@article { ISI:000249627100033, title = {Practical formal synthesis of camptothecin}, journal = {Tetrahedron Letter}, volume = {48}, number = {37}, year = {2007}, month = {SEP}, pages = {6561-6563}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The synthesis of the DE ring of camptothecin using simple and inexpensive starting materials, employing an addition elimination reaction and selective esterification of an aliphatic carboxylic acid as key steps is described. (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {alkaloid, Anticancer, camptothecin, Natural product}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2007.07.017}, author = {Chavan, Subhash P. and Pathak, Ashok B. and Kalkote, Uttam R.} } @article { ISI:000255827100025, title = {Concise synthesis of protected (2S,4R)-4-hydroxyornithine}, journal = {Tetrahedron Letters}, volume = {49}, number = {20}, year = {2008}, month = {MAY}, pages = {3297-3299}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A short synthesis of the nonproteinogenic amino acid, (2S,4R)-4-hydroxyornithine is described. Starting from racemic benzyl glycidol, the scaffold of the target compound was constructed in high enantio- and diastereoselectivity using Jacobsen{\textquoteright}s hydrolytic kinetic resolution (HKR) and regioselective opening of an epoxide as key steps. (c) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {Epoxide, Grignard reaction, hydroxyornithine, Jacobsen{\textquoteright}s HKR, Natural product}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2008.03.076}, author = {Pandey, Satyendra Kumar and Pandey, Menaka and Kumar, Pradeep} } @article { ISI:000257640400029, title = {Serine protease inhibitor from hemolymph of green mussel, perna viridis}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {18}, number = {14}, year = {2008}, month = {JUL}, pages = {3963-3967}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Bioactivity guided fractions of cell-free hemolymph of bacterially challenged marine mussel, Perna viridis led to the isolation of a novel quaternary alkaloid 1, which was identified by its spectral data. The isolated molecule 1 has been found to be a potent serine protease inhibitor ( SPI) showing IC(50) and K(i) values of 102.5 and 97.1-104.68 mu M, respectively. The E(t)/K(i) value of SPI is 6.3, whereas E(t)/K(m) value is 1.04. The Van{\textquoteright}t Hoff analysis showed that the value of K(i) decreases with increase in temperature, and the binding of the inhibitor is entropically driven. (c) 2008 Elsevier Ltd. All rights reserved.

}, keywords = {hemolymph, Natural product, Perna viridis, protease inhibitor}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2008.06.010}, author = {Khan, M. S. and Goswami, U. and Rojatkar, S. R. and Khan, Mohammad Islam} } @article { ISI:000295564100011, title = {Formal synthesis of valiolamine from myo-inositol}, journal = {Tetrahedron}, volume = {67}, number = {41}, year = {2011}, month = {OCT}, pages = {7963-7970}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An efficient formal synthesis of racemic valiolamine starting from readily available myo-inositol is reported. In all the synthetic steps only one regioisomer is formed, which circumvents laborious purification of products. Regioselective benzylation of myo-inositol orthoformate, super-hydride mediated deoxygenation of a cyclitol derivative and stereoselective addition of dichloromethyllithium to an inosose are the key reactions in the synthesis. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Amino sugar, Carbohydrate, Cyclitol, Inositol, Natural product, Valiolamine}, issn = {0040-4020}, doi = {10.1016/j.tet.2011.08.027}, author = {Jagdhane, Rajendra C. and Shashidhar, Mysore S.} } @article { ISI:000350056800015, title = {Proline-catalyzed alpha-aminooxylation of beta-amino aldehydes: access to enantiomerically pure syn- and anti-3-amino-3-aryl-1,2-alkanediols}, journal = {Synlett}, volume = {26}, number = {3}, year = {2015}, month = {FEB}, pages = {355-358}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A new synthetic method for enantioselective synthesis of syn 3-amino-3-aryl-1,2-alkanediols via praline catalyzed alpha-aminaoxn y ylation of beta-amino aldehydes des are described. This methodology is successfully applied to a concise and protecting group-free asymmetric synthesis of (-)-cytoxazone (+)-epi-cytoxazone and formal synthesis of N-thiolated 2-oxazolidinone.

}, keywords = {amino aldehydes, Asymmetric synthesis, catalysis, diastereoselectivity, Enantioselectivity, Natural product}, issn = {0936-5214}, doi = {10.1055/s-0034-1379735}, author = {Venkataramasubramanian, V. and Kiran, I. N. Chaithanya and Sudalai, Arumugam} } @article { ISI:000364803200007, title = {Total syntheses and biological evaluation of (+/-)-botryosphaeridione, (+/-)-pleodendione, 4-epi-periconianone B, and analogues}, journal = {ACS Medicinal Chemistry Letters}, volume = {6}, number = {11}, year = {2015}, month = {NOV}, pages = {1117-1121}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

The total syntheses of (+/-)-botryosphaeridione, (+/-)-pleodendione, (+/-)-hoaensieremodione, 4-epi-periconianone B, and their analogues have been accomplished for the first time. All the synthesized target compounds were screened in neural anti-inflammatory assays using LPS induced microglia cells (N9). Among them, compounds 1 and 21 were identified as potential lead compounds for further profiling.

}, keywords = {antineuroinflammatoty agents, bohyosphaeridione, Natural product, pleodendione, Total synthesis}, issn = {1948-5875}, doi = {10.1021/acsmedchemlett.5b00241}, author = {Handore, Kishor L. and Jadhav, Prakash D. and Hazra, Bibhabasu and Basu, Anirban and Reddy, D. Srinivasa} } @article { ISI:000380599800018, title = {Multi-gram scale synthesis of hunanamycin A, an antibiotic natural product from the marine source}, journal = {Tetrahedron Letters}, volume = {57}, number = {32}, year = {2016}, month = {AUG}, pages = {3662-3663}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A simple, practical, and biomimetic approach to access antibiotic natural product hunanamycin A starting from readily available inexpensive material Riboflavin is disclosed here. The present synthesis consists of three operationally simple, protecting group free steps and it is far superior when compared with the previous route. Using this route one can make multi-gram quantities of the natural product which will help in further biological assays, in particular exploring the potential of treating food infections. (C) 2016 Elsevier Ltd. All rights reserved.

}, keywords = {Antibacterial, Biomimetic synthesis, Gram scale synthesis, Natural product, Riboflavin}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2016.07.003}, author = {Shingare, Rahul D. and Farhana, Sa Ada and Reddy, D. Srinivasa} } @article { ISI:000377612300008, title = {Synthesis of revised structure of klaivanolide (acetylmelodorinol)}, journal = {Arkivoc}, number = {2}, year = {2016}, month = {OCT}, pages = {116-122}, publisher = {ARKAT USA INC}, address = {C/O ALAN R KATRITZKY, UNIV FLORIDA, DEPT CHEMISTRY, PO BOX 117200, GAINESVILLE, FL 32611 USA}, abstract = {

Klaivanolide (acetylmelodorinol) is an anti-leishmanial/anti-trypanosomal agent isolated from Uvaria klaineana and the structure was originally assigned as a 7-membered lactone with extended conjugation and S-configuration at the lactone junction. Very recently, the structure of klaivanolide was revised as previously known compound acetylmelodorinol. Now, we have synthesized the revised structure in racemic form using a short route.

}, keywords = {acetylmelodorinol, Klaivanolide, leishmaniasis, Natural product}, issn = {1551-7004}, doi = {10.3998/ark.5550190.p009.231}, author = {Raut, Gajanan N. and Wagh, Sachin B. and Reddy, D. Srinivasa} } @article {44556, title = {Regioselective and efficient enzymatic synthesis of antimicrobial andrographolide derivatives}, journal = {Bioorganic \& Medicinal Chemistry Letters}, volume = {28}, year = {2018}, month = {APR }, pages = {1132-1137}, abstract = {

Labdane diterpene andrographolide (1) is a major constituent of Andrographis paniculata and known to exhibit wide spectrum of biological activities. In this study, regioselective monoesters of (1) have been synthesized by using Amano lipase AK (Pseudomonas fluorescens) as a biocatalyst. Amano lipase AK was able to execute highly efficient esterification of hydroxyl group attached to C-14 carbon of (1) in presence of acyl donors. Among the various synthesized derivatives including two novel compounds such as andrographolide-14-propionate (3) and andrographolide-14-caproate (5) displayed antimicrobial activity against Staphylococcus aureus with low minimal inhibitory concentration (MIC) 4 mu g/mL and 16 mu g/mL respectively. Furthermore, they have shown low hemolysis activity at their respective MIC and increase in the permeability of the bacterial cell membrane as delineated by FITC uptake and SEM imaging studies. (C) 2018 Elsevier Ltd. All rights reserved.

}, keywords = {Acylation, Andrographolide, Antimicrobial activity, biocatalysis, Hemolysis, Lipase, Natural product}, issn = {0960-894X}, doi = {10.1016/j.bmcl.2018.01.007}, author = {Patil, Harshal S. and Jadhav, Dipesh D. and Paul, Ajay and Mulani, Fayaj A. and Karegaonkar, Shrikant J. and Thulasiram, Hirekodathakallu V.} } @article {47680, title = {One-pot oxidation of secondary alcohols to alpha-hydroxy ketones: application to synthesis of oxoaplysinopsin D, E, F, \& G}, journal = {European Journal of Organic Chemistry}, volume = {2021}, year = {2021}, month = {APR }, pages = {2188-2192}, type = {Article}, abstract = {A simple one-pot transformation of secondary alcohols to alpha-hydroxy ketones using pyridinium dichromate (PDC) in DMF has been developed and substrate scope tested with 25 compounds of hydantoin derivatives. Using this method, we have devised a common dihydroxy intermediate and synthesized four natural products oxoaplysinopsins D, E, F, and G for the first time.}, keywords = {alpha-Hydroxylation, Hydantoin, Natural product, Oxoaplysinopsin, Retro-aldol}, issn = {1434-193X}, doi = {10.1002/ejoc.202100184}, author = {Kulkarni, Akshay S. and Ramesh, Eagala and Reddy, D. Srinivasa} } @article {47402, title = {Total synthesis of twelve membered resorcyclic acid lactones, (R)-penicimenolide A, (R)-resorcyclide and (R)-dihydroresorcyclide}, journal = {Tetrahedron}, volume = {85}, year = {2021}, month = {APR}, pages = {132059}, type = {Article}, abstract = {

Resorcyclic Acid Lactones or RALs are a class of fungal secondary polyketides isolated from a variety of fungal strains like Lasiodiplodia theobromae, Penicillium sp., Syncephalastrum racemosum etc. This class of macrocyclic lactones are found to exhibit a broad spectrum of biological activities and are of significant synthetic importance. Herein, we report the first total synthesis of (R)-penicimenolide A, twelve membered RAL (RAL12) isolated from Penicillium sp. (NO. SYP-F-7919). Besides, we also report the total synthesis of two other members, namely, (R)-trans-resorcyclide and (R)-dihydroresorcyclide. In the course of synthesis, we have utilized ring closing metathesis (RCM) as the key step in constructing the core macrolactone scaffold. (C) 2021 Elsevier Ltd. All rights reserved.

}, keywords = {Macrocycle, Natural product, organic synthesis, Total synthesis}, issn = {0040-4020}, doi = {10.1016/j.tet.2021.132059}, author = {Das, Pronay and Reddy, D. Srinivasa} } @article {47403, title = {Wittig reactions of maleimide-derived stabilized ylides with alkyl pyruvates: concise approach to methyl ester of (+/-)-chaetogline A}, journal = {Synthesis-Stuttgart}, volume = {53}, year = {2021}, month = {APR }, type = {Article}, abstract = {

A facile synthesis of methyl ester of chaetogline A is reported starting from the corresponding methyl 1-methyltryptophanate-derived- maleimide. A stereoselective Wittig olefination with a carbonyl function in methyl pyruvate followed by phosphorous pentoxide-induced- regioselective dehydrative cyclization are the essential reactions. An acid-induced thermodynamically driven stereoselective beta- to alpha-position migration of the exocyclic C=C bond unit in ethyl tetrahydroindolizinoindolylidenepropanoate is described.

}, keywords = {Amino acid, chaetogline A, dehydrative cyclization, maleimide, methyl pyruvate, Natural product, Wittig reaction}, issn = {0039-7881}, doi = {10.1055/a-1477-6043, Early Access Date = APR 2021}, author = {Shelar, Santosh V. and Argade, Narshinha P.} } @article {48212, title = {Ultra-high performance liquid chromatography Q-Orbitrap MS/MS-based profiling and quantification of limonoids in Meliaceae plants}, journal = {Analytical and Bioanalytical Chemistry}, volume = {414}, year = {2022}, month = {AUG}, pages = {6093-6106}, type = {Article}, abstract = {

Meliaceae plants have been extensively used in agriculture, folklore, and traditional medicine. They are the major storehouses for structurally diverse limonoids (meliacins) possessing various bioactivities like antifeedant, insecticidal, antimicrobial, etc. However accurate detection of these tetranortriterpenes from the vast pool of metabolites in plant tissue extracts or biological sample is a crucial challenge. Though the mass spectrum (MS) provides the molecular mass and the corresponding elemental composition, it cannot be relied precisely. The exact identification of a specific metabolite demands the MS/MS spectrum containing the signature product ions. In the present study, we have developed the UHPLC Q-Orbitrap-based method for identification, quantification, and characterization of limonoids in different plant tissue extracts requiring minimum plant material. Using this method, we carried out the limonoid profiling in different tissue extracts of sixteen Meliaceae plants and the identification of limonoids was performed by comparing the retention time (RT), ESI-(+)-MS spectrum, and HCD-MS/MS of the purified fifteen limonoids used as reference standards. Our results revealed that early intermediates of the limonoid biosynthetic pathway such as azadiradione, epoxyazadiradione, and gedunin occurred more commonly in Meliaceae plants. The MS/MS spectrum library of the fifteen limonoids generated in this study can be utilized for identification of these limonoids in other plant tissue extracts, botanical fertilizers, agrochemical formulations, and bio pesticides.

}, keywords = {LC-HRMS, LC-MS/MS, Limonoids, Meliaceae, Natural product, Quantification}, issn = {1618-2642}, doi = {10.1007/s00216-022-04169-2}, author = {Mulani, Fayaj A. and Nandikol, Sharvani S. and Kajjihundi, Jagadeesh S. and Pathappa, Niranjana and Puttappa, Sharanappa and Thulasiram, V. Hirekodathakallu} }