine organisms

The Ocean, which is called the ‘mother of origin of life’, is also the source of structurally unique natural products that are mainly accumulated in living organisms. Several of these compounds show pharmacological activities and are helpful for the invention and discovery of bioactive compounds, primarily for deadly diseases like cancer, acquired immuno-deficiency syndrome (AIDS), arthritis, etc., while other compounds have been developed as analgesics or to treat inflammation, etc. The life-saving drugs are mainly found abundantly in microorganisms, algae and invertebrates, while they are scarce in vertebrates. Modern technologies have opened vast areas of research for the extraction of biomedical compounds from oceans and seas.     

Drugs from the Sea -Opportunities and Obstacles

The supply problem with regard to drug development and sustainable production lies in the limited amounts of biomass of most marine invertebrates available from wild stocks. Thus, most pharmacologically active marine natural products can only be isolated in minute yields. Total synthesis of pharmacologically active natural products has been successfully established but is in many cases economically not feasible due to the complexity of the molecular structures and the low yields. To solve the pressing supply issue in marine drug discovery, other strategies appear to be more promising. One of these is mariculture which has successfully been established with the bryozoan Bugula neritina (the source of the bryostatins) and the tunicate Ecteinascidia turbinata (the source of ET-743). Another strategy involves partial synthesis from precursors which are biotechnologically available. An example is ET-743 that can be partially synthesized from safracin B which is a metabolite of Pseudomonas fluorescens. There have been many examples of striking structural similarities between natural products obtained from marine invertebrates and those of microbial origin which suggests that microorganisms living in their invertebrate hosts could be the actual producers of these secondary metabolites. With regard to sustainable biotechnological production of pharmacologically important metabolites from marine invertebrates and their “endosymbionts”, a more advanced strategy is to focus on cloning and expression of the respective key biosynthetic gene clusters. This molecular biological approach will open up new avenues for biotechnological production of drugs or drug candidates from the sea.     

不同早熟龙眼品种（系）果实生长发育和品质变化规律比较

本文以‘桂丰早’‘桂冠早’‘桂龙1号’‘古山2号’‘石硖’5个早熟品种（系）为材料,研究不同品种（品系）果实生长发育和品质变化规律。结果表明：在果实发育过程中,5个早熟龙眼品种（系）的横纵径、单果重、可食率、色差a^*和c^*值均呈上升或波动上升;色差L^*和b^*值呈快速上升后缓慢波动;可溶性固形物含量和大多数品种的维生素C呈先快速上升后缓慢下降;色差hº值和大多数品种的可滴定酸呈逐渐下降或波动下降;可溶性糖在成熟前是逐渐上升的,到后期则波动变化;可溶性蛋白呈“M”或“W”型波动;‘桂丰早’和‘桂冠早’比‘石硖’提前1周进入成熟期;‘桂龙1号’的退糖最慢;‘桂丰早’的横径、单果重及可溶性蛋白质含量最大,‘桂冠早’的纵径最大,‘桂龙1号’的可溶性固形物含量、维生素C和可溶性糖含量最高而可滴定酸含量最低,‘石硖’的可食率最高;综合评价成熟期的果实品质,则‘桂丰早’最佳,其次是‘石硖’,最后是‘桂龙1号’‘古山2号’和‘桂冠早’。     

行业协会主导农产品区域公用品牌创建的研究——以“射阳大米”为例

以射阳县大米协会成功创建“射阳大米”品牌为案例,将“射阳大米”品牌创建过程分为初创期、成长期、成熟期等三个阶段,考察了射阳县大米协会在品牌创建各阶段的行为,分析了射阳县大米协会成功创牌的原因。研究表明,在政府的支持下,行业协会通过自身建设和科学运作,可以不断解决农产品区域公用品牌创建中的瓶颈问题,从品牌规划、质量提升、规范管理、市场营销和打假维护等方面推进品牌提升。“政府赋能与管理、行业协会主导”的“射阳大米”区域公用品牌创建模式值得借鉴。     

Glycosaminoglycans from Litopenaeus vannamei Inhibit the Alzheimer’s Disease β Secretase,BACE1

Only palliative therapeutic options exist for the treatment of Alzheimer’s Disease; no new successful drug candidates have been developed in over 15 years. The widely used clinical anticoagulant heparin has been reported to exert beneficial effects through multiple pathophysiological pathways involved in the aetiology of Alzheimer’s Disease, for example, amyloid peptide production and clearance, tau phosphorylation, inflammation and oxidative stress. Despite the therapeutic potential of heparin as a multi-target drug for Alzheimer’s disease, the repurposing of pharmaceutical heparin is proscribed owing to the potent anticoagulant activity of this drug. Here, a heterogenous non-anticoagulant glycosaminoglycan extract, obtained from the shrimp Litopenaeus vannamei, was found to inhibit the key neuronal β-secretase, BACE1, displaying a more favorable therapeutic ratio compared to pharmaceutical heparin when anticoagulant activity is considered.     

Lamellarin O,a Pyrrole Alkaloid from an Australian Marine Sponge,Ianthella sp., Reverses BCRP Mediated Drug Resistance in Cancer Cells

ATP binding cassette (ABC) transporters, such as P-gp, BCRP and MRP1, can increase efflux of clinical chemotherapeutic agents and lead to multi-drug resistance (MDR) in cancer cells. While the discovery and development of clinically useful inhibitors has proved elusive to date, this molecular target nevertheless remains a promising strategy for addressing and potentially overcoming MDR. In a search for new classes of inhibitor, we used fluorescent accumulation and efflux assays supported by cell flow cytometry and MDR reversal assays, against a panel of sensitive and MDR human cancer cell lines, to evaluate the marine sponge co-metabolites 1–12 as inhibitors of P-gp, BCRP or MRP1 initiated MDR. These studies identified and characterized lamellarin O (11) as a selective inhibitor of BCRP mediated drug efflux. A structure–activity relationship analysis inclusive of the natural products 1–12 and the synthetic analogues 13–19, supported by in silico docking studies, revealed key structural requirements for the lamellarin O (11) BCRP inhibitory pharmacophore.     

Signal Transducers and Activators of Transcription (STAT) Regulatory Networks in Marine Organisms: From Physiological Observations towards Marine Drug Discovery

Part of our ocean’s richness comes from its extensive history of supporting life, resulting in a highly diverse ecological system. To date, over 250,000 species of marine organisms have been identified, but it is speculated that the actual number of marine species exceeds one million, including several hundreds of millions of species of marine microorganisms. Past studies suggest that approximately 70% of all deep-sea microorganisms, gorgonians, and sea sponges produce secondary metabolites with anti-cancer activities. Recently, novel FDA-approved drugs derived from marine sponges have been shown to reduce metastatic breast cancer, malignant lymphoma, and Hodgkin’s disease. Despite the fact that many marine natural products have been shown to possess a good inhibition potential against most of the cancer-related cell signaling pathways, only a few marine natural products have been shown to target JAK/STAT signaling. In the present paper, we describe the JAK/STAT signaling pathways found in marine organisms, before elaborating on the recent advances in the field of STAT inhibition by marine natural products and the potential application in anti-cancer drug discovery.     

Quality not Quantity: The Role of Marine Natural Products in Drug Discovery and Reverse Chemical Proteomics

Reverse chemical proteomics combines affinity chromatography with phage display and promises to be a powerful new platform technology for the isolation of natural product receptors, facilitating the drug discovery process by rapidly linking biologically active small molecules to their cellular receptors and the receptors’ genes. In this paper we review chemical proteomics and reverse chemical proteomics and show how these techniques can add value to natural products research. We also report on techniques for the derivatisation of polystyrene microtitre plates with cleavable linkers and marine natural products that can be used in chemical proteomics or reverse chemical proteomics. Specifically, we have derivatised polystyrene with palau’amine and used reverse chemical proteomics to try and isolate the human receptors for this potent anticancer marine drug.     

Exploitation of Marine Molecules to Manage Alzheimer’s Disease

Neurodegenerative diseases are sociosanitary challenges of today, as a result of increased average life expectancy, with Alzheimer’s disease being one of the most prevalent. This pathology is characterized by brain impairment linked to a neurodegenerative process culminating in cognitive decline and behavioral disorders. Though the etiology of this pathology is still unknown, it is usually associated with the appearance of senile plaques and neurofibrillary tangles. The most used prophylaxis relies on anticholinesterase drugs and NMDA receptor antagonists, whose main action is to relieve symptoms and not to treat or prevent the disease. Currently, the scientific community is gathering efforts to disclose new natural compounds effective against Alzheimer’s disease and other neurodegenerative pathologies. Marine natural products have been shown to be promising candidates, and some have been proven to exert a high neuroprotection effect, constituting a large reservoir of potential drugs and nutraceutical agents. The present article attempts to describe the processes of extraction and isolation of bioactive compounds derived from sponges, algae, marine bacteria, invertebrates, crustaceans, and tunicates as drug candidates against AD, with a focus on the success of pharmacological activity in the process of finding new and effective drug compounds.     

The Invasion of Megachile policaris (Hymenoptera: Megachilidae) to Hawai‘i

Islands are insular environments that are negatively impacted by invasive species. In Hawai‘i, at least 21 non-native bees have been documented to date, joining the diversity of >9,000 non-native and invasive species to the archipelago. The goal of this study is to describe the persistence, genetic diversity, and natural history of the most recently established bee to Hawai‘i, Megachile policaris Say, 1831 (Hymenoptera: Megachilidae). Contemporary surveys identify that M. policaris is present on at least O‘ahu, Maui, and Hawai‘i Island, with the earliest detection of the species in 2017. Furthermore, repeated surveys and observations by community members support the hypothesis that M. policaris has been established on Hawai‘i Island from 2017 to 2020. DNA sequenced fragments of the cytochrome oxidase I locus identify two distinct haplotypes on Hawai‘i Island, suggesting that at least two founders have colonized the island. In their native range, M. policaris is documented to forage on at least 21 different plant families, which are represented in Hawai‘i. Finally, ensemble species distribution models (SDMs) constructed with four bioclimatic variables and occurrence data from the native range of M. policaris predicts high habitat suitability on the leeward side of islands throughout the archipelago and at high elevation habitats. While many of the observations presented in our study fall within the predicted habitat suitability on Hawai‘i, we also detected the M. policaris on the windward side of Hawai‘i Island suggesting that the SDMs we constructed likely do not capture the bioclimatic niche flexibility of the species.     

高温胁迫下8个绣球品种的生理生化响应

中国南方地区夏季高温是限制绣球在该地区引种栽植与园林应用的重要因素之一,探讨绣球在高温胁迫下生理生化的响应机理,对绣球在特殊立地条件下的应用有重要参考意义。试验以8个绣球品种为材料,利用人工气候箱模拟高温胁迫44℃/33℃（昼/夜）下9项指标的生理生化指标变化。结果表明,高温胁迫下,8个绣球品种的热害指数呈上升趋势,且由高到低依次为‘灵感’>‘银边’>‘纱织小姐’>‘小町’>‘爱莎’>‘含羞叶’>‘花手鞠’>‘头花’;相对电导率、丙二醛呈持续上升趋势,‘纱织小姐’‘银边’及‘小町’叶片的相对电导率与丙二醛含量增幅最大,‘爱莎’‘头花’及‘含羞叶’叶片的相对电导率与丙二醛含量增幅均最小;过氧化物酶、超氧化物歧化酶和过氧化氢酶的活性均产生显著影响,适度的高温诱导了绣球叶片上述3种酶活性的上升;可溶性糖含量在高温胁迫前期变化较小,但总体呈上升趋势;可溶性蛋白含量呈上升趋势,‘银边’与‘灵感’的蛋白质合成速率最低,‘头花’与‘含羞叶’的蛋白质合成速率最高;游离脯氨酸含量呈上升趋势,‘花手鞠’与‘头花’通过游离脯氨酸进行渗透调节的能力显著强于其他品种,‘灵感’与‘银边’通过游离脯氨酸进行渗透调节的能力显著弱于其他品种。利用模糊隶属函数分析8个绣球品种耐高温能力,‘纱织小姐’为最耐高温的品种,其次为‘含羞叶’‘小町’‘花手鞠’‘头花’‘灵感’‘爱莎’,‘银边’为最不耐高温的品种。本研究为探究绣球品种在高温胁迫下的生理生化响应机制提供了理论依据。     

Pollination Services of Mango Flower Pollinators

Measuring wild pollinator services in agricultural production is very important in the context of sustainable management. In this study, we estimated the contribution of native pollinators to mango fruit set production of two mango cultivars Mangifera indica (L). cv. ‘Sala’ and ‘Chok Anan’. Visitation rates of pollinators on mango flowers and number of pollen grains adhering to their bodies determined pollinator efficiency for reproductive success of the crop. Chok Anan failed to produce any fruit set in the absence of pollinators. In natural condition, we found that Sala produced 4.8% fruit set per hermaphrodite flower while Chok Anan produced 3.1% per flower. Hand pollination tremendously increased fruit set of naturally pollinated flower for Sala (>100%), but only 33% for Chok Anan. Pollinator contribution to mango fruit set was estimated at 53% of total fruit set production. Our results highlighted the importance of insect pollinations in mango production. Large size flies Eristalinus spp. and Chrysomya spp. were found to be effective pollen carriers and visited more mango flowers compared with other flower visitors.     

Chemoinformatic Analysis as a Tool for Prioritization of Trypanocidal Marine Derived Lead Compounds

Marine trypanocidal natural products are, most often, reported with trypanocidal activity and selectivity against human cell lines. The triaging of hits requires a consideration of chemical tractability for drug development. We utilized a combined Lipinski’s rule-of-five, chemical clustering and ChemGPS-NP principle analysis to analyze a set of 40 antitrypanosomal natural products for their drug like properties and chemical space. The analyses identified 16 chemical clusters with 11 well positioned within drug-like chemical space. This study demonstrated that our combined analysis can be used as an important strategy for prioritization of active marine natural products for further investigation.     

Marine Natural Products with P-Glycoprotein Inhibitor Properties

P-glycoprotein (P-gp) is a protein belonging to the ATP-binding cassette (ABC) transporters superfamily that has clinical relevance due to its role in drug metabolism and multi-drug resistance (MDR) in several human pathogens and diseases. P-gp is a major cause of drug resistance in cancer, parasitic diseases, epilepsy and other disorders. This review article aims to summarize the research findings on the marine natural products with P-glycoprotein inhibitor properties. Natural compounds that modulate P-gp offer great possibilities for semi-synthetic modification to create new drugs and are valuable research tools to understand the function of complex ABC transporters.     

不同品种、地区茶叶籽仁含油量及茶叶籽油中脂肪酸组分和含量差异性分析

为了筛选出含油量高且脂肪酸组分丰富的茶树品种,对9个省区49个茶树品种茶叶籽进行研究.结果发现,不同品种茶树茶叶籽含油量范围为16.29％～33.80％.采用气相色谱法测定各个品种茶叶籽油中脂肪酸的组分和含量,共检测出19种脂肪酸,主要为油酸、亚油酸、棕榈酸、硬脂酸和α-亚麻酸,分别占总脂肪酸含量的46.00％～72....     

外源水杨酸诱导香蕉苯丙烷类代谢提高对枯萎病抗性

由尖孢镰刀菌古巴专化型热带4号生理小种（Fusarium oxysporum f. sp. cubense tropical race 4, TR4）引起的香蕉枯萎病严重阻碍我国香蕉产业的绿色可持续发展。外源水杨酸（SA）处理能诱导香蕉体内SA合成及信号传导途径关键酶基因上调表达,激活香蕉植株内系统获得抗性,增强对各种生物和非生物胁迫的抵抗能力,在此基础上,本研究对香蕉感病品种‘巴西蕉’和抗病品种‘农科1号’进行SA诱导处理,随后接种TR4,结果显示2个品种的病情指数均降低。为了进一步探究水杨酸信号途径下游的苯丙烷类途径在SA诱导的香蕉植株抗病过程中的作用,本研究运用实时荧光定量PCR技术（RT-qPCR）,对SA处理的感病品种‘巴西蕉’和抗病品种‘农科1号’中苯丙烷类途径关键基因的表达情况进行分析,结果发现分支途径中常规苯丙烷类途径关键酶基因C4H和4CL、木质素合成途径关键酶基因CAD和CCoAOMT、黄酮类物质生物合成途径关键酶基因CHS和CHI,对SA处理和TR4接种均有响应。在仅接种TR4的情况下,‘巴西蕉’相关基因主要表现为显著下调表达,而‘农科1号’相关基因主要表现为上调表达;仅用SA处理时,2个品种的C4H和4CL被诱导上调表达;SA处理并接种TR4,2个品种C4H和4CL依然保持上调表达的趋势,变化幅度在‘农科1号’中偏高;‘巴西蕉’CAD经SA诱导上调表达,但在接种TR4后,CAD相对表达量降低,而‘农科1号’CAD被SA诱导显著上调表达,SA和TR4共同作用下,表达水平亦显著升高;‘巴西蕉’CCoAOMT被TR4诱导显著上调表达,在SA处理并接种TR4的‘巴西蕉’植株中也表现为上调表达,‘农科1号’CCoAOMT在SA处理或SA、TR4共同作用下表现为强烈上调表达;CHS和CHI在SA处理的2个品种中主要表现为上调表达,SA和TR4双重作用下,依然表现为上调表达。结果表明外源SA处理可诱导感病和耐病香蕉根组织中苯丙烷类途径关键酶基因上调表达,该途径在SA诱导的香蕉抗枯萎病过程中起着重要作用。     

8个杧果品种胶乳挥发性成分及胶乳的灼伤机制初探

以‘台农1号’‘贵妃’‘金煌’‘玉文’‘红象牙’‘四季蜜杧’‘金穗’和‘红杉林’8个杧果品种的胶乳为材料,利用气相色谱–质谱联用技术对其挥发性成分进行测定,用NIST 11标准谱库对测定的质谱数据进行自动检索对照,保留匹配度大于90%的化合物,并对不同杧果品种的胶乳挥发性成分进行差异性分析,旨在为确定杧果胶乳中灼伤果皮的主要挥发性成分提供科学参考,并采用超景深三维显微镜观察果皮灼伤前后变化,为初步探索胶乳灼伤果皮机制提供参考。结果表明：（1）8个杧果品种共鉴定出30种匹配度大于90%的化合物,这些化合物分为萜烯类、酚类、醛类和烷烃类。其中,萜烯类是主要挥发性成分,酚类、醛类和烷烃类占比极少。8个杧果品种胶乳中共有的化合物有α-蒎烯、3-蒈烯、α-水芹烯、4-蒈烯、(R)-(+)-柠檬烯、桧烯、(1R)-(+)-α-蒎烯、萜品油烯、L-石竹烯和2,4-二叔丁基苯酚共10种。其中,3-蒈烯和萜品油烯为8个杧果品种胶乳的主要挥发性成分。（2）根据8个杧果品种胶乳中各挥发性成分的相对含量为数据源进行主成分分析将其分为5类：第一类为‘贵妃’和‘金煌’,第二类为‘台农1号’和‘四季蜜杧’,第三类为‘红象牙’和‘金穗’,第四类为‘玉文’,第五类为‘红杉林’。同一类别杧果品种其胶乳的主要挥发性成分及相对含量相似,不同类别杧果品种其胶乳的主要挥发性成分及相对含量差异较大。（3）杧果胶乳导致果皮皮孔褐变损伤,‘台农1号’接触胶乳的1 h后发生轻微灼伤,贵妃接触胶乳10 min时明显灼伤。研究结果明确了8个杧果品种乳胶中挥发性成分及其在不同品种中相对含量的差异,为揭示不同杧果品种胶乳灼伤果皮机制提供了基础。     

不同遗传背景香蕉品种间轮作控制香蕉枯萎病的效果分析

香蕉种质资源丰富,不同香蕉品种对各个枯萎病生理小种的耐受性不同,利用遗传背景差异大、抗性不同的香蕉品种进行轮作可能达到防控香蕉枯萎病的效果。本研究选取华南地区常见的香牙蕉、粉蕉、龙牙蕉、贡蕉等栽培蕉类型作为研究材料,通过对24个香蕉品种的遗传多样性进行分析,结合生产应用,筛选遗传背景不同并且具有一定抗枯萎病的品种,进行香蕉品种间轮作模式对香蕉枯萎病的防控效果研究,以筛选高效栽培模式。利用29对SRAP引物对24份香蕉资源进行遗传多样性分析,选择属于不同遗传类群的5个抗病品种：‘粉杂1号’（第1类群）、‘海贡’（第2类群）、‘农科1号’（第5类群）、‘抗枯1号’（第5类群）和‘南天黄’（第5类群）进行品种轮作模式研究,统计土壤中枯萎病菌的数量以及枯萎病的田间发病率。试验筛选出29对扩增清晰、多态性好的SRAP引物,对24份香蕉资源进行遗传多样性分析,聚类结果表明,遗传相似系数变异范围为0.1~1.0,遗传差异较大,构建的聚类树状图在相似性系数为0.80时,可以将24个香蕉品种分为6类,分类结果与传统的形态分类基本一致,同时发现香牙蕉品种具有一定的遗传分化,可见SRAP分子标记适用于亚种或者更细的香蕉分类。在连作‘农科1号’的蕉地上分别轮作1 a‘粉杂1号’‘海贡’‘抗枯1号’‘南天黄’后,‘粉杂1号’和‘海贡’的根围土壤中的枯萎病菌数量显著降低;再种回‘农科1号’,轮作处理组的枯萎病发病率均降低,并且‘农科1号’-‘粉杂1号’1 a -‘农科1号’1 a、‘农科1号’-‘海贡’1 a -‘农科1号’1 a这2种轮作模式的枯萎病发病率显著降低,是控制香蕉枯萎病发生的有效栽培模式。可见采用遗传背景差异大的抗病品种进行合理轮作可以有效降低土壤中枯萎病菌的数量和香蕉枯萎病的发病率,达到防病的效果。     

水稻半矮杆突变体‘双辐矮糯’的农艺性状与遗传分析

倒伏是影响水稻（Oryza sativa L.）生产的重要因素,半矮杆是协调高产和抗倒性的理想资源。前期通过辐射诱变‘湘辐糯1号’获得了半矮杆突变体‘双辐矮糯’。本研究分析了‘双辐矮糯’的茎节配置特点、基本农艺性状及其遗传规律。结果表明：‘双辐矮糯’株高较‘湘辐糯1号’（133.13 cm）降低了24.88 cm,穗、第1节和第2节长度显著缩短,降幅分别达到18.10%、23.06%和19.13%,而第3、4、5节长度缩短程度不明显,表明其株高突变基因主要控制穗和高位茎节的伸长。‘双辐矮糯’的单株有效穗为10.4个,是‘湘辐糯1号’（5.2个）的2.04倍,其强分蘖能力确保了在每穗总粒数下降20.24%和千粒重下降7.51%情况下单株产量仍表现出25.26%的增长。品质分析发现,‘双辐矮糯’的粒长、粒宽、长宽比等外观品质指标及直链淀粉含量、胶稠度等食味品质指标与‘湘辐糯1号’无显著差异,说明‘双辐矮糯’株高的下降未对外观品质与食味品质产生不利影响。遗传分析发现,48对SSR标记在‘双辐矮糯’与‘湘辐糯1号’间扩增出了完全一致的基因型,二者遗传背景相似度达到了100.00%,证实了‘双辐矮糯’是源于‘湘辐糯1号’的真实变异。利用‘双辐矮糯’与‘湘辐糯1号’构建了2个正反交F₂群体,分析发现群体中半矮杆植株与野生型植株理论分离比符合1∶3,表明半矮杆性状受一个隐性细胞核基因控制。本研究明确了‘双辐矮糯’的株高表型和遗传特点,为深入挖掘其育种价值奠定基础。