TORONTO, June 4, 2013 /PRNewswire/ – Bontan Corporation Inc. (‘the Company”)
(OTCBB: BNTNF) (“Bontan”) is pleased to announce the official signing
and completion of a share exchange agreement with all the shareholders
of Portage Pharma Limited (“PPL”), a private Biotech corporation formed
under the laws of the British Virgin Islands. Under the terms of the
agreement, all the shares of PPL have been exchanged for approximately
81.7 million common shares of Bontan and approximately 71.4 million
warrants valid for two years from the date of closing, exercisable to
convert into an equal number of common shares of Bontan at an
exercisable price of US$0.29 per share. Additionally Bontan issued
approximately 9.8 million shares to Culminant Capital Inc., a St. Kitts
private corporation, as compensation for financial services rendered to
Bontan and PPL in connection with this transaction. All shares and
warrants issued will be restricted until registered.

After giving effect to the share exchange transaction, Bontan will have
approximately 175 million common shares issued and outstanding of which
approximately 91.5 million common shares will be restricted securities.
Bontan will also have approximately 140 million options and warrants
outstanding which are exercisable into an equal number of common
shares.

The transaction resulted in PPL merging into Portage Acquisition Inc., a
wholly owned subsidiary of Bontan, incorporated in the BVI. The merged
entity will be named Portage Pharma Inc. (“Portage”) which will be a
subsidiary of Bontan. The senior managers of Portage, Dr. Bruce Littman
and Dr. Frank Marcoux, will continue to hold 33,542 options to acquire
up to 7% equity in Portage valid for five years at an exercise price of
US$1.10 per option. The options vest in agreed instalments over a two
year period.

Portage holds an exclusive licence in non-oncology fields under patents
granted in the USA, Australia, Israel and New Zealand and patents
applied for in Japan and Canada, and an exclusive worldwide licence in
non-oncology fields and the know-how relating to the Antennapedia
protein (ANTP) transduction technology developed by Trojantec for
non-oncology products, treatments or medications.

After completion of the initial share exchange, Mr. Shah will resign as
CEO while retaining his role as CFO of Bontan. Dr. Declan Doogan will
become the CEO of Bontan.

Mr. Dean Bradley and Mr. Brett Rees will resign as independent directors
of Bontan and will be replaced by Dr. Gregory Bailey and Mr. Jim Mellon
as independent directors. The new Board will be comprised of Mr. Shah,
Dr. Doogan, Dr. Bailey and Mr. Mellon.

PPL currently has nine consultants headed by Dr. Bruce Littman as CEO
and Dr. Frank Marcoux, as Chief Scientific Officer. This same team will
manage Portage. This team will continue their development of
ANTP-containing peptides for non-oncology indications and review other
potential opportunities for inclusion in the PPL drug discovery and
development portfolio.

The outgoing CEO, Mr. Kam Shah commented, “After a very lengthy period
of comprehensive due diligence we are delighted to finalize this
exciting transaction with PPL which will look to develop new drugs for
the Antennapedia platform. The Company has over US $3.4 million in cash
which will meet the initial development costs for the current
initiatives at Portage. I am confident that Portage’s development team,
having over 200 years of combined experience in the financing and the
development of new drugs, will position Bontan at the forefront of
biotech research and development and should create substantial and
sustainable shareholder value.”

Dr. Declan Doogan, the incoming CEO commented, “We believe that this
merger with Bontan provides our team with access to the capital markets
and opportunity to not only to develop ANTP but to look for other
compelling drug development opportunities to in-license. I personally
am very excited that we have been able to assemble this team of biotech
professionals, especially as many of us have worked together on a
variety of other successful projects during our professional careers.”

The following are the backgrounds of the new management and Board
members:

Declan Doogan M.D. is the co-founder and Chairman of PPL and will be the CEO of Bontan.
Previously the CEO and Head of R&D at Amarin Inc. (AMRN:NASDAQ) and the
former Head of Worldwide Drug Development at Pfizer Inc. He has held
Visiting Professorships at Harvard School of Public Health, Glasgow
University Medical School and Kitasato University (Tokyo) and sits on
the boards of Pulmonary Vascular Research Institute UK, Sosei (Japan
Biotech), Trojantec (UK, oncology) and Spinifex (Melbourne). He
continues to provide medical advice to Amarin Inc.

Gregory Bailey M.D. is a co-founder and Chief Business Officer of PPL. Co-founder of Ascent
Healthcare Solutions, the #1 re-processor of used surgical equipment;
VirnetX Inc. (VHC: AMEX), internet security; and Duramedic Inc., a
medical products company. He is a former financier of Medivation Inc.
(MDVN: NASDAQ) and was a director from 2005 to 2012.

Jim Mellon is a co-founder of PPL. A principal of Charlemagne Capital, a listed
fund management company; Regent Pacific, an Asian mining group; and the
controlling shareholder of Manx Financial, an Isle of Man based-bank;
Speymill Group, a property business; and Webis Holdings. Co-founder of
Uramin and Red Dragon Resources, both mining groups. Burnbrae, his
private company, is a substantial landlord in Germany and in the Isle
of Man, and owns a hotel chain. Mr Mellon is on twitter @: https://twitter.com/jimmhk.

Bruce H. Littman, M.D., will be the CEO of Portage. He has over 30 years of research and drug
development experience. He was Vice President and Global Head of
Translational Medicine in Pfizer and also has a strong academic
background in immunology, rheumatology and inflammation. His skill set
is particularly suited to developing de-risking strategies and using an
understanding of how drugs behave in the body to evaluate early drug
candidates. He has an excellent track record in early clinical
development. After retiring from Pfizer at the end of 2007 he became an
independent consultant. Prior to that, he served for 13 years on the
faculty of Virginia Commonwealth University’s Medical College of
Virginia. He is an author and co-editor of “Translational Medicine and
Drug Discovery” published in 2011 by Cambridge University Press.

Frank W. Marcoux, Ph.D. is the CSO of Portage. He has over 25 years of pharmaceutical company
and academic research experience. He was the VP Quantitative and
Innovative Medicine in WW Development at Pfizer and former VP WW
Discovery Biology Discipline Head until 2008 when he became an
independent consultant. Previously he worked for Parke-Davis
Pharmaceutical Research for seventeen years. Dr. Marcoux’s consulting
focus is on high confidence translation of drug discovery programs to
early clinical proof of concept and is aimed at biotech, Pharma and
academic medical centres. Dr. Marcoux holds a Ph.D. in Physiology and
Biophysics and held research positions prior to industry at Harvard
Medical School/Massachusetts General Hospital, University of Alabama,
Birmingham, Medical Center, and at the University of Vermont, College
of Medicine.

About Bontan Corporation Inc:

Bontan and its new subsidiary, Portage Pharma Inc., will be engaged in
researching and developing pharmaceutical and biotech products through
to proof of concept with an early focus on unmet clinical needs and
orphan drugs. Following proof of concept, the Company will look to sell
or licence the products to large pharmaceutical companies to gain
global distribution. For further information, contact Kam Shah CFO of
Bontan, at 416-929-1806 or kam@bontancorp.com.

Forward-Looking Statements

This news release includes forward-looking statements within the meaning
of the U.S. federal and Canadian securities laws. Any such statements
reflect Bontan’s current views and assumptions about future events and
financial performance. Bontan cannot assure that future events or
performance will occur. Important risks and factors that could cause
actual results or events to differ materially from those indicated in
our forward-looking statements.

Bontan assumes no obligation and expressly disclaims any duty to update
the information in this News Release.

SOURCE Bontan Corporation Inc.