Alan J. Freyer

4.9k total citations · 1 hit paper
135 papers, 4.1k citations indexed

About

Alan J. Freyer is a scholar working on Organic Chemistry, Molecular Biology and Pharmacology. According to data from OpenAlex, Alan J. Freyer has authored 135 papers receiving a total of 4.1k indexed citations (citations by other indexed papers that have themselves been cited), including 68 papers in Organic Chemistry, 37 papers in Molecular Biology and 32 papers in Pharmacology. Recurrent topics in Alan J. Freyer's work include Chemical synthesis and alkaloids (27 papers), Traditional and Medicinal Uses of Annonaceae (26 papers) and Berberine and alkaloids research (22 papers). Alan J. Freyer is often cited by papers focused on Chemical synthesis and alkaloids (27 papers), Traditional and Medicinal Uses of Annonaceae (26 papers) and Berberine and alkaloids research (22 papers). Alan J. Freyer collaborates with scholars based in United States, Chile and United Kingdom. Alan J. Freyer's co-authors include Maurice Shamma, Ashok D. Patil, Brad Carté, Mark F. Bean, Randall K. Johnson, Víctor Fajardo, Emir Valencia, Robert D. Minard, Paul B. Taylor and Lew Killmer and has published in prestigious journals such as Journal of the American Chemical Society, Environmental Science & Technology and Applied and Environmental Microbiology.

In The Last Decade

Alan J. Freyer

133 papers receiving 3.9k citations

Hit Papers

align trajectories

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

Novel Alkaloids from the Sponge Batzella sp.: Inhibitors of HIV gp120-Human CD4 Binding

1995 540 citations Ashok D. Patil, Mark F. Bean et al. profile →

Peers

Countries citing papers authored by Alan J. Freyer

Since Specialization

Citations

This map shows the geographic impact of Alan J. Freyer's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Alan J. Freyer with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Alan J. Freyer more than expected).

Fields of papers citing papers by Alan J. Freyer

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Alan J. Freyer. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Alan J. Freyer. The network helps show where Alan J. Freyer may publish in the future.

Co-authorship network of co-authors of Alan J. Freyer

This figure shows the co-authorship network connecting the top 25 collaborators of Alan J. Freyer. A scholar is included among the top collaborators of Alan J. Freyer based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Alan J. Freyer. Alan J. Freyer is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

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20 of 20 papers shown

#	Work	Indexed citations
1	Improved methods for ¹H–³H heteronuclear shift correlation 2004 ·Magnetic Resonance in Chemistry ·Frederick G. Vogt, Alan J. Freyer, (unknown), Arthur Y. L. Shu, J. Richard Heys	2
2	Piperpense, a Tetrahydropyridine Alkaloid fromPiper PonapenseStems and Leaves 1997 ·Natural product letters ·Ashok D. Patil, Alan J. Freyer, (unknown), Glenn A. Hofmann, Randall K. Johnson	1
3	Frondosins, five new sesquiterpene hydroquinone derivatives with novel skeletons from the sponge Dysidea frondosa: Inhibitors of interleukin-8 receptors 1997 ·Tetrahedron ·Ashok D. Patil, Alan J. Freyer, Lew Killmer, Priscilla Offen, Brad Carté, Anthony J. Jurewicz, Randall K. Johnson	119
4	Protein Kinase C Inhibitors: Novel Spirosesquiterpene Aldehydes from a Marine Sponge Aka (=Siphonodictyon) coralliphagum 1994 ·Journal of Natural Products ·James A. Chan, Alan J. Freyer, Brad Carté, Mark E. Hemling, Glenn A. Hofmann, Michael R. Mattern, (unknown), John Westley	33
5	The inophyllums, novel inhibitors of HIV-1 reverse transcriptase isolated from the Malaysian tree, Calophyllum inophyllum Linn 1993 ·Journal of Medicinal Chemistry ·Ashok D. Patil, Alan J. Freyer, Drake S. Eggleston, R. Curtis Haltiwanger, Mark F. Bean, Paul B. Taylor, Mary Jo Caranfa, Ann Breen, (unknown)	339
6	The Tetracyclic Erythrina Alkaloids 1991 ·Journal of Natural Products ·Masouda E. Amer, Maurice Shamma, Alan J. Freyer	88
7	A new subgroup of bisbenzylisoquinoline alkaloids: (+)-cycleatjehenine and (+)-cycleatjehine 1990 ·Tetrahedron ·(unknown), (unknown), (unknown), Alan J. Freyer, Hélène Guinaudeau, Maurice Shamma	8
8	(+)-N-Formylnornantenine, a New Aporphine Alkaloid from Cyclea atjehensis 1989 ·Journal of Natural Products ·(unknown), (unknown), (unknown), Hélène Guinaudeau, Alan J. Freyer, Maurice Shamma	14
9	The Homoaporphine Alkaloids of Androcymbium palaestinum 1989 ·Journal of Natural Products ·Emília Tojo, Musa H. Abu Zarga, Salim S. Sabri, Alan J. Freyer, Maurice Shamma	5
10	(--)-Siculinine: A Lycorine-Type Alkaloid from Sternbergia sicula 1989 ·Journal of Natural Products ·Pascal Richomme, (unknown), Tekant Gözler, Alan J. Freyer, Maurice Shamma	21
11	Transformation of Metalaxyl by the Fungus Syncephalastrum racemosum 1989 ·Applied and Environmental Microbiology ·Zhong Zheng, Shu‐Yen Liu, Alan J. Freyer, Jean‐Marc Bollag	14
12	2,5-diaryl-3,4-dimethyltetrahydrofuranoid lignans 1987 ·Phytochemistry ·Alejandro Urzúa, Alan J. Freyer, Maurice Shamma	34
13	The protoberberine alkaloids of Stephania suberosa 1987 ·Phytochemistry ·Amarendra Patra, (unknown), Alan J. Freyer, Hélène Guinaudeau, Maurice Shamma, (unknown), (unknown)	37
14	Aristolodione, a 4,5-Dioxoaporphine from Aristolochia chilensis 1987 ·Journal of Natural Products ·Alejandro Urzúa, Alan J. Freyer, Maurice Shamma	6
15	Berbamine 2'-β-N-oxide, a New Bisbenzylisoquinoline from Berberis brandisiana 1986 ·Journal of Natural Products ·Saddam Hussain, (unknown), (unknown), Alan J. Freyer, Hélène Guinaudeau, Maurice Shamma	7
16	Haplomyrtin and (−)-haplomyrfolin: two lignans from haplophyllum myrtifolium 1986 ·Phytochemistry ·(unknown), Belkıs Gözler, Alan J. Freyer, Maurice Shamma	24
17	Enzyme‐Catalyzed Complex‐Formation of Amino Acid Esters and Phenolic Humus Constituents 1985 ·Soil Science Society of America Journal ·Shu‐Yen Liu, Alan J. Freyer, Robert D. Minard, Jean‐Marc Bollag	25
18	(±)-Nuevamine, an isoindoloisoquinoline alkaloid, and (±)-lennoxamine, an isoindolobenzazepine 1984 ·Tetrahedron Letters ·Emir Valencia, Alan J. Freyer, Maurice Shamma, Víctor Fajardo	179
19	(+)-Turkiyenine: an unusual extension of the biogenetic sequence for the isoquinoline alkaloids 1984 ·Journal of the American Chemical Society ·Tekant Gözler, Belkıs Gözler, (unknown), Alan J. Freyer, Maurice Shamma	14
20	Chiloenamine and chiloenine: two unusual isoquinoline derived alkaloids. A new insight into the catabolism of aporphines 1983 ·Journal of the Chemical Society Chemical Communications ·Maurice Shamma, (unknown), Alan J. Freyer, John E. Leet, Alejandro Urzúa, Víctor Fajardo	4

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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