A new synthesis of spirocyclic oxindole analogue spiro[piperidine-4,3＇-pyrrolol2,3-b]pyridin]-2＇（1＇H）-one 1 is described. The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ...A new synthesis of spirocyclic oxindole analogue spiro[piperidine-4,3＇-pyrrolol2,3-b]pyridin]-2＇（1＇H）-one 1 is described. The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ring by an intramolecular Buchwald-Hartwig amidation of carboxylic amide and aryl chloride. A small library was obtained by reductive amination of 1 with various aldehydes and was screened against human lung cancer cell A549, human liver cancer cell BEL7402, and human colon cancer cell HCT-8. The results show that most of the library compounds 2 have some inhibitory activities. 2-（Trifluoromethoxy） benzylic substituted spirocyclic azaoxindole 2e was identified as a nanomolar inhibitor against human lung cancer cell A-549 （IC50 = 50 nmol/L）.展开更多
A stereocontrolled construction of the side chain of brassinosteroid was developed via the separated dialkylation and the tandem dialkylation of the pyranone moiety as the key step.
A stereocontrolled construction of the side chain of brassinclide and homobrassinolide has been achieved via the tandem vicinal dialkylation of the pyranone moiety as a key step.
4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α...4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α-amino acid by hydrolysis of 4,4-dialkyl-2-oxazolin-5-ones.展开更多
青海湖晚第四纪的古环境演化和湖面变化是学术界长期关注的热点问题，争议也较多。我们对青海湖地区种羊场（ZYC）剖面（120 cm厚）全新世风尘堆积的GDGTs （甘油二烷基甘油四醚）化合物相关指标的古环境意义进行了初步研究，以期从一...青海湖晚第四纪的古环境演化和湖面变化是学术界长期关注的热点问题，争议也较多。我们对青海湖地区种羊场（ZYC）剖面（120 cm厚）全新世风尘堆积的GDGTs （甘油二烷基甘油四醚）化合物相关指标的古环境意义进行了初步研究，以期从一个新的角度对上述问题进行探讨。研究结果表明：1） ZYC剖面的TEX86（由86个碳原子组成的四醚指标）与磁化率正相关，而Ri/b比值（类异戊二烯GDGTs与支链GDGTs丰度的比值）与磁化率负相关。2） ZYC剖面的TEX86指标与湖泊岩芯胖真星介（Eucypris inflata）壳体δ18O指示的7月古水温及长链烯酮（U37K）指示的夏季古水温变化具有相似的变化特征，显示TEX86指标较可靠地指示了青海湖地区的大气温度变化。然而，ZYC剖面的MBT （甲基化指数）和CBT （环化指数）指标在重建古气温方面具有一定的局限性，可能与青海湖地区全新世出现的干旱环境有关。3） ZYC剖面的Ri/b比值与湖泊岩芯E.inflata壳体Sr/Ca比值指示的青海湖湖水的古盐度具有较一致的变化特征，表明Ri/b比值较有效地指示了青海湖地区环境的干湿状况。4） TEX86和Ri/b指标揭示青海湖区在9.5~7.5 ka B.P.为冷干时期；7.5~5.5 ka B.P.为独特的温干阶段，温度在6.2 ka B.P.左右达到最高值；5.5~1.7 ka B.P.为温湿时期；1.7~0 ka B.P.为冷干时期。5）风尘堆积的GDGTs记录表明：7.5~5.5 ka B.P.由于环境干旱，青海湖不太可能出现高湖面；5.5~1.7 ka B.P.由于环境湿润，青海湖很可能出现全新世高湖面；1.7 ka B.P.以来，青海湖地区的气候快速变干。展开更多
A facile one-pot synthesis of 3,4,5-substituted furan-2（5H）-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using t...A facile one-pot synthesis of 3,4,5-substituted furan-2（5H）-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.展开更多
The MBT/CBT （Methylation Index of Branched Tetraethers/Cyclisation ratio of Branched Tetraether） proxy, a terrestrial paleothermometer based on bacterial branched glycerol dialkyl glycerol tetraethers CoGDGTs）, was...The MBT/CBT （Methylation Index of Branched Tetraethers/Cyclisation ratio of Branched Tetraether） proxy, a terrestrial paleothermometer based on bacterial branched glycerol dialkyl glycerol tetraethers CoGDGTs）, was employed to indicate altimetry; however, the mechanistic control on this proxy is still ambiguous. Here, we investigated the bGDGTs＇ distribution and associated environmental factors along an altitude transect of Mt. Shennongjia in China in order to determine the applicability of bGDGT-based proxies to altimetry reconstruction. The MBT index exhibits only a weak correlation with estimated mean annual air temperature （MATe, estimated according to the meteorological record and lapse rate） or altitude. Likewise, MBT shows weak or no relationship with temperature or altitude at four other mountains （Mts. Meghalaya, Jianfengling, Gongga, and Rungwe）. It is notable that mean annual air temperature （MAT） or altitude estimated by the MBT/CBT proxy largely relies on CBT, rather than on MBT, which was generally acknowledged. The poor relationship between MBT and MATe for Mt. Shennongjia can be ascribed to the insensitive response of bGDGT-I to temperature. Our data fxom this mountain imply that care should be taken if the MBT/CBT proxy is employed as an indication of paleoaltimetry. We propose that the fractional abundance of bGDGTs may be a better paleoaltimeter than the MBT/ CBT proxy, because specific bGDGT subsets that might show the most sensitive response to temperature can be preferentially selected using a statistical method and used to establish local calibration. This local calibration was applied to Mt. Shennongjia and apparently improves the accuracy of temperature and altimetry reconstruction. The differential response of bGDGTs to temperature among mountains suggests that local calibrations are needed to better constrain the altimetry.展开更多
An expedient,synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline,dialkyl acetylenedicarboxylates and dialkyl chloromalonate.
Three-component reaction of arylsulfonamides,dialkyl acetylenedicarboxylates,and ethyl chlorooxoacetate promoted by triphenylphosphine and triethylamine provides a sufficient route for the synthesis of dialkyl N-（ary...Three-component reaction of arylsulfonamides,dialkyl acetylenedicarboxylates,and ethyl chlorooxoacetate promoted by triphenylphosphine and triethylamine provides a sufficient route for the synthesis of dialkyl N-（arylsulfonyl）-4-ethoxy-5-oxo-2,5-dihydro -1H-pyrolle-2,3-dicarboxylates in good yields.展开更多
Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for diffe...Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for different spreading time prior to the transfer film. Floating monolayer films stability is an important parameter to obtain high-quality Langmuir-Blodgett films for their aplications. Hysteresis loop of the compression-decompression (μ-A) isotherms of Langmuir film GDNT used to analyze the thermodynamic stability of the monolayer films and its features. Langmuir films stability of tetraether lipid GDNT shown more stable at the time of spreading longer than a short time.展开更多
Developing practical strategies for the synthesis of organophosphorus compounds(OPCs)from white phosphorus(P_(4))without the use of Cl_(2) and PCl_(3) remains a significant challenge.The first multicomponent oxidative...Developing practical strategies for the synthesis of organophosphorus compounds(OPCs)from white phosphorus(P_(4))without the use of Cl_(2) and PCl_(3) remains a significant challenge.The first multicomponent oxidative α-phosphonylation of amines with P_(4) and alcohols has been developed.With the use of copper(Ⅱ)as the catalyst and air as the safe oxidant,structurally sophisticated α-aminophosphonates have been prepared in high yields.Furthermore,this method is also suitable for selective construction of P-O-P compounds.The reaction is characterized by a complete conversion of P_(4).The activation of P_(4) with transition metals often leads to formation of complexes[M_(x)P_(y)]_(n) associated with the deactivation of transition metals.This breakthrough showcases the potential of transition-metal-catalyzed reactions in elemental phosphorus chemistry.展开更多
Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass...Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass spectrometry (ESI MS)in conjunction with tandem mass spectrometry.The fragmentation pathways of dialkyl puerarin-7-yl phosphates were investigated.展开更多
Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution...Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs （bGDGTs） in these hot springs were also investigated. The results revealed different profiles ofiGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs.展开更多
A simple synthesis of highly functionalized 2,5-diaminofurans based pyrimidine derivatives from 1-（carboxymethyl）uracil via a multi-component reaction is described. The reactive 1：1 intermediate produced from the r...A simple synthesis of highly functionalized 2,5-diaminofurans based pyrimidine derivatives from 1-（carboxymethyl）uracil via a multi-component reaction is described. The reactive 1：1 intermediate produced from the reaction of tert-butyl isocyanide and dialkyl acetylenedicarboxylates was trapped at room temperature by 1-（carboxymethyl）uracil derivatives to yield polyfunctio- nalized furan rings in fairly good yields.展开更多
Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between t...Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between them.In this study,we described an asymmetric hydrogenation of dialkyl imines by a chiral iridium catalyst containing spiro phosphine-amine-phosphine ligand.By precisely adjusting the chiral pocket of catalyst,a highly efficient catalyst was developed.Using this catalyst,a variety of dialkyl imines were hydrogenated to chiral amines with high yield and enantioselectivity.展开更多
We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of t...We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.展开更多
基金supported by the program of research fund for returning scholars of Ministry of Education of China(No.200812)the Open Foundation of Chemical Engineering Subject(No.200903),Qingdao University of Science & Technology,China
文摘A new synthesis of spirocyclic oxindole analogue spiro[piperidine-4,3＇-pyrrolol2,3-b]pyridin]-2＇（1＇H）-one 1 is described. The key steps involve dialkylation of arylacetonitrile and cyclization of the azaoxindole ring by an intramolecular Buchwald-Hartwig amidation of carboxylic amide and aryl chloride. A small library was obtained by reductive amination of 1 with various aldehydes and was screened against human lung cancer cell A549, human liver cancer cell BEL7402, and human colon cancer cell HCT-8. The results show that most of the library compounds 2 have some inhibitory activities. 2-（Trifluoromethoxy） benzylic substituted spirocyclic azaoxindole 2e was identified as a nanomolar inhibitor against human lung cancer cell A-549 （IC50 = 50 nmol/L）.
文摘A stereocontrolled construction of the side chain of brassinosteroid was developed via the separated dialkylation and the tandem dialkylation of the pyranone moiety as the key step.
文摘 A stereocontrolled construction of the side chain of brassinclide and homobrassinolide has been achieved via the tandem vicinal dialkylation of the pyranone moiety as a key step.
文摘4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α-amino acid by hydrolysis of 4,4-dialkyl-2-oxazolin-5-ones.
文摘青海湖晚第四纪的古环境演化和湖面变化是学术界长期关注的热点问题，争议也较多。我们对青海湖地区种羊场（ZYC）剖面（120 cm厚）全新世风尘堆积的GDGTs （甘油二烷基甘油四醚）化合物相关指标的古环境意义进行了初步研究，以期从一个新的角度对上述问题进行探讨。研究结果表明：1） ZYC剖面的TEX86（由86个碳原子组成的四醚指标）与磁化率正相关，而Ri/b比值（类异戊二烯GDGTs与支链GDGTs丰度的比值）与磁化率负相关。2） ZYC剖面的TEX86指标与湖泊岩芯胖真星介（Eucypris inflata）壳体δ18O指示的7月古水温及长链烯酮（U37K）指示的夏季古水温变化具有相似的变化特征，显示TEX86指标较可靠地指示了青海湖地区的大气温度变化。然而，ZYC剖面的MBT （甲基化指数）和CBT （环化指数）指标在重建古气温方面具有一定的局限性，可能与青海湖地区全新世出现的干旱环境有关。3） ZYC剖面的Ri/b比值与湖泊岩芯E.inflata壳体Sr/Ca比值指示的青海湖湖水的古盐度具有较一致的变化特征，表明Ri/b比值较有效地指示了青海湖地区环境的干湿状况。4） TEX86和Ri/b指标揭示青海湖区在9.5~7.5 ka B.P.为冷干时期；7.5~5.5 ka B.P.为独特的温干阶段，温度在6.2 ka B.P.左右达到最高值；5.5~1.7 ka B.P.为温湿时期；1.7~0 ka B.P.为冷干时期。5）风尘堆积的GDGTs记录表明：7.5~5.5 ka B.P.由于环境干旱，青海湖不太可能出现高湖面；5.5~1.7 ka B.P.由于环境湿润，青海湖很可能出现全新世高湖面；1.7 ka B.P.以来，青海湖地区的气候快速变干。
基金fnancial support from the Research Council of the University of Sistan and Baluchestan
文摘A facile one-pot synthesis of 3,4,5-substituted furan-2（5H）-one derivatives from a three-component reaction of aniline derivatives, dialkylacetylenedicarboxylates and aromatic aldehydes under mild conditions using tetra-n-butylammonium bisulfate as a catalyst has been developed.
文摘The MBT/CBT （Methylation Index of Branched Tetraethers/Cyclisation ratio of Branched Tetraether） proxy, a terrestrial paleothermometer based on bacterial branched glycerol dialkyl glycerol tetraethers CoGDGTs）, was employed to indicate altimetry; however, the mechanistic control on this proxy is still ambiguous. Here, we investigated the bGDGTs＇ distribution and associated environmental factors along an altitude transect of Mt. Shennongjia in China in order to determine the applicability of bGDGT-based proxies to altimetry reconstruction. The MBT index exhibits only a weak correlation with estimated mean annual air temperature （MATe, estimated according to the meteorological record and lapse rate） or altitude. Likewise, MBT shows weak or no relationship with temperature or altitude at four other mountains （Mts. Meghalaya, Jianfengling, Gongga, and Rungwe）. It is notable that mean annual air temperature （MAT） or altitude estimated by the MBT/CBT proxy largely relies on CBT, rather than on MBT, which was generally acknowledged. The poor relationship between MBT and MATe for Mt. Shennongjia can be ascribed to the insensitive response of bGDGT-I to temperature. Our data fxom this mountain imply that care should be taken if the MBT/CBT proxy is employed as an indication of paleoaltimetry. We propose that the fractional abundance of bGDGTs may be a better paleoaltimeter than the MBT/ CBT proxy, because specific bGDGT subsets that might show the most sensitive response to temperature can be preferentially selected using a statistical method and used to establish local calibration. This local calibration was applied to Mt. Shennongjia and apparently improves the accuracy of temperature and altimetry reconstruction. The differential response of bGDGTs to temperature among mountains suggests that local calibrations are needed to better constrain the altimetry.
基金Sanandaj Branch, Islamic Azad University Research Council for the fnancial support of this research
文摘An expedient,synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline,dialkyl acetylenedicarboxylates and dialkyl chloromalonate.
基金the financial support from the Research Council of Islamic Azad University,Mahshahr Branch
文摘Three-component reaction of arylsulfonamides,dialkyl acetylenedicarboxylates,and ethyl chlorooxoacetate promoted by triphenylphosphine and triethylamine provides a sufficient route for the synthesis of dialkyl N-（arylsulfonyl）-4-ethoxy-5-oxo-2,5-dihydro -1H-pyrolle-2,3-dicarboxylates in good yields.
文摘Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for different spreading time prior to the transfer film. Floating monolayer films stability is an important parameter to obtain high-quality Langmuir-Blodgett films for their aplications. Hysteresis loop of the compression-decompression (μ-A) isotherms of Langmuir film GDNT used to analyze the thermodynamic stability of the monolayer films and its features. Langmuir films stability of tetraether lipid GDNT shown more stable at the time of spreading longer than a short time.
基金the National Key Research and Development Program of China(grant no.2020YFA0608300)the Space Application System of China Manned Space Program(grant no.KJZ-YY-WSM01)National Natural Science Foundation of China(grant nos.21772163,21778042,and 41876072).
文摘Developing practical strategies for the synthesis of organophosphorus compounds(OPCs)from white phosphorus(P_(4))without the use of Cl_(2) and PCl_(3) remains a significant challenge.The first multicomponent oxidative α-phosphonylation of amines with P_(4) and alcohols has been developed.With the use of copper(Ⅱ)as the catalyst and air as the safe oxidant,structurally sophisticated α-aminophosphonates have been prepared in high yields.Furthermore,this method is also suitable for selective construction of P-O-P compounds.The reaction is characterized by a complete conversion of P_(4).The activation of P_(4) with transition metals often leads to formation of complexes[M_(x)P_(y)]_(n) associated with the deactivation of transition metals.This breakthrough showcases the potential of transition-metal-catalyzed reactions in elemental phosphorus chemistry.
文摘Puerarin,an isoflavone compound,is the bioactive component of traditional Chinese medicine.A novel dialkyl puerarin-7-yl phosphate was synthesized and investigated by positive ion electrospray ionization ion trap mass spectrometry (ESI MS)in conjunction with tandem mass spectrometry.The fragmentation pathways of dialkyl puerarin-7-yl phosphates were investigated.
基金supported by the National Natural Science Foundation of China(Grant No.40972211)the US National Science Foundation(Grant Nos.ETBC-1024614 and OISE- 0968421 )
文摘Isoprenoidal glycerol dialkyl glycerol tetraethers （iGDGTs） from the Gulu hot springs （23--83.6 ℃, pH 〉 7） and Yangbajing hot springs （80-128 ℃, pH 〉 7） were analyzed in order to investigate the distribution of archaeal lipids among different hot springs in Tibet. A soil sample from Gulu was incubated at different temperatures and analyzed for changes in iGDGTs to help evaluate whether surrounding soil may contribute to the iGDGTs in hot springs. The sources of bacterial GDGTs （bGDGTs） in these hot springs were also investigated. The results revealed different profiles ofiGDGTs between Gulu and Yangbajing hot springs. Core iGDGTs and polar iGDGTs also presented different patterns in each hot spring. The PCA analysis showed that the structure of polar iGDGTs can be explained by three factors and suggested multiple sources of these compounds. Bivariate correlation analysis showed significant positive correlations between polar and core bGDGTs, suggesting the in situ production of bGDGTs in the hot springs. Furthermore, in the soil incubation experiment, temperature had the most significant influence on concentration of bGDGTs rather than iGDGTs, and polar bGDGTs had greater variability than core bGDGTs with changing temperature. Our results indicated that soil input had little influence on the composition of GDGTs in Tibetan hot springs.
基金supported by the Research Council of the University of Mazandaran,Iran
文摘A simple synthesis of highly functionalized 2,5-diaminofurans based pyrimidine derivatives from 1-（carboxymethyl）uracil via a multi-component reaction is described. The reactive 1：1 intermediate produced from the reaction of tert-butyl isocyanide and dialkyl acetylenedicarboxylates was trapped at room temperature by 1-（carboxymethyl）uracil derivatives to yield polyfunctio- nalized furan rings in fairly good yields.
基金supported by the National Key R&D Program of China(grant no.2022YFA1504302)the National Natural Science Foundation of China(grant nos.22188101,91956000,and 92256301)the Fundamental Research Funds for the Central Universities,and the Haihe Laboratory of Sustainable Chemical Transformations.
文摘Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between them.In this study,we described an asymmetric hydrogenation of dialkyl imines by a chiral iridium catalyst containing spiro phosphine-amine-phosphine ligand.By precisely adjusting the chiral pocket of catalyst,a highly efficient catalyst was developed.Using this catalyst,a variety of dialkyl imines were hydrogenated to chiral amines with high yield and enantioselectivity.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.NRF-2016R1A2B3015388)
文摘We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.
